Background Non-adherence to immunosuppressive medications following renal transplantation is a risk factor for rejection and graft loss. Despite the dire consequences, adherence lapses, both unintentional and intentional, are common and poorly understood. Objective The present study sets to compare the rates and determinants of unintentional, intentional and overall self-reported non-adherence. Setting Outpatient clinic at the National University Centre for Organ Transplantation, Singapore. Method This was a cross-sectional survey administered to N = 152 renal transplant recipients. Main outcome measure They completed the Transplant Effects Questionnaire, Beliefs about Medications Questionnaire, Multidimensional Scale of Perceived Social Support, the Depression, Anxiety and Stress Scale, and the Medication Adherence Report Scale. Clinical and laboratory information were also assessed. Results The prevalence rates for overall, unintentional, and intentional self-reported non-adherence were 19.7, 47.4, and 15.1% respectively. Unintentional non-adherence was predicted by engagement in formal work, a primary diagnosis of autoimmune nephritis, and being a recipient of a living-donor renal transplant (i.e. stable characteristics). In contrast, intentional non-adherence was predicted by co-morbid burden and patients' evaluation of the side effects of their medications. Overall non-adherence was predicted by a deliberate decision-making process involving the weighing of the costs of using immunosuppressive drugs against their perceived benefits. Conclusion The survey highlighted the importance of making a distinction between unintentional and intentional non-adherence in renal transplant recipients, and suggested that modifiable factors may be targeted in different ways in interventions to increase adherence.
Keywords: Immunosuppressive medications; Intentional; Non-adherence; Renal transplant; Self-reported; Singapore; Unintentional.