Polish adaptation and psychometric validation of the Lung Transplant Quality of Life (LT-QoL) questionnaire

Background Survival after lung transplantation has improved, increasing the need for disease-specific assessment of health-related quality of life (HRQoL). The Lung Transplant Quality of Life (LT-QoL) Questionnaire is a transplant-specific patient-reported outcome measure, but no Polish version has been available. This study aimed to translate the LT-QoL into Polish and evaluate its psychometric properties. Methods The LT-QoL was translated using a forward-backward procedure with sworn translators, multidisciplinary review, and consultation with the original authors. In this cross-sectional study, 70 adult lung transplant recipients were included at a single tertiary center; 67 provided analyzable LT-QoL data for the principal psychometric analyses. Participants self-completed the Polish LT-QoL together with the SF-36, EQ-5D-5L, St George’s Respiratory Questionnaire (SGRQ), and Hospital Anxiety and Depression Scale (HADS). Analyses included internal consistency, inter-subscale correlations, convergent and divergent validity, known-groups comparisons, hierarchical regression models for external quality-of-life and psychological outcomes, and LASSO regression predicting SF-36 global QoL. Results Cronbach’s alpha ranged from 0.44 to 0.97, with most LT-QoL domains at or above 0.70. The three second-order composites, Pulmonary Symptoms, GI Symptoms, and Anxiety/Depression, showed good reliability; the stand-alone two-item General Quality of Life scale also showed high reliability. Shortness of Breath (α = 0.44) and Neuromuscular Symptoms (α = 0.67) showed weaker internal consistency and therefore warrant cautious interpretation. Correlations among subscales supported the intended multidimensional structure. Respiratory LT-QoL domains correlated moderately to strongly with SGRQ, emotional domains with HADS, and global/physical domains with SF-36 QoL and EQ-5D-5L, while GI and sexual domains showed weaker associations with respiratory measures. Known-groups analyses showed expected differences primarily by dyspnea, health distress and sex, with more limited differences according to time since transplantation. LT-QoL domains explained additional variance in QoL, health status and distress beyond age, sex and time since transplant. The LASSO model predicting SF-36 QoL performed well (R 2 = 0.57) and highlighted Worry About Future Health, Shortness of Breath, General Quality of Life, Anxiety/Depression, Pulmonary Symptoms and Cognitive Limitations as key predictors. Conclusions The Polish LT-QoL shows satisfactory reliability and construct validity and appears suitable for use in clinical practice and research, with larger multicenter and longitudinal studies warranted.