(106) - Development and Validation of a Lung Transplant-Specific Disability Questionnaire

Abstract

Lung transplant (LT) aims to extend survival and improve patient-centered outcomes (PCOs) by reducing disability and improving health-related quality of life (HRQL). Few PCO instruments have been validated in LT populations. We aimed to develop and validate a shortened version of the Valued Life Activities (VLA) disability scale specific to LT. We used data from 140 subjects participating in an ongoing cohort study of LT. Subjects completed a survey battery, including VLA items, and physical assessments before LT. To develop a shortened lung transplant specific VLA (LT-VLA), we iteratively deleted items from a longer 32-item VLA battery, retaining the instrument’s conceptual framework, scoring and performance characteristics. We evaluated LT-VLA validity by testing correlations with a HRQL measure (Short Form-12 Physical Function [SF-12 PF] subscale), FVC% predicted, and 6-minute walk distance (6MWD). Responsiveness was evaluated in 84 subjects who completed assessments before and after LT. The 15-item LT-VLA scoring closely matched the longer VLA (correlations ≥0.96) and had excellent internal consistency (Cronbach’s alpha: 0.92). The LT-VLA required only 3 minutes or less to administer compared to 8-9 for the original. The LT-VLA, measured as mean difficulty in performing each of the 15 activities queried, correlated with FVC% predicted (r= -0.30), 6MWD (r= -0.38) and SF-12 PF (r= -0.47) (all p<0.01). The strength and direction of these correlations were as hypothesized, a priori. The LT-VLA mean difficulty was responsive to change from before to after LT: (63% improvement; effect size=1.60). The LT-VLA is a short, easy to administer, valid, and responsive disease-specific PCO instrument that may be useful in clinical and research applications for lung transplantation.