Table 3. Risk factors for lung cancer and adjusted ORs after multivariable analysis.
| Characteristics | Non-lung cancer (n=4,425) | Lung cancer (n=53) | Crude OR | Adjusted OR | |||
|---|---|---|---|---|---|---|---|
| OR (95% CI) | P value | OR (95% CI) | P value | ||||
| Sex | 0.40 | 0.19 | |||||
| Male | 2,465 (55.7) | 33 (62.3) | 1.31 (0.75–2.29) | 0.58 (0.26–1.30) | |||
| Female | 1,960 (44.3) | 20 (37.7) | Reference | Reference | |||
| Age, years | <0.001*** | 0.004** | |||||
| ≥55 | 2,375 (53.7) | 47 (88.7) | 6.76 (2.89–15.85) | 4.82 (1.68–13.86) | |||
| <55 | 2,050 (46.3) | 6 (11.3) | Reference | Reference | |||
| Ethnicity | 0.29 (Chi-squared) | ||||||
| Thai | 2,923 (66.1) | 33 (62.3) | – | ||||
| Caucasian | 608 (13.7) | 6 (11.3) | – | ||||
| Others Asian | 567 (12.8) | 6 (11.3) | – | ||||
| Hispanic | 300 (6.8) | 7 (13.2) | – | ||||
| African | 27 (0.6) | 1 (1.9) | – | ||||
| Thai or others | 0.56 | 0.65 | |||||
| Thai | 2,923 (66.1) | 33 (62.3) | 1.18 (0.67–2.06) | 0.86 (0.48–1.55) | |||
| Others | 1,502 (33.9) | 20 (37.7) | Reference | Reference | |||
| Smoking history | <0.001*** (Chi-squared) | ||||||
| Current smoker | 502 (11.3) | 14 (26.4) | – | ||||
| Never | 3,732 (84.3) | 31 (58.5) | – | ||||
| Ex-smoker | 191 (4.3) | 8 (15.1) | – | ||||
| Asthma | 0.10 | 0.93 | |||||
| Yes | 316 (7.1) | 7 (13.2) | 1.98 (0.89–4.41) | 1.05 (0.31–3.61) | |||
| No | 4,109 (92.9) | 46 (86.8) | Reference | Reference | |||
| Bronchiectasis | 0.15 | 0.33 | |||||
| Yes | 277 (6.3) | 6 (11.3) | 1.91 (0.81–4.51) | 0.46 (0.09–2.22) | |||
| No | 4,148 (93.7) | 47 (88.7) | Reference | Reference | |||
| Emphysema | <0.001*** | 0.06 | |||||
| Yes | 142 (3.2) | 8 (15.1) | 5.36 (2.48–11.59) | 3.40 (0.94–12.30) | |||
| No | 4,283 (96.8) | 45 (84.9) | Reference | Reference | |||
| Pulmonary tuberculosis | 0.62 | 0.005** | |||||
| Yes | 79 (1.8) | 1 (1.9) | 1.058 (0.14–7.75) | 0.002 (0.00–0.17) | |||
| No | 4,346 (98.2) | 52 (98.1) | Reference | Reference | |||
| Fibro calcified lesions compatible with old pulmonary tuberculosis | 0.001** | <0.001*** | |||||
| Yes | 3 (0.1) | 2 (3.8) | 57.80 (9.46–353.33) | 153.45 (18.58–1,267.55) | |||
| No | 4,422 (99.9) | 51 (96.2) | Reference | Reference | |||
| COPD | <0.001*** | 0.29 | |||||
| Yes | 23 (0.5) | 5 (9.4) | 19.94 (7.28–54.63) | 0.28 (0.03–2.97) | |||
| No | 4,402 (99.5) | 48 (90.6) | Reference | Reference | |||
| Coronary artery calcification | <0.001*** | 0.01* | |||||
| Yes | 5 (0.1) | 12 (22.6) | 258.73 (87.20–767.73) | 23.63 (2.09–266.98) | |||
| No | 4,420 (99.9) | 41 (77.4) | Reference | Reference | |||
| Ischemic heart disease | <0.001*** | 0.48 | |||||
| Yes | 46 (1.0) | 9 (17.0) | 19.47 (8.98–42.21) | 2.00 (0.30–13.52) | |||
| No | 4,379 (99.0) | 44 (83.0) | Reference | Reference | |||
| Arrhythmia | <0.001*** | 0.76 | |||||
| Yes | 42 (0.9) | 6 (11.3) | 13.32 (5.40–32.85) | 0.60 (0.02–17.08) | |||
| No | 4,383 (99.1) | 47 (88.7) | Reference | Reference | |||
| Heart failure | 0.35 | 0.66 | |||||
| Yes | 35 (0.8) | 1 (1.9) | 2.41 (0.32–17.94) | 0.42 (0.01–20.00) | |||
| No | 4,390 (99.2) | 52 (98.1) | Reference | Reference | |||
| Previous stroke | <0.001*** | 0.24 | |||||
| Yes | 22 (0.5) | 5 (9.43) | 20.85 (7.58–57.34) | 3.42 (0.44–26.73) | |||
