Objective To study the risk factors of lung cancer and provide scientific evidence for preventing and managing such disease. Methods?The database of MEDLINE, CNKI, and CBM were searched and literature domestically and internationally from January 1997 to January 2007 was collected. The RevMan 4.2 software was used for meta-analysis. Results A total of 40 studies involving 16 559 cases and 25 119 controls were included. The pooled OR values and population attributable risk percentage (PARP) for smoking, female passive smoking from husband, female passive smoking from colleague, chronic bronchitis, emphysema, pulmonary tuberculosis, family history of cancer, and family history of lung cancer were 5.75 (69.16%), 1.32 (14.52%), 1.21 (5.87%), 1.68 (7.45%), 2.70 (10.18%), 1.58 (1.91%), 1.24 (8.92%), and 1.59 (5.33%), respectively. Conclusion Risk factors related to the incidence of lung cancer are smoking, female passive smoking from husband and colleague, chronic bronchitis, emphysema, pulmonary tuberculosis, family history of cancer, family history of lung cancer and so on. Besides, the results of PARP indicate that smoking is the most important factor, followed by female passive smoking from husband, emphysema, family history of cancer sequentially, which suggest that environmental and genetic factors play important roles in the development of lung cancer.
Etiological and prognostic studies always directly reported effect size with its 95% confidence interval, hence, data transformation was needed when performing meta-analysis based on these studies. Using the data of risk ratio, hazard ratio, odds ratio and 95% confidence interval as an example, this paper introduces the process of using RevMan 5.3 software to convert data and perform meta-analysis.