Changes in Mild Neurocognitive Disorder Status in Mobility Limited Older Primary Care Patients: Implications for Rehabilitative Care.

19% of the baseline Boston RISE participants had missing data, and those missing had slower gait, more limited mobility, and poorer global cognition at baseline, so the analysed sample may not represent the most impaired people. The sample was not population-based and was mostly non-Hispanic White women, so it may not apply to more diverse older adults. Boston RISE excluded people with MMSE score below 18 and SPPB score below 4, which limits generalizability to people with more severe cognitive or physical impairment. The study was observational, so it cannot show that improving gait speed or reducing depressive symptoms causes cognitive status to change. Mild neurocognitive disorder was classified only by neuropsychological test cut points, not by clinician concern, so some people called impaired may reflect test performance rather than a diagnosed disorder. Race and ethnicity were analysed as a composite other category, so the paper cannot conclude meaningful differences by race or ethnicity. Physical activity was measured by PASE, which combines all activities rather than moderate-to-vigorous activity, and participants had mobility problems, so the null finding for physical activity may not apply to moderate-to-vigorous activity.

The supplied text does not include an author competing-interest declaration. The publication types list NIH extramural and U.S. Government, non-PHS research support.

Do not conclude that improving gait speed or treating depression will improve cognition. This was an observational cohort study, and the authors state that its findings cannot determine causality.