Use of ultrasound for the palpable undescended testis: a wasteful practice

Use of ultrasound for the palpable undescended testis: a wasteful practice Abstract Background Many primary care physicians order an ultrasound (US) before referral to specialist care for suspected undescended testis; however, the value of this practice is questionable. Objective To determine the proportion of boys referred for suspected undescended testis who had accompanying US, the cost of this practice and the accuracy of US for testis localization when compared with physical examination by a pediatric urologist. Methods This was a retrospective chart review at a pediatric urology service, including all patients referred for suspected undescended testis from 2008 to 2012. We determined the cost of US ordered, and calculated Cohen’s kappa, sensitivity and specificity, and positive and negative predictive value. Results We identified 894 eligible patients; 32% (289/894) were accompanied by US. In 77% (223/289), the urologist was able to palpate the testis: 51% (147/289) had a normal/retractile testis and 26% (76/289) had a palpable undescended testis. At a cost of 71.10 CAD per US, 20 547.90 CAD was expended on this practice. Of the 223 patients with palpable testes, we were able to gather detailed US and physical examination results for 214 patients. Cohen’s kappa was 0.06 (95% CI −0.005, 0.11; P = 0.10). US had 92.8% sensitivity (95% CI 84.1, 96.9%) and 15.2% specificity (95% CI 10.2, 21.9%) to detect an undescended testis. The positive predictive value was 34.2% (95% CI 27.8, 41.3%), while the negative predictive value was 81.5% (95% CI 63.3, 91.8%). Conclusions Referral of patients for suspected undescended testis should not be accompanied by an US study as US is not useful in these cases. Cryptorchidism, diagnostic imaging, general practitioners, pediatrics, urology Background Cryptorchidism is the most common genital abnormality identified in male infants (1), with approximately 3% of those born at term having at least one undescended testis (2–4). Referrals for undescended testis are therefore commonplace in pediatric urology and pediatric general surgery practice, with many primary care physicians ordering an ultrasound (US) of the suspected undescended testis before referral to a specialist. In Ontario, each US performed for a suspected undescended testis costs the provincial health insurance plan 71.10 CAD (5). In addition, on top of the direct cost of each US are the costs incurred by patients’ families when parents must take time off work, travel and pay for parking for the US appointment. Of course, there is an emotional cost as well, as parents and children suffer anxiety when medical tests are performed, and an inaccurate result may cause additional undue worry (5–8). Our clinical experience led us to hypothesize that US is inferior to physical examination by a pediatric urologist to locate an undescended testis, and thus, the ordering of an US for this purpose by a primary care physician is not warranted. Therefore, we aimed to determine the proportion of consultations requested by primary care physicians for suspected undescended testis that had accompanying US studies and whether the results of the US correlated to the results of clinical examination by a pediatric urologist. Furthermore, we wanted to assess the financial impact of these diagnostic assessments on the provincial healthcare system in Ontario, Canada. Methods After obtaining approval from our institution’s research ethics board, we retrospectively reviewed the clinical charts, operative reports and referral letters of all patients referred to the Division of Pediatric Urology at our institution—comprised of a total of four pediatric urologists over the study time period—for suspected undescended testis between January 2008 and December 2012. We collected patient demographics, the urologist’s impression of the testis location at the first visit where the patient was over 6 months of age and, if available, the results of the scrotal US. We performed descriptive analyses of the patients’ demographics and clinical data and measured the agreement between the testis location on US to that according to the urologist’s examination using Cohen’s kappa, sensitivity and specificity, and positive and negative predictive value (PPV and NPV, respectively). A two-sided P-value of 0.05 was considered significant. We also calculated the total cost of US for patients referred for suspected undescended testis based on the current Ontario Health Insurance Plan fee schedule (5). Results We identified 894 eligible patients. Median age at first visit with the pediatric urologist was 2.2 years (range 6 months to 17.9 