IntroductionThe success rate of smoking cessation outpatients remains modest. Previous studies have highlighted the importance of social networks for quitting smoking, yet there is a substantial lack of studies examining participants in outpatient smoking cessation programs, especially regarding their smoking index.AimWe aimed to identify the associations between the social network characteristics of smoking cessation outpatients and their smoking indexes. The association was analyzed with participants in Grade-A Tertiary Hospitals in Kunming, the capital of Yunnan province in China.MethodsA multicenter cross-sectional survey was conducted in Kunming in six randomly sampled Grade-A tertiary hospitals. Participants included 351 smoking cessation outpatients who provided data on cigarette smoking and social networks. Multivariate logistic regression was used to examine the association between social network characteristics and smoking index across outpatients. Strong associations were identified using adjusted odds ratios and a 95% confidence interval.ResultsLarge network size (AOR=1.79, 95%CI=0.99, 3.86), having children (AOR = 6.35, 95%CI = 2.26, 19.86), and at least one highly influential person in the network (AOR = 2.74, 95% CI =1.13, 7.01)were all associated with the risk of a high smoking index. However, having drinking friends (AOR = 0.28, 95% CI = 0.14, 0.56), non-smoking and non-drinking friends in the network (AOR = 0.44, 95% CI = 0.21, 0.88), and a network member who provided health advice (AOR = 0.41, 95% CI = 0.11, 1.35) were associated with a lower risk of a high smoking index.The results were sustained even after adjusting for demographic details.ConclusionsThe study findings suggest the importance of social network characteristics for smoking cessation physicians when formulating a personalized smoking cessation plan for outpatients.