Associations of close social connections with smoking and vaping: a population study in England.

Introduction: Studies consistently demonstrate smoking is a socially contagious behaviour, but less is known about the influence of social connections on vaping. This study examined associations between having close social connections who smoke or vape and relevant smoking and vaping outcomes.

Methods: This was a representative cross-sectional survey of adults (≥16y) in England. Participants (n=1,618) were asked how many people they discuss important matters with (i.e., close social connections) and how many of them smoke/vape. We tested associations between (i) smoking and (ii) vaping among close social connections and participants' own smoking and vaping status; harm perceptions of e-cigarettes (among current smokers); attempts and success in quitting smoking (among past-year smokers); and use of e-cigarettes as a smoking cessation aid (among past-year smokers who tried to quit).

Results: Adults with ≥1 close social connection who smoke were more likely than those with none to smoke themselves (32.8% vs. 9.4%; ORadj=7.23[95%CI 4.74-11.0]) and had an uncertain lower likelihood to quit (12.2% vs. 19.8%; ORadj=0.46[0.17-1.23]). Those with ≥1 close social connection who vape were more likely than those with none to vape themselves (29.6% vs. 6.3%; ORadj=5.16[3.15-8.43]) and to use e-cigarettes in their most recent attempt to quit (57.0% vs. 27.9%; ORadj=18.0[1.80-181]), and had an uncertain higher likelihood to perceive e-cigarettes as less harmful than cigarettes (30.8% vs. 12.2%; ORadj=2.37[0.82-6.90]).

Conclusions: In England, we replicated well-established associations with smoking and found similar evidence for vaping. People were much more likely to vape and to use e-cigarettes to quit smoking if they had close social connections who vaped.

Implications: The cross-sectional design means it is not clear whether smoking/vaping among close social connections influences people to smoke/vape themselves, or whether people who smoke/vape select to form close social connections with others who similarly smoke/vape. Further research is required to establish causality. If the associations we observed are causal, interventions that encourage smokers to switch to vaping may have positive spillover effects on social connections' perceptions of e-cigarettes and use of these products to support smoking cessation.