Table 3.
The RV/TLC ratio and the risk of COPD exacerbation.
| Moderate to severe exacerbation | Severe exacerbation | |||
|---|---|---|---|---|
| N = 410 | Unadjusted OR (95% CI, p) | Adjusted OR (95% CI, p) | Unadjusted OR (95% CI, p) | Adjusted OR (95% CI, p) |
| RV/TLC ratio | ||||
| Per 10% increase | 1.63 (1.47–2.01, <0.001) | 1.35 (1.06–1.74, 0.017) | 1.62 (1.32–2.00, <0.001) | 1.36 (1.05–1.75, 0.019) |
| RV/TLC ratio quartiles | ||||
| 1Q: <34% | 1 (ref.) | 1 (ref.) | 1 (ref.) | 1 (ref.) |
| 2Q: 35–40% | 1.44 (0.76–2.77, 0.266) | 1.20 (0.60–2.44, 0.604) | 0.80 (0.32–2.05, 0.643) | 0.67 (0.25–1.85, 0.436) |
| 3Q: 41–48% | 1.82 (0.97–3.46, 0.064) | 1.32 (0.64–2.75, 0.449) | 2.10 (0.97–4.87, 0.069) | 1.72 (0.70–4.44, 0.243) |
| 4Q: ≥49% | 3.87 (2.05–7.40, <0.001) | 2.18 (0.99–4.86, 0.054) | 3.49 (1.71–7.76, 0.001) | 2.18 (0.88–5.73, 0.102) |
Adjustment for multivariable model: age, sex, college graduate, occupational exposure, BMI, mMRC, categorized FEV1 %-predicted, smoking amount, triple inhaled therapy, cardiovascular disease, hypertension, and diabetes mellitus. The bold values indicate statistically significance at the p <0.05 level.
COPD, chronic obstructive pulmonary disease; OR, odds ratio; CI, confidence interval; RV, residual volume; TLC, total lung capacity; Q, quartile; BMI, body mass index; mMRC, modified medical research council; FEV1, forced expiratory volume in 1 second.