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Epidemiology of hip fracture: Worldwide geographic variation

Epidemiology of hip fracture: Worldwide geographic variation Review Article Epidemiology of hip fracture: Worldwide geographic variation 1 1 1,2 Dinesh K Dhanwal, Elaine M Dennison , Nick C Harvey , Cyrus Cooper ABstrA ct Osteoporosis is a major health problem, especially in elderly populations, and is associated with fragility fractures at the hip, spine, and wrist. Hip fracture contributes to both morbidity and mortality in the elderly. The demographics of world populations are set to change, with more elderly living in developing countries, and it has been estimated that by 2050 half of hip fractures will occur in Asia. This review conducted using the PubMed database describes the incidence of hip fracture in different regions of the world and discusses the possible causes of this wide geographic variation. The analysis of data from different studies show a wide geographic variation across the world, with higher hip fracture incidence reported from industrialized countries as compared to developing countries. The highest hip fracture rates are seen in North Europe and the US and lowest in Latin America and Africa. Asian countries such as Kuwait, Iran, China, and Hong Kong show intermediate hip fracture rates. There is also a north–south gradient seen in European studies, and more fractures are seen in the north of the US than in the south. The factors responsible of this variation are population demographics (with more elderly living in countries with higher incidence rates) and the influence of ethnicity, latitude, and environmental factors. The understanding of this changing geographic variation will help policy makers to develop strategies to reduce the burden of hip fractures in developing countries such as India, which will face the brunt of this problem over the coming decades. Key words: Epidemiology, geographic variation, hip fracture, incidence rate, osteoporosis i ntroduction rising life expectancy throughout the globe, the number of elderly individuals is increasing in every geographical steoporosis represents a major public health region, and it is estimated that the incidence of hip fracture problem because of its association with low-energy will rise from 1.66 million in 1990 to 6.26 million by 2050. Otrauma or fragility fractures. Hip fracture has been recognized as the most serious consequence of osteoporosis Studies over the last few decades have demonstrated because of its complications, which include chronic pain, geographic variation in the incidence of hip fracture across disability, diminished quality of life, and premature death. continents as well as among different parts of a region. Osteoporotic hip fracture is an established health problem Incidence of hip fracture is highest in Sweden and North in the West and is increasingly recognized as a growing America, with almost seven-fold lower rates in Southern problem in Asia as per the Asian Audit Report, 2009. With 3 European countries. Hip fracture rates are also lower in Asian and Latin American populations. But as three-quarters of Maulana Azad Medical College, New Delhi, India, MRC Epidemiology Resource the world’s population live in Asia, it is projected that Asian Center, University of Southampton, Southampton General Hospital, Southampton countries will contribute more to the pool of hip fractures in SO16 6YD, UK and Botnar Research Center, Institute of Musculoskeletal Sciences, University of Oxford OX3 7LD, UK coming years. It is estimated that by 2050 more than 50% of all Address for correspondence: Prof. Dinesh K Dhanwal, osteoporotic fractures will occur in Asia. This variation in the Department of Medicine (Endocrinology), Maulana Azad Medical College, distribution of hip fracture over different regions of the world New Delhi, India 110002. E-mail: [email protected] demonstrate that genetic and environmental factors play a role in the etiology of hip fracture. It is therefore worthwhile to Access this article online examine the geographic variations in hip fracture and speculate Quick Response Code: on the factors responsible for these differences. This review Website: www.ijoonline.com will serve as an update of the epidemiology of hip fracture worldwide, with special emphasis on the geographic variations and etiological factors. This review was conducted using DOI: 10.4103/0019-5413.73656 the PubMed database. The keywords that were employed included hip fracture, incidence rate, geographic variation, 15 Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 Dhanwal, et al.: Geographic variation in hip fracture incidence osteoporosis, and epidemiology. The articles were chosen hip fractures in men decreased from 162.8/100 000 in on the basis of 1) focus (studies that specifically focused on 2001 to 137.5/100 000 in 2004, a 15.5% decrease. geographic variation in hip fracture); 2) language (studies that The direct medical care costs of hip fracture increased were in English); and 3) methods (studies that used statistical from $62 707 697 in 2001 to $65 200 035 in 2004, tests to examine hip fracture incidence rates). and the proportional cost of hip fractures in the national medical costs increased by 4.5% over 4 years (from 0.200% in 2001 to 0.209% in 2004). On analysis of the AsiA population-based data obtained from the whole country from 2001 to 2004, the incidence rate of hip fractures in Hip fracture rates are available from many countries across women (but not in men) and its cost have increased in Asia, including from Singapore, Taiwan, Japan, Malaysia, Korea. This gender difference in the distribution of hip China, and the Middle East. Unfortunately, only projected fractures underlines the need for aggressive intervention figures are available from India, which is second most in osteoporosis in elderly women. populous country in the world. Studies on hip fracture incidence rates are available from Japan, particularly In 1995, the incidence rates of hip fracture from Hong Kong from the Tottori prefecture, a region representative of were 110/100 000 in women and 50/100 000 in men as per the Japanese population in terms of demographic and data from public hospitals. Secular trends on hip fracture economic status. A recent survey (Hagino et al.) identified from Hong Kong suggest that over the last three decades 851, 901, and 1059 patients with hip fracture (aged 35 the age-specific incidence increased 2.5-fold in women years and older) in 2004, 2005, and 2006, respectively. and 1.7-fold in men. The incidence rates were found to The residual lifetime risk of hip fracture at 50 years of age similar to those seen in the Wessex health region of UK. In was estimated to be 5.6% for men and 20% for women. Beijing, China, hip fracture incidence were calculated from The study concluded that in the Japanese population admissions to 76 city hospitals between 1988 and 1992. aged 35 years or older, the crude incidence of hip fracture It was presumed that all the fracture cases from Beijing go was 244.8 per 100 000 person-years from 2004 to 2006 to these public hospitals only. Based upon the 1990 China and the gender-specific incidence was 99.6 per 100 000 census, age-standardized rates of hip fracture were 87/100 person-years for men and 368 per 100 000 person-years 000 for women and 97/100 000 for men. These data further for women. When these incidence rates were compared demonstrate that from 1988 to 1992, the rates in Beijing with that from 30 years ago, the authors concluded that increased by 34% in women and 33% in men. the incidence of hip fracture in the Japanese population is increasing. This increasing incidence is due to the increase Maximum data from the Middle East is available from Iran in the population of the elderly in Japan over the last three from the Iranian Multicenter Study on Accidental Injuries. decades. This study reported age-standardized incidence rates of hip fracture of 127.3/100 000 person-years in men and The highest incidence of hip fractures from Asia has been 164.6/100 000 person-years in women, which is much reported from Singapore. A study by Koh et al. revealed lower than the rates reported from any of the Western that hip fracture rates from 1991 to 1998 (per 100 000) countries, including the US. Smaller studies are available were 152 in men and 402 in women; this was respectively from Kuwait and show similar results. 