Development and validation of the Function In Sitting Test in adults with acute stroke

Research studies indicate that sitting balance ability is a substantial predictor of functional recovery after stroke. There are no gold standards for sitting balance assessment, and commonly used balance measures do not isolate sitting balance abilities. This study was designed to develop, pilot test, and analyze reliability and validity of a short test of functional sitting balance in patients following acute stroke.

The Function In Sitting Test (FIST) was constructed after reviewing balance measures and interviewing 15 physical therapists. A written survey regarding the FIST items and scoring scales was designed, pilot tested, and sent to 12 additional physical therapists with expertise in measurement construction, balance assessment, and/or research. Thirty-one adults who were within 3 months following stroke participated in this study.

The expert panel survey was returned by 83.3% of the participants. Survey feedback and weighted rank analysis reduced the number of FIST items from 26 to 17. After subject testing, Item Response Theory analysis eliminated 3 additional items. The person separation index was 0.978 and the coefficient alpha was 0.98, indicating high internal consistency of the FIST. The Item Response Theory analysis confirmed content and construct validity. Concurrent validity was supported by high correlations to the modified Rankin Scale, static balance indices, and dynamic balance grades.

The 14-item FIST is reliable and valid in adults following acute stroke. Studies of intra- or intertester reliability and evaluative validity studies including applications to other patient populations with sitting balance dysfunction are now necessary.