Modeling future COPD epidemiology

Background: Anticipating future trends in COPD epidemiology and identifying their major modulators is mandatory to build public health policies. Objective: To develop prediction models for COPD epidemiology and identify variables contributing most to variations in estimates, at a country level (France). Methods: A dynamic population model based on current epidemiological data from French and international studies was built to estimate COPD prevalence, incidence, distribution of GOLD grades of severity of airflow obstruction and mortality in 2025. Baseline data was extracted from the most recent French general population study available (n=4763; year 2005). Sensitivity analyses used data from international studies regarding baseline prevalence, smoking habits, incidence, transition rates between GOLD grades and mortality. Results: The model predicted an increase in COPD prevalence from 84.5‰ in 2005 to 95.8‰ in 2025, which was more pronounced in women (prevalence increase from 106.6‰ to 114.7‰ in men; from 67.3‰ to 82.8‰ in women). A marked increase in the prevalence of severe and very severe cases (from 3.5‰ to 8.9-19.6‰) was predicted. Sensitivity analyses showed that projected prevalence estimates were robust and, as expected, mostly influenced by baseline prevalence, incidence and mortality rates. Transition rates between GOLD grades and mortality were the main determinants of variations in the final distribution of airflow obstruction severity. Conclusion: Where reliable data on the current prevalence of COPD in the general population are available, models can provide robust estimates of future COPD prevalence. In France, COPD prevalence will increase constantly in the next 10 years, with an increasing proportion of women and severe disease.