1.5 and 5 times higher than corresponding rates in 1960s. Examined by ethnicity, since 1960, the main increase in hip fracture rates has been seen in Chinese and Malays, l Atin AMEricA while the rates in the Indian ethnic group appear to Limited data is available from South American countries. have decreased. The factors responsible for these racial differences include differences in the demographic profile, Reira-Espinoza recently reviewed data from L atin body weight, physical activity, prevalence of cigarette America. In a study published from Mexico in 2005, the smoking and alcohol consumption, calcium intake, and annual rate of hip fracture in the two public health care systems were 169 in women and 98 in men per 100000 frequency of falls in the community in elderly. person-years. These fracture rates are similar to that In Korea, Lim et al. analyzed the incidence and cost reported from the southern countries of Europe. Recently, of hip fracture from 2001 to 2004 using data from the hip fracture incidence has been reported from Rosario, 6 14 Health Insurance Review Agency, Korea. In individuals Argentina. The annual incidence among inhabitants over over 50 years of age, the number of hip fractures in the age of 50 years was 290/100 000 (405/100 000 for women increased from 250.9/100 000 persons in 2001 women and 137/100 000 for men; female/male ratio: 2.96). to 262.8/100 000 in 2004, a 4.7% increase. However, In the population over 65 years of age, the incidence was Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 16 Dhanwal, et al.: Geographic variation in hip fracture incidence 646/100 000 and 345/100 000, respectively. These values men the rates did not change significantly over this time are similar to the values reported in people older than 65 period. There was an overall improvement in the hospital years in the US. Reports from Venezuela have shown that survival rates in men aged over 85 years and females over the incidence of hip fracture in women over 50 years was 75 years of age.The Framingham study, a population-based 98/100 000 and in men 37/100 000. With an increasing cohort study conducted from 1948 to 1996, found that population of elderly individuals in this part of the world, as compared with women born by 1900, hip fracture incidence well as limited health care resources, clinicians and health was 1.2 times and 1.4 times greater among women born authorities will face an enormous challenge in the coming from 1901 to 1910 and from 1911 to 1921, respectively. years in Latin America. This study demonstrates an important birth cohort effect over this period, consistent with studies conducted in 22 23 England and Finland. A Californian study looked at AfricA hip fracture rates between 1983 and 2000, with special attention paid to the Hispanic population, the largest and A few studies are available from Africa on the incidence fastest-growing ethnic minority in the US. Hip fractures of hip fracture. Osteoporosis and fragility fractures are were identified using the annual hospital patient discharge believed to be uncommon in Africa. Zebaze et al. conducted database. Among non-Hispanic white women in California, a study in Cameroon by documenting all patients aged 35 the standardized annular hip fracture rates for those ≥55 years and older admitted to the two main urban hospitals years fell steadily over the past two decades by 0.6% per in Cameroon over a 2-year period with a diagnosis of year in women (and 0.5% in men). No significant change fracture. Using the 1997 estimates of the population, the occurred among black or Asian women migrants to the US. incidence of low-energy trauma fractures at the hip (per By contrast, the annual fracture rates amongst Hispanic 100 000 persons over 35 years) were 57.1 in women and women increased by 4.9% per year (and by 4.2% per year 43.7 in men. Similar low fracture rates have been reported in the men). This supports the hypothesis that residence from Morocco in 2005. Based on these two fairly well- in early life has a much greater association with variation conducted studies from Africa it is difficult to make a general in hip fracture rates that does current region of residence. statement about hip fracture incidence from Africa, but it Another explanation may be that Hispanic men and women seems that as in American blacks, the hip fracture rates in the African population are much lower than in the western have been shown to partake in less physical activity and are more likely to have nutritional deficits than non-Hispanic population. whites. In a recent study by Brauer and co-workers (2009), it was concluded that in the US, hip fracture rates and n orth AMEricA subsequent mortality among persons ≥65 years of age are declining and that the comorbidities among patients with Hip fracture rates among the US population are the highest hip fractures have increased. This group looked at the data in the world. Melton et al. and Ho et al. have reported from a 20% sample of Medicare claims from 1985–2005 age-standardized annual incidence of hip fracture per 100 in patients ≥65 years. The annual mean number of hip 000 as 201 and 197 in men and 511 and 553 in women, fractures was 957.3/100 000 for women and 414.4/100 respectively. A recently published study has reported the 000 for men. The age-adjusted incidence of hip fracture secular trends in Minnesota in the US over the period from increased from 1986 to 1995 and then steadily declined 1928 to 1992. This study looked at all proximal femur from 1995 to 2005. Leslie et al. have recently published fractures that occurred among residents during the 65-year data from Canada in a population-based study and made period. The annual age-adjusted incidence rates among international comparisons. According to this group, during women rose rapidly until 1950, only to fall slowly thereafter. 2000–2005, 147 982 hip fractures were identified. The age- Age-adjusted rates in men rose more steadily before adjusted fracture incidence was 86.4/100 000 in women beginning a downturn after 1980. Incidence rates rose and 53./100 000 in men. On comparison with data from exponentially with age in both men and women. Another the US, the overall fracture rate in Canadian women was study from the US used the national hospital discharge 30% lower than in US women in 2001 and 26% lower than survey (which covers 0.6% of all patient discharges) to in German women in 2004. Canadian men showed similar analyze secular trends in the white population from 1970 overall hip fracture rates as American men prior to age 80 to 1983. An overall increase of 9.3% in age- and sex- years but a 26% lower rate after 80 years of age. adjusted hip fracture incidence rates was observed over the 14-year period. A second study using the same database looked at age-specific rates between 1965 and 1993. Hip EuropE fractures increased linearly for males in the age-groups of 80–84 years and ≥85 years, but for women and young The majority of studies detailing hip fracture rates have been 17 Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 Dhanwal, et al.: Geographic variation in hip fracture incidence performed in the last five decades. Scandinavia has the age-adjusted incidence fell nationally by 2.4% annually highest reported incidence of hip fracture worldwide. There in women and 0.9% in men in 2004. A smaller study in are a large number of studies looking at incidence rates as central Finland between 1992–2003 showed that the age- well as secular trends in this geographically northern region. adjusted rates increased considerably from 2.0 per 1000 The incidence rates vary from North to South Europe, with person-years to 3.9 per 1000 person-years in men and from the highest being in Sweden and Norway and the lowest 2.8 per 1000 person-years to 5.6 per 1000 person-years in France and Switzerland. From Norway, the reported in women. There is no obvious explanation why central age-standardized annual incidence rate of hip fracture is Finland should have increasing rates compared to the rest 920/100 000 in women and 399.3/100 000 in men and of the country. One possibility is that only two time points that in Switzerland is 346/10000 and 137.8/100 000 in were examined in this study, whereas most other studies women and men, respectively. A study on secular trends have examined the secular trends; it is possible that a sharp from Uppsala, Sweden, (1965–1980) showed an annual rise in the rates may have occurred during the early part of increase of 2.2% for age- and sex-adjusted hip fracture rates, the study period and then stabilized. which increased from 430/100 000 in 1965 to 650/100 Overall, the epidemiological data from Scandinavia 000 in 1980. The age-specific incidence increased especially in the group aged ≥85 years, in whom fractures indicates that although early studies (dating to the1950s) of the femoral neck were three times more common and described an increase in hip fracture incidence, the rates trochanteric fractures four times more common in 1980 appear to have fallen in the most recent periods. The decline in fracture rate appears to have occurred several years later than in 1965. Studies from Malmo, Sweden, showed an exponential increase in hip fracture incidence from 1950 in Finland compared to Sweden and Norway. The rise to 1985 in both men and women over age 50, increasing in the incidence of hip fracture in Finland from the early from an annual age-adjusted incidence of 150–390/100 000 1970s until the late 1990s has been followed by declining in men and 300–830/100 000 in women. Increases were fracture rates. The exact reasons for this are unknown, but seen for both trochanteric and cervical fractures. However, a cohort effect toward a healthier aging population and the most recent data from Malmo from 1992–1995 shows increased average body weight and improved functional that this fracture rate is now steady, in line with many of ability among elderly Finns cannot be ruled out as possible 29 34 the Northern American studies. If the data is broken down causes. according to fracture subtypes, however, the incidence of cervical fractures had decreased (210–170/100000 in men Data from central Europe includes studies from the UK, Netherlands, Germany, Switzerland, Austria, and Hungary. and 420–410/100000 in women), whereas there