The Association Between the TUG Test and Different Stages of Mild Cognitive Impairment and Alzheimer’s Disease: An Updated Systematic Review with Meta-Analysis of Cross-Sectional Studies

The purpose of this study was to determine the association between the Timed Up and Go (TUG) test and mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Cross-sectional studies were identified by searching five electronic databases and cross-referencing. Effect sizes were pooled using the inverse variance heterogeneity (IVhet) model, and certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) instrument. Twenty-eight studies representing 1340 MCI, 1752 AD, and 37,561 healthy controls (HC) were included. Significantly greater completion time, in seconds, was observed for the MCI versus HC groups (X¯, 0.87, 95% CI, 0.38 to 1.37, p = 0.001; Q = 85.5, p < 0.001; I2 = 77.8%, 95% CI, 41.9 to 88.4%; 95% PI, −0.84 to 2.59) and AD versus HC groups when one major outlier was deleted from the model (X¯, 3.82, 95% CI, 2.57 to 5.07, p < 0.001; Q = 187.5, p < 0.001; I2 = 89.3%, 95% CI, 74.5 to 94.2.4%; 95% PI, −1.29 to 8.93). Based on GRADE, the overall certainty of evidence was considered very low. The current findings suggest very low-certainty evidence that the TUG test may be associated with MCI and AD when compared to HC. Additional, well-designed studies are needed before any level of conclusiveness can be established.