title: Development and validation of a lung transplant-specific disability questionnaire.
abstract: BACKGROUND
  Lung transplant (LT) aims to extend survival and improve patient-centred 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.
  
  
  METHODS
  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 LT-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), forced vital capacity % (FVC%) predicted and 6 minute walk distance (6MWD). Responsiveness was evaluated in 84 subjects who completed assessments before and after LT.
  
  
  RESULTS
  The 15-item LT-VLA scoring closely matched the longer VLA (correlations ≥0.96) and had excellent internal consistency (Cronbach's α 0.92). The LT-VLA required only 3 min or less to administer. 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 LT-VLA mean difficulty was responsive to change from before to after LT (63% improvement; effect size=1.60).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California, , San Francisco, USA.
authors.forename: Jonathan Paul
authors.initials: JP
authors.lastname: Singer
authors.forename: Paul David
authors.initials: PD
authors.lastname: Blanc
authors.forename: Y Monica
authors.initials: YM
authors.lastname: Dean
authors.forename: Steven
authors.initials: S
authors.lastname: Hays
authors.forename: Lorriana
authors.initials: L
authors.lastname: Leard
authors.forename: Jasleen
authors.initials: J
authors.lastname: Kukreja
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Golden
authors.forename: Patricia P
authors.initials: PP
authors.lastname: Katz
mesh_terms: D004185:Disability Evaluation; D006233:Persons with Disabilities / Q000523:psychology / Q000706:statistics & numerical data*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000503:physiopathology; D016040:Lung Transplantation / Q000534:rehabilitation*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014797:Vital Capacity; D016138:Walking / Q000502:physiology
keywords: Lung Transplantation