title: Falls among adults: the association of cardiorespiratory fitness and physical activity with walking-related falls.
abstract: BACKGROUND
  Falls are a major cause of deaths, hospitalizations, and emergency room visits in the U.S., but circumstances surrounding falls are not well described. Among the elderly, balance and gait disorders and muscle weakness are associated with increased risk for falling, but the relationship of cardiorespiratory fitness and physical activity with falls is unclear.
  
  
  OBJECTIVE
  This purpose of this study is to describe characteristics of falls among adults and assess the association of cardiorespiratory fitness and physical activity with walking-related falls.
  
  
  METHODS
  Data on participants enrolled in the Aerobics Center Longitudinal Study (ACLS) from 1970 through 1989 who responded to questions on falls on the 1990 follow-up survey were analyzed in 2008-2009. The percentage of participants reporting at least one fall during the year before the follow-up survey was calculated and the activities at the time of falling were described. The relative risk and 95% CIs for the association of baseline fitness and physical activity with walking-related falls were calculated and logistic regression models for walking-related falls were developed.
  
  
  RESULTS
  Of 10,615 participants aged 20-87 years, 20% (95% CI=19%, 21%) reported falling during the past year. Of those falling, 54% (95% CI=52%, 56%) fell during sports or exercise; 15% (95% CI=14%,17%) while walking; and 4% (95% CI=3%, 5%) from a stool or ladder. People aged >or=65 years were no more likely than younger people to report falling in general, but they were more likely than people aged <45 years to report falling while walking (RR=1.9, 95% CI=1.2, 3.0 for men; RR=2.2, 95% CI=1.3, 3.9 for women). Men with a low level of fitness were more likely to fall while walking than men who were highly fit (RR=2.2, 95% CI=1.5, 3.3). In the multivariate analysis, walking-related falls were associated with low levels of fitness (AOR=1.8, 95% CI=1.1, 2.8) and with physical inactivity (AOR=1.7, 95% CI=1.1, 2.7) in men but not in women.
  
  
  CONCLUSIONS
  Falls are common throughout adulthood but activities at time of falls differ by age. Low fitness levels and physical inactivity may increase risk for walking-related falls.
authors.affiliation: Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA. mertzk@edc.pitt.edu
authors.forename: Kristen J
authors.initials: KJ
authors.lastname: Mertz
authors.forename: Duck-Chul
authors.initials: DC
authors.lastname: Lee
authors.forename: Xuemei
authors.initials: X
authors.lastname: Sui
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Powell
authors.forename: Steven N
authors.initials: SN
authors.lastname: Blair
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006306:Health Surveys; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D015999:Multivariate Analysis; D010809:Physical Fitness; D012307:Risk Factors; D012737:Sex Factors; D016138:Walking; D055815:Young Adult