title: Life-Space Mobility and Mortality in Older Women: Prospective Results from the Study of Osteoporotic Fractures.
abstract: To evaluate the relationship between life-space mobility (extent, frequency, independence of movement) and mortality in older women.
  
  
  
  Prospective cohort study.
  
  
  
  Four U.S. clinical sites.
  
  
  
  Women (N = 1,498) aged 75 to 102 (mean 87.6) followed from 2006 to 2015.
  
  
  
  Life-space during the past 4 weeks was assessed in an interview, scored from 0 (daily restriction to bedroom) to 120 (daily trips outside town without assistance), and categorized (0-20, 21-40, 41-60, 61-80, 81-120). All-cause mortality was the primary outcome; noncancer, cardiovascular, cancer, and noncardiovascular noncancer mortality were secondary outcomes.
  
  
  
  Over a mean 5.2 years, 842 (56.2%) women died. Unadjusted risk of all-cause mortality was 82.6% in women with the lowest level of life-space (0-20 points) and 36.2% in those with the highest level (81-120 points). In multivariable proportional hazards models, there was a strong relationship between less life-space and greater risk of all-cause mortality (Ptrend< .001). Women with the lowest level of life-space (0-20 points) had a risk of all-cause mortality that was 2.4 times as high (95% confidence interval (CI) = 1.5-4.0) as that of women with the highest level (81-120 points); women with life-space scores between 21 and 60 had a risk of all-cause mortality that was 1.5 times as high as that of women with the highest level. Each standard deviation decrease in life-space was associated with a 1.2 times greater (95% CI = 1.1-1.4) risk of all-cause mortality. Women unable to travel beyond their neighborhood without assistance had a risk of all-cause mortality that was 1.4 times (95% CI = 1.1-1.7) as high as that of women who could travel beyond their neighborhood without assistance. Results were similar for noncancer, cardiovascular, and other mortality and did not change after controlling for underlying disease or living arrangement.
  
  
  
  Life-space scores of 60 or less were associated with mortality in older women independent of other strong risk factors.
authors.affiliation: Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada.|Centre for Hip Health and Mobility, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Dawn C
authors.initials: DC
authors.lastname: Mackey
authors.affiliation: Research Institute, California Pacific Medical Center, San Francisco, California.
authors.forename: Li-Yung
authors.initials: LY
authors.lastname: Lui
authors.affiliation: Research Institute, California Pacific Medical Center, San Francisco, California.
authors.forename: Peggy M
authors.initials: PM
authors.lastname: Cawthon
authors.affiliation: Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Kristine
authors.initials: K
authors.lastname: Ensrud
authors.affiliation: San Francisco Veterans Affairs Medical Centre, University of California, San Francisco, San Francisco, California.
authors.forename: Kristine
authors.initials: K
authors.lastname: Yaffe
authors.affiliation: Research Institute, California Pacific Medical Center, San Francisco, California.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Cummings
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D051346:Mobility Limitation; D058866:Osteoporotic Fractures / Q000401:mortality* / Q000503:physiopathology*; D011446:Prospective Studies; D014481:United States / Q000453:epidemiology
keywords: aged; death; independence; mobility; survival