Prognostic validity of the Timed Up-and-Go test, a modified Get-Up-and-Go test, staff's global judgement and fall history in evaluating fall risk in residential care facilities.

OBJECTIVES: to evaluate and compare the prognostic validity relative to falls of the Timed Up-and-Go test (TUG), a modified Get-Up-and-Go test (GUG-m), staff's judgement of global rating of fall risk (GLORF) and fall history among frail older people.
DESIGN: cohort study, 6-month prospective follow-up for falls. PARTICIPANTS: 183 frail persons living in residential care facilities in Sweden, mean age 84 years, 73% women.
METHODS: the occurrence of falls during the follow-up period were compared to the following assessments at baseline: the TUG at normal speed; the GUG-m, a rating of fall risk scored from 1 (no risk) to 5 (very high risk); the GLORF, staff's rating of fall risk as 'high' or 'low'; a history of falls in the previous 6 months. These assessment tools were evaluated using sensitivity, specificity and positive and negative likelihood ratios (LR(+) to rule in and LR(-) to rule out a high fall risk).
RESULTS: 53% of the participants fell at least once. Various cut-off values of the TUG (12, 15, 20, 25, 30, 35, 40 s) and the GUG-m showed LR(+) between 0.9 and 2.6 and LR(-) between 0.1 and 1.0. The GLORF showed an LR(+) of 2.8 and an LR(-) of 0.6 and fall history showed an LR(+) of 2.4 and an LR(-) of 0.6.
CONCLUSIONS: in this population of frail older people, staff judgement of their residents' fall risk as well as previous falls both appear superior to the performance-based measures TUG and GUG-m in ruling in a high fall risk. A TUG score of less than 15 s gives guidance in ruling out a high fall risk but insufficient information in ruling in such a risk. The grading of fall risk by GUG-m appears of very limited value.