Table 4.
Multiple adjusted associations of the impact factors correlated with presence of PRISm, pre-COPD, young COPD, and mild COPD.
| Variables | PRISm vs controls |
Pre-COPD vs controls |
Young COPD vs controls |
Mild COPD vs controls |
Overall p value | ||||
|---|---|---|---|---|---|---|---|---|---|
| OR (95% CI) | p value | OR (95% CI) | p value | OR (95% CI) | p value | OR (95% CI) | p value | ||
| Age (years) | 0.98 (0.97–1.00) | 0.0819 | 1.03 (1.02–1.04) | <0.0001 | NAa | NAa | 1.14 (1.12–1.16) | <0.0001 | <0.0001 |
| Male | 1.18 (0.83–1.66) | 0.3298 | 0.95 (0.78–1.15) | 0.5712 | 0.75 (0.39–1.44) | 0.3670 | 2.79 (2.00–3.90) | <0.0001 | <0.0001 |
| Waist-to-hip ratio (%) | 1.03 (1.00–1.06) | 0.0333 | 1.00 (0.98–1.02) | 0.9857 | 1.03 (1.01–1.05) | 0.0071 | 1.00 (0.98–1.03) | 0.9072 | 0.0599 |
| Education level | 0.0002 | ||||||||
| College or higher | ref. | ref. | ref. | ref. | |||||
| Middle or high school | 1.26 (0.80–1.98) | 0.2947 | 1.06 (0.73–1.54) | 0.7320 | 3.42 (1.39–8.42) | 0.0104 | 1.90 (1.14–3.18) | 0.0168 | |
| Primary school or less | 2.19 (1.20–4.00) | 0.0132 | 1.35 (0.90–2.01) | 0.1329 | 5.26 (2.47–11.22) | 0.0002 | 2.11 (1.10–4.05) | 0.0267 | |
| Urban residents | 1.18 (0.73–1.92) | 0.4839 | 1.45 (1.04–2.03) | 0.0319 | 1.74 (0.50–6.09) | 0.3659 | 0.75 (0.51–1.12) | 0.1517 | 0.0212 |
| Biomass use | 0.78 (0.49–1.26) | 0.2958 | 1.37 (1.08–1.74) | 0.0119 | 0.84 (0.22–3.22) | 0.7869 | 1.95 (1.23–3.12) | 0.0075 | 0.0646 |
| Dust, allergen, or harmful gas exposure for more than three months | 0.88 (0.62–1.23) | 0.4263 | 1.60 (1.09–2.34) | 0.0195 | 1.19 (0.43–3.30) | 0.7193 | 1.07 (0.67–1.73) | 0.7584 | <0.0001 |
| Chronic cough in childhood | <0.0001 | ||||||||
| Rare | ref. | ref. | ref. | ref. | |||||
| Sometimes | 1.20 (0.70–2.07) | 0.4808 | 1.53 (1.10–2.11) | 0.0138 | 2.04 (1.02–4.07) | 0.0438 | 0.85 (0.61–1.18) | 0.3069 | |
| Frequent | 1.45 (0.88–2.39) | 0.1399 | 3.33 (2.16–5.12) | <0.0001 | 6.98 (2.43–20.07) | 0.0011 | 2.77 (1.33–5.80) | 0.0095 | |
| Smoke exposure (pack-years) | <0.0001 | ||||||||
| 0 | ref. | ref. | ref. | ref. | |||||
| 1–9 | 1.19 (0.75–1.88) | 0.4434 | 1.30 (0.87–1.94) | 0.1932 | 1.34 (0.70–2.57) | 0.3525 | 0.79 (0.41–1.54) | 0.4708 | |
| 10–19 | 0.58 (0.38–0.88) | 0.0138 | 1.42 (0.93–2.18) | 0.0977 | 1.81 (0.89–3.66) | 0.0957 | 1.46 (0.99–2.16) | 0.0556 | |
| ≥20 | 1.95 (0.89–4.27) | 0.0914 | 3.05 (2.11–4.41) | <0.0001 | 5.49 (2.76–10.91) | 0.0001 | 2.57 (2.12–3.12) | <0.0001 | |
| Cardiovascular disease | 1.35 (0.90–2.04) | 0.1417 | 1.47 (1.17–1.84) | 0.0022 | 0.33 (0.13–0.85) | 0.0246 | 1.36 (0.89–2.09) | 0.1445 | 0.0009 |
| Gastroesophageal reflux disease | 1.23 (0.48–3.13) | 0.6519 | 1.72 (1.27–2.33) | 0.0015 | 2.99 (1.63–5.51) | 0.0014 | 1.11 (0.61–2.01) | 0.7224 | 0.0025 |
A fully adjusted multivariable multinomial logistic regression model was established between PRISm, pre-COPD, young COPD, and mild COPD versus controls to determine the associations with potential impact factors. The included covariates were age, male gender, waist-to-hip ratio, education level, urban residency, biomass use, occupational exposure, chronic cough in childhood, smoke exposure in pack-years, comorbid with cardiovascular disease and gastroesophageal reflux disease.
The association of age was not estimated for young COPD because age was included in the defining criteria of young COPD. CI = confidence interval. COPD = chronic obstructive pulmonary disease. NA = not applicable. OR = odds ratio. PRISm = preserved ratio impaired spirometry.