Life-space mobility and cognition in community-dwelling late-life women: A cross-sectional analysis

Background: Life-space mobility captures the daily, enacted mobility of older adults. We determined cross-sectional associations between life-space mobility and cognitive impairment (CI) among community-dwelling women in the 9th and 10th decades of life. Methods: A total of 1375 (mean age 88 years; 88% White) community-dwelling women enrolled in a prospective cohort of older women. Life-space score was calculated with range 0 (daily restriction to one's bedroom) to 120 (daily trips leaving town without assistance) and categorized (0–20, 21–40, 41–60, 61–80, 81–120). The primary outcome was adjudicated CI defined as mild cognitive impairment or dementia; scores on a 6-test cognitive battery were secondary outcomes. Results: Compared to women with life-space scores of 81–120 and after adjustment for demographics and depressive symptoms, the odds of CI was 1.4-fold (OR 1.36, 95% CI 0.91–2.03) higher for women with life-space scores of 61–80, twofold (OR 1.98, 95% CI 1.33–2.94) higher for women with life-space scores of 41–60, 2.6-fold (OR 2.62, 95% CI 1.71–4.01) higher for women with life-space scores of 21–40, and 2.7-fold (OR 2.71, 95% CI 1.27–5.79) higher for women with life-space scores of 0–20. The association of life-space scores with adjudicated CI was primarily due to higher odds of dementia; the odds of dementia versus normal cognition was eightfold (OR 8.63, 95% CI 3.20–23.26) higher among women with life-space scores of 0–20 compared to women with life-space scores of 81–120. Lower life-space scores were associated in a graded manner with lower mean scores on tests of delayed recall (California Verbal Learning Test-II delayed recall) and language and executive function (phonemic fluency, category fluency, and Trails B). Life-space score was not associated with scores on tests of attention and working memory (forward and backward digit span). Conclusions: Lower life-space mobility is associated in a graded manner with CI among community-dwelling White women in the 9th and 10th decades of life.