SPPB reference values and performance in assessing sarcopenia in community-dwelling Singaporeans – Yishun Study

BACKGROUND The Short Physical Performance Battery (SPPB) is an established test of physical performance. We provide reference values for SPPB and determine SPPB performance and cut-offs in assessing sarcopenia for Asian community-dwelling older adults. METHODS Five hundred thirty-eight (57.8% women) community-dwelling adults aged 21-90 years were recruited. SPPB and its subtest scores and timings (8 ft. gait speed (GS), five-times repeated chair sit-to-stand (STS) and balance) were determined. Appendicular lean mass divided by height-squared, muscle strength (handgrip) and physical performance (6 m GS, STS and SPPB) were assessed to define sarcopenia for various Asian criteria. Area under the ROC curve (AUC) was used to assess performance of SPPB and subtests in discriminating sarcopenia in adults aged ≥60 years. Optimal SPPB and GS subtest cut-offs for each sarcopenia criterion were determined by maximizing sensitivity and specificity. RESULTS The mean SPPB score was 11.6(SD 1.1) in men and 11.5(SD1.2) in women. Majority of participants(≥50%) aged 21-80 years achieved the maximum SPPB score. SPPB total and subtest scores generally decreased with age (all p < 0.001), but did not differ between sex. Among older adults (≥60 years), SPPB and GS subtest had varied performance in assessing sarcopenia (AUC 0.54-0.64 and 0.51-0.72, respectively), and moderate-to-excellent performance in assessing severe sarcopenia (AUC 0.69-0.98 and 0.75-0.95, respectively), depending on sarcopenia definitions. The optimal cut-offs for discriminating sarcopenia in both sexes were SPPB ≤11points and GS subtest ≤1.0 m/s. The most common optimal cut-offs for discriminating severe sarcopenia according to various definitions were SPPB ≤11points in both sexes, and GS ≤0.9 m/s in men and ≤ 1.0 m/s in women. CONCLUSIONS Population-specific normative SPPB values are important for use in diagnostic criteria and to interpret results of studies evaluating and establishing appropriate treatment goals. Performance on the SPPB should be reported in terms of the total sum score and registered time to complete the repeated-chair STS and 8-ft walk tests. The performance of GS subtest was comparable to SPPB and could be a useful, simple and accessible screening tool for discriminating severe sarcopenia in community-dwelling older adults.