Evaluation of a specific activity questionnaire to predict mortality in men referred for exercise testing

Abstract

A self-administered symptom questionnaire developed at our institution (Veterans Specific Activity Questionnaire [VSAQ]) is routinely used to estimate a patient's exercise capacity to individualize the exercise test in accordance with current guidelines. This study was performed to evaluate the association of the VSAQ with all-cause mortality. The VSAQ was administered to 1185 consecutive male patients (mean age 58 +/- 12 years) referred for exercise testing for clinical reasons. The VSAQ is designed to determine which specific daily activities are associated with cardiovascular symptoms (fatigue, chest pain, or shortness of breath) to provide an estimate of exercise tolerance (in metabolic equivalents [METs]) before exercise testing. Patients were classified into 1 of 3 groups according to VSAQ score: <5 METs, 5 to 8 METs, and >8 METs. The association between exercise capacity estimated by the VSAQ, other clinical and exercise test variables, and all-cause mortality was assessed by Cox proportional hazards. The mean follow-up period was 4.5 +/- 2.9 years. There were a total of 132 deaths during the follow-up period, resulting in an average annual mortality of 2.7%. In a multivariate analysis including clinical risk factors and exercise test variables, age-adjusted predictors of mortality, in rank order, were the VSAQ score in METs, history of chronic heart failure, history of smoking, and diabetes (for VSAQ: hazard ratio [HR] 0.90, 95% CI 0.83-0.98; for chronic heart failure: HR 2.67; 95% CI 1.51-4.72; for smoking: HR 1.74, 95% CI 1.18-2.57; and for diabetes: HR 1.84, 95% CI 1.15-2.95). Expressed in tertiles, age-adjusted relative risks for the VSAQ were 1.0, 0.54, and 0.22 (P for trend <.001). Each 1-MET increase in the VSAQ conferred a 10% survival benefit. A simple self-administered symptom questionnaire strongly and independently predicted all-cause mortality. The VSAQ is a useful adjunct to clinical and exercise test data for stratifying risk in patients undergoing exercise testing for clinical reasons.