years); 18% (158/894) of patients were less than 12 months old. The primary care physician ordered an US prior to referral in 32% (289/894). In 77% (223/289) of these patients, the urologist was able to palpate the testis: 51% (147/289) had a normal/retractile testis, and 26% (76/289) had a palpable undescended testis (Fig. 1). At a cost of 71.10 CAD per US, 20 547.90 CAD was expended on this practice in direct cost to the healthcare system. Figure 1. View largeDownload slide Flow chart of included patients Figure 1. View largeDownload slide Flow chart of included patients Of the 223 patients with palpable testes, we were able to correlate physical examination results with US findings in 214 patients (Table 1); the remaining nine patients were excluded from further analyses because the US report was not available in the medical record. US results were in disagreement with the urologist’s findings in 60% (128/214) of patients. Cohen’s kappa comparing the results of US and urologist assessment was 0.06 (95% CI −0.005, 0.11; P = 0.10). US had 92.8% sensitivity (95% CI 84.1, 96.9%) and 15.2% specificity (95% CI 10.2, 21.9%) to detect an undescended testis. The PPV was 34.2% (95% CI 27.8, 41.3%), while the NPV was 81.5% (95% CI 63.3, 91.8%). In 84% (116/138) of patients with normal/retractile testes, the US showed at least one inguinal testis. In fact, in 10% of cases, US identified a normal testis as inguinal on the side contralateral to the one of concern to the referring doctor. Table 1. Cross tabulation of ultrasound result versus urologist examination result for palpable testes Urologist examination result Ultrasound result Normal/retractile Undescended Total Normal/retractile 22 123 145 Undescended 5 64 69 Total 27 187 214 Urologist examination result Ultrasound result Normal/retractile Undescended Total Normal/retractile 22 123 145 Undescended 5 64 69 Total 27 187 214 View Large Table 1. Cross tabulation of ultrasound result versus urologist examination result for palpable testes Urologist examination result Ultrasound result Normal/retractile Undescended Total Normal/retractile 22 123 145 Undescended 5 64 69 Total 27 187 214 Urologist examination result Ultrasound result Normal/retractile Undescended Total Normal/retractile 22 123 145 Undescended 5 64 69 Total 27 187 214 View Large Discussion Our results show that US is of little use in localizing an undescended testis. In fact, our results suggest that US is more likely than not to mislabel a normal or retractile testis as undescended, which is misleading to the referring physician and patient’s family, and may cause undue worry. The ordering of an US study for suspected undescended testes for patients referred to our institution cost the Ontario provincial health insurance plan 20 547.90 CAD from 2008 to 2012, which is not an optimal use of healthcare resources. Prospective studies have similarly shown that US is not useful for testis localization. For example, results from Wong et al. were very similar to ours, revealing sensitivity of 100% (95% CI 95–100%) and specificity of 16% (95% CI 11–22%) of US to detect an undescended testis, with agreement between US and clinical evaluation in only 34% of cases (9). Snodgrass reported that out of the 29 cases in their cohort where US results indicated an undescended testis, the testis was truly undescended in only 15 (52%) cases (10). Even in cases of true impalpable undescended testes, US alone has proven to be a generally ineffective method of localization (11–13). Furthermore, the use of US before referral to a pediatric specialist may delay appropriate care of boys with true undescended testes (14), in whom early surgery is important to preserve future fertility (15). In fact, many professional organizations, including the European Association of Urology, American Urological Association and Choosing Wisely Canada, recommend US not be performed for undescended testis (16–18). Encouragingly, the rates of US before referral in our study were low compared with those reported elsewhere (9,14). However, an effective strategy to inform family doctors and pediatricians that US is not useful in this context is needed. At our institution, we began such a strategy in 2014, following a joint initiative by Pediatric Urology, Pediatric General Surgery and Diagnostic Imaging. The Diagnostic Imaging unit, upon receipt of an US order for suspected undescended testis from a primary care provider, sends a letter stating that US may not be necessary and recommending referral to a pediatric urologist or pediatric general surgeon instead of imaging. The primary care provider may then choose to either follow the letter’s recommendation or re-request the US at our institution