| No | 4,403 (99.5) | 48 (90.6) | Reference | Reference | |||
| Parkinsonism | >0.99 | 0.99 | |||||
| Yes | 4 (0.1) | 0 (0.0) | 9.18 (0.49–172.69) | 0.00 (0.00–∞) | |||
| No | 4,421 (99.9) | 53 (100.0) | Reference | Reference | |||
| Hypothyroidism | 0.21 | 0.99 | |||||
| Yes | 126 (2.8) | 0 (0) | 0.318 (0.02–5.17) | 0.00 (0.00–∞) | |||
| No | 4,299 (97.2) | 53 (100) | Reference | Reference | |||
| Hyperthyroidism | 0.10 | 0.009** | |||||
| Yes | 43 (1.0) | 2 (3.8) | 4.00 (0.94–16.94) | 0.004 (0.004–0.25) | |||
| No | 4,382 (99.0) | 51 (96.3) | Reference | Reference | |||
| Autoimmune disease | <0.001*** | 0.52 | |||||
| Yes | 13 (0.3) | 3 (5.7) | 20.36 (5.63–73.68) | 2.22 (0.20–24.22) | |||
| No | 4,412 (99.7) | 50 (94.3) | Reference | Reference | |||
| Liver cirrhosis | >0.99 | 0.99 | |||||
| Yes | 5 (0.1) | 0 (0.0) | 7.51 (0.41–137.55) | 0.00 (0.00–∞) | |||
| No | 4,420 (99.9) | 53 (100.0) | Reference | Reference | |||
| Chronic hepatitis | >0.99 | 0.99 | |||||
| Yes | 18 (0.4) | 0 (0.0) | 2.23 (0.13–37.43) | 0.00 (0.00–∞) | |||
| No | 4,407 (99.6) | 53 (100.0) | Reference | Reference | |||
| Peptic ulcer | 0.002** | 0.12 | |||||
| Yes | 4 (0.1) | 2 (3.8) | 43.34 (7.76–241.97) | 10.82 (0.56–210.47) | |||
| No | 4,421 (99.9) | 51 (96.2) | Reference | Reference | |||
| End stage renal disease | 0.006** | 0.20 | |||||
| Yes | 59 (1.3) | 4 (7.5) | 6.04 (2.11–17.28) | 3.09 (0.55–17.46) | |||
| No | 4,366 (98.7) | 49 (94.5) | Reference | Reference | |||
| Diabetes | <0.001*** | 0.55 | |||||
| Yes | 466 (10.5) | 15 (28.3) | 3.35 (1.83–6.14) | 1.37 (0.49–3.83) | |||
| No | 3,959 (89.5) | 38 (71.7) | Reference | Reference | |||
| Hypertension | 0.002** | 0.47 | |||||
| Yes | 1,287 (29.1) | 26 (49.1) | 2.35 (1.37–4.04) | 0.72 (0.30–1.74) | |||
| No | 3,138 (70.9) | 27 (50.9) | Reference | Reference | |||
| Extrapulmonary malignancy | <0.001*** | <0.001*** | |||||
| Yes | 7 (0.2) | 18 (34.0) | 324.59 (127.52–826.17) | 173.54 (42.73–704.77) | |||
| No | 4,418 (99.8) | 35 (66.0) | Reference | Reference | |||
| History of extra pulmonary malignancy | <0.001*** | 0.29 | |||||
| Yes | 3 (0.1) | 3 (5.7) | 88.44 (17.43–448.87) | 0.19 (0.01–4.12) | |||
| No | 4,422 (99.9) | 50 (94.3) | Reference | Reference | |||
| Family history of lung cancer | <0.001*** | 0.98 | |||||
| Yes | 0 (0.0) | 4 (7.6) | 804.64 (42.75–15,146.59) | <0.001 (0–∞) | |||
| No | 4,425 (100.0) | 49 (92.5) | Reference | Reference | |||
| Family history of non-lung cancer | 0.002** | 0.04* | |||||
| Yes | 4 (0.1) | 2 (3.8) | 43.34 (7.76–241.97) | 22.14 (1.24–395.50) | |||
| No | 4,421 (99.9) | 51 (96.3) | Reference | Reference | |||
| Family history of heart attack | 0.04* | 0.93 | |||||
| Yes | 2 (0.1) | 1 (1.9) | 42.53 (3.80–476.35) | 2.20 (0–∞) | |||
| No | 4,423 (99.9) | 52 (98.1) | Reference | Reference | |||
Data are presented as number (%). *, P<0.05; **, P<0.01; ***, P<0.001. Crude ORs were calculated using univariate logistic regression. Variables with P<0.05 in univariate analysis were included in the multivariable logistic regression model, adjusted for age, sex, race and smoking history. A P value <0.05 was considered statistically significant. CI, confidence interval; COPD, chronic obstructive pulmonary disease; OR, odds ratio.