The Short Physical Performance Battery is a valid tool in survivors of critical illness: international clinimetric secondary analysis

Purpose: Evaluate the clinimetric properties and clinical utility of the Short Physical Performance Battery (SPPB) in survivors of critical illness up to 6 months post-hospital discharge. Materials and methods: Clinimetric analysis of three international datasets (n = 488 ICU survivors) from the United States and Australia. Results: At hospital discharge, the SPPB demonstrated moderate-to-excellent construct validity with the six-minute walk test (rho = 0.81, p < 0.001), Timed Up and Go (TUG) (rho = −0.87, p < 0.001), and dual TUG (rho = −0.75, p < 0.001); and fair-to-moderate construct validity with handgrip and quadriceps strength. At hospital discharge it predicted minimal to mild limitations (score 7–12) at 6 months post (AUC 0.78 [0.72–0.84]). Responsiveness was observed, with the largest effect size (0.72) between hospital discharge and 3 months. Minimal clinical difference (from distribution-based methods) ranged from 1.21 to 1.43 out of 12 across timepoints. Floor effects were present at hospital discharge (18.8%) and ceiling effects at 3- and 6-months post (26.5% and 28.1%). At 3 months post, participants with moderate-to-severe limitations (score 0–6) performed worse on physical and strength-based measures. Conclusions: The SPPB is a valid tool that can be used to monitor physical function recovery. It may have the potential for prediction of physical limitations particularly at hospital discharge, however further validation is required.