Gender Bias in Cardiovascular Testing Persists after Adjustment for Presenting Characteristics and Cardiac Risk

Objectives: Previous studies have found that female patients receive fewer invasive tests for cardiovascular disease than male patients. The authors assessed whether different clinical characteristics at emergency department presentation account for this gender bias. Methods: Patients with potential acute coronary syndrome (ACS) who presented to a university hospital were prospectively identified. A structured data instrument that included demographic information, chest pain description, history, physical examination, chest radiography, and electrocardiogram (ECG) data was completed. Hospital course was tracked daily. Patients received 30-day telephone follow-up. The main outcome was whether the patients received objective evaluation for coronary artery disease after adjustment for cardiac risk, including race, age, total number of risk factors, Thrombolysis in Myocardial Infarction (TIMI) score, ECG, and whether the patient sustained an acute myocardial infarction on index hospitalization. Results: There were 3,514 women (58%) and 2,547 men (42%) studied. They had similar presenting characteristics: chest pain quality (pressure/tightness: female 60% vs. male 59%