or elsewhere. A study is currently underway to see whether this educational strategy has reduced the number of patients undergoing US before their specialist appointment. Limitations The main limitation of this study was its retrospective design. Because of this, we were forced to exclude nine patients from analyses due to missing data; however, we do not anticipate that the exclusion of this small number of patients introduced any meaningful bias into our results. The nature of the retrospective review may also have resulted in misclassification of the location of some testes. Conclusions Referral of patients for suspected undescended testis should not be accompanied by US as it is unnecessary and misleading in these cases and consumes healthcare resources. We request the help of our primary care colleagues to eliminate this practice. Declaration Funding: There was no specific funding supporting the conduct of this study. Ethical approval: The study was approved by institutional research ethics board. Conflict of interest: none. Acknowledgement We thank Nick Barrowman for his help with the statistical analyses. References 1. Christensen JD , Dogra VS . The undescended testis . Semin Ultrasound CT MR 2007 ; 28 : 307 – 16 . Google Scholar CrossRef Search ADS PubMed 2. Ghirri P , Ciulli C , Vuerich M et al. Incidence at birth and natural history of cryptorchidism: a study of 10,730 consecutive male infants . J Endocrinol Invest 2002 ; 25 : 709 – 15 . Google Scholar CrossRef Search ADS PubMed 3. Berkowitz GS , Lapinski RH , Dolgin SE et al. Prevalence and natural history of cryptorchidism . Pediatrics 1993 ; 92 : 44 – 9 . Google Scholar PubMed 4. Scorer CG . The descent of the testis . Arch Dis Child 1964 ; 39 : 605 – 9 . Google Scholar CrossRef Search ADS PubMed 5. Ministry of Health and Long-Term Care . Schedule of Benefits for Physician Services Under the Health Insurance Act . Toronto : Government of Ontario , 2015 . 6. Sorenson JR , Levy HL , Mangione TW et al. Parental response to repeat testing of infants with ‘false-positive’ results in a newborn screening program . Pediatrics 1984 ; 73 : 183 – 7 . Google Scholar PubMed 7. Elkins PD , Roberts MC . Psychological preparation for pediatric hospitalization . Clin Psychol Rev . 1983 ; 3 : 275 – 295 . Google Scholar CrossRef Search ADS 8. Racine NM , Riddell RR , Khan M et al. Systematic review: predisposing, precipitating, perpetuating, and present factors predicting anticipatory distress to painful medical procedures in children . J Pediatr Psychol 2016 ; 41 : 159 – 81 . Google Scholar CrossRef Search ADS PubMed 9. Wong NC , Bansal RK , Lorenzo AJ et al. Misuse of ultrasound for palpable undescended testis by primary care providers: a prospective study . Can Urol Assoc J 2015 ; 9 : 387 – 90 . Google Scholar CrossRef Search ADS PubMed 10. Snodgrass W , Bush N , Holzer M et al. Current referral patterns and means to improve accuracy in diagnosis of undescended testis . Pediatrics 2011 ; 127 : e382 – 8 . Google Scholar CrossRef Search ADS PubMed 11. Maghnie M , Vanzulli A , Paesano P et al. The accuracy of magnetic resonance imaging and ultrasonography compared with surgical findings in the localization of the undescended testis . Arch Pediatr Adolesc Med 1994 ; 148 : 699 – 703 . Google Scholar CrossRef Search ADS PubMed 12. Weiss RM , Carter AR , Rosenfield AT . High resolution real-time ultrasonography in localization of the undescended testis . Acta Radiol Diagn (Stockh) 1985 ; 26 : 453 – 456 . Google Scholar CrossRef Search ADS PubMed 13. Tasian GE , Copp HL . Diagnostic performance of ultrasound in nonpalpable cryptorchidism: a systematic review and meta-analysis . Pediatrics 2011 ; 127 : 119 – 28 . Google Scholar CrossRef Search ADS PubMed 14. Kanaroglou N , To T , Zhu J et al. Inappropriate use of ultrasound in management of pediatric cryptorchidism . Pediatrics 2015 ; 136 : 479 – 86 . Google Scholar CrossRef Search ADS PubMed 15. Chan E , Wayne C , Nasr A . Ideal timing of orchiopexy: a systematic review . Pediatr Surg Int 2014 ; 30 : 87 – 97 . Google Scholar CrossRef Search ADS PubMed 16. European Association of Urology . 2017 . Paediatric Urology Guidelines . [online] Uroweb. http://uroweb.org/guideline/paediatric-urology/ (accessed on 22 August 2017 ). 17. Kolon TF , Herndon CDA , Baker LA et al. Evaluation and Treatment of Cryptorchidism: AUA Guideline . Linthicum : American Urological Association , 2017 . 18. Choosing Wisely Canada [Internet] . Ottawa : Canadian Medical Association [cited 2016 October 25]. http://www.choosingwiselycanada.org/. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Family Practice Oxford University Press

Use of ultrasound for the palpable undescended testis: a wasteful practice

