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.