Summary Annual assessment of adherence would strengthen long‐term outcome assessments from registry data. The objective of this study was to evaluate tools suitable for annual routine capture of adherence data in renal transplant recipients. A single‐centre open prospective trial included 295 renal transplant recipients on tacrolimus. Two‐thirds of the patients were included 4 weeks post‐transplant, randomized 1:1 to intensive or single‐point adherence assessment in the early phase and 1‐year post‐transplant. One‐third were included 1‐year post‐transplant during a cross‐sectional investigation. Adherence was assessed using multiple methods: The “Basel Assessment of Adherence to Immunosuppressive Medication Scale” (BAASIS©) questionnaire was used to assess self‐reported adherence. The treating clinician scored patient′s adherence and tacrolimus trough‐concentration variability was calculated. In the analyses, the data from the different tools were dichotomized (adherent/nonadherent). The BAASIS© overall response rate was over 80%. Intensive BAASIS© assessment early after transplantation increased the chance of capturing a nonadherence event, but did not influence the 1‐year adherence prevalence. The adherence tools generally captured different populations. Combining the tools, the nonadherence prevalence at 1 year was 38%. The different tools identified to a large degree different patients as nonadherent. Combining these tools is feasible for annual capture of adherence status.

Radiological examination is valuable in confirming the diagnosis of ALCD. CT was the radiological modality that best demonstrated ALCD and revealed complications (e.g. pericolic abscesses) during the course of the illness.