Inﬂuence of Prehospital Function and Strength on Outcomes of
Critically Ill Older Adults
D. Clark Files, MD,*
Rebecca Neiberg, MS,
Julia Rushing, MStat,
Peter E. Morris, MD,
Michael P. Young, MD,* Hilsa Ayonayon, PhD,** Tamara Harris, MD,
Anne Newman, MD,
Susan Rubin, MD,** Eric Shiroma, MEd,
Denise Houston, PhD,
Michael E. Miller,
and Stephen B. Kritchevsky, PhD
OBJECTIVES: To understand the inﬂuence of prehospital
physical function and strength on clinical outcomes of crit-
ically ill older adults.
DESIGN: Secondary analysis of prospective cohort study.
SETTING: Health, Aging and Body Composition (Health
PARTICIPANTS: Of 3,075 older adult Health ABC par-
ticipants, we identiﬁed 575 (60% white, 61% male, mean
age 79) with prehospital function or grip strength measure-
ments within 2 years of an intensive care unit stay.
MEASUREMENTS: The primary analysis evaluated the
association between prehospital walk speed and mortality,
and secondary analyses focused on associations between
function or grip strength and mortality or hospital length
of stay. Function and grip strength were analyzed as con-
tinuous and categorical predictors.
RESULTS: Slower prehospital walk speed was associated
with greater risk of 30-day mortality (for each 0.1 m/s
slower, odds ratio = 1.13, 95% conﬁdence interval
(CI) = 1.04–1.23, P = .004). Grip strength, chair stands,
and balance had weaker, non-statistically signiﬁcant asso-
ciations with 30-day mortality. Participants with slower
prehospital walk speed (hazard ratio (HR) = 0.94, 95%
CI = 0.90–0.98, P = .005) and weak grip strength
(HR = 0.85, 95% CI = 0.73–0.99, P = .03) were less
likely to be discharged from the hospital alive. All function
and strength measures were signiﬁcantly associated with
CONCLUSION: Slow prehospital walk speed was
strongly associated with greater 30-day mortality and
longer hospital stay in critically ill older adults, and mea-
sures of function and strength were associated with 1-year
mortality. These data add to the accumulating evidence on
the relationship between physical function and critical care
outcomes. J Am Geriatr Soc 2018.
Key words: critical care; weakness; aging; gait speed;
lder persons are more likely than younger adults to
develop and die from critical illnesses requiring inten-
sive care services, such as severe pneumonia, acute respira-
tory distress syndrome, congestive heart failure,
myocardial infarction, and sepsis.
The sources of these
age-related disparities in death across seemingly different
disease states are incompletely understood.
One factor that may contribute to poor outcomes in
older adults experiencing an acute illness is their prehospi-
talization functional status. Previous studies have shown
that physical function is a major determinant of hospital
admissions, length of stay (LOS), and mortality in older
adults with wide-ranging medical conditions.
these ﬁndings support the concept that physical function is
an important variable predicting mortality and morbidity
across differing domains, the effect of prehospital physical
function on individuals subsequently experiencing a critical
illness has been understudied. The relevance of preillness
physical function to traditional critical care outcomes, such
as mortality, is important to understand because critical
care severity-of-illness scoring systems do not account for
baseline physical function.
The lack of longitudinal
databases in the critical care ﬁeld limits the ability to
explore this question adequately.
From the *Divisions of Pulmonary;
Division of Gerontology and
Geriatric Medicine, Department of Internal Medicine;
Injury and Recovery Research Center;
Department of Biostatistical
Sciences, School of Medicine, Wake Forest University, Winston-Salem,
Division of Pulmonary, Critical Care and Sleep
Medicine, University of Kentucky, Lexington, Kentucky; **University of
California, San Francisco, San Francisco, California;
of Health, National Institute on Aging, Bethesda, Maryland; and
Department of Epidemiology, University of Pittsburgh, Pittsburgh,
Address correspondence to D. Clark Files, MD, Pulmonary, Critical Care,
Allergy and Immunologic Diseases, Medical Center Boulevard, Wake
Forest Baptist Medical Center, Winston-Salem, NC 27157.
© 2018, Copyright the Authors
Journal compilation © 2018, The American Geriatrics Society 0002-8614/18/$15.00
outcomes. J Am Geriatr Soc 66:525–531, 2018.
JAGS 66:525–531, 2018
2018, Copyright the Authors
2018, The American Geriatrics Society 0002-8614/18/$15.00