Smoking cessation behavior in patients with a diagnosis of a non-communicable disease: The impact of perceived disease severity of and susceptibility to the disease

INTRODUCTION: The Health Belief Model comprises two constructs influencing changed behaviors impacting on health, namely perceived severity and susceptibility. The aim of this study was to identify the impact of the combination of, or interactions between, these two constructs on quitting smoking in smokers with a diagnosis of a non-communicable disease (NCD). METHODS: From the large insurance claims database maintained by JMDC database (JMDC, Tokyo), we extracted data on 13284 participants who smoked. All participants were stratified according to their NCD diagnosis based on perceived severity and susceptibility as follows: Category I (high severity and high susceptibility) – acute myocardial infarction, and lung cancer; Category II (high severity and low susceptibility) – colorectal cancer, and stomach cancer; Category III (low severity and high susceptibility) – asthma, and transient ischemic attack; Category IV (low severity and low susceptibility) – appendicitis, and glaucoma. We performed multi-variable logistic regression analysis and calculated the proportion of those who were smoking at the first health check-up after the diagnosis and every three years thereafter. RESULTS: Using glaucoma as the reference, the adjusted odds ratios for smoking cessation were 14.2 (95% CI: 11.4–17.8) to 14.8 (95% CI: 12.5–17.4) in Category I; 4.5 (95% CI: 3.8–5.4) to 6.6 (95% CI: 5.4–8.0) in Category II; and 1.9 (95% CI: 1.7–2.1) to 2.8 (95% CI: 2.2–3.7) in Category III. In Categories I and II, the proportion of smokers rapidly decreased after diagnosis and mostly remained low thereafter. Smoking cessation rates for Categories I and II were not associated with readiness to improve lifestyles prior to NCD diagnosis. CONCLUSIONS: Our study confirms the significant impact of perceived severity of and susceptibility to the diagnosed disease on smoking cessation. The multiplicative effect of these two constructs at NCD diagnosis represents a ‘teachable moment’, a window of opportunity, for encouraging successful long-term smoking cessation.