[Psychometric properties of a quality of life questionnaire specific to liver transplant].
ABSTRACT To translate and evaluate the psychometric properties of a quality of life questionnaire specific to liver transplant patients.
The questionnaire was administered to 60 patients on the waiting list for liver transplant in the Cruces Hospital Transplant Unit, and again at 6 months after the transplant. The reliability, validity, sensitivity to change, and minimum detectable change (MDC) were studied. Two questionnaires, the SF-36 (Health Survey Short Form 36) and HADS (Hospital Anxiety and Depression Scale), were used to evaluate the convergent validity.
The specific questionnaire presented a Cronbach s alpha coefficient of over 0.7. The factor analysis demonstrates a single dimension. Correlations with the areas of SF-36 varied between -0.34 and -0.71 in the preoperative phase, and between -0.21 and -0.67 at 6 months. With respect to the HAD-anxiety scale, the coefficients were 0.44 in the preoperative phase and 0.51 at 6 months, and for the HAD-depression scale these were 0.64 and 0.39, respectively. Discriminant validation studies confirm that the questionnaire shows differences between patients with cirrhosis of various etiologies and severities. In the study of sensitivity to change, values were obtained for the SES (standardised effect size) and SRM (standardised response mean) indices of 0.92 and 0.99, respectively. Furthermore, 58.33% of patients had scores higher than MDC.
The specific questionnaire has adequate psychometric properties. Its use in these patients may therefore be recommended as another scale for evaluating the results of this intervention.