Background: Although chronic obstructive pulmonary disease (COPD) increasingly affects women, they remain under-represented in randomized controlled trials (RCTs). Understanding enrollment patterns is essential to ensure the generalizability of COPD therapeutic evidence. Methods: We systematically identified RCTs of pharmacologic interventions for COPD published between 2010 and 2024. For each trial, we calculated the Enrollment Disparity Difference (EDD)—defined as the trial’s percentage of women minus the Global Burden of Disease (GBD) sex-specific prevalence. Random-effects meta-analyses were conducted to pool EDD across trials; heterogeneity was explored using subgroup analyses (region, sample size, therapy class, age group, funding source) and meta-regression models. Temporal trends were evaluated, and a weighted annual EDD trajectory with forecasted values through 2026 was generated. Results: A total of 190 RCTs were included. Women comprised 31.7% of enrolled participants. Pooled EDD was – 0.21 (95% CI, – 0.22 to – 0.19), indicating relative underrepresentation. Heterogeneity was very high (I 2 = 100%). Underrepresentation varied significantly across regions, with the greatest gaps observed in Asia and Africa and the smallest in North and South America. Age was a significant moderator (β = – 0.0070 per year, p = 0.0006), with greater disparities in trials enrolling older patients. Industry funding, sample size, and therapy class were not significant predictors. A continuous-year meta-regression demonstrated an improvement in female representation over time (β = 0.0068 per year, p = 0.0269). Conclusion: Women remain underrepresented in COPD RCTs. Although modest improvements have occurred, significant gaps persist. Ensuring equitable representation is essential for generating evidence that reflects the COPD population. Plain Language Summary: Chronic obstructive pulmonary disease (COPD) affects both men and women, but women are often underrepresented in medical research. This underrepresentation matters because women often experience COPD differently than men. They may have more shortness of breath, different types of lung disease, different responses to inhalers, and higher rates of anxiety and depression related to their illness. To understand how well women are included in COPD clinical trials, we reviewed 190 randomized controlled trials that tested medications for COPD. We found that women were consistently underrepresented: on average, trials enrolled about 20% fewer women than expected based on real-world disease patterns. When trials do not include enough women, the results may not fully reflect how well treatments work for everyone. This can affect how confidently doctors can use evidence from trial to guide treatment decisions for their patients specifically women. We also found that women’s representation in trials has slowly improved over time, especially after 2020, but there is still a substantial gap. Overall, our findings highlight the need for more inclusive research practices, such as broader eligibility criteria, targeted recruitment of women, and routine reporting of trial results separately for men and women. Ensuring that clinical trials reflect the real-world population with COPD is essential for developing treatments that work for everyone. Keywords: COPD, gender disparities, clinical trial enrollment
Umer et al. (Sun,) studied this question.