Abstract

Background

Chronic obstructive pulmonary disease (COPD) is a leading cause of global morbidity, mortality and healthcare utilisation, with acute exacerbations representing a major driver of disease burden. While moderate and severe exacerbations are routinely captured within healthcare records, mild exacerbations are frequently self-managed and underreported. As most COPD management occurs in primary care, reliance on healthcare-recorded exacerbations alone may underestimate true disease burden.

Aim

The primary aim was to examine the global incidence of mild and moderate COPD exacerbations in adults managed in primary care. The secondary aim was to explore how differences in exacerbation definitions influence reported incidence estimates.

Method

MEDLINE, EMBASE, Scopus, CINAHL and the Cochrane Library were searched from database inception to 14 February 2026 for observational and cohort studies reporting the incidence of mild and/or moderate COPD exacerbations in adults managed in primary care. Screening and data extraction were completed independently by two reviewers, with disagreements resolved through discussion and third-reviewer adjudication. Risk of bias was assessed using the Newcastle–Ottawa Scale. Due to substantial methodological heterogeneity, findings were synthesised narratively.

Results

Twelve studies involving more than 489,000 participants were included. Annual exacerbation incidence ranged from 0.081 to 5.09 exacerbations per patient-year. Studies using symptom-based definitions reported the highest incidence estimates (4.0–5.09 exacerbations per patient-year), prescription-based definitions reported intermediate estimates (0.36–2.045), and electronic health record-based definitions reported the lowest incidence estimates (0.081–0.89). Most included studies were conducted in Western European primary care settings, with no studies identified from low- or middle-income countries.

Conclusion

Reported incidence estimates of mild and moderate COPD exacerbations in primary care vary substantially depending on the method used to define exacerbations. Reliance on healthcare-recorded events alone likely underestimates the true burden of COPD exacerbations, particularly milder self-managed events. Improved and standardised approaches to identifying mild exacerbations are needed to support more accurate disease surveillance, risk stratification and proactive COPD management within primary care.