OBJECTIVES: To test the hypothesis that, in older persons, sense of personal mastery, defined as the extent to which one regards one's life chance as being under one's own control, predicts change in lower extremity performance during a 6-year follow-up.
DESIGN: Prospective cohort study.
SETTING: Community based.
PARTICIPANTS: Six hundred twenty-six participants aged 65 and older.
MEASUREMENTS: Personal mastery was assessed at baseline using Pearlin's mastery scale. Lower extremity performance was measured at baseline and at 6-year follow-up using the Short Physical Performance Battery (SPPB) of lower extremity function.
RESULTS: Higher sense of mastery was associated with a significantly less-steep decline in lower extremity performance. Participants in the two lowest quartiles of personal mastery had, respectively, a 2.6 (95% confidence interval (CI)=1.4–5.1, P=.01) and 3.2 (95% CI=1.6–6.6, P=.002) higher risk of experiencing a substantial decline (≥3 points) in SPPB scores after 6 years as those in the highest quartile.
CONCLUSIONS: Older individuals with poor sense of personal mastery are at high risk of accelerated lower extremity physical function decline. Whether interventions aimed at improving personal mastery may prevent disability remains unknown.