Trail Making Test Predicts Physical Impairment and Mortality in Older Persons

OBJECTIVES To examine whether performance in the Trail Making Test (TMT) predicts mobility impairment and mortality in older persons. DESIGN Prospective cohort study. SETTING Community-dwelling older persons enrolled in the Invecchiare in Chianti (InCHIANTI) Study. PARTICIPANTS Five hundred eighty-three participants aged 65 and older and free of major cognitive impairment (Mini-Mental State Examination score > 21) with baseline data on TMT performance. Of these, 427 performed the Short Physical Performance Battery (SPPB) for the assessment of lower extremity function at baseline and after 6 years. Of the initial 583 participants, 106 died during a 9-year follow-up. MEASUREMENTS The TMT Parts A and B (TMT-A and TMT-B) and SPPB were administered at baseline and 6-year follow-up. Impaired mobility was defined as an SPPB score less than 10. Vital status was ascertained over a 9-year follow-up. RESULTS InCHIANTI participants in the fourth quartile of the time to complete TMT-B minus time to complete TMT-A (TMT (B-A)) were significantly more likely to develop an SPPB score less than 10 during the 6-year follow-up than those in the first quartile (relative risk (RR)=2.4, 95% confidence interval (CI)=1.4-3.9, P=.001). After adjusting for potential confounders, these findings were substantially unchanged (RR=2.2, 95% CI=1.4-3.6, P=.001). Worse performance on the TMT was associated with significantly greater decline in SPPB score over the 6-year follow-up, after adjusting for age, sex, and baseline SPPB scores (beta=-0.01, standard error=0.003, P=.004). During the 9-year follow-up, 18.2% of the participants died. After adjustment for age and sex, the proportion of participants who died was higher in participants in the worst than the best performance quartile of TMT (B-A) scores (hazard ratio (HR)=1.7, 95% CI=1.0-2.9, P=.048). Results were similar in a parsimonious adjusted model (HR=1.8, 95% CI=1.0-3.2, P=.04). CONCLUSION Performance on the TMT is a strong, independent predictor of mobility impairment, accelerated decline in lower extremity function, and death in older adults living in the community. The TMT could be a useful addition to geriatric assessment.