The value of short physical performance battery (SPPB) as an alternative component of the BODE Index in predicting death in chronic obstructive pulmonary disease (COPD) in the ERICA cohort.

Abstract

Aims and objectives: The BODE Index can be used to predict mortality in individuals with COPD but includes a six minute walk (6MW) test. We investigated whether a BODE Index in which the 6MW was replaced by the SPPB retained predictive ability. Methods: We analysed 714 individuals with COPD who had completed a baseline Evaluation of the Role of Inflammation Chronic Airways disease (ERICA) cohort visit and had linked mortality data with up to 6-year follow-up. Predictive models were developed using stratified and adjusted multivariate Cox regression and predictive ability was assessed by the C-index. Results: In total 149 individuals (21%) died. Higher BODE with 6MW or BODE with SPPB scores were similarly associated with an increased risk of mortality: HR 1.28 per one-point increase in BODE with 6MW, 95% CI 1.20 to 1.38 vs. HR 1.30 per one-point increase in BODE with SPPB, 95% CI 1.21 to 1.41. When predicting mortality, the BODE with 6MW provided slightly better discrimination relative to the BODE with SPPB (C-index 0.71 vs. 0.68, p = 0.041). Conclusions: The SPPB or its components (i.e. 4-meter gait speed, balance, and chair stand), which are simpler to administer in the clinic, has potential to replace the 6MW in the BODE Index without loss of predictive power, potentially enhancing the utility of such risk measures in clinical practice.