Prevalence of Non-Adherence to Immunosuppressive Medications in Kidney Transplant Recipients: Barriers and Predictors

BACKGROUND: Non-adherence to immunosuppressant therapy (IST) is a major risk factor for graft rejection. Limited reports are available regarding the prevalence of non-adherence to IST in kidney transplant recipients (KTRs) as well as the predictors and barriers of non-adherence. MATERIAL/METHODS: The study included ambulatory KTRs, ≥18 years of age, with a functional kidney, from January 2017 to November 2018. The primary outcome was the prevalence of non-adherence, assessed with: 1) A telephone interview to complete the Arabic-translated and validated Immunosuppressant Therapy Adherence Instrument Scale (ITAS) and 2) IST serum blood levels within therapeutic levels. The secondary outcomes were the barriers to adherence using the validated Immunosuppressant Therapy Barriers of Adherence Scale (ITBS). RESULTS: We enrolled 102 of 141 patients screened. The mean±SD for age, body mass index, and the baseline of the estimated glomerular filtration rate were 45.5±15.6 years, 29.1±6 kg/m(2), and 72.7±21.9 ml/min/1.73 m(2), respectively. The prevalence of non-adherence was 5.9%, 95% CI (2.19–12.36%) and 14.7%, 95% CI (8.47–23.09%) using the ITAS and the average blood serum drug levels, respectively. The concordance of the 2 methods demonstrated an agreement of 81.3%, kappa of 0.01, and 95% CI (−0.16 to 0.18). The median, interquartile range (IQR) for ITBS, and uncontrollable and controllable barriers for adherence were 21, (18–25), 15, (12–18), and 6, (5–8), respectively. CONCLUSIONS: The current study demonstrated a low to moderate prevalence of non-adherence to IST in KTRs. The barriers for adherence with IST necessitate additional targeted interventions to manage and optimize therapeutic and clinical outcomes.