Differences in spousal influence on smoking cessation by gender and education among Japanese couples

BACKGROUND Previous studies have reported that spousal non-smoking has a spillover effect on the partner's cessation. However, discussion is lacking on the factors modifying that association. We examined whether the spillover effect of spousal non-smoking was associated with the couple's educational attainment. METHODS We used paired marital data from the Japanese Study on Stratification, Health, Income, and Neighborhood (J-SHINE), which targeted residents aged 25-50 years in four Japanese municipalities. We selected a spouse smoker at the time of marriage (target respondent), and set his/her smoking status change (continued or quit smoking after marriage) as an outcome, regressed on the counterpart's smoking status (continued smoking or non-smoking) and combinations of each couple's educational attainment as explanatory variables using log-binomial regression models (n =1001 targets; 708 men and 293 women). RESULTS Regression results showed that a counterpart who previously quit smoking or was a never-smoker was associated with the target male spouse's subsequent cessation. However, for women, the association between husband's non-smoking and their own cessation was significant only for couples in which both spouses were highly educated. CONCLUSIONS Our findings suggest that a spouse's smoking status is important for smoking cessation interventions in men. For women, however, a couple's combined educational attainment may matter in the interventions.