Table 5. Univariate and multivariate analysis of factors associated with BAL detected lower air tract infections.
| Parameters included in univariate regression | Primary infection by BAL (n=41), n (%) | Without primary infection by BAL (n=183), n (%) | Univariate regression | Multivariate regression | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Odds ratio | 95% CI | P value | Odds ratio | 95% CI | P value | |||||
| Age | ||||||||||
| ≥75 years old | 15 (36.6) | 25 (13.75) | 3.7 | 1.70–7.82 | 0.001* | 3.0 | 1.29–7.06 | 0.011* | ||
| Gender | ||||||||||
| Male | 21 (51.2) | 103 (56.3) | 0.8 | 0.42–1.68 | 0.62 | |||||
| Smoking status | ||||||||||
| Current | 9 (22.0) | 44 (24.0) | 0.9 | 0.35–2.05 | 0.710 | |||||
| Former | 21 (51.2) | 98 (53.6) | 1.4 | 0.50–3.75 | 0.534 | |||||
| Comorbidities | ||||||||||
| COPD | 13 (31.7) | 27 (14.8) | 2.5 | 1.12–5.56 | 0.025* | 2.7 | 1.14–6.26 | 0.023* | ||
| DM | 15 (36.6) | 22 (12.0) | 4.1 | 1.84–9.20 | 0.001* | 4.5 | 1.90–10.44 | 0.001* | ||
| CHF | 2 (4.9) | 5 (2.7) | 1.2 | 0.22–6.81 | 0.220 | |||||
| CKD | 3 (7.3) | 6 (3.3) | 2.4 | 0.54–10.25 | 0.255 | |||||
| Neural deficit | 3 (7.3) | 4 (2.2) | 2.8 | 0.58–13.86 | 0.198 | |||||
| Active cancer in previous 5 years | 22 (53.7) | 95 (51.9) | 1.2 | 0.22–6.81 | 1.826 | |||||
| Pneumonia in recent 3 months | 4 (9.8) | 11 (6.0) | 1.3 | 0.39–4.60 | 0.645 | |||||
| Medication/treatment | ||||||||||
| Systemic steroids | 5 (12.2) | 17 (9.3) | 1.2 | 0.41–3.61 | 0.724 | |||||
| Immunosuppressant | 4 (9.8) | 8 (4.4) | 2.2 | 0.60–7.92 | 0.235 | |||||
| Chemotherapy§ | 13 (31.7) | 46 (25.1) | 1.4 | 0.67–3.02 | 0.363 | |||||
| Radiation therapy§ | 7 (17.1) | 12 (6.6) | 2.7 | 0.97–7.62 | 0.058 | |||||
| Pulmonary infiltration/consolidation | 21 (51.2) | 74 (40.4) | 1.6 | 0.78–3.14 | 0.206 | |||||
| Pulmonary symptoms | ||||||||||
| Cough | 19 (46.3) | 81 (44.3) | 1.1 | 0.52–2.11 | 0.887 | |||||
| Purulent secretion | 3 (7.3) | 13 ((7.1) | 1.0 | 0.27–3.92 | 0.961 | |||||
| Hemoptysis | 6 (14.6) | 15 (8.2) | 1.7 | 0.60–4.87 | 1.010 | |||||
| Dyspnea | 4 (9.8) | 40 (21.9) | 0.4 | 0.14–1.32 | 0.144 | |||||
| Chest pain | 7 (17.1) | 15 (8.2) | 2.0 | 0.74–5.48 | 0.168 | |||||
| Lab results† | ||||||||||
| WBC <4,000/mL | 5 (15.2) | 7 (4.6) | 4.1 | 1.06–15.55 | 0.041* | |||||
| WBC >10,000/mL | 10 (30.3) | 41 (27.0) | 1.1 | 0.44–2.76 | 0.827 | |||||
| Lymphocyte <1,000/mL | 8 (25.0) | 40 (28.2) | 1.0 | 0.39–2.36 | 0.917 | |||||
| Hemoglobin <10g/L | 6 (18.2) | 12 (7.9) | 2.9 | 0.88–9.24 | 0.081 | |||||
*, risk factors show significant association; †, WBC and hemoglobin counts were available in 185 patients; lymphocyte counts were available in 174 patients. Because of missing data, blood counts couldn’t be included in the multiple regression analysis; §, chemotherapy and radiation therapy in previous one year. For inclusion of univariate variables, the author panel made decision based on common understanding of pulmonary infection, clinical experience and previous publications regarding risk factors for lower airway track infection (12-14). BAL, bronchoalveolar lavage; CHF, chronic heart failure; CKD, chronic kidney disease; WBC, white blood cell.