Timed Up-and-Go test bests other measures at gauging death risk in older adults

The Timed Up-and-Go (TUG) test is a strong predictor of long-term mortality in community-dwelling older adults, outperforming other physical and functional measures, according to a Singapore study.

“Taken together with evidence of the ability of the TUG to predict falls and other adverse health outcomes, the TUG appears to be uniquely positioned for use in early comprehensive geriatric assessment, and particularly in regard to shared clinical decision making requiring the prognostication of future life expectancy,” the researchers said.

The present prospective cohort study included 2,906 community-dwelling older adults (mean age 66.6 years, 62.9 percent women) who underwent a battery of evaluations at baseline, including the TUG test, gait velocity (GV), knee extension strength, Mini-Mental State Examination (MMSE), and Frailty Index (FI), among others. Assessments for medical history and morbidities were also performed.

Over 16,976.7 person-years of follow-up, 111 participants died, yielding an overall mortality rate of 38 percent. Cancer was the leading cause of death, with 40 percent dying due to various malignancies. This was followed by cardiovascular diseases (25 percent), pneumonia (15 percent), and chronic obstructive pulmonary disease (5 percent). [Aging 2021;doi:10.18632/aging.203756]

After controlling for baseline sociodemographic and lifestyle factors, Cox proportional hazard models showed that TUG was a significant predictor of mortality, such that each standard deviation (SD) increase in TUG led to a 64-percent jump in the likelihood of death (hazard ratio [HR], 1.64, 95 percent confidence interval [CI], 1.20–2.19; p<0.001).

The same was true when TUG was taken as a binary variable. Results ≥9 vs <9 s more than doubled the risk of death (HR, 2.66, 95 percent CI, 1.67–4.23; p<0.001).

Notably, TUG remained significantly and independently correlated with mortality risk even after considering all other physical and functional measures (HR per SD increase, 1.45, 95 percent CI, 1.01–2.07; p<0.05).

Receiver operating characteristic curve analysis further showed that TUG (area under the curve [AUC], 0.737) was a more accurate predictor of mortality than GV (AUC, 0.666; p<0.001), MMSE (AUC, 0.63; p<0.001), physical frailty (AUC, 0.610; p<0.001), and FI (AUC, 0.620; p<0.001).

Similarly, TUG outperformed multimorbidity (AUC, 0.589), chronic diseases (AUC, 0.552), body mass index (AUC, 0.386), central obesity (AUC, 0.480), and smoking (AUC, 0.662) in predicting mortality.

“Our findings contribute to a greater appreciation of the TUG as a powerful clinical tool predicting not only physical and cognitive impairment, sarcopenia, frailty, and other adverse health outcomes, but long-term mortality as well,” the researchers said.

“Further studies should explore whether combinations of clinical and functional markers could improve its prognostication value,” they added. Additional investigations in other non-Asian ethnic groups should also be conducted.