Effectiveness and safety of Bufei granules in treatment of preserved ratio impaired spirometry Study protocol for a randomized controlled trial

Introduction: Early identification and monitoring of preserved ratio impaired spirometry (PRISm) population and suitable intervention can reduce the incidence rate of chronic obstructive pulmonary disease (COPD) and delay the disease process. Although Traditional Chinese medicine (TCM) has been used to treat COPD for many years, few data are available for the PRISm population. This study aims to evaluate the efficacy and safety of Bufei granules in preventing progression from PRISm to COPD. 

Methods: This is a multicenter, randomized, double-blind, placebo-controlled trial targeting the PRISm population. One thousand one hundred PRISm patients will be randomly divided into two groups, with the experimental group receiving Bufei granules and the control group receiving placebo granules. The treatment regimen is to take one packet after meals, twice daily, for a period of two years. The main outcome is the incidence rate of COPD, and the secondary outcomes are lung function, COPD screening score, quality of life, clinical symptoms, 6-minute walking distance (6MWD), dyspnea score, biochemical indicators, and economic evaluation. Blood and urine routine tests, liver and kidney function tests, electrocardiogram, and chest computed tomography scans will be employed as safety indicators for the trial, with any adverse events occurring during the trial period being accurately recorded. The planned observation duration per patient is 2 years and will be followed up every 6 months. 

Discussion: This study will provide evidence to assess the efficacy and safety of Bufei granules in preventing progression from PRISm to COPD. It is expected that PRISm volunteers will show a reduced incidence rate and will exhibit improved lung function and quality of life. The data will be released after the research is completed. Trial registration: ClinicalTrials.gov registration number: NCT06375824.