Objectives: This study sought to establish the validity, reproducibility and responsiveness of the Seattle Angina Questionnaire, a 19-item self-administered questionnaire measuring five dimensions of coronary artery disease: physical limitation, anginal stability, anginal frequency, treatment satisfaction and disease perception.
Background: Assessing the functional status of patients is becoming increasingly important in both clinical research and quality assurance programs. No current functional status measure quantifies all of the important domains affected by coronary artery disease.
Methods: Cross-sectional or serial administration of the Seattle Angina Questionnaire was carried out in four groups of patients: 70 undergoing exercise treadmill testing, 58 undergoing coronary angioplasty, 160 with initially stable coronary artery disease and an additional 84 with coronary artery disease. Evidence of validity was sought by comparing the questionnaire's five scales with the duration of exercise treadmill tests, physician diagnoses, nitroglycerin refills and other validated instruments. Reproducibility and responsiveness were assessed by comparing serial responses over a 3-month interval.
Results: All five scales correlated significantly with other measures of diagnosis and patient function (r = 0.31 to 0.70, p < or = 0.001). Questionnaire responses of patients with stable coronary artery disease did not change over 3 months. The questionnaire was sensitive to both dramatic clinical change, as seen after successful coronary angioplasty, and to more subtle clinical change, as seen among outpatients with initially stable coronary artery disease.
Conclusions: The Seattle Angina Questionnaire is a valid and reliable instrument that measures five clinically important dimensions of health in patients with coronary artery disease. It is sensitive to clinical change and should be a valuable measure of outcome in cardiovascular research.