Abstract 54: The SAQ-7: A Short Version of the Seattle Angina Questionnaire

Abstract

Background: The Seattle Angina Questionnaire (SAQ) is a well-validated and widely used 19-item instrument that measures patient-reported symptoms, function and quality of life for patients with coronary artery disease. We sought to develop a shortened version to reduce response burden and facilitate greater use within busy clinical environments. Methods: We used data from 4 U.S. multicenter longitudinal cohorts studies (2 PCI: n=1,507 and 2,206; 2 AMI: n=2,487 and 4,340) to develop and validate a short version of the SAQ. We included items from the Physical Limitation, Angina Frequency and Quality of Life scales, which directly measure patients’ current health status. We conducted parallel analyses for 3 distinct clinical scenarios (stable CAD, peri-PCI, acute MI). In development cohorts, we used equidistant item-total correlation methods to identify items that best correlated with their respective full-version score across the entire range of scores. We also considered item response variability and missingness in choosing between similarly performing items. Using the selected items, we calculated summary scores for each of the 3 scales, and an overall summary score as the average of the 3 scale scores. (As in the full SAQ, scores were rescaled so that 0 denotes the worst and 100 the best possible health status.) Finally, in independent validation cohorts, we conducted a range of analyses to investigate the validity, reproducibility, and responsiveness of the short-version scores. Results: We identified 7 items that tracked strongly with their corresponding full-version scores (3 of 9 Physical Limitation items; 2 of 2 Angina Frequency items; 2 of 3 Quality of Life items). These items were consistently identified across all 3 clinical scenarios. Correlations between the resulting short-version and full-version scores were excellent (r=0.95 to 1.00), and missing rates were the same or lower for all scores. In validation studies, the SAQ-7 demonstrated strong performance comparable to the full SAQ (Table). Conclusions: The SAQ-7 is a valid, reproducible, responsive instrument for assessing disease-specific health status among patients with coronary artery disease, with properties and performance similar to the full SAQ but with a substantially reduced response burden.