Rasch analysis of the Short Physical Performance Battery in older inpatients with heart failure

PURPOSE: The physical function of older patients with heart failure (HF) is likely to decline, and the Short Physical Performance Battery (SPPB) is widely used for its evaluation. No study has analyzed the SPPB by using Rasch model in these patients. The aim of this study was to examine the structural validity and item response of the SPPB in older inpatients with HF. MATERIALS AND METHODS: In this multicenter cross-sectional study, we investigated 106 older inpatients with HF. We evaluated the SPPB's rating scale structure, unidimensionality, and measurement accuracy (0 = poor performance to 4 = normal performance). RESULTS: The SPPB rating scale fulfilled the category functioning criteria. All items fit the underlying scale construct. The SPPB demonstrated adequate reliability (person reliability = 0.81) and separated persons into four strata: those with very low, low, moderate, and high physical performance. Item-difficulty measures were -0.59 to 0.96 logits, and regarding the person ability-item difficulty matching for the SPPB, the item was somewhat easy (the mean of person ability = 0.89 logits; mean of item difficulty = 0.00). CONCLUSION: The SPPB has strong measurement properties and is an appropriate scale for quantitatively evaluating physical function in older patients with HF.