Table 3.
Tiotropium use in relation to reported respiratory diagnoses, disease severity, and socioeconomic status (SES): Multiple logistic regression analysis
| COPD, emphysema, chronic bronchitis (n = 427) | COPD or emphysema† n = (240) | |||
|---|---|---|---|---|
| MODEL ONE¶ | Tiotropium use | |||
| OR | 95% CI (p value) | OR | 95% CI (p value) | |
| Respiratory conditions* | ||||
| COPD | 2.6 | 1.3–5.3 (0.007) | 1.7 | 0.7–4.0 (0.21) |
| Emphysema | 5.9 | 2.7–13 (<0.001) | 3.4 | 1.4–8.7 (0.01) |
| Chronic bronchitis | 1.1 | 0.5–2.3 (0.80) | 1.4 | 0.7–3.0 (0.36) |
| Concomitant asthma | 2.1 | 1.0–4.4 (0.05) | 1.9 | 0.9–4.0 (0.11) |
| ≤HS education | 0.7 | 0.3–1.4 (0.29) | 0.6 | 0.3–1.3 (0.17) |
| MODELTWO¶ | Tiotropium use | |||
| OR | 95% CI (p value) | OR | 95% CI (p value) | |
| Respiratory conditions* | ||||
| COPD | 1.7 | 0.8–3.7 (0.16) | 1.2 | 0.5–3.1 (0.63) |
| Emphysema | 4.5 | 1.9–10.4 (<0.001) | 2.9 | 1.1–7.8 (0.03) |
| Chronic bronchitis | 0.8 | 0.4–1.8 (0.64) | 1.1 | 0.5–2.6 (0.88) |
| Concomitant asthma | 1.6 | 0.7–3.5 (0.25) | 1.4 | 0.6–3.2 (0.39) |
| COPD Severity Score | 2.9‡ | 1.9–4.6 (<0.001) | 2.6‡ | 1.6–4.1 (<0.001) |
| ≤HS education | 0.5 | 0.2–1.04 (0.06) | 0.4 | 0.2–0.96 (0.04) |
| MODELTHREE¶ | Tiotropium use | |||
| OR | 95% CI (p value) | OR | 95% CI (p value) | |
| Respiratory conditions* | ||||
| COPD | 1.6 | 0.9–4.5 (0.20) | 1.1 | 0.5–2.9 (0.78) |
| Emphysema | 4.2 | 1.8–9.7 (<0.001) | 2.7 | 1.0–7.2 (0.05) |
| Chronic bronchitis | 0.8 | 0.4–1.7 (0.54) | 1.0 | 0.5–2.3 (0.98) |
| Concomitant asthma | 1.6 | 0.7–3.5 (0.27) | 1.4 | 0.6–3.3 (0.39) |
| COPD Severity Score | 3.3‡ | 2.1–5.4 (<0.001) | 3.0‡ | 1.8–5.0 (<0.001) |
| ≤HS education or income <$20,000 | 0.3 | 0.1–0.7 (0.005) | 0.3 | 0.1–0.6 (0.002) |
*
Notes: Each respiratory condition entered as a separate dummy variable. Condition diagnoses may overlap;
†
Bronchitis alone without concomitant COPD or emphysema excluded;
‡
OR expressed per 8 point (1 SD) severity score;
¶
Model Two adds COPD Severity Score to the variables in Model One. Model Three substitutes ≤HS education or income <$20,000 for ≤HS education alone. All multivariate models also include age and gender.
Abbreviations: COPD, chronic obstructive pulmonary disease; CI, confidence interval; HS, high school; Income, annual household income; OR, odds ratio.