was still a small rise in trochanteric fractures (180–190/100000 in The highest number of studies comes from the UK. The first men and 410–440/100000 in women). study on this subject assessed hip fracture data from the hospital inpatient enquiry for England and Wales between The incidence of hip fractures in Oslo, Norway, between 1968–78. In this study, the age-specific rates increased 1978 and 1997 was assessed using electronic diagnosis steadily in women by 61% and in men by 73% until 1979. registers. The age-adjusted fracture rates per 10000 were No further increases occurred in either sex up to 1985. The Oxford Record Linkage Study which looked at the 118.0 and 44.0 in 1996/97, 124.3 and 44.9 in 1988/89, and 104.5 and 35.8 in 1978/79 for women and men, period 1968–1986 found a similar pattern, although there respectively, indicating that the incidence of hip fractures in was a more continuous trend. Age, cohort, and period Oslo has not changed significantly during the last decade. modelling were used in this study to look at the incidence Denmark used its national patient register to look at hip rates. There was a clear cohort effect in both the studies and fracture incidence between 1987 and 1997 in Viborg the difference in incidence rates was apparent from births County. The incidence of age-adjusted first hip fractures in 1883 to 1917 in addition to the age. A birth cohort effect increased significantly by 18 and 8 per 100 000 per year for was confirmed in subsequent analyses of the Framingham women and men, respectively; peri-trochanteric fractures data, showing that in progressive birth cohorts from increased by 10 per 100 000 per year There are a number of 1887–1921 there were age-specific increases in fracture studies from Finland, all using the Finnish National Hospital incidence rate ratios up from 1.0 to 1.2–1.4 in women and discharge register. The first study drew its hip fracture 1.0 to 2.0 in men. The most recent study from the UK data from the entire >50-year-old population. Between looked at hospital episode statistics from 1989–1998. Age- 1970–997, the age-adjusted hip fracture rate increased standardized incidence rates increased by 32% in women from 292/100 000 to 467/100 000 in women and from and 38% in men up to 1991–92 and thereafter remained 112/100 000 to 233/100 000 in men. In a further follow- stable. In the Netherlands, data from the Dutch Medical up study using the same population from 1997–2004, the Registry shows that between 1972–1987 the age-adjusted Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 18 Dhanwal, et al.: Geographic variation in hip fracture incidence incidence of hip fractures rose linearly from 479/100 000 to in cervical fractures as opposed to trochanteric fractures. 669/100 000 per year in women and from 198/100 000 to 308/100 000 per year in men aged ≥65 years. In a later o cEAniA study conducted between 1986 and 2002 using the Dutch Medical Registry, the age incidence of hip fracture increased Studies of hip fracture epidemiology have also been linearly from 1986–1993 in patients over 45 years; after performed in both New Zealand and Australia and the this the incidence decreased by 0.5% annually until 2002. fracture incidence rates are comparable to that seen in In Germany, between 1995 and 2004 (in a study using the Caucasian population in Europe and North America. the national hospital discharge register) the age- and sex- A study from New Zealand between 1950–1987 looked adjusted hip fracture incidence increased by 0.5% per year at nationwide hip fractures in those aged ≥65 years. A in women and 0.7% per year in men. In women aged ≥40 disproportionate increase in the number of fractures in years there was a tendency for a decrease up to the age of relation to the increase in population size was observed. 74 years, but there was a pronounced increase in patients The group at highest risk were women over the age of 85 over 75 years. Interestingly, the increase was significantly years. A later study from 1988–1999, using data from the higher in Eastern Germany compared to Western Germany, New Zealand Health Information Service, found that the particularly in the older age-groups, which suggests that the numbers of males and females aged ≥65 years with hip differences between the East and West decreased over time. fracture did not meet the predictions. In fact, age-specific hip fracture rates dropped significantly for females in all the Hip fracture trends in Geneva, Switzerland, between age bands tested and have remained unchanged in men. 1991 and 2000 have been studied using computerized medical records from the main hospital. The study found In Australia there have been two major studies. The first, a significant decline of 1.4% annually for age-adjusted by Chang et al., looked at fracture rates between 1989 rates in women, but the rates remained stable in men. and 2000 in Dubbo (a semi-urban city 400 km Northwest In neighbouring Austria, between 1994 and 2006, after of Sydney). They showed that there was a significant adjustment for age and sex, the incidence rates rose from reduction in the overall fracture incidence rate by 4% 471/100 000 to 567/100 000 per year in men and from per year in women and 6% per year in men. There was 637/100 000 to 759/100 000 per year in women. This no significant change in the number of hip fractures rise is predominantly accounted for by the rise seen in over the same period; however, the total number of hip patients aged over 80 years. Hip fracture rates in Hungary fractures seen in this study was relatively low and hence are available for the period 1999–2003 from the National it was underpowered. A second study looked at hospital Health Insurance Fund database. This database covers admissions for hip fracture in New South Wales between the whole population of Hungary. The age-adjusted 1990–2000. Whilst the crude incidence rose, age-adjusted incidence of hip fracture was 430/100 000 in women and rates remained unchanged at around 130/100 000 person- 223/100 000 in men; these rates have remained stable years in men and 390/100 000 person-years in women. over this period.A lesser number of studies are available Women aged 65–75 years were the only age-specific group from southern Europe; two of these have been chosen to with a 1% decline in annual incidence of hip fracture, the represent hip fractures from this region. An Italian study incidence in the other age-groups remaining unchanged looked at the incidence of hip fracture in the county of during the period.What might explain the variation in hip Sienna from 1980–1991 using records from the orthopedic fracture incidence in different regions of world? departments of various hospitals. During this 12-year period, the temporal trend rose linearly in men from Age is the main risk factor for hip fractures. The incidence 57.5/100 000 person-years to 108.9/100 000 person-years: of hip fracture increases exponentially with age in both a 7.4% annual increase. In females, no significant trend was genders. In females younger than 35 years, the incidence observed. The overall incidence rate during this period was is 2/100 000 person-years, whereas it is 3032/100 000 157/100 000, much lower than that in northern or central person-years in women older than 85 years. In men, the European countries. Another study from Spain looked at corresponding rates are 4 and 190 per 100 000 person- hip fracture trends in northern Spain between 1988 and years. Most hip fractures occur in the elderly: 52% after 2002 using clinical records from all hospitals in the region the age of 80 years and 90% after the age of 50 years. of Cantabria. Whilst the crude hip fracture incidence The decline in bone mineral density and the increase in increased during this period, no significant changes were frequency of falls in elderly people are mainly responsible noticed following adjustment for age. Neither was there a for this high incidence of hip fractures. Only 1% of falls noticeable trend in age-specific incidence rates. The crude lead to a hip fracture, but 90% of these fractures is related rate increased mainly among with a more noticeable rise to a fall from standing height or less. To investigate this 19 Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 Dhanwal, et al.: Geographic variation in hip fracture incidence 49 30 issue, Schwarts et al. carried out a cross-national study for women and 384/100 000 for men. The rates are of hip fracture in five geographic areas – Beijing, China; intermediate in Asia, China, and Kuwait and lowest in black Budapest, Hungary; Hong Kong; Porto Alegre, Brazil; and populations. While studies in central Norway suggest a Reykjavik, Iceland – during the years 1990–1992. Cases stabilization in fracture rates in recent years, a Californian of hip fracture among women and men of ≥20 years were study published in 2004 reported a doubling of hip fracture identified using hospital discharge data in conjunction with rates in Hispanics, while no significant change occurred medical records, operating room logs, and radiology logs. among black or Asian men or women. In many cases, Estimated rates varied widely, with Beijing reporting the the lower incidence rates seen in the developing countries lowest rates (45.4/100 000 in men and 39.6/100 000 in can be partially explained by the lower life expectancy; women) and Reykjavik the highest rates (men: 141.3/100 in Latin America only 5.7% of the population is over 65. 