Abstract 13810: Development and Validation of the Peripheral Artery Questionnaire for Critical Limb Ischemia-(PAQ-CLI) Instrument

Abstract

Background: Patients with critical limb ischemia (CLI) experience pain, non-healing wounds, and amputation, which impacts their health status. There are no CLI-specific health status instruments that meet FDA standards. We sought to develop and validate a CLI-specific health status instrument to supplement the Peripheral Artery Questionnaire (PAQ). Methods: Using the PAQ conceptual framework, the PAQ-CLI was created in 3 phases: (1) construct validity was established through qualitative input from patients and vascular specialists; (2) items were elicited for CLI clinical phenotypes (rest pain; wound; post-amputation) and tested with cognitive interviewing; (3) psychometric testing in the prospective SCOPE-CLI registry was completed to confirm factor structure, convergent validity (against the EQ-5D, maximum walking distance, and Wifi), internal consistency, and 1-month test-retest reliability (against 46 stable patients determined by global assessment of functioning change). Results: The original domain structure of the PAQ captured the full range of health status experiences, including physical function, symptom stability, symptoms, treatment satisfaction, quality of life, and social limitations, confirmed by eigenvalues >1.77. After item-reduction (30 items for all clinical phenotype modules combined), the correlation with the PAQ-CLI summary score, EQ-5D Index, maximum walking distance, and Wifi wound and Ischemia score was 0.67, 0.38, -0.23 and -0.28, respectively. Cronbach’s alphas ranged from 0.85-0.88 and one-month test-retest reliability for the summary score was r=0.67. Baseline PAQ-CLI summary scores were lowest for rest pain (39.7±17.2), followed by wounds (49.0± 20.2), and highest for post amputation status (52.2±21.4) ( Figure) . Conclusion: The PAQ-CLI is a novel, validated instrument for patients with CLI meeting quality benchmarks for instrument development as defined by classical test theory.