Nonduplicated pooled prevalence estimates for all diagnoses, including diagnostic criterion-specific estimates
| Estimates n | Prevalence % | Pooled prevalence % | |
| COPD | 37 | 8.9 (2.1–26.4) | 7.6 (6.0–9.5) |
| Spirometry | 26 | 10.1 (2.1–26.4) | 9.2 (7.7–11.0) |
| Patient-reported diagnosis | 7 | 3.7 (3.0–10.5) | 4.9 (2.8–8.3) |
| Physician diagnosis | 4 | 4.1 (2.3–18.2) | 5.2 (3.3–7.9) |
| Physical/radiography | 1 | 13.7 (12.9–14.5) | |
| Chronic Bronchitis | 38 | 6.7 (1.2–22.7) | 6.4 (5.3–7.7) |
| Symptoms# | 29 | 7.7 (1.4–15.9) | 6.7 (5.4–8.2) |
| Patient-reported diagnosis | 15 | 4.4 (1.2–22.7) | 5.3 (3.9–7.1) |
| Emphysema | 8 | 1.8 (0.5–5.7) | 1.8 (1.3–2.6) |
| Physical/radiography | 1 | 3.2 (2.8–3.6) | |
| Patient-reported diagnosis | 7 | 1.5 (0.5–5.7) | 1.7 (1.2–2.5) |
Prevalences are presented as median (range) and pooled prevalences as pooled prevalence estimate (95% confidence interval). COPD: chronic obstructive pulmonary disease. Heterogeneity within each stratum, as calculated by the Q statistic, was significant for all strata with more than one estimate (p<0.0001). #: chronic productive cough.