Development and validation of a short version of the Seattle angina questionnaire

Abstract

Background: Clinical trials and national performance measures increasingly mandate reporting patients' perspectives of their health status: their symptoms, function, and quality of life. Although the Seattle Angina Questionnaire (SAQ) is a validated disease-specific health status instrument for coronary artery disease (CAD) with high test-retest reliability, predictive power, and responsiveness, its use in routine clinical practice has been limited, in part, by its length (19 items).

Methods and results: Using data from 10 408 patients with CAD from 5 multicenter registries, we derived and validated a shortened version of the SAQ (SAQ-7) among patients presenting with stable CAD, undergoing percutaneous coronary intervention, and after acute myocardial infarction. We examined the psychometric properties of the SAQ-7 as compared with the full SAQ. Seven items from the Physical Limitation, Angina Frequency, and Quality of Life domains were identified for the SAQ-7, with high levels of concordance (0.88-1.00) with each original SAQ domain. The SAQ-7 demonstrated good construct validity (compared with Canadian Cardiovascular Society class for angina), with a correlation of 0.62 and 0.38 for patients with stable CAD and undergoing percutaneous coronary intervention, respectively. It was highly reproducible in patients with stable CAD (intraclass correlation, ≥0.78) and exhibited excellent responsiveness in patients after percutaneous coronary intervention (≥18 points in each SAQ domain). Finally, the SAQ-7 was predictive of 1-year mortality and readmission.

Conclusions: To increase the feasibility of measuring patient-reported outcomes in patients with CAD, we developed and validated a shortened 7-item SAQ instrument for use in clinical trials and routine care.

Keywords: coronary artery disease; health services research; health status.

Conflict of interest statement

Conflict of Interest Disclosures:

1. Dr. Spertus owns patent rights for the Seattle Angina Questionnaire.

2. None of the other authors had any conflicts of interest to disclose.

© 2014 American Heart Association, Inc.

Figures

Figure 1. The Shortened SAQ-7 Instrument

Although the original SAQ instrument was designed to independently assess patients’ symptoms, function and quality of life, the 19 items of the SAQ made interpretation more complex and less feasible to administer. In this figure, we present the shortened SAQ-7 instrument, with similar construct validity, predictiveness, reliability, and responsiveness as the original SAQ instrument.