Beyond Reported Rates: Detection-Adjusted COPD Prevalence and Underdiagnosis Patterns in Colombia.

Area of Science:

• Public Health
• Epidemiology
• Health Services Research

Background:

• Chronic obstructive pulmonary disease (COPD) is significantly underdiagnosed in Colombia, especially in rural regions with limited spirometry access.
• Regional disparities in diagnostic capacity and socioeconomic factors contribute to underdiagnosis.
• Accurate COPD prevalence estimates are crucial for public health planning.

Purpose of the Study:

• To generate COPD prevalence estimates in Colombia that account for regional differences in diagnostic capacity.
• To identify factors influencing COPD underdiagnosis across Colombian departments.
• To provide a more accurate picture of the COPD burden to inform targeted interventions.

Main Methods:

• Ecological study using aggregated administrative data from 2020-2023.
• Bayesian generalized additive model fitted to a Composite Bias-Correction Multiplier.
• Multiplier adjusted for spirometry utilization, COPD lethality, poverty, fuel type, and age structure.
• Applied multiplier to diagnosis-based prevalence to obtain detection-adjusted estimates for adults aged ≥40 years.

Main Results:

• Population-weighted national COPD prevalence estimated at 2.22%.
• Detection-adjusted departmental prevalence varied widely, from 0.81% in Vichada to 3.50% in Caldas.
• Spirometry utilization strongly correlated with diagnosis-based prevalence (r = 0.85).
• Higher COPD lethality and poverty correlated with larger adjustment multipliers.

Conclusions:

• COPD prevalence in Colombia exhibits significant regional heterogeneity due to demographic factors and unequal diagnostic access.
• Andean departments show the highest burden, while remote regions suffer from substantial underdiagnosis.
• Findings support expanding spirometry and chronic respiratory care in underserved areas.
• Accounting for detection bias improves chronic disease surveillance in low- and middle-income settings.