#2846 development of the japanese version of the basel assessment of adherence to immunosuppressive medications scale

Abstract Background and Aims One of the major barriers for long-term transplant outcomes in kidney transplant recipients is medication non-adherence, which is a risk factor for de novo donor-specific antibody development leading to antibody-mediated rejection and graft loss. Identifying non-adherent patients is the first step in minimizing the risk of complications of medication non-adherence. However, to date, there is no validated Japanese self-report instrument to evaluate the MA for transplant patients. This study aimed to determine the reliability and validity of the Japanese version of the Basel Assessment of Adherence to Immunosuppressive Medications Scale (J-BAASIS). Method We conducted a single-center cross-sectional study for kidney transplant recipients who visited our hospital. The eligible and willing participants were randomly assigned to two groups, the J-BAASIS group and the J-BAASIS+MEMS group, with random numbers generated by computer. All participants filled out a questionnaire including the J-BAASIS (the first survey). They filled out a questionnaire again including the J-BAASIS in similar conditions during their following outpatient visit 4-6 weeks later (the second survey). The participants in the J-BAASIS+MEMS group took the methylprednisolone tablets daily using the MEMS until the second survey. We analyzed the reliability (test-retest reliability and measurement error) and validity of the J-BAASIS (concurrent validity with the medication event monitoring system (MEMS) and the 12-item Medication Adherence Scale) referring to the COSMIN Risk of Bias tool. Results A total of 106 kidney transplant recipients (the J-BAASIS group, 56; the J-BAASIS+MEMS group, 50) were included in this study. In the analysis of test-retest reliability, Cohen's kappa coefficient was 0.62. In the analysis of measurement error, the positive and negative agreement were 0.78 and 0.84, respectively. In the analysis of concurrent validity with the MEMS, sensitivity and specificity were 0.84 and 0.90, respectively. In the analysis of concurrent validity with the 12-item Medication Adherence Scale, the point-biserial correlation coefficient for the “medication compliance” subscale was 0.38 (p<0.001). Conclusion The J-BAASIS was determined to have good reliability and validity. Using the J-BAASIS to evaluate medication adherence may help clinicians to identify non-adherent transplant patients and institute appropriate corrective measures to improve transplant outcomes. Moreover, this study, which demonstrated the concurrent validity with the MEMS, the gold standard for measuring medication adherence, further strengthens the evidence for the psychometric properties of the original BAASIS.