The IMPROVE trial: study protocol for a pragmatic cluster randomised controlled trial to assess the effectiveness of using lay health workers to improve uptake and completion of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease.

Background: Pulmonary rehabilitation (PR) is a programme of exercise and education and the most effective treatment for the symptoms and disability associated with chronic obstructive pulmonary disease. However, the benefits of PR are limited by poor uptake and completion. This trial will determine whether using trained volunteer lay health workers, called "PR buddies," improves uptake and completion of PR and is cost-effective.