ABSTRACT
Abstract Introduction: Phenylketonuria (PKU) is caused by the deficient activity of phenylalanine hydroxylase. Aim: To identify the factors associated with treatment adherence among patients with PKU seen at a southern Brazil reference center. Methodology: A cross-sectional, outpatient-based study including 56 patients with PKU (median age, 12 years) for whom a Phe-restrict diet plus specific metabolic formula have been prescribed. Patients were considered adherent or nonadherent depending on the median phenylalanine concentration for the 12 months prior to study and target levels of phenylalanine for each age range (<13 years = ≤360 µmol/L; ≥13 years = ≤900 µmol/L). Data were collected through a review of patient's medical records and a set of interviews with patients and their relatives. Results: Eighteen patients (32.1%; ≥13 years, 11) were classified as treatment adherent. Among all factors analyzed, only mental retardation, living with parents, and level of maternal education were associated with adherence to treatment. Conclusion: Our findings reinforce the importance of the family as promoting factor for treatment adherence.
ABSTRACT
Introdução: Fenilcetonúria (PKU) é um erro inato do metabolismo no qual ocorre um aumento dos níveis séricos do aminoácido fenilalanina. Objetivo: O presente estudo teve como objetivo avaliar a adesão ao tratamento de pacientes com PKU atendidos em um centro de referência do Rio Grande do Sul. Métodos: Estudo transversal de pacientes com PKU atendidos no ambulatório do Serviço de Genética Médica do Hospital de Clínicas de Porto Alegre, Brasil. Os parâmetros de adesão considerados foram a mediana de fenilalanina plasmática no último ano (critério 1); o consumo de fenilalanina (critério 2); o consumo de fórmula metabólica (critério 3); e o questionamento direto aos pacientes/familiares (critério 4). Resultados: Dos 45 pacientes incluídos no estudo, (mediana de idade de 11 anos), 51% eram do sexo masculino. De acordo com o critério utilizado, foram considerados aderentes 20 (critério 1); 16 (critério 2); 27 (critério 3) e 33 (critério 4) pacientes, respectivamente. Não houve concordância entre os critérios de adesão utilizados. Foram encontradas diferenças quando comparados os critérios 1 e 2 (P=0,027), critérios 1 e 3 (P=0,002) e critérios 3 e 4 (P=0,015). Conclusão: A adesão ao tratamento é dificilmente quantificada por parâmetros isolados. A distinta percepção por parte dos pacientes dá suporte à necessidade de busca de novas estratégias que promovam adesão, bem como do estudo de métodos que avaliem a mesma.
Introduction: Phenylketonuria (PKU) is an inborn error of metabolism in which there is an increase in the serum amino acid phenylalanine. Aim:This study aimed at evaluating the adherence to treatment of patients with PKU treated at a center of reference in Rio Grande do Sul. Methods: A cross-sectional study of PKU patients seen at the outpatient clinic of the Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Brazil. The parameters considered for adherence were: median of plasma phenylalanine in the past year (criterion 1); consumption of phenylalanine (criterion 2); consumption of metabolic formula (criterion 3); and direct questioning of patients/families (criterion 4). Results: Of the 45 patients included in the study (median age of 11 years), 51% were male. According to the criteria used, the following number of patients were considered compliant: 20 (criterion 1); 16 (criterion 2); 27 (criterion 3); and 33 (criterion 4), respectively. There was no agreement among the adherence criteria used. Differences were found when comparing criteria 1 and 2 (P=0.027), criteria 1 and 3 (P=0.002), and criteria 3 and 4 (P=0.015). Conclusion: Adherence to treatment is barely quantified by isolated parameters. The patients different perception support the need of searching for new strategies to promote adherence and also new methods of assessment.