Annual rate of PEs and rate ratios (RRs) from the univariate negative binomial regression models by quartiles of LCI and FEV1 z-scores in all patients and in patients with a normal FEV1
| All patients (n=63) | Patients with normal FEV1 (n=53) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Parameter | Annual PE rate (95% CI) | p Value* | RR (95% CI) | p Value* | Parameter | Annual PE rate (95% CI) | p Value* | RR (95% CI) | p Value* |
| LCI z-score | LCI z-score | ||||||||
| ≤2.4 | 0.1 (0.0–0.6) | 1 | ≤2.3 | 0.1 (0.0–0.6) | 1 | ||||
| 2.6–5.0 | 0.4 (0.1–1.0) | 0.088 | 2.9 (0.5–16.5) | 0.238 | 2.4–3.9 | 0.5 (0.2–1.2) | 0.462 | 3.3 (0.6–19.04) | 0.186 |
| 5.3–10.6 | 0.7 (0.3–1.6) | 0.016 | 5.4 (1.0–29.0) | 0.045 | 4.2–6.8 | 0.6 (0.2–1.5) | 0.302 | 4.1 (0.7–23.4) | 0.114 |
| ≥11.4 | 1.8 (1.0–3.3) | 0.003 | 13.6 (2.8–67.1) | 0.001 | ≥7.1 | 0.9 (0.4–2.0) | 0.043 | 6.5 (1.2–34.5) | 0.029 |
| FEV1 z-score | FEV1 z-score | ||||||||
| >=−0.1 | 0.3 (0.1–0.8) | 1 | >=0.1 | 0.3 (0.1–0.9) | 1 | ||||
| −0.8–−0.2 | 0.6 (0.3–1.4) | 0.130 | 2.3 (0.6–9.0) | 0.228 | −0.4–−0.1 | 0.2 (0.0–0.7) | 0.488 | 0.5 (0.1–3.4) | 0.499 |
| −1.5–−0.8 | 0.7 (0.3–1.5) | 0.111 | 2.4 (0.6–9.5) | 0.200 | −1.1–−0.6 | 1.0 (0.5–2.2) | 0.114 | 3.4 (0.9–13.3) | 0.073 |
| ≤−1.6 | 1.5 (0.8–2.8) | 0.016 | 5.5 (1.5–19.6) | 0.009 | ≤−1.2 | 0.7 (0.3–1.6) | 0.280 | 2.3 (0.5–9.4) | 0.260 |
*p Value for the difference among each quartile and the best quartile from the univariate negative binomial regression models.
CF, cystic fibrosis; FEV1, forced expiratory volume in 1 s; LCI, lung clearance index; PE, pulmonary exacerbation.