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Abstract

Abstract Background Many primary care physicians order an ultrasound (US) before referral to specialist care for suspected undescended testis; however, the value of this practice is questionable. Objective To determine the proportion of boys referred for suspected undescended testis who had accompanying US, the cost of this practice and the accuracy of US for testis localization when compared with physical examination by a pediatric urologist. Methods This was a retrospective chart review at a pediatric urology service, including all patients referred for suspected undescended testis from 2008 to 2012. We determined the cost of US ordered, and calculated Cohen’s kappa, sensitivity and specificity, and positive and negative predictive value. Results We identified 894 eligible patients; 32% (289/894) were accompanied by US. In 77% (223/289), the urologist was able to palpate the testis: 51% (147/289) had a normal/retractile testis and 26% (76/289) had a palpable undescended testis. At a cost of 71.10 CAD per US, 20 547.90 CAD was expended on this practice. Of the 223 patients with palpable testes, we were able to gather detailed US and physical examination results for 214 patients. Cohen’s kappa was 0.06 (95% CI −0.005, 0.11; P = 0.10). US had 92.8% sensitivity (95% CI 84.1, 96.9%) and 15.2% specificity (95% CI 10.2, 21.9%) to detect an undescended testis. The positive predictive value was 34.2% (95% CI 27.8, 41.3%), while the negative predictive value was 81.5% (95% CI 63.3, 91.8%). Conclusions Referral of patients for suspected undescended testis should not be accompanied by an US study as US is not useful in these cases. Cryptorchidism, diagnostic imaging, general practitioners, pediatrics, urology Background Cryptorchidism is the most common genital abnormality identified in male infants (1), with approximately 3% of those born at term having at least one undescended testis (2–4). Referrals for undescended testis are therefore commonplace in pediatric urology and pediatric general surgery practice, with many primary care physicians ordering an ultrasound (US) of the suspected undescended testis before referral to a specialist. In Ontario, each US performed for a suspected undescended testis costs the provincial health insurance plan 71.10 CAD (5). In addition, on top of the direct cost of each US are the costs incurred by patients’ families when parents must take time off work, travel and pay for parking for the US appointment. Of course, there is an emotional cost as well, as parents and children suffer anxiety when medical tests are performed, and an inaccurate result may cause additional undue worry (5–8). Our clinical experience led us to hypothesize that US is inferior to physical examination by a pediatric urologist to locate an undescended testis, and thus, the ordering of an US for this purpose by a primary care physician is not warranted. Therefore, we aimed to determine the proportion of consultations requested by primary care physicians for suspected undescended testis that had accompanying US studies and whether the results of the US correlated to the results of clinical examination by a pediatric urologist. Furthermore, we wanted to assess the financial impact of these diagnostic assessments on the provincial healthcare system in Ontario, Canada. Methods After obtaining approval from our institution’s research ethics board, we retrospectively reviewed the clinical charts, operative reports and referral letters of all patients referred to the Division of Pediatric Urology at our institution—comprised of a total of four pediatric urologists over the study time period—for suspected undescended testis between January 2008 and December 2012. We collected patient demographics, the urologist’s impression of the testis location at the first visit where the patient was over 6 months of age and, if available, the results of the scrotal US. We performed descriptive analyses of the patients’ demographics and clinical data and measured the agreement between the testis location on US to that according to the urologist’s examination using Cohen’s kappa, sensitivity and specificity, and positive and negative predictive value (PPV and NPV, respectively). A two-sided P-value of 0.05 was considered significant. We also calculated the total cost of US for patients referred for suspected undescended testis based on the current Ontario Health Insurance Plan fee schedule (5). Results We identified 894 eligible patients. Median age at first visit with the pediatric urologist was 2.2 years (range 6 months to 17.9 years); 18% (158/894) of patients were less than 12 months old. The primary