Chronic obstructive pulmonary disease (COPD) risk factors and factors associated with previous diagnosis of COPD: multiple logistic regression analysis
| Variable | COPD risk factors | Factors associated with previous diagnosis of COPD |
| OR (95% CI) | OR (95% CI) | |
| Age: | ||
| 50–59 years | 1.7 (1.1 to 2.5) | 4.2 (0.9 to 17.7) |
| 60–69 years | 4.0 (2.7 to 5.8) | 3.9 (0.9 to 16.0) |
| 70–80 years | 7.6 (5.1 to 11.2) | 6.4 (1.6 to 25.2) |
| Gender, men | 1.9 (1.4 to 2.5) | 1.9 (0.8 to 4.5) |
| Smoking: | ||
| 1–14 pack-years | 1.0 (0.68 to 1.6) | 0.4 (0.06 to 2.2) |
| 15–30 pack-years | 2.6 (1.86 to 3.7) | 1.5 (0.5 to 4.7) |
| More than 30 pack-years | 5.1 (3.69 to 7.1) | 3.1 (1.2 to 7.9) |
| Education: | ||
| Less than primary school | 1.6 (1.1 to 2.5) | 0.7 (0.2 to 2.1) |
| Primary school | 1.3 (0.9 to 1.8) | 0.6 (0.3 to 1.6) |
| Secondary school | 1.1 (0.8 to 1.5) | 0.5 (0.2 to 1.4) |
| Severity of COPD: | ||
| GOLD II | NA (NA) | 1.9 (1.0 to 3.6) |
| GOLD III–IV | 16.7 (3.9 to 70.8) | |
| SGRQ: | ||
| 5–17 units (second tertile) | NA (NA) | 4.7 (1.3 to 17.5) |
| More than 17 units (third tertile) | 11.4 (3.1 to 41.2) |
Reference categories: age, between 40 and 49 years; gender, female; never smoker; education, University degree.
Severity of COPD: GOLD I; SGRQ <5 units (first tertile).
GOLD, Global Initiative for Chronic Obstructive Lung Disease; SGRQ, Saint George’s Respiratory Questionnaire.