{'fraction_non_alphanumeric': 0.018401380103507763, 'fraction_numerical': 0.0011500862564692352, 'mean_word_length': 5.877470355731226, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Pulmonary Rehabilitation and Clinical Trial Design in Patients with Severe COPD

Pulmonary rehabilitation confers significant benefit to patients with COPD. The beneficial effects are seen in dyspnea and health-related quality of life. These measures are often considered in clinical trials as study endpoints. Pulmonary rehabilitation may affect the study population and study enrollment in clinical trials of other therapies in COPD, so it is important to anticipate the effects of pulmonary rehabilitation when designing and performing clinical trials. We review pulmonary rehabilitation and clinical trial design in patients with severe COPD. No publications were found that specifically address the impact of pulmonary rehabilitation on study design. No consensus statements, guidelines, or pharmaceutical studies in COPD were found that addressed pulmonary rehabilitation and study design. Pre-operative pulmonary rehabilitation is almost universal with lung transplantation and lung volume reduction surgery (LVRS). The National Emphysema Treatment Trial (NETT) included a mandatory pre-operative pulmonary rehabilitation program. The NETT reported that the mandatory pre-operative program reduced their study population by 32%. The NETT pre-operative program is required for Medicare reimbursement for LVRS, restricting the surgery to the subgroup of patients completing the program. Pulmonary rehabilitation can affect selection of the study population, study enrollment, outcome measures, and influence whether the results can be generalized to other patients. Clinical trials with medications, devices, or surgery for severe COPD should consider study designs that anticipate the significant effects of pulmonary rehabilitation.