Rating scale analysis of the Berg Balance Scale.

OBJECTIVES

To examine, using Rasch analysis, the rating scale performance of the Berg Balance Scale (BBS) and to describe the 45/56 cutoff score in functional terms.

DESIGN

Retrospective chart review of BBS scores. Rasch rating scale analysis was performed on these data.

SETTING

Outpatient Veterans Affairs medical center.

PARTICIPANTS

One hundred (99 men, 1 woman) community-dwelling veterans referred for balance deficits (age range, 64-88y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

The BBS.

RESULTS

Condensing item-rating categories allowed the elimination of underutilized categories and constructed categories that better separated people of differing abilities. Rating pivot points were developed for each item to represent a transition between passing and failing. Following pivot-point development and rating scale rescoring, person and item measures became more evenly distributed across the BBS and resulted in changes in item difficulty order. In our sample, functional indicators of a score of at least 45/56 were a rating of passing the item "tandem stance," as well as passing 2 of the following 3 items: "alternating foot," "standing on one leg," and "look behind."

CONCLUSIONS

Our findings provide direction for improving the rating scale structure for each of the items and establish a connection between the BBS cutoff score of 45/56 and functional ability.