care physician ordered an US prior to referral in 32% (289/894). In 77% (223/289) of these patients, the urologist was able to palpate the testis: 51% (147/289) had a normal/retractile testis, and 26% (76/289) had a palpable undescended testis (Fig. 1). At a cost of 71.10 CAD per US, 20 547.90 CAD was expended on this practice in direct cost to the healthcare system. Figure 1. View largeDownload slide Flow chart of included patients Figure 1. View largeDownload slide Flow chart of included patients Of the 223 patients with palpable testes, we were able to correlate physical examination results with US findings in 214 patients (Table 1); the remaining nine patients were excluded from further analyses because the US report was not available in the medical record. US results were in disagreement with the urologist’s findings in 60% (128/214) of patients. Cohen’s kappa comparing the results of US and urologist assessment was 0.06 (95% CI −0.005, 0.11; P = 0.10). US had 92.8% sensitivity (95% CI 84.1, 96.9%) and 15.2% specificity (95% CI 10.2, 21.9%) to detect an undescended testis. The PPV was 34.2% (95% CI 27.8, 41.3%), while the NPV was 81.5% (95% CI 63.3, 91.8%). In 84% (116/138) of patients with normal/retractile testes, the US showed at least one inguinal testis. In fact, in 10% of cases, US identified a normal testis as inguinal on the side contralateral to the one of concern to the referring doctor. Table 1. Cross tabulation of ultrasound result versus urologist examination result for palpable testes Urologist examination result Ultrasound result Normal/retractile Undescended Total Normal/retractile 22 123 145 Undescended 5 64 69 Total 27 187 214 Urologist examination result Ultrasound result Normal/retractile Undescended Total Normal/retractile 22 123 145 Undescended 5 64 69 Total 27 187 214 View Large Table 1. Cross tabulation of ultrasound result versus urologist examination result for palpable testes Urologist examination result Ultrasound result Normal/retractile Undescended Total Normal/retractile 22 123 145 Undescended 5 64 69 Total 27 187 214 Urologist examination result Ultrasound result Normal/retractile Undescended Total Normal/retractile 22 123 145 Undescended 5 64 69 Total 27 187 214 View Large Discussion Our results show that US is of little use in localizing an undescended testis. In fact, our results suggest that US is more likely than not to mislabel a normal or retractile testis as undescended, which is misleading to the referring physician and patient’s family, and may cause undue worry. The ordering of an US study for suspected undescended testes for patients referred to our institution cost the Ontario provincial health insurance plan 20 547.90 CAD from 2008 to 2012, which is not an optimal use of healthcare resources. Prospective studies have similarly shown that US is not useful for testis localization. For example, results from Wong et al. were very similar to ours, revealing sensitivity of 100% (95% CI 95–100%) and specificity of 16% (95% CI 11–22%) of US to detect an undescended testis, with agreement between US and clinical evaluation in only 34% of cases (9). Snodgrass reported that out of the 29 cases in their cohort where US results indicated an undescended testis, the testis was truly undescended in only 15 (52%) cases (10). Even in cases of true impalpable undescended testes, US alone has proven to be a generally ineffective method of localization (11–13). Furthermore, the use of US before referral to a pediatric specialist may delay appropriate care of boys with true undescended testes (14), in whom early surgery is important to preserve future fertility (15). In fact, many professional organizations, including the European Association of Urology, American Urological Association and Choosing Wisely Canada, recommend US not be performed for undescended testis (16–18). Encouragingly, the rates of US before referral in our study were low compared with those reported elsewhere (9,14). However, an effective strategy to inform family doctors and pediatricians that US is not useful in this context is needed. At our institution, we began such a strategy in 2014, following a joint initiative by Pediatric Urology, Pediatric General Surgery and Diagnostic Imaging. The Diagnostic Imaging unit, upon receipt of an US order for suspected undescended testis from a primary care provider, sends a letter stating that US may not be necessary and recommending referral to a pediatric urologist or pediatric general surgeon instead of imaging. The primary care provider may then choose to either follow the letter’s recommendation or re-request the US at our institution or elsewhere. A study is currently underway to see whether this educational