Enhancing the short physical performance battery: proposing norm values for the 4-Meter walking test for multimorbid older adults

Labott, Berit, K.; Belkin, Vera; Wollesen, Bettina; Voelcker-Rehage, Claudia

Zusammenfassung

Background: The Short Physical Performance Battery (SPPB) is a common tool for examining lower extremity physical functioning and respective intervention effects in older adults. It is primarily used in community-dwelling older adults, but also in multimorbid populations such as nursing home residents. However, previous literature reported floor effects (receiving the lowest score) in this vulnerable population, particularly for the scoring of the 4-meter walking subtest. Aim: This study aimed to propose norm values and a scoring system addressing floor effects, to compare sensitivity to performance changes between the original and revised systems, and to externally validate the revised scoring. Methods: Data from three randomized controlled trials (PROCARE (n=399, 84.0± 7.8 years, 77% female), PROfit (n=97, 82.4± 9.8 years, 72% female), and PROGRESS (n=97, 84.6± 7.7 years, 75% female)) were re-analyzed. SPPB was administered at baseline and post-intervention. Quartiles for time to complete the 4-meter walking test at baseline of the PROCARE dataset were analyzed, and norm values and a corresponding scoring system (0– 4 points) were proposed. Floor effects were analyzed by comparing the number of participants in each scoring category. Sensitivity of the new scoring was evaluated by comparing means and standard deviations of time for completion at baseline and post-interventions. External validation was done using the PROfit and PROGRESS datasets. Results: Based on the adjusted scoring system, a completion time faster than 5.65 seconds (old: 4.82 seconds) corresponded to the highest score (4 points), and a time exceeding 10.80 seconds (old: 8.70 seconds) to the lowest score (1 point). The proposed scoring system reduced the floor effect from 36% to 21%, and analysis of sensitivity revealed a better fit with time to completion. External validation indicated that the proposed scoring categories appropriately reflected participants’ functional and cognitive characteristics. Conclusion: The new scoring differentiated walking performance in a multimorbid sample, particularly within the group of low performers and better displayed changes in performance. Thus, it can contribute to detecting changes due to physiological deterioration, limited mobility, and use of walking aids which otherwise may be missed in this vulnerable population.