Introduction: Medication adherence is critical in chronic immune-mediated inflammatory diseases (IMIDs) and could be affected by patients' treatment-related beliefs. The objective of this study was to determine beliefs about systemic medications in patients with IMIDs and to explore the association of those beliefs and other factors with adherence.
Methods: This was a multi-country, cross-sectional, self-administered survey study. Included were adults diagnosed with one of six IMIDs receiving conventional systemic medications and/or tumor necrosis factor inhibitors (TNFi). Patients' necessity beliefs/concerns towards and adherence to treatments were assessed by the Beliefs about Medicines Questionnaire and four-item Morisky Medication Adherence Scale. Correlation of patients' beliefs about treatment and other factors with adherence were evaluated by multivariable regression analyses.
Results: Among studied patients (N = 7197), 32.0% received TNFi monotherapy, 27.7% received TNFi-conventional combination therapy, and 40.3% received conventional medications. Across IMIDs, high adherence to systemic treatment was more prevalent in TNFi groups (61.3-80.7%) versus corresponding conventional treatment groups (28.4-64.7%). In at least four IMIDs, greater perception of the illness continuing forever (P < 0.001), of the treatment helping (P < 0.001), and more concerns about the illness (P < 0.01), but not clinical parameters, were associated with higher treatment necessity beliefs. Higher treatment necessity beliefs, older age, Caucasian race, and TNFi therapy were associated with high medication adherence in at least four IMIDs.
Conclusions: Treatment necessity beliefs were higher than concerns about current medication in patients with IMID. Illness perceptions had a greater impact on treatment necessity beliefs than clinical parameters. Older age, greater treatment necessity beliefs, and TNFi therapy were associated with high self-reported medication adherence in at least four IMIDs.
Trial registration: ACTRN12612000977875.
Keywords: Crohn’s disease; Cross-sectional study; Illness perception; Medication beliefs; Rheumatoid arthritis; Ulcerative colitis.