Use of the Berg Balance Scale for predicting multiple falls in community-dwelling elderly people: a prospective study.

BACKGROUND AND PURPOSE Falls are a significant public health concern for older adults; early identification of people at high risk for falling facilitates the provision of rehabilitation treatment to reduce future fall risk. The objective of this prospective cohort study was to examine the predictive validity of the Berg Balance Scale (BBS) for 3 types of outcomes-any fall (> or =1 fall), multiple falls (> or =2 falls), and injurious falls-by use of sensitivity, specificity, receiver operating characteristic (ROC) curves, area under the curve, and likelihood ratios. SUBJECTS AND METHODS A sample of 210 community-dwelling older adults received a comprehensive geriatric assessment at baseline, which included the BBS to measure balance. Data on prospective falls were collected monthly for a year. The predictive validity of the BBS for the identification of future fall risk was evaluated. RESULTS The BBS had good discriminative ability to predict multiple falls when ROC analysis was used. However, the use of the BBS as a dichotomous scale, with a threshold of < or =45, was inadequate for the identification of the majority of people at risk for falling in the future, with sensitivities of 25% and 45% for any fall and for multiple falls, respectively. The use of likelihood ratios, maintaining the BBS as a multilevel scale, demonstrated a gradient of risk across scores, with fall risk increasing as scores decreased. DISCUSSION AND CONCLUSION The use of the BBS as a dichotomous scale to identify people at high risk for falling should be discouraged because it fails to identify the majority of such people. The predictive validity of this scale for multiple falls is superior to that for other types of falls, and the use of likelihood ratios preserves the gradient of risk across the whole range of scores.