000; women: 274.1/100 000). The rates were higher for Reduced longevity may also be the explanation for the low women than for men in all areas except Beijing. The study fracture rates observed in Morocco.Genetic factors may play demonstrated large differences in hip fracture incidence an important role in the etiology of hip fracture, as also rates, with age-adjusted incidence rates in women being 6 environmental factors. However, those factors that have times higher and in men over 3 times higher in Reykjavik been studied so far – such as alcohol consumption, smoking, compared with Beijing. The results of this study indicate the activity levels, obesity, and migration status – have not substantial limitations of relying on the hospital discharge explained these trends. Further research is clearly needed data alone to estimate hip fracture incidence rates; however, to explain these important environmental factors. Diseases the error found in the discharge lists is smaller than the large associated with secondary osteoporosis and with increased international variation found. The study concluded that risk of falling are an important cause of hip fractures, but the differences reported among countries reflect genuine more so in men than in women. variation in the hip fracture incidence rates. The influence of ethnicity on risk of osteoporotic fractures was analyzed by The incidence of hip fracture varies among different Ellaine et al. from our center (unpublished data). The rates countries and populations [Table 1 and Figure 1]. Rates vary considerably according to the geographic area and race are higher in Scandinavia than in Western Europe and and may vary widely within the same country and within Oceania. A north–south gradient in age-standardized risk populations of a given sex and race [Figure 1]. In Europe, is found in Europe and US, with higher rates in north. The hip fracture rates vary by as much as 7-fold between age-adjusted increase in incidence that has been observed countries. In general, people who live in latitudes far from in several countries over the last 50 years appears to have the equator seem to have a higher incidence of fracture. levelled off in some of these countries, especially in Europe The highest rates of hip fracture are seen in Caucasians and the US. The incidence increases with poor economic living in northern Europe, especially Scandinavians. A study status, reduced winter sunlight, and water fluoridation. from 1989 found that the age-adjusted 1-year cumulative Fractures occur more commonly in the winter season due incidence of hip fracture in Norway was 903/100 000 to altered neuromuscular coordination and vitamin D MEN WOMEN Incidence (per 10 p-y) Figure 1: Hip fracture per 100 000 person-years in different continents Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 20 Afric a Asia Europe North America Oceania South America Africa Asia Europe North America Oceania South America Dhanwal, et al.: Geographic variation in hip fracture incidence Table 1: Age-standardized hip fracture rates (per 100 000 costs and burden of osteoporosis in Asia. Beizing, China: An population) across different continents International Osteoporosis Foundation (IOF) publication; 2009. rd Continent Country Men Women 2. Cooper C, Campion G, Melton LJ 3 . Hip fractures in the elderly: A world-wide projection. Osteoporos Int 1992;2:285-9. Morocco, Rabat 57.7 79.9 3. Johnell O, Gullberg B, Allander E, Kanis JA. The apparent Cameroon 43.7 52.1 incidence of hip fracture in Europe: A study of national register Asia China, Beijing 87 97 sources. MEDOS Study Group. Osteoporos Int 1992;2:298-302. China, Shenyang 101.3 80.9 4. Hagino H, Katagiri H, Okano T, Yamamoto K, Teshima R. Korea 137 262 Increasing incidence of hip fracture in Tottori Prefecture, Japan: Iran 127.3 164.6 Trend from 1986 to 2001. Osteoporos Int 2005;16:1963-8. Malaysia 87.4 212.5 5. Koh LK, Saw SM, Lee JJ, Leong KH, Lee J; National Working Japan, Tottori 107.3 297.3 Committee on Osteoporosis. Hip fracture incidence rates in Japan 99.6 368 Singapore 1991-1998. Osteoporos Int 2001;12:311-8. Kuwait 216.6 316 6. Lim S, Koo BK, Lee EJ, Park JH, Kim MH, Shin KH, et al. Incidence Singapore 152 402 of hip fractures in Korea. J Bone Miner Metab 2008;26:400-5. Hong Kong 193 484.3 7. Lau EM, Cooper C, Fung H, Lam D, Tsang KK. Hip fracture in Hong Kong 50 110 Hong Kong over the last decade--a comparison with the UK. J Taiwan 233.4 496.8 Public Health Med 1999;21:249-50. 8. Lau EM, Cooper C, Wickham C, Donnan S, Barker DJ. Hip fracture South America Mexoci 98 169 in Hong Kong and Britain. Int J Epidemiol 1990;19:1119-21. Brazil, Sobral 59.3 168.4 9. Xu L, Lu A, Zhao X, Chen X, Cummings SR. Very low rates of Argentina 137 405 hip fracture in Beijing, People’s Republic of China the Beijing Venezuela 37 98 Osteoporosis Project. Am J Epidemiol 1996;144:901-7. Europe Switzerland 137.8 346 10. Moayyeri A, Soltani A, Larijani B, Naghavi M, Alaeddini F, Former East Germany 137.8 354.7 Abolhassani F. Epidemiology of hip fracture in Iran: Results Former West Germany 154.5 399.4 from the Iranian multicenter study on accidental injuries. England 143.6 418.2 Osteoporos Int 2006;17:1252-7. Greece 201.7 469.9 11. Memon A, Pospula WM, Tantawy AY, Abdul-Ghafar S, Suresh A, Sweden 302.7 709.5 Al-Rowaih A. Incidence of hip fracture in Kuwait. Int J Epidemiol Norway, 352 763.6 1998;27:860-5. Norway, Oslo 399.3 920.7 12. Riera-Espinoza G. Epidemiology of osteoporosis in Latin Austria 567 759 America 2008. Salud Publica Mex 2009;51:S52-5. Hungary 223 430 13. Clark P, Lavielle P, Franco-Marina F, Ramírez E, Salmerón J, The Netherlands 308 669 Kanis JA, et al. Incidence rates and life-time risk of hip fractures North America United States, Minnesota 201.6 511.5 in Mexicans over 50 years of age: A population-based study. Osteoporos Int 2005;16:2025-30. United States 197.2 553.5 14. Morosano M, Masoni A, Sanchez A. Incidence of hip fractures in Oceania New Zealand, Maori 197 516 the city of Rosario, Argentina. Osteoporos Int 2005;16:1339-44. Non-Maori 288 827 15. Zebaze RM, Seeman E. Epidemiology of hip and wrist fractures New South Wales 191.8 475.1 in Cameroon, Africa. Osteoporos Int 2003;14:301-5. Australia 187.8 504.2 16. El Maghraoui A, Koumba BA, Jroundi I, Achemlal L, Bezza A, Tazi Australia 130 390 MA. Epidemiology of hip fracture in 2002 in Rabat, Morocco. Osteoporos Int 2005;16:597-602. deficiency. The incidence of hip fracture is significantly lower 17. Saeed I, Carpenter RD, Leblanc AD, Li J, Keyak JH, Sibonga JD, et al. Quantitative computed tomography reveals the effects in black and Asian people. These geographical and racial of race and sex on bone size and trabecular and cortical bone differences could be explained as being due to the reduced density. J Clin Densitom 2009;12:330-6. life expectancy in Asian countries, the genetic background, rd 18. Melton LJ 3 , Crowson CS, O’Fallon WM. Fracture incidence and high physical activity. No studies are available from the in Olmsted County, Minnesota: Comparison of urban with Indian subcontinent regarding hip fracture incidence. With rural rates and changes in urban rates over time. Osteoporos Int 1999;9:29-37. changing the demographic profile of Indian population, rd 19. Melton LJ 3 , Therneau TM, Larson DR. Long-term trends in we are going to witness a sharp rise in hip fractures over hip fracture prevalence: The influence of hip fracture incidence the next three decades. Therefore, there is urgent need to and survival. Osteoporos Int 1998;8:68-74. carry out epidemiological studies from India and other parts 20. Rodriguez JG, Sattin RW, Waxweiler RJ. Incidence of hip fractures, United States, 1970-83. Am J Prev Med 1989; of Asia to allow health administrators to plan policies for 5:175-81. prevention of hip fracture in elderly population. 21. Bacon WE. Secular trends in hip fracture occurrence and survival: Age and sex differences. J Aging Health 1996;8:538-53. r EfErEncEs 22. Samelson EJ, Zhang Y, Kiel DP, Hannan MT, Felson DT. Effect of birth cohort on risk of hip fracture: Age-specific incidence rates 1. Mithal A, Dhingra V, Lau E. The asian audit: Epidemiology, in the Framingham Study. Am J Public Health 2002;92:858-62. 21 Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 Dhanwal, et al.: Geographic variation in hip fracture incidence 23. Evans JG, Seagroatt V, Goldacre MJ. Secular trends in proximal 38. G o e t t s c h W G , d e J o n g R B , K r a m a r z P , H e r i n g s R M . femoral fracture, Oxford record linkage study area and England Developments of the incidence of osteoporosis in The 1968-86. J Epidemiol Community Health 1997;51:424-9. Netherlands: A PHARMO study. Pharmacoepidemiol Drug 24. Kannus P, Niemi S, Parkkari J, Palvanen M, Vuori I, Jarvinen Saf 2007;16:166-72. M. Hip fractures in Finland between 1970 and 1997 and 39. Icks A, Haastert B, Wildner M, Becker C, Meyer G. Trend of predictions for the future. Lancet 1999;353:802-5. hip fracture incidence in Germany 1995-2004: A population- rd 25. Zingmond DS, Melton LJ 3 , Silverman SL. Increasing hip based study. Osteoporos Int 2008;19:1139-45. fracture incidence in California Hispanics, 1983 to 2000. 