Medication non-adherence in inflammatory bowel diseases is associated with disability

Background/aims: Medication non-adherence is common in inflammatory bowel diseases (IBD). The short-term consequences of non-adherence include increased disease relapse but the long-term impact upon patients in terms of daily functional impairment are less well characterized. Identifying negative outcomes, such as disability, may encourage adherence.

Methods: Consecutive ambulatory IBD subjects completed the Medication Adherence Rating Scale (MARS; non-adherence defined as ≤16), Inflammatory Bowel Diseases Disability Index (IBD-DI; disability: <3.5) and Beliefs about Medicines Questionnaire (high necessity/concerns: ≥16). The primary outcome was the association between medication non-adherence and disability. Secondary outcomes were the predictors of these outcomes.

Results: A total of 173 subjects on IBD maintenance medications were recruited (98 Crohn's disease, 75 ulcerative colitis: median IBD-DI, -5.0; interquartile range [IQR], -14.0 to 4.0 and median MARS, 19.0; IQR, 18 to 20) of whom 24% were non-adherent. Disability correlated significantly with medication non-adherence (r=0.38, P<0.0001). Median IBD-DI for non-adherers was significantly lower than adherers (-16.0 vs. -2.0, P<0.0001). Predictors of disability included female sex (P=0.002), previous hospitalization (P=0.023), management in a referral hospital clinic (P=0.008) and medication concerns (P<0.0001). Non-adherence was independently associated with difficulty managing bowel movements (odds ratio [OR], 3.71; 95% confidence interval [CI], 1.50-9.16, P=0.005), rectal bleeding (OR, 2.69; 95% CI, 1.14-6.36; P=0.024) and arthralgia/arthritis (OR, 2.56; 95% CI, 1.11-5.92; P=0.028).

Conclusions: Medication non-adherence was associated with significantly increased disability in IBD. Female gender, higher disease severity and medication concerns were additional predictors of disability.