The study aimed to assess adherence to immunosuppressive medications among kidney transplant patients (KTPs) and to compare adherence rates for tacrolimus, cyclosporine, and sirolimus. Out of 63 patients treated at the Clinic of Nephrology, Clinical Centre Niš, Serbia, 60 participated in the study. Medication adherence was evaluated using the Simplified Medication Adherence Questionnaire (SMAQ), and patients were classified as adherent (43) or nonadherent (17). Statistical analysis was performed using the Student’s t-test.
Results showed that 71.7% of patients were adherent to their prescribed therapy, while 28.3% were nonadherent. Nonadherent patients had significantly lower estimated glomerular filtration rate (eGFR) compared to adherent patients, indicating poorer graft function. Additionally, tacrolimus levels were significantly lower in the nonadherent group. The findings highlight that although adherence levels were generally high, nonadherence remains associated with worse transplant outcomes, emphasizing the need for early identification and interventions to improve medication adherence.
This cross-sectional study was conducted at the Clinic of Nephrology, Clinical Centre Niš, Serbia. A total of 63 kidney transplant patients attending follow-up visits between January and April 2013 were included. Participants were ≥18 years old, had undergone kidney transplantation at least one year earlier, were on continuous immunosuppressive therapy (Tacrolimus, Cyclosporine A, or Sirolimus) for at least one year, and had only one renal transplant. The main causes of end-stage kidney disease were chronic glomerulonephritis, chronic pyelonephritis and diabetic nephropathy. All patients received immunosuppressants along with mycophenolate mofetil and prednisone. Ethical approval was obtained, and informed consent was collected from all participants.
Medication adherence was assessed through face-to-face interviews using a structured questionnaire and the Simplified Medication Adherence Questionnaire (SMAQ). The six-item SMAQ evaluated forgetfulness, treatment routine, adverse effects, and missed doses. Patients were classified as adherent if they followed all adherence criteria and missed no more than two doses in the last week or two days in the previous three months; otherwise, they were classified as nonadherent.
Additional clinical data—including donor type, immunosuppressant regimen, number of medications, time since transplant, primary kidney disease, weight, blood pressure, and drug levels—were collected from medical records. Estimated glomerular filtration rate (eGFR) was calculated using the MDRD formula, and blood samples were taken on the same day as the questionnaire.
Data were analyzed using SPSS version 19.0. The Student’s t-test was used to compare variables between groups, and p < 0.05 was considered statistically significant. Results were expressed as mean ± standard deviation.
Out of 63 patients approached, 60 kidney transplant recipients participated in the study (response rate 96.8%). The mean age was 44.45 ± 11.37 years, with 63.3% males and 36.7% females. Most patients (76.7%) received grafts from living donors, and the average time since transplantation was 5.34 ± 3.84 years. Tacrolimus was the most commonly prescribed immunosuppressant (75%), followed by cyclosporine (18.3%) and sirolimus (6.7%). According to the SMAQ, 71.7% of patients were adherent to their medication regimen.
Nonadherence was slightly higher among patients receiving cyclosporine (36.4%) compared to tacrolimus (26.7%) and sirolimus (25%), though the difference was not statistically significant. Nonadherent patients had significantly poorer graft function, with lower eGFR than adherent patients. Tacrolimus levels were also significantly lower in nonadherent patients, although still within therapeutic ranges. The main reason for nonadherence was forgetfulness (88.2%), while intentional discontinuation due to feeling worse accounted for 11.8% of cases.
Adherence to immunosuppressive therapy among kidney transplant patients was high (71.7%) based on the SMAQ assessment. A significant association was observed between medication adherence and tacrolimus levels as well as graft function (eGFR), with nonadherent patients showing lower tacrolimus levels and poorer graft function. However, no significant relationship was found between adherence and factors such as age, gender, time since transplant, donor type, blood pressure, or number of medications. The most common cause of nonadherence was forgetfulness, while intentional discontinuation of medication was rare.
Overall, only 28.3% of patients were nonadherent, which is comparable to findings from other studies. Good adherence may be influenced by patients’ awareness of the risk of graft loss and return to dialysis. The study highlights the importance of patient education, counseling, simplified medication regimens, and reminder strategies (such as alarms or pillboxes) to improve adherence. Despite limitations such as small sample size and cross-sectional design, the findings emphasize that consistent use of immunosuppressive medications is crucial for maintaining graft function and long-term transplant survival.
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