40. Chevalley T, Guilley E, Herrmann FR, Hoffmeyer P, Rapin Osteoporos Int 2004;15:603-10. CH, Rizzoli R. Incidence of hip fracture over a 10-year 26. Brauer CA, Coca-Perraillon M, Cutler DM, Rosen AB. Incidence period (1991-2000): Reversal of a secular trend. Bone 2007; and mortality of hip fractures in the United States. JAMA 40:1284-9. 2009;302:1573-9. 41. Mann E, Icks A, Haastert B, Meyer G. Hip fracture incidence 27. Leslie WD, O’Donnell S, Lagace C, Walsh P, Bancej C, Jean in the elderly in Austria: An epidemiological study covering S, et al. Population-based Canadian hip fracture rates with the years 1994 to 2006. BMC Geriatr 2008;8:35. international comparisons. Osteoporos Int 2010;21:1317-22. 42. Pentek M, Horvath C, Boncz I, Falusi Z, Toth E, Sebestyen A, et 28. Zain Elabdien BS, Olerud S, Karlstrom G, Smedby B. Rising al. Epidemiology of osteoporosis related fractures in Hungary incidence of hip fracture in Uppsala, 1965-1980. Acta Orthop from the nationwide health insurance database, 1999-2003. Scand 1984;55:284-9. Osteoporos Int 2008;19:243-9. 29. Sernbo I, Gullberg B, Johnell O. Hip fracture in Malmo over 43. Agnusdei D, Camporeale A, Gerardi D, Rossi S, Bocchi L, three decades. Bone 1993;14:S19-22. Gennari C. Trends in the incidence of hip fracture in Siena, 30. Rogmark C, Sernbo I, Johnell O, Nilsson JA. Incidence of hip Italy, from 1980 to 1991. Bone 1993;14:S31-4. fractures in Malmo, Sweden, 1992-1995. A trend-break. Acta 44. Hernandez JL, Olmos JM, Alonso MA, Gonzalez-Fernandez Orthop Scand 1999;70:19-22. CR, Martinez J, Pajaron M, et al. Trend in hip fracture 31. Lofthus CM, Osnes EK, Falch JA, Kaastad TS, Kristiansen IS, epidemiology over a 14-year period in a Spanish population. Nordsletten L, et al. Epidemiology of hip fractures in Oslo, Osteoporos Int 2006;17:464-70. Norway. Bone 2001;29:413-8. 45. Rockwood PR, Horne JG, Cryer C. Hip fractures: A future 32. Giversen IM. Time trends of age-adjusted incidence rates epidemic? J Orthop Trauma 1990;4:388-93. of first hip fractures: A register-based study among older 46. Fielden J, Purdie G, Horne G, Devane P. Hip fracture incidence people in Viborg County, Denmark, 1987-1997. Osteoporos in New Zealand, revisited. N Z Med J 2001;114:154-6. Int 2006;17:552-64. 47. Chang KP, Center JR, Nguyen TV, Eisman JA. Incidence of hip 33. Kannus P, Niemi S, Parkkari J, Palvanen M, Vuori I, Jarvinen M. and other osteoporotic fractures in elderly men and women: Nationwide decline in incidence of hip fracture. J Bone Miner Dubbo osteoporosis epidemiology study. J Bone Miner Res Res 2006;21:1836-8. 2004;19:532-6. 34. Lonnroos E, Kautiainen H, Karppi P, Huusko T, Hartikainen 48. Boufous S, Finch CF, Lord SR. Incidence of hip fracture in S, Kiviranta I, et al. Increased incidence of hip fractures. A New South Wales: Are our efforts having an effect? Med J population based-study in Finland. Bone 2006;39:623-7. Aust 2004;180:623-6. 35. Spector TD, Cooper C, Lewis AF. Trends in admissions for hip 49. Schwartz AV, Kelsey JL, Maggi S, Tuttleman M, Ho SC, fracture in England and Wales, 1968-85. BMJ 1990;300:1173-4. Jonsson PV, et al. International variation in the incidence of 36. Balasegaram S, Majeed A, Fitz-Clarence H. Trends in hospital hip fractures: Cross-national project on osteoporosis for the admissions for fractures of the hip and femur in England, World Health Organization Program for Research on Aging. 1989-1990 to 1997-1998. J Public Health Med 2001;23:11-7. Osteoporos Int 1999;9:242-53. 37. Boereboom FT, de Groot RR, Raymakers JA, Duursma SA. The incidence of hip fractures in The Netherlands. Neth J Med Source of Support: Nil, Conflict of Interest: None. 1991;38:51-8. Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 22 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Indian Journal of Orthopaedics Pubmed Central

Epidemiology of hip fracture: Worldwide geographic variation

Dhanwal, Dinesh K; Dennison, Elaine M; Harvey, Nick C; Cooper, Cyrus
Indian Journal of Orthopaedics , Volume 45 (1) – Jul 1, 168
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0019-5413
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10.4103/0019-5413.73656
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Abstract

Review Article Epidemiology of hip fracture: Worldwide geographic variation 1 1 1,2 Dinesh K Dhanwal, Elaine M Dennison , Nick C Harvey , Cyrus Cooper ABstrA ct Osteoporosis is a major health problem, especially in elderly populations, and is associated with fragility fractures at the hip, spine, and wrist. Hip fracture contributes to both morbidity and mortality in the elderly. The demographics of world populations are set to change, with more elderly living in developing countries, and it has been estimated that by 2050 half of hip fractures will occur in Asia. This review conducted using the PubMed database describes the incidence of hip fracture in different regions of the world and discusses the possible causes of this wide geographic variation. The analysis of data from different studies show a wide geographic variation across the world, with higher hip fracture incidence reported from industrialized countries as compared to developing countries. The highest hip fracture rates are seen in North Europe and the US and lowest in Latin America and Africa. Asian countries such as Kuwait, Iran, China, and Hong Kong show intermediate hip fracture rates. There is also a north–south gradient seen in European studies, and more fractures are seen in the north of the US than in the south. The factors responsible of this variation are population demographics (with more elderly living in countries with higher incidence rates) and the influence of ethnicity, latitude, and environmental factors. The understanding of this changing geographic variation will help policy makers to develop strategies to reduce the burden of hip fractures in developing countries such as India, which will face the brunt of this problem over the coming decades. Key words: Epidemiology, geographic variation, hip fracture, incidence rate, osteoporosis i ntroduction rising life expectancy throughout the globe, the number of elderly individuals is increasing in every geographical steoporosis represents a major public health region, and it is estimated that the incidence of hip fracture problem because of its association with low-energy will rise from 1.66 million in 1990 to 6.26 million by 2050. Otrauma or fragility fractures. Hip fracture has been recognized as the most serious consequence of osteoporosis Studies over the last few decades have demonstrated because of its complications, which include chronic pain, geographic variation in the incidence of hip fracture across disability, diminished quality of life, and premature death. continents as well as among different parts of a region. Osteoporotic hip fracture is an established health problem Incidence of hip fracture is highest in Sweden and North in the West and is increasingly recognized as a growing America, with almost seven-fold lower rates in Southern problem in Asia as per the Asian Audit Report, 2009. With 3 European countries. Hip fracture rates are also lower in Asian and Latin American populations. But as three-quarters of Maulana Azad Medical College, New Delhi, India, MRC Epidemiology Resource the world’s population live in Asia, it is projected that Asian Center, University of Southampton, Southampton General Hospital, Southampton countries will contribute more to the pool of hip fractures in SO16 6YD, UK and Botnar Research Center, Institute of Musculoskeletal Sciences, University of Oxford OX3 7LD, UK coming years. It is estimated that by 2050 more than 50% of all Address for correspondence: Prof. Dinesh K Dhanwal, osteoporotic fractures will occur in Asia. This variation in the Department of Medicine (Endocrinology), Maulana Azad Medical College, distribution of hip fracture over different regions of the world New Delhi, India 110002. E-mail: [email protected] demonstrate that genetic and environmental factors play a role in the etiology of hip fracture. It is therefore worthwhile to Access this article online examine the geographic variations in hip fracture and speculate Quick Response Code: on the factors responsible for these differences. This review Website: www.ijoonline.com will serve as an update of the epidemiology of hip fracture worldwide, with special emphasis on the geographic variations and etiological factors. This review was conducted using DOI: 10.4103/0019-5413.73656 the PubMed database. The keywords that were employed included hip fracture, incidence rate, geographic variation, 15 Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 Dhanwal, et al.: Geographic variation in hip fracture incidence osteoporosis, and epidemiology. The articles were chosen hip fractures in men decreased from 162.8/100 000 in on the basis of 1) focus (studies that specifically focused on 2001 to 137.5/100 000 in 2004, a 15.5% decrease. geographic variation in hip fracture); 2) language (studies that The direct medical care costs of hip fracture increased were in English); and 3) methods (studies that used statistical from $62 707 697 in 2001 to $65 200 035 in 2004, tests to examine hip fracture incidence rates). and the proportional cost of hip fractures in the national medical costs increased by 4.5% over 4 years (from 0.200% in 2001 to 0.209% in 2004). On analysis of the AsiA population-based data obtained from the whole country from 2001 to 2004, the incidence rate of hip fractures in Hip