Earlier research has suggested that lower variability indicates greater adherence [24]. In the attitude ��concerned and vigilant�� we found evidence for a relationship between anxiety about the selleck chem Dasatinib medication regime and nonadherence, as indicated by the significantly higher variability of tacrolimus in the blood of these patients. DiMatteo et al. [25] also found a difference in risk of nonadherence between anxious and nonanxious patients. They argued that patients were worried about their future and that this translated into frequent monitoring, fear of forgetting, and noncompliance. In our study, significantly more patients with a high intrapatient variability loaded on this ��concerned and vigilant�� attitude.
These findings suggest that individuals characterised by anxiety about their medication regime may be less adherent or, alternatively, that patients who have more problems with their medication are more worried. This association between attitude and adherence was, however, only found when adherence was measured using levels of medication found in the blood, not when using self-report. Although the patients defining attitude 2 seem to indicate they are reliable in their medication taking, the high intra-patient variability in the pharmacokinetics of tacrolimus suggests differently. This discrepancy suggests a potential underreporting of nonadherence in this group on the self-report measure. Several studies before have found differences between self-reported nonadherence, which is simpler to measure but more susceptible to error, and direct measures for defining nonadherence such as drug levels or a clinical indicator, which are more objective and accurate but expensive [19, 26, 27].
Patients with the attitude ��appearance oriented and assertive�� want to live a normal life, be in control, and think they are capable of taking care of their kidney, and they are also the patients that indicate experiencing side effects. Although their intrapatient variability of tacrolimus was not elevated, we speculate that these patients may have a higher risk of nonadherence in the future because they are concerned about (cosmetic) side effects of their medication regimen. The Q-methodology study thus uncovered different attitudes towards medication adherence, which were associated with intrapatient Carfilzomib variability of tacrolimus but not with self-reported nonadherence and with clinical endpoints such as graft rejection or graft survival. In contrast, self-reported nonadherence 6 weeks after transplantation was associated with graft failure in the subsequent 2-year period, but variability of tacrolimus was not. The findings reported should be interpreted in the light of a number of limitations.