Are scores on the physical performance test useful in determination of risk of future falls in individuals with dementia?

BACKGROUND AND
PURPOSE: Presence of dementia influences postural control and increases fall risk. The 7-item physical performance test (PPT) is a valid measure of balance in older adults; however, its validity has not been established in people with dementia. The purpose of this research was to establish predictive validity of the PPT for falls in people with dementia.
METHODS: Subjects with dementia (N=34, mean MMSE score 18.4 + 3.3) were tested with the PPT and then followed for four months for fall occurrences. DATA ANALYSIS: A stepwise logistic regression (variables of age, previous history of a fall, and PPT score) determined predictors of a fall. Sensitivity, specificity, and likelihood ratios for each of the significant measures were calculated.
RESULTS: Twelve subjects (35%) reported at least one fall in the four months. History of a fall in the previous six months was the only significant predictor of a subsequent fall (p=.044), increasing the odds by almost five times. Calculated sensitivity and specificity for history of a fall were 58% and 77% respectively and positive and negative likelihood ratios were 2.52 and .58 respectively. DISCUSSION: A fall in the previous six months was the strongest predictor of a fall in the subsequent four months in people with dementia. Score on the PPT was not a significant predictor of falls. Further research is warranted, however, since 8 of the 13 subjects falsely identified as a faller by their PPT score (false positives) had other strong indicators of postural control dysfunction.