Table 4.
Subgroup analysis of the prevalence of lung cancer in COPD.
| Subgroups | Studies | Total | Events | Model | ES | Heterogeneity | P difference | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| n | (95%CI) | I 2 | P | ||||||||
| Gender | |||||||||||
| Male | 9 | 62627 | 3472 | random | 5.09% (3.48%, 6.70%) | 98.80% | 0 | 0.000 | |||
| Female | 8 | 45620 | 1724 | random | 2.52% (1.57%, 4.05%) | 99.90% | 0 | 0.000 | |||
| Smoking status | |||||||||||
| Never smoking | 4 | 52863 | 744 | random | 0.68% (0.10%, 4.65%) | 100% | 0 | 0.000 | |||
| Former smoking | 4 | 20812 | 323 | random | 3.42% (1.51%, 5.32%) | 97.600% | 0 | 0.000 | |||
| Current smoking | 5 | 9879 | 731 | random | 8.98% (4.61%, 13.35%) | 98.40% | 0 | 0.000 | |||
| COPD severity | |||||||||||
| Mild | 6 | 5311 | 151 | random | 3.89% (2.14%, 7.06%) | 99.40% | 0 | 0.000 | |||
| Moderate | 3 | 1986 | 141 | random | 6.67% (3.20%, 10.14%) | 87.00% | 0 | 0.000 | |||
| Severe | 2 | 835 | 70 | random | 5.57% (1.89%, 16.39%) | 94.70% | 0 | 0.000 | |||
| Cancer type | |||||||||||
| Small cell carcinoma | 3 | 8213 | 35 | random | 0.78% (0.78%, 1.77%) | 99.70% | 0 | 0.000 | |||
| Adenocarcinoma | 3 | 8213 | 68 | random | 1.59% (0.23%, 2.94%) | 90.90% | 0 | 0.022 | |||
| Squamous cell carcinoma | 3 | 8213 | 75 | random | 1.35% (0.57%, 3.23%) | 99.70% | 0 | 0.000 | |||
| Region | |||||||||||
| European | 15 | 531191 | 18711 | random | 3.21% (2.36%, 4.06%) | 99.6% | 0 | 0.000 | |||
| Western Pacific region | 12 | 287245 | 17558 | random | 7.78% (5.06%, 10.5%) | 99.9% | 0 | 0.000 | |||
| Americas | 2 | 6888 | 180 | random | 3.25% (0.88%, 5.61%) | 94.40% | 0 | 0.007 | |||
CH, Cohort study; CS, Cross-sectional study; CC, Case-control study.