strategy has reduced the number of patients undergoing US before their specialist appointment. Limitations The main limitation of this study was its retrospective design. Because of this, we were forced to exclude nine patients from analyses due to missing data; however, we do not anticipate that the exclusion of this small number of patients introduced any meaningful bias into our results. The nature of the retrospective review may also have resulted in misclassification of the location of some testes. Conclusions Referral of patients for suspected undescended testis should not be accompanied by US as it is unnecessary and misleading in these cases and consumes healthcare resources. We request the help of our primary care colleagues to eliminate this practice. Declaration Funding: There was no specific funding supporting the conduct of this study. Ethical approval: The study was approved by institutional research ethics board. Conflict of interest: none. Acknowledgement We thank Nick Barrowman for his help with the statistical analyses. References 1. Christensen JD , Dogra VS . The undescended testis . Semin Ultrasound CT MR 2007 ; 28 : 307 – 16 . Google Scholar CrossRef Search ADS PubMed 2. Ghirri P , Ciulli C , Vuerich M et al. Incidence at birth and natural history of cryptorchidism: a study of 10,730 consecutive male infants . J Endocrinol Invest 2002 ; 25 : 709 – 15 . Google Scholar CrossRef Search ADS PubMed 3. Berkowitz GS , Lapinski RH , Dolgin SE et al. Prevalence and natural history of cryptorchidism . Pediatrics 1993 ; 92 : 44 – 9 . Google Scholar PubMed 4. Scorer CG . The descent of the testis . Arch Dis Child 1964 ; 39 : 605 – 9 . Google Scholar CrossRef Search ADS PubMed 5. Ministry of Health and Long-Term Care . Schedule of Benefits for Physician Services Under the Health Insurance Act . Toronto : Government of Ontario , 2015 . 6. Sorenson JR , Levy HL , Mangione TW et al. Parental response to repeat testing of infants with ‘false-positive’ results in a newborn screening program . Pediatrics 1984 ; 73 : 183 – 7 . Google Scholar PubMed 7. Elkins PD , Roberts MC . Psychological preparation for pediatric hospitalization . Clin Psychol Rev . 1983 ; 3 : 275 – 295 . Google Scholar CrossRef Search ADS 8. Racine NM , Riddell RR , Khan M et al. Systematic review: predisposing, precipitating, perpetuating, and present factors predicting anticipatory distress to painful medical procedures in children . J Pediatr Psychol 2016 ; 41 : 159 – 81 . Google Scholar CrossRef Search ADS PubMed 9. Wong NC , Bansal RK , Lorenzo AJ et al. Misuse of ultrasound for palpable undescended testis by primary care providers: a prospective study . Can Urol Assoc J 2015 ; 9 : 387 – 90 . Google Scholar CrossRef Search ADS PubMed 10. Snodgrass W , Bush N , Holzer M et al. Current referral patterns and means to improve accuracy in diagnosis of undescended testis . Pediatrics 2011 ; 127 : e382 – 8 . Google Scholar CrossRef Search ADS PubMed 11. Maghnie M , Vanzulli A , Paesano P et al. The accuracy of magnetic resonance imaging and ultrasonography compared with surgical findings in the localization of the undescended testis . Arch Pediatr Adolesc Med 1994 ; 148 : 699 – 703 . Google Scholar CrossRef Search ADS PubMed 12. Weiss RM , Carter AR , Rosenfield AT . High resolution real-time ultrasonography in localization of the undescended testis . Acta Radiol Diagn (Stockh) 1985 ; 26 : 453 – 456 . Google Scholar CrossRef Search ADS PubMed 13. Tasian GE , Copp HL . Diagnostic performance of ultrasound in nonpalpable cryptorchidism: a systematic review and meta-analysis . Pediatrics 2011 ; 127 : 119 – 28 . Google Scholar CrossRef Search ADS PubMed 14. Kanaroglou N , To T , Zhu J et al. Inappropriate use of ultrasound in management of pediatric cryptorchidism . Pediatrics 2015 ; 136 : 479 – 86 . Google Scholar CrossRef Search ADS PubMed 15. Chan E , Wayne C , Nasr A . Ideal timing of orchiopexy: a systematic review . Pediatr Surg Int 2014 ; 30 : 87 – 97 . Google Scholar CrossRef Search ADS PubMed 16. European Association of Urology . 2017 . Paediatric Urology Guidelines . [online] Uroweb. http://uroweb.org/guideline/paediatric-urology/ (accessed on 22 August 2017 ). 17. Kolon TF , Herndon CDA , Baker LA et al. Evaluation and Treatment of Cryptorchidism: AUA Guideline . Linthicum : American Urological Association , 2017 . 18. Choosing Wisely Canada [Internet] . Ottawa : Canadian Medical Association [cited 2016 October 25]. http://www.choosingwiselycanada.org/. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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Family PracticeOxford University Press

Published: Dec 10, 2017

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