fracture rates are available from many countries across women (but not in men) and its cost have increased in Asia, including from Singapore, Taiwan, Japan, Malaysia, Korea. This gender difference in the distribution of hip China, and the Middle East. Unfortunately, only projected fractures underlines the need for aggressive intervention figures are available from India, which is second most in osteoporosis in elderly women. populous country in the world. Studies on hip fracture incidence rates are available from Japan, particularly In 1995, the incidence rates of hip fracture from Hong Kong from the Tottori prefecture, a region representative of were 110/100 000 in women and 50/100 000 in men as per the Japanese population in terms of demographic and data from public hospitals. Secular trends on hip fracture economic status. A recent survey (Hagino et al.) identified from Hong Kong suggest that over the last three decades 851, 901, and 1059 patients with hip fracture (aged 35 the age-specific incidence increased 2.5-fold in women years and older) in 2004, 2005, and 2006, respectively. and 1.7-fold in men. The incidence rates were found to The residual lifetime risk of hip fracture at 50 years of age similar to those seen in the Wessex health region of UK. In was estimated to be 5.6% for men and 20% for women. Beijing, China, hip fracture incidence were calculated from The study concluded that in the Japanese population admissions to 76 city hospitals between 1988 and 1992. aged 35 years or older, the crude incidence of hip fracture It was presumed that all the fracture cases from Beijing go was 244.8 per 100 000 person-years from 2004 to 2006 to these public hospitals only. Based upon the 1990 China and the gender-specific incidence was 99.6 per 100 000 census, age-standardized rates of hip fracture were 87/100 person-years for men and 368 per 100 000 person-years 000 for women and 97/100 000 for men. These data further for women. When these incidence rates were compared demonstrate that from 1988 to 1992, the rates in Beijing with that from 30 years ago, the authors concluded that increased by 34% in women and 33% in men. the incidence of hip fracture in the Japanese population is increasing. This increasing incidence is due to the increase Maximum data from the Middle East is available from Iran in the population of the elderly in Japan over the last three from the Iranian Multicenter Study on Accidental Injuries. decades. This study reported age-standardized incidence rates of hip fracture of 127.3/100 000 person-years in men and The highest incidence of hip fractures from Asia has been 164.6/100 000 person-years in women, which is much reported from Singapore. A study by Koh et al. revealed lower than the rates reported from any of the Western that hip fracture rates from 1991 to 1998 (per 100 000) countries, including the US. Smaller studies are available were 152 in men and 402 in women; this was respectively from Kuwait and show similar results. 1.5 and 5 times higher than corresponding rates in 1960s. Examined by ethnicity, since 1960, the main increase in hip fracture rates has been seen in Chinese and Malays, l Atin AMEricA while the rates in the Indian ethnic group appear to Limited data is available from South American countries. have decreased. The factors responsible for these racial differences include differences in the demographic profile, Reira-Espinoza recently reviewed data from L atin body weight, physical activity, prevalence of cigarette America. In a study published from Mexico in 2005, the smoking and alcohol consumption, calcium intake, and annual rate of hip fracture in the two public health care systems were 169 in women and 98 in men per 100000 frequency of falls in the community in elderly. person-years. These fracture rates are similar to that In Korea, Lim et al. analyzed the incidence and cost reported from the southern countries of Europe. Recently, of hip fracture from 2001 to 2004 using data from the hip fracture incidence has been reported from Rosario, 6 14 Health Insurance Review Agency, Korea. In individuals Argentina. The annual incidence among inhabitants over over 50 years of age, the number of hip fractures in the age of 50 years was 290/100 000 (405/100 000 for women increased from 250.9/100 000 persons in 2001 women and 137/100 000 for men; female/male ratio: 2.96). to 262.8/100 000 in 2004, a 4.7% increase. However, In the population over 65 years of age, the incidence was Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 16 Dhanwal, et al.: Geographic variation in hip fracture incidence 646/100 000 and 345/100 000, respectively. These values men the rates did not change significantly over this time are similar to the values reported in people older than 65 period. There was an overall improvement in the hospital years in the US. Reports from Venezuela have shown that survival rates in men aged over 85 years and females over the incidence of hip fracture in women over 50 years was 75 years of age.The Framingham study, a population-based 98/100 000 and in men 37/100 000. With an increasing cohort study conducted from 1948 to 1996, found that population of elderly individuals in this part of the world, as compared with women born by 1900, hip fracture incidence well as limited health care resources, clinicians and health was 1.2 times and 1.4 times greater among women born authorities will face an enormous challenge in the coming from 1901 to 1910 and from 1911 to 1921, respectively. years in Latin America. This study demonstrates an important birth cohort effect over this period, consistent with studies conducted in 22 23 England and Finland. A Californian study looked at AfricA hip fracture rates between 1983 and 2000, with special attention paid to the Hispanic population, the largest and A few studies are available from Africa on the incidence fastest-growing ethnic minority in the US. Hip fractures of hip fracture. Osteoporosis and fragility fractures are were identified using the annual hospital patient discharge believed to be uncommon in Africa. Zebaze et al. conducted database. Among non-Hispanic white women in California, a study in Cameroon by documenting all patients aged 35 the standardized annular hip fracture rates for those ≥55 years and older admitted to the two main urban hospitals years fell steadily over the past two decades by 0.6% per in Cameroon over a 2-year period with a diagnosis of year in women (and 0.5% in men). No significant change fracture. Using the 1997 estimates of the population, the occurred among black or Asian women migrants to the US. incidence of low-energy trauma fractures at the hip (per By contrast, the annual fracture rates amongst Hispanic 100 000 persons over 35 years) were 57.1 in women and women increased by 4.9% per year (and by 4.2% per year 43.7 in men. Similar low fracture rates have been reported in the men). This supports the hypothesis that residence from Morocco in 2005. Based on these two fairly well- in early life has a much greater association with variation conducted studies from Africa it is difficult to make a general in hip fracture rates that does current region of residence. statement about hip fracture incidence from Africa, but it Another explanation may be that Hispanic men and women seems that as in American blacks, the hip fracture rates in the African population are much lower than in the western have been shown to partake in less physical activity and are more likely to have nutritional deficits than non-Hispanic population. whites. In a recent study by Brauer and co-workers (2009), it was concluded that in the US, hip fracture rates and n orth AMEricA subsequent mortality among persons ≥65 years of age are declining and that the comorbidities among patients with Hip fracture rates among the US population are the highest hip fractures have increased. This group looked at the data in the world. Melton et al. and Ho et al. have reported from a 20% sample of Medicare claims from 1985–2005 age-standardized annual incidence of hip fracture per 100 in patients ≥65 years. The annual mean number of hip 000 as 201 and 197 in men and 511 and 553 in women, fractures was 957.3/100 000 for women and 414.4/100 respectively. A recently published study has reported the 000 for men. The age-adjusted incidence of hip fracture secular trends in Minnesota in the US over the period from increased from 1986 to 1995 and then steadily declined 1928 to 1992. This study looked at all proximal femur from 1995 to 2005. Leslie et al. have recently published fractures that occurred among residents during the 65-year data from Canada in a population-based study and made period. The annual age-adjusted incidence rates among international comparisons. According to this group, during women rose rapidly until 1950, only to fall slowly thereafter. 