Life-space mobility and mortality in older men: a prospective cohort study.

OBJECTIVES

To evaluate the relationship between life-space (the extent, frequency, and independence of an individual's movement) and mortality in older men.

DESIGN

Prospective cohort study.

SETTING

Six U.S. clinical sites.

PARTICIPANTS

Men aged 71 to 98 followed from 2007 to 2011 (N = 3,892).

MEASUREMENTS: Life-space during the past month was assessed as 0 (daily restriction to one's bedroom) to 120 (daily trips outside one's town without assistance) and categorized into 20-point intervals. The primary outcome was noncancer mortality, and secondary outcomes were all-cause, cardiovascular, cancer, and noncardiovascular noncancer mortality.

RESULTS

Over 2.7 years (2007-2011), 373 (9.6%) men died, 230 from noncancer causes. Unadjusted risk of noncancer mortality was 41.2% in men with the lowest level of life-space (0-20 points, n = 34) and 2.4% in men with the highest level of life-space (101-120 points, n = 868), a 17 times difference. In multivariable-adjusted models, there was a strong linear trend between decreasing life-space and increasing risk of noncancer mortality (P = .005). Risk of noncancer mortality was 3.8 times higher (95% confidence interval (CI)=1.3,11.5) in men with the lowest life-space than in those with the highest life-space. Risk of noncancer mortality was 1.3 times higher (95% CI=1.1-1.5) for each standard-deviation (24 point) decrease in life-space. Risk of noncancer mortality was 1.5 times higher (95% CI=1.0-2.3) in men who did not travel beyond their neighborhood without assistance (n = 471). Results were similar for all-cause mortality and did not change after control for chronic disease burden.

CONCLUSION

Life-space predicted a variety of mortality endpoints in older men; scores of 40 or less were associated with mortality independent of other risk factors.