Smoking is Associated with Higher Disease-related Costs and Lower Health-related Quality of Life in Inflammatory Bowel Disease

BACKGROUND AND AIMS: Smoking affects the course of inflammatory bowel disease IBD. We aimed to study the impact of smoking on IBD-specific costs and health-related quality-of-life HrQoL among adults with Crohn's disease CD and ulcerative colitis UC. METHODS: A large cohort of IBD patients was prospectively followed during 1 year using 3-monthly questionnaires on smoking status, health resources, disease activity and HrQoL. Costs were calculated by multiplying used resources with corresponding unit prices. Healthcare costs, patient costs, productivity losses, disease course items and HrQoL were compared between smokers, never-smokers and ex-smokers, adjusted for potential confounders. RESULTS: In total, 3030 patients 1558 CD, 1054 UC, 418 IBD-unknown were enrolled; 16% smoked at baseline. In CD, disease course was more severe among smokers. Smoking was associated with > 30% higher annual societal costs in IBD (€7,905 95% confidence interval €6,234 - €9,864 vs €6,017 €5,186 - €6,946 in never-smokers and €5,710 €4,687 - €6,878 in ex-smokers, p = 0.06 and p = 0.04, respectively). In CD, smoking patients generated the highest societal costs, primarily driven by the use of anti-tumour necrosis factor compounds. In UC, societal costs of smoking patients were comparable to those of non-smokers. Societal costs of IBD patients who quitted smoking > 5 years before inclusion were lower than in patients who quitted within the past 5 years (€ 5,135 95% CI €4,122 - €6,303 vs €9,342 €6,010 - €12,788, p = 0.01). In both CD and UC, smoking was associated with a lower HrQoL. CONCLUSIONS: Smoking is associated with higher societal costs and lower HrQoL in IBD patients. Smoking cessation may result in considerably lower societal costs.