Document resource
Background Pulmonary rehabilitation (PR) is an internationally recommended intervention for individuals living with Chronic Obstructive Pulmonary Disease (COPD). An individual’s characteristics are reported to influence PR outcomes.Aim To identify predictors of achieving the minimal clinically important difference (MCID) in PR outcomes using a National Respiratory Audit Programme (NRAP) dataset for England and Wales.Methods 52,669 individuals with COPD entered into the NRAP were assessed for PR from March 2019-September 2023 completed a PR programme. Generalised linear mixed models with a logit link function were used to explore the characteristics associated with achieving MCIDs in PR outcomes. Covariates included age, gender, ethnicity, Medical Research Council dyspnoea grade and index of multiple deprivation (IMD) quintile. Models included exercise capacity (incremental shuttle walk test and six-minute walk test combined, with MCIDs of ≥35m and ≥30m respectively), endurance (endurance shuttle walk test, MCID ≥174 seconds) and health related quality of life (HRQoL) (COPD assessment test and Chronic Respiratory Questionnaire combined, with MCIDs of reduction of ≥2 points and increase of ≥2 points respectively). Meeting the MCID was binary (yes/no).Results Overall, 60.43% (23,730/39,267) met the MCID for exercise capacity, 47.66% (1,700/3,567) for endurance and 61.56% (29,485/47,898) for HRQoL. Age ≥75 years or MRC grades 4 and 5 had significantly reduced odds of meeting the MCID for exercise capacity (p<0.01), while age <65 years or IMD 1 and 2 groups (most deprived) had greater odds (p<0.01) ( figure 1). Similarly for endurance, MRC grade 3, 4 and 5 groups had reduced odds of meeting the MCID (MRC 3: OR 0.72, 0.59–0.88, p<0.01; MRC 4: OR 0.53, 0.45–0.66, p<0.01; MRC 5: OR 0.38, 0.28–0.52, p<0.01). For HRQoL, individuals aged >80 years had reduced odds of achieving the MCID (OR 0.84, 0.78–0.90, p<0.01) and MRC grade 4 or 5 groups had increased odds (MRC 4: OR 1.19, 1.12–1.26, p<0.01; MRC 5: OR 1.28, 1.17–1.40, p<0.01).Abstract S137 Figure 1Plot showing the odds ratios for meeting the minimal clinically important difference in exercise capacity outcome measures across individual characteristics (OR: odds ratios; CI: confidence intervals; MCID: minimal clinically important difference; MRC: Medical Research Council; IMD: Index of Multiple Deprivation)Conclusions The odds of meeting the MCID in PR outcomes varied across characteristics, with higher MRC grades associated with reduced odds of achieving the MCID in exercise capacity and endurance outcomes, but increased odds of meeting the MCID in HRQoL outcomes.