Multimorbidity in patients with COPD and pulmonary rehabilitation

Abstract

Background: Chronic Obstructive Pulmonary Disease (COPD) is a major health challenge, with an increasing morbidity and mortality worldwide. COPD is associated with several comorbidities, including skeletal muscle loss and dysfunction and osteoporosis, which impact the patient’s quality of life and increase the risk of falls and fractures. Pulmonary rehabilitation (PR) is a core management for COPD and has been proven to improve dyspnoea, exercise capacity, and quality of life. The PR programme includes patient education, exercise training, and psychosocial/behavioural intervention that aim to reduce COPD symptoms and enhance the patient’s quality of life. COPD guidelines recommend that patients with COPD who have Medical Research Council dyspnoea score of grade 3 or worse should be referred to PR. However, the pattern of PR referral in the UK is unknown. Large primary care data may provide the opportunity to explore the patterns of PR referral among the population of patients with COPD. Furthermore, to evaluate the quality of the PR service, the clinical outcomes of patient performance after PR should be assessed. Data from a recent UK National COPD audit programme PR workstream may facilitate quality control by allowing comparisons of patients’ performances between different programmes. Method: A systematic review was undertaken to assess the impact of PR on two outcomes: survival and falls (balance). Using The Health Improvement Network (THIN) database, a large database of UK primary care records, the recording of the PR events among patients diagnosed with COPD were analysed. A survival analysis was also conducted, which compared patients with records of PR and those without. Using this large dataset, a comparison of the incidence of falls between age- and sex-matched patients with COPD and individuals without COPD was conducted. Subsequently, the UK National COPD audit programme PR workstream data were used for two investigations. First, due to the differences in the capacities of PR programmes across the UK, the effect of these variations on the clinical outcomes associated with PR was investigated. Second, the number of patients who underwent PR assessment and performed a practice exercise walk test during PR baseline assessment, along with its association with the clinical response of PR, were investigated. Results: An assessment of PR recording in THIN showed that only 9.8% of patients with COPD have ever had a coded PR record. The systematic review demonstrated some evidence of the benefits of PR on balance but it had no effect on survival. However, the survival evidence from the THIN primary care data analysis found that patients with a record of PR on at least one occasion were 22% less likely to die than those with no record [adjusted hazard ratio (aHR) 0.78; 95% CI 0.69 – 0.88]. The investigation of the incidence of falls in THIN showed that patients with COPD were 55% more likely to have a recorded incidence of a fall than the non-COPD subjects (aHR, 1.55; 95% CI, 1.50 to 1.59) The investigation of the National COPD audit programme data showed that larger PR programmes with high staff/patient ratios were better at enrolling patients within three months of referral and achieved minimal clinical importance differences in the 6-minute walk test. Only 22.6% of patients who were assessed for PR had a practice exercise walk test at assessment. The practice walk test was significantly related to better baseline exercise distance, better enrolment and completion rates, and better improvement in dyspnoea scores. Conclusion: The low incidence of PR recording among patients with COPD in UK primary care records demonstrates the need for further strategies to improve pulmonary rehabilitation recording. Moreover, the demonstrated increased risk of falls in patients with COPD in THIN suggests a need for fall risk assessments at COPD diagnosis. The audit analysis demonstrated an enrolment delay more than 90 days of referral at small PR programmes, which could worsen the patient’s condition. Furthermore, the second audit analysis found that a substantial proportion of patients who were assessed for PR had not had a practice exercise walk test at their baseline assessment. The analysis also demonstrated its role in maximising the PR benefits and suggested the importance of issues that limit its application to PR programmes