2000–2005, 147 982 hip fractures were identified. The age- Age-adjusted rates in men rose more steadily before adjusted fracture incidence was 86.4/100 000 in women beginning a downturn after 1980. Incidence rates rose and 53./100 000 in men. On comparison with data from exponentially with age in both men and women. Another the US, the overall fracture rate in Canadian women was study from the US used the national hospital discharge 30% lower than in US women in 2001 and 26% lower than survey (which covers 0.6% of all patient discharges) to in German women in 2004. Canadian men showed similar analyze secular trends in the white population from 1970 overall hip fracture rates as American men prior to age 80 to 1983. An overall increase of 9.3% in age- and sex- years but a 26% lower rate after 80 years of age. adjusted hip fracture incidence rates was observed over the 14-year period. A second study using the same database looked at age-specific rates between 1965 and 1993. Hip EuropE fractures increased linearly for males in the age-groups of 80–84 years and ≥85 years, but for women and young The majority of studies detailing hip fracture rates have been 17 Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 Dhanwal, et al.: Geographic variation in hip fracture incidence performed in the last five decades. Scandinavia has the age-adjusted incidence fell nationally by 2.4% annually highest reported incidence of hip fracture worldwide. There in women and 0.9% in men in 2004. A smaller study in are a large number of studies looking at incidence rates as central Finland between 1992–2003 showed that the age- well as secular trends in this geographically northern region. adjusted rates increased considerably from 2.0 per 1000 The incidence rates vary from North to South Europe, with person-years to 3.9 per 1000 person-years in men and from the highest being in Sweden and Norway and the lowest 2.8 per 1000 person-years to 5.6 per 1000 person-years in France and Switzerland. From Norway, the reported in women. There is no obvious explanation why central age-standardized annual incidence rate of hip fracture is Finland should have increasing rates compared to the rest 920/100 000 in women and 399.3/100 000 in men and of the country. One possibility is that only two time points that in Switzerland is 346/10000 and 137.8/100 000 in were examined in this study, whereas most other studies women and men, respectively. A study on secular trends have examined the secular trends; it is possible that a sharp from Uppsala, Sweden, (1965–1980) showed an annual rise in the rates may have occurred during the early part of increase of 2.2% for age- and sex-adjusted hip fracture rates, the study period and then stabilized. which increased from 430/100 000 in 1965 to 650/100 Overall, the epidemiological data from Scandinavia 000 in 1980. The age-specific incidence increased especially in the group aged ≥85 years, in whom fractures indicates that although early studies (dating to the1950s) of the femoral neck were three times more common and described an increase in hip fracture incidence, the rates trochanteric fractures four times more common in 1980 appear to have fallen in the most recent periods. The decline in fracture rate appears to have occurred several years later than in 1965. Studies from Malmo, Sweden, showed an exponential increase in hip fracture incidence from 1950 in Finland compared to Sweden and Norway. The rise to 1985 in both men and women over age 50, increasing in the incidence of hip fracture in Finland from the early from an annual age-adjusted incidence of 150–390/100 000 1970s until the late 1990s has been followed by declining in men and 300–830/100 000 in women. Increases were fracture rates. The exact reasons for this are unknown, but seen for both trochanteric and cervical fractures. However, a cohort effect toward a healthier aging population and the most recent data from Malmo from 1992–1995 shows increased average body weight and improved functional that this fracture rate is now steady, in line with many of ability among elderly Finns cannot be ruled out as possible 29 34 the Northern American studies. If the data is broken down causes. according to fracture subtypes, however, the incidence of cervical fractures had decreased (210–170/100000 in men Data from central Europe includes studies from the UK, Netherlands, Germany, Switzerland, Austria, and Hungary. and 420–410/100000 in women), whereas there was still a small rise in trochanteric fractures (180–190/100000 in The highest number of studies comes from the UK. The first men and 410–440/100000 in women). study on this subject assessed hip fracture data from the hospital inpatient enquiry for England and Wales between The incidence of hip fractures in Oslo, Norway, between 1968–78. In this study, the age-specific rates increased 1978 and 1997 was assessed using electronic diagnosis steadily in women by 61% and in men by 73% until 1979. registers. The age-adjusted fracture rates per 10000 were No further increases occurred in either sex up to 1985. The Oxford Record Linkage Study which looked at the 118.0 and 44.0 in 1996/97, 124.3 and 44.9 in 1988/89, and 104.5 and 35.8 in 1978/79 for women and men, period 1968–1986 found a similar pattern, although there respectively, indicating that the incidence of hip fractures in was a more continuous trend. Age, cohort, and period Oslo has not changed significantly during the last decade. modelling were used in this study to look at the incidence Denmark used its national patient register to look at hip rates. There was a clear cohort effect in both the studies and fracture incidence between 1987 and 1997 in Viborg the difference in incidence rates was apparent from births County. The incidence of age-adjusted first hip fractures in 1883 to 1917 in addition to the age. A birth cohort effect increased significantly by 18 and 8 per 100 000 per year for was confirmed in subsequent analyses of the Framingham women and men, respectively; peri-trochanteric fractures data, showing that in progressive birth cohorts from increased by 10 per 100 000 per year There are a number of 1887–1921 there were age-specific increases in fracture studies from Finland, all using the Finnish National Hospital incidence rate ratios up from 1.0 to 1.2–1.4 in women and discharge register. The first study drew its hip fracture 1.0 to 2.0 in men. The most recent study from the UK data from the entire >50-year-old population. Between looked at hospital episode statistics from 1989–1998. Age- 1970–997, the age-adjusted hip fracture rate increased standardized incidence rates increased by 32% in women from 292/100 000 to 467/100 000 in women and from and 38% in men up to 1991–92 and thereafter remained 112/100 000 to 233/100 000 in men. In a further follow- stable. In the Netherlands, data from the Dutch Medical up study using the same population from 1997–2004, the Registry shows that between 1972–1987 the age-adjusted Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 18 Dhanwal, et al.: Geographic variation in hip fracture incidence incidence of hip fractures rose linearly from 479/100 000 to in cervical fractures as opposed to trochanteric fractures. 669/100 000 per year in women and from 198/100 000 to 308/100 000 per year in men aged ≥65 years. In a later o cEAniA study conducted between 1986 and 2002 using the Dutch Medical Registry, the age incidence of hip fracture increased Studies of hip fracture epidemiology have also been linearly from 1986–1993 in patients over 45 years; after performed in both New Zealand and Australia and the this the incidence decreased by 0.5% annually until 2002. fracture incidence rates are comparable to that seen in In Germany, between 1995 and 2004 (in a study using the Caucasian population in Europe and North America. the national hospital discharge register) the age- and sex- A study from New Zealand between 1950–1987 looked adjusted hip fracture incidence increased by 0.5% per year at nationwide hip fractures in those aged ≥65 years. A in women and 0.7% per year in men. In women aged ≥40 disproportionate increase in the number of fractures in years there was a tendency for a decrease up to the age of relation to the increase in population size was observed. 74 years, but there was a pronounced increase in patients The group at highest risk were women over the age of 85 over 75 years. Interestingly, the increase was significantly years. A later study from 1988–1999, using data from the higher in Eastern Germany compared to Western Germany, New Zealand Health Information Service, found that the particularly in the older age-groups, which suggests that the numbers of males and females aged ≥65 years with hip differences between the East and West decreased over time. fracture did not meet the predictions. In fact, age-specific hip fracture rates dropped significantly for females in all the Hip fracture trends in Geneva, Switzerland, between age bands tested and have remained unchanged in men. 1991 and 2000 have been studied using computerized medical records from the main hospital. The study found In Australia there have been two major studies. The first, a significant decline of 1.4% annually for age-adjusted by Chang et al., looked at fracture rates between 1989 rates in women, but the rates remained stable in men. and 2000 in Dubbo (a semi-urban city 400 km Northwest In neighbouring Austria, between 1994 and 2006, after of Sydney). They showed that there was a significant adjustment for age and sex, the incidence rates rose from reduction in the overall fracture incidence rate by 4% 471/100 000 to 567/100 000 per year in men and from per year in women and 6% per year in men. There was 637/100 000 to 759/100 000 per year in women. This no significant change in the number of hip fractures rise is predominantly accounted for by the rise seen in over the same period; however, the total number