Modifiable risk factors for non-adherence to immunosuppressants in renal transplant recipients: a cross-sectional study

Background. Non-adherence to immunosuppressants is a major cause of renal transplant failure. Interventions to improve adherence need to target modifiable risk factors. Methods. Adherence was measured using the 'gold standard' measure of electronic monitoring in 58 adult renal transplant recipients from a UK transplant unit. Subjects were identified from a stratified random sample of 153 recipients recruited to a larger cross-sectional study comparing different measures of adherence. Inclusion criteria included age over 18 years and a functioning renal transplant, transplanted 6-63 months previously. Exclusion criteria included residence outside the region served by the unit and inability to give informed consent. Health beliefs, depression and functional status were measured using standardized questionnaires (Beliefs about Medicines Questionnaire, Illness Perception Questionnaire, Revised Clinical Interview Schedule and SF-36) and semi-structured interview. Transplant and demographic details were collected from the notes. Results. Seven [12%, 95% confidence interval (CI) 4-20%] subjects missed at least 20% of days medication and 15 (26%, 15-37%) missed at least 10% of days. Lower belief in the need for medication and having a transplant from a live donor were the major factors associated with non-adherence. Depression was common, although not strongly associated with non-adherence. Conclusions. Beliefs about medication are a promising target for interventions designed to improve adherence. The lower adherence in recipients of transplants from live donors needs confirming but may be clinically important in light of the drive to increase live donation.