Nonadherence in inflammatory bowel disease: results of factor analysis

The purpose of the study was to assess overall nonadherence to treatment among patients with Crohn's disease (CD) and ulcerative colitis (UC) in a single tertiary center.

A total of 177 patients were enrolled in this study (84 males, 93 females; 117 CD, 60 UC). Patients were interviewed about their nonadherent behavior and their answers were analyzed using factor analysis. Urine samples were collected from a subcohort of 47 patients treated by mesalamine to verify the presence of 5-ASA or its metabolites.

Overall intentional nonadherence was reported by 38.9% of patients; 18.6% of the patients discontinued the treatment at least once. Intentional dose reduction was reported by 18% of patients; 14.7% of patients occasionally did not refill their medications on time. There were no differences in adherence between males and females, disease type, previous bowel surgery, or marital, smoking, and nonsmoking status. More than 38% of patients reported unintentional nonadherence. Factor analysis proved that nonadherence increased with a higher education level of the patients and decreased with older age. Adverse drug effects strongly contributed to nonadherence. Nonadherent patients were more likely to be chronically active or in relapse (tau = 0.212; P = 0.002). In the group of 47 patients whose urine was analyzed, 6 cases (12.7%) were negative for mesalamine or its metabolite.

The overall intentional nonadherence with medical therapy is relatively high among IBD patients and should be taken into account when a patient's response to treatment is unsatisfactory. Therefore, problems of nonadherence should be discussed with all IBD patients.