Tacrolimus trough levels in kidney transplant recipients

Psychometric Properties of the BAASIS: A Meta-analysis of Individual Participant Data

BACKGROUND

Nonadherence to immunosuppressives, a risk factor for poor posttransplant outcomes, can be assessed by self-report using the Basel Assessment of Adherence to Immunosuppressive Medications Scale (BAASIS). Available in written and interview versions, and previously validated on content, the BAASIS is widely used in research and clinical practice. The aim of this study was to investigate its psychometric properties.

METHODS

Using a literature search and our BAASIS database, this meta-analysis identified completed studies in adult transplant recipients whose data were usable to examine the BAASIS' reliability and 3 validity aspects: (1) relationships with other variables (electronic monitoring, other self-report scales, tacrolimus blood-level variability, collateral report, depressive symptoms, psycho-behavioral constructs, and interventions); (2) response processes; and (3) internal structure. Testing used random-effects logistic regressions.

RESULTS

Our sample included 12 109 graft recipients from 26 studies. Of these 26, a total of 20 provided individual participant data. Evidence of the BAASIS' stability over time supports its reliability. Validity testing of relationships with other variables showed that BAASIS-assessed nonadherence was significantly associated with the selected variables: electronically monitored nonadherence ( P < 0.03), other self- and collaterally-reported nonadherence ( P < 0.001), higher variability in tacrolimus concentrations ( P = 0.02), higher barriers ( P < 0.001), lower self-efficacy ( P < 0.001), lower intention ( P < 0.001), and higher worries ( P = 0.02). Nonadherence also decreased after regimen change interventions ( P = 0.03). Response process evaluation indicated good readability and slightly higher nonadherence with the written version. Structurally, items on taking and timing shared variability.

CONCLUSIONS

The BAASIS shows good validity and reliability as a self-report instrument to assess medication nonadherence in transplantation.

Efficacy and Safety of Tacrolimus as Treatment for Bleeding Caused by Hereditary Hemorrhagic Telangiectasia: An Open-Label, Pilot Study

Haploinsufficiency for Endoglin (ENG) and activin A receptor type II-like I (ACVRL1/ALK1) lead to the formation of weak and abnormal vessels in hereditary hemorrhagic telangiectasia (HHT). These cause epistaxis (nosebleeds) and/or gastrointestinal blood loss. In vitro in cultured endothelial cells, tacrolimus has been shown to increase ENG and ALK1 expression. It is, therefore, a potential treatment option. We report here a proof-of-concept study in patients with HHT and severe epistaxis and/or gastrointestinal bleeding who were treated daily with orally-administered tacrolimus for twenty weeks. Twenty-five patients with HHT (11 females (44%)) and median age of 59 years were enrolled. Five patients (20%) stopped the trial prematurely-four due to (serious) adverse events ((S)AE). Twenty patients were included in further analyses. Hemoglobin levels increased during tacrolimus treatment from 6.1 (IQR 5.2-6.9) mmol/L at baseline (9.8 g/dL) to 6.7 (6.5-7.1) mmol/L (10.8 g/dL), p = 0.003. The number of blood transfusions over the twenty weeks decreased from a mean of 5.0 (±9.2) to 1.9 (±3.5), p = 0.04. In 64% of the patients, at least one AE occurred. Oral tacrolimus, thus, significantly increased hemoglobin levels and decreased blood transfusion needs, epistaxis and/or gastrointestinal bleeding in patients with HHT. However, side-effects were common. Further investigation of the potential therapeutic benefit is justified by the outcome of the study.