of hip patients aged over 80 years. Hip fracture rates in Hungary fractures seen in this study was relatively low and hence are available for the period 1999–2003 from the National it was underpowered. A second study looked at hospital Health Insurance Fund database. This database covers admissions for hip fracture in New South Wales between the whole population of Hungary. The age-adjusted 1990–2000. Whilst the crude incidence rose, age-adjusted incidence of hip fracture was 430/100 000 in women and rates remained unchanged at around 130/100 000 person- 223/100 000 in men; these rates have remained stable years in men and 390/100 000 person-years in women. over this period.A lesser number of studies are available Women aged 65–75 years were the only age-specific group from southern Europe; two of these have been chosen to with a 1% decline in annual incidence of hip fracture, the represent hip fractures from this region. An Italian study incidence in the other age-groups remaining unchanged looked at the incidence of hip fracture in the county of during the period.What might explain the variation in hip Sienna from 1980–1991 using records from the orthopedic fracture incidence in different regions of world? departments of various hospitals. During this 12-year period, the temporal trend rose linearly in men from Age is the main risk factor for hip fractures. The incidence 57.5/100 000 person-years to 108.9/100 000 person-years: of hip fracture increases exponentially with age in both a 7.4% annual increase. In females, no significant trend was genders. In females younger than 35 years, the incidence observed. The overall incidence rate during this period was is 2/100 000 person-years, whereas it is 3032/100 000 157/100 000, much lower than that in northern or central person-years in women older than 85 years. In men, the European countries. Another study from Spain looked at corresponding rates are 4 and 190 per 100 000 person- hip fracture trends in northern Spain between 1988 and years. Most hip fractures occur in the elderly: 52% after 2002 using clinical records from all hospitals in the region the age of 80 years and 90% after the age of 50 years. of Cantabria. Whilst the crude hip fracture incidence The decline in bone mineral density and the increase in increased during this period, no significant changes were frequency of falls in elderly people are mainly responsible noticed following adjustment for age. Neither was there a for this high incidence of hip fractures. Only 1% of falls noticeable trend in age-specific incidence rates. The crude lead to a hip fracture, but 90% of these fractures is related rate increased mainly among with a more noticeable rise to a fall from standing height or less. To investigate this 19 Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 Dhanwal, et al.: Geographic variation in hip fracture incidence 49 30 issue, Schwarts et al. carried out a cross-national study for women and 384/100 000 for men. The rates are of hip fracture in five geographic areas – Beijing, China; intermediate in Asia, China, and Kuwait and lowest in black Budapest, Hungary; Hong Kong; Porto Alegre, Brazil; and populations. While studies in central Norway suggest a Reykjavik, Iceland – during the years 1990–1992. Cases stabilization in fracture rates in recent years, a Californian of hip fracture among women and men of ≥20 years were study published in 2004 reported a doubling of hip fracture identified using hospital discharge data in conjunction with rates in Hispanics, while no significant change occurred medical records, operating room logs, and radiology logs. among black or Asian men or women. In many cases, Estimated rates varied widely, with Beijing reporting the the lower incidence rates seen in the developing countries lowest rates (45.4/100 000 in men and 39.6/100 000 in can be partially explained by the lower life expectancy; women) and Reykjavik the highest rates (men: 141.3/100 in Latin America only 5.7% of the population is over 65. 000; women: 274.1/100 000). The rates were higher for Reduced longevity may also be the explanation for the low women than for men in all areas except Beijing. The study fracture rates observed in Morocco.Genetic factors may play demonstrated large differences in hip fracture incidence an important role in the etiology of hip fracture, as also rates, with age-adjusted incidence rates in women being 6 environmental factors. However, those factors that have times higher and in men over 3 times higher in Reykjavik been studied so far – such as alcohol consumption, smoking, compared with Beijing. The results of this study indicate the activity levels, obesity, and migration status – have not substantial limitations of relying on the hospital discharge explained these trends. Further research is clearly needed data alone to estimate hip fracture incidence rates; however, to explain these important environmental factors. Diseases the error found in the discharge lists is smaller than the large associated with secondary osteoporosis and with increased international variation found. The study concluded that risk of falling are an important cause of hip fractures, but the differences reported among countries reflect genuine more so in men than in women. variation in the hip fracture incidence rates. The influence of ethnicity on risk of osteoporotic fractures was analyzed by The incidence of hip fracture varies among different Ellaine et al. from our center (unpublished data). The rates countries and populations [Table 1 and Figure 1]. Rates vary considerably according to the geographic area and race are higher in Scandinavia than in Western Europe and and may vary widely within the same country and within Oceania. A north–south gradient in age-standardized risk populations of a given sex and race [Figure 1]. In Europe, is found in Europe and US, with higher rates in north. The hip fracture rates vary by as much as 7-fold between age-adjusted increase in incidence that has been observed countries. In general, people who live in latitudes far from in several countries over the last 50 years appears to have the equator seem to have a higher incidence of fracture. levelled off in some of these countries, especially in Europe The highest rates of hip fracture are seen in Caucasians and the US. The incidence increases with poor economic living in northern Europe, especially Scandinavians. A study status, reduced winter sunlight, and water fluoridation. from 1989 found that the age-adjusted 1-year cumulative Fractures occur more commonly in the winter season due incidence of hip fracture in Norway was 903/100 000 to altered neuromuscular coordination and vitamin D MEN WOMEN Incidence (per 10 p-y) Figure 1: Hip fracture per 100 000 person-years in different continents Indian Journal of Orthopaedics | January 2011 | Vol. 45 | Issue 1 20 Afric a Asia Europe North America Oceania South America Africa Asia Europe North America Oceania South America Dhanwal, et al.: Geographic variation in hip fracture incidence Table 1: Age-standardized hip fracture rates (per 100 000 costs and burden of osteoporosis in Asia. Beizing, China: An population) across different continents International Osteoporosis Foundation (IOF) publication; 2009. rd Continent Country Men Women 2. Cooper C, Campion G, Melton LJ 3 . Hip fractures in the elderly: A world-wide projection. Osteoporos Int 1992;2:285-9. Morocco, Rabat 57.7 79.9 3. Johnell O, Gullberg B, Allander E, Kanis JA. The apparent Cameroon 43.7 52.1 incidence of hip fracture in Europe: A study of national register Asia China, Beijing 87 97 sources. MEDOS Study Group. Osteoporos Int 1992;2:298-302. China, Shenyang 101.3 80.9 4. Hagino H, Katagiri H, Okano T, Yamamoto K, Teshima R. Korea 137 262 Increasing incidence of hip fracture in Tottori Prefecture, Japan: Iran 127.3 164.6 Trend from 1986 to 2001. Osteoporos Int 2005;16:1963-8. Malaysia 87.4 212.5 5. Koh LK, Saw SM, Lee JJ, Leong KH, Lee J; National Working Japan, Tottori 107.3 297.3 Committee on Osteoporosis. Hip fracture incidence rates in Japan 99.6 368 Singapore 1991-1998. Osteoporos Int 2001;12:311-8. Kuwait 216.6 316 6. Lim S, Koo BK, Lee EJ, Park JH, Kim MH, Shin KH, et al. Incidence Singapore 152 402 of hip fractures in Korea. J Bone Miner Metab 2008;26:400-5. Hong Kong 193 484.3 7. Lau EM, Cooper C, Fung H, Lam D, Tsang KK. Hip fracture in Hong Kong 50 110 Hong Kong over the last decade--a comparison with the UK. J Taiwan 233.4 496.8 Public Health Med 1999;21:249-50. 8. Lau EM, Cooper C, Wickham C, Donnan S, Barker DJ. Hip fracture South America Mexoci 98 169 in Hong Kong and Britain. Int J Epidemiol 1990;19:1119-21. Brazil, Sobral 59.3 168.4 9. Xu L, Lu A, Zhao X, Chen X, Cummings SR. Very low rates of Argentina 137 405 hip fracture in Beijing, People’s Republic of China the Beijing Venezuela 37 98 Osteoporosis Project. Am J Epidemiol 1996;144:901-7. Europe Switzerland 137.8 346 10. Moayyeri A, Soltani A, Larijani B, Naghavi M, Alaeddini F, Former East Germany 137.8 354.7 Abolhassani F. Epidemiology of hip fracture in Iran: Results Former West Germany 154.5 399.4 from the Iranian multicenter study on accidental injuries. England 143.6 418.2 Osteoporos Int 2006;17:1252-7. Greece 201.7 469.9 11. Memon A, Pospula WM, Tantawy AY, Abdul-Ghafar S, Suresh A, Sweden 302.7 709.5 Al-Rowaih A. 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