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

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.

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.

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).

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