Objective: To analyze the prevalence of passive smoking among inland residents in China from 2000 to 2009 and to analyze the differences between sex, urban/rural geographic distribution, different levels of economic development etc..
Methods: Electronic search strategy was carried out, using WanFang database, China Journal Full-text database, VIP database, CBM and PubMed database to collect data on smoking, and passive smoking status, among residents in China. Fixed effects model or random effects model was employed according to statistical tests for homogeneity. Publication bias was assessed by rank correlation test. All statistical analysis was conducted with R 2.8.0.
Results: Nineteen studies were selected with a total of 195 349 non-smokers and 70 781 passive smokers involved. The overall prevalence of passive smoking was 47.04% (95%CI: 38.88% - 55.27%). The prevalence of passive smoking was stratified by factors as sex, urban/rural, year and areas of the study, and areas where passive smoking was studied. The pooled prevalence rates of passive smoking were as follows: 44.80% (95%CI: 34.07% - 55.79%) and 49.09% (95%CI: 39.62% - 58.59%), P < 0.05 for male and female; 46.10% (95%CI: 28.88% - 63.82%), 47.55% (95%CI: 17.85% - 78.25%), P < 0.05 for urban and rural, respectively. The pooled prevalence rates of passive smoking were 47.59% (95%CI: 38.31% - 56.95%) in the study year of 2000 - 2004 and 46.90% (95%CI: 33.19% - 60.87%) in 2005 - 2009 (P < 0.05). The pooled prevalence rates of passive smoking for eastern and western areas were 41.38% (28.88% - 54.47%) and 74.38% (95%CI: 59.08% - 87.10%) (P < 0.05), and 73.03% (95%CI: 60.41% - 84.00%), 14.72% (95%CI: 8.83% - 21.82%) and 25.90% (95%CI: 5.65% - 54.24%) for family, workplace and public place, respectively (P < 0.05).
Conclusion: The pooled prevalence of passive smoking was higher in females than males, in rural than in urban and in the western area than in the eastern areas. The prevalence of passive smoking in the study year of 2005 - 2009 was lower than of 2000 - 2004. The pooled passive smoking rate in the family was higher than in the workplace or in public.