Table 3.
Factors associated with persistent sputum production at baseline: comparative and multivariable analyses
| Baseline factors | Persistent sputum n = 1609 |
Transient sputum n = 1022 |
p value | OR (95% CI) for persistent sputum | p value |
|---|---|---|---|---|---|
| Age, yeara | 54.9 ± 13.3 | 53.6 ± 13.8 | 0.01 | 1.10 (1.04–1.17) | 0.002 |
| Male sex, % | 50.4 | 40.6 | < 0.0001 | 1.35 (1.10–1.65) | 0.004 |
| BMI, kg/m2 | 22.6 ± 3.3 | 22.5 ± 3.4 | 0.4 | ||
| Smoking history (ex or current), % | 49.8 | 40.9 | < 0.0001 | 1.28 (1.04–1.56) | 0.02 |
| COPD, % | 2.1 | 1.5 | 0.3 | ||
| Asthma, % | 6..6 | 5.5 | 0.2 | ||
| Allergic rhinitis, % | 39.0 | 37.0 | 0.3 | ||
| Sinusitis, % | 15.7 | 12.5 | 0.02 | 1.17 (0.92–1.48) | 0.2 |
| Post-nasal drip, % | 35.5 | 28.8 | 0.0003 | 1.40 (1.16–1.67) | 0.0003 |
| Diabetes mellitus, % | 7.1 | 6.5 | 0.5 | ||
| FSSG scores ≥ 8, % | 36.5 | 26.7 | < 0.0001 | 1.58 (1.32–1.88) | < 0.0001 |
| Stress, % | 74.5 | 73.3 | 0.5 |
Transient; sputum production at baseline only. Persistent; sputum production at both baseline and follow-up assessments
OR odds ratio, CI confidence interval, BMI body mass index, COPD chronic obstructive pulmonary disease, FSSG Frequency Scale for Symptoms of Gastroesophageal Reflux Disease
aAge per 10-year increase
For multivariable analysis