Longitudinal analysis of peer social support and quitting Smoking: Moderation by sex and implications for cessation interventions.

Social support predicts better health and lower mortality, but the benefits of peer social support for helping cigarette smokers quit are unclear. Moreover, sex as a moderating factor has not been investigated despite sex differences in social support processes. This study of smokers' perceived availability of peer social support in quitting cigarette smoking is a secondary analysis of 1,010 individuals enrolled in an RCT that provided quitting assistance using tailored emails scheduled around a quit date. Participants completed measures of peer support for quitting cigarettes at enrollment (baseline), and at 1-, 3-, and 6-month follow-ups. Peer support at follow-ups was categorized as never-present, always-present, or mixed. A Generalized Estimating Equation (GEE) examined the association between peer support and 7-day point prevalence abstinence at follow-ups, controlling for baseline peer support, experimental condition, stress, depression, and sociodemographic and smoking behavior-related variables. Interactions of peer support × time, and peer support × sex, were tested. Results indicated that among women, always-present or mixed peer support was associated with, respectively, odds of abstinence that were 4.36 (95 % CI, 2.54-7.49,  = 0.0001), and 2.21 (OR = 2.21, 95 % CI, 1.27-3.85,  = 0.005) greater than among women reporting never-present peer support. Among men, peer support did not predict abstinence. Women who smoke may be especially receptive to the benefits of peer support when attempting to quit. Investigation of the basis of their perceptions, how they might be increased, and whether interventions to change them would be effective, is warranted.