Cultural validation of the post-Liver transplant quality of life (pLTQ) questionnaire for the Brazilian population

Abstract

Background and rationale. The post-Liver Transplant Quality of Life (pLTQ) questionnaire, developed in the United States, is a disease-targeted instrument designed to evaluate health-related quality of life (HRQoL) in liver transplant recipients. Our study sought to validate a version of the pLTQ for use in the Brazilian population. Translation and cross-cultural adaptation were carried out in accordance with international standard practices for questionnaire validation. Validity was measured by means of convergent validity (correlations between pLTQ domains and WHOQOL-Bref domains). Reliability was assessed by measurement of internal consistency (Cronbach’s alpha coefficient), reproducibility (intraclass correlation coefficient), sensitivity to change (effect size), and floor and ceiling effects.Results. The study sample comprised 160 liver transplant recipients, with a mean age of 56.9 ± 10.4 years, treated at a tertiary hospital in Southern Brazil. The sample was largely male (62.5%), and the predominant indication for liver transplant was hepatocellular carcinoma (49.4%). Only two questionnaire items were modified during the translation and cross-cultural validation stage. The mean total pLTQ score was 5.58 ± 0.9, with < 20% floor/ceiling effect. Correlations between pLTQ and WHOQOL-Bref domains were acceptable (r = 0.37 - 0.40). For similar dimensions, the correlations between WHOQOL-Bref and pLTQ were statistically significant (p ≤ 0.001). Cronbach’s alpha for the total score was 0.91 (95% CI 0.89 - 0.93), with a range of 0.51 to 0.77 across domains. Reproducibility was 0.90, and sensitivity to change was 0.84.Conclusion. In conclusion, the Brazilian Portuguese version of the pLTQ exhibited good psychometric performance, suggesting that it can be a useful tool in the Brazilian cultural context.