Não aderência no pós-transplante renal : validação do instrumento the basel assessment of adherence with imunossupressive medication scale e condições associadas

Abstract

Chronic Kidney Disease (CKD) is now an important medical and public health problem. Kidney transplantation is currently the best therapeutic option for patients with CKD, both from the medical, the social or economic´s points of view. To promote safety and therapeutic control of clinical and surgical complications, some strategies are fundamental. An issue that is considered very important is nonadherence (NA) to the use of medications and the proposed treatment. Adherence is defined as the degree of agreement between the behavior of a patient in relation to the advice of the physician and/or other healthcare professional. It is a multidimensional phenomenon that involves factors determined by socio-economic issues, the health system, health professionals, factors related to therapy and to the patient. For the diagnosis of NA we can apply direct and indirect methods. This study aimed to validate to the Brazilian transplant population the instrument “The Basel Assessment of Medication Adherence with Imunossupressive Scale” (BAASIS), using a sample of renal transplant patients, form the outpatient clinic of the NúcleoInterdisciplinar de Estudos e PesquisasemNefrologia da Universidade Federal de Juiz de Fora (Niepen),to assess the frequencyof NAin the studied population, evaluatedby employingthree diagnostic methodsand to evaluate theassociation betweenrisk factorsand the presence ofNA. This is a cross-sectional study of 100 renal transplant recipients with more than one year of transplant, followed as an outpatient at Niepen. The BAASIS (English version) was transculturally adapted and psychometric properties were assessed. Transcultural adaptation was performed using the Guillemin protocol (i.e. translation, back translation, analysis by an expert committee, and pre-testing). Psychometric testing included intra and inter observer reproducibility,Cronbach’salpha,correlation between BAASIS and Measure of Adherence to Treatment and factorial analysis. In alsounivariate and multivariate analyzes for factors associated with NA. Patients were classified into two groups: adherent and non-adherent using three diagnostic methods (The BAASIS, the professionals' opinion and imunossupressivesblood levels) and the conditions associated with NA were collected from a questionnaire and medical files. The mean age of patients was 45 ± 13.5 years, 65% were men and 89% received a graft from a living donor. On testing the psychometric properties of reliability, intra-observer reproducibility showed a variance of 0.007, with inter-observer reproducibility having a variance of 0.003, suggesting preciseness was achieved. For Validity, in construct validity, exploratory factorial analysis demonstrated unidimensionality of the first three questions (r=0.76; r=0.80, and r=0.68). For criterion validity, the adapted BAASIS was correlated with another self-reporting instrument – Measure of Adherence to Treatment (MAT) and showed good congruence/correlation (r=0.65). Cronbach's alpha was0.7. 51% of patients were considered nonadherente using three methods to assess adherence to immunosuppressive treatment. Variables related to NA were: living more than 100 km from the transplant center (54.9 vs. 38.8%, p<0.07), family income higher than five minimum wages (21.6 vs. 4%, p<0.009), and access to lab tests from health insurance (35.3% vs. 18.4%, p<0.01). In the logistic regression model only low family income higher than five minimum wages was a risk factor for NA (OR 5.0 CI: 1.01 to 25.14, p<0.04). The results showed the BAASIS has good psychrometric properties and this study enables its use in clinical practice and in researches on adherence in kidney transplant. In this sample, the variables associated with NA were related to socioeconomic conditions: living far from the transplant center, better income and having access to private health insurance. We emphasize that this is the first Brazilian study, with appropriate methodology, on risk factors and frequency of NA post kidney transplantation.