Background: The most common indication for treating patients with peripheral arterial disease is to improve their health status: their symptoms, function, and quality of life. Quantifying health status requires a valid, reproducible, and sensitive disease-specific measure. The Peripheral Artery Questionnaire (PAQ) is a 20-item questionnaire developed to meet this need by quantifying patients' physical limitations, symptoms, social function, treatment satisfaction, and quality of life.
Methods: Psychometric and clinical properties of the PAQ were evaluated in a prospective cohort study of 44 patients undergoing elective percutaneous peripheral revascularization. To establish reproducibility, 2 assessments were performed 2 weeks apart and before revascularization. The change in scores before and 6 weeks after revascularization were used to determine the instruments' responsiveness and were compared with the Short Form-36 and the Walking Impairment Questionnaire. A series of cross-sectional analyses were performed to establish the construct validity of the PAQ.
Results: The 7 domains of the PAQ were internally reliable, with Cronbach alpha = 0.80 to 0.94. The test-retest reliability analyses revealed insignificant mean changes of 0.6 to 2.3 points (P = not significant for all). Conversely, the change after revascularization ranged from 13.7 to 41.9 points (P < or =.001 for all), reflecting substantial sensitivity of the PAQ to clinical improvement. The PAQ Summary Scale was the most sensitive of all scales tested. Construct validity was established by demonstrating correlations with other measures of patient health status.
Conclusions: The PAQ is a valid, reliable, and responsive disease-specific measure for patients with peripheral arterial disease. It may prove to be a useful end point in clinical trials and a potential aid in disease management.