Perceived effectiveness of cigarette warning labels in reducing household smoking: A mixed-methods study with Japanese smokers

OBJECTIVES: This study aimed to examine the influence of warning-label content and smokers' individual differences on perceived label effectiveness in the reduction of household smoking. STUDY DESIGN: Cross-sectional online questionnaire study conducted between June 28 and July 2, 2025. METHODS: Adult Japanese smokers rated self- and family-oriented risk text warnings. Multiple regression analysis was utilized to test how warning content and individual characteristics could predict the perceived effectiveness in reducing overall and household smoking. Content analysis explored open-ended questions regarding reasons regarding smoking at home and attitudes toward warning labels. RESULTS: Responses from 170 participants were analyzed. Family- and self-oriented warnings were perceived to be similarly effective (B = -0.10, 95 % CI [-0.39, 0.19], p = .50). However, smokers with more cohabitants and those living in detached houses (vs. multi-unit housing) viewed warning labels as more effective in reducing overall smoking (B = 0.43, 95 % CI [0.07, 0.77], p = .02). Smokers who smoked more at home perceived the labels as less effective at controlling household smoking (B = -0.26, 95 % CI [-0.47, -0.04], p = .02). Content analysis showed that smoking at home was mainly attributed to stress relief, addiction, and designated smoking areas at home. Many smokers reported feeling nothing when seeing the labels. While some participants said that the labels made consider smoking cessation, some also stated that they believed the labels had no effect. CONCLUSIONS: In Japan, the residential environments of smokers shape how effectively they perceive warning labels. This calls for the tailoring of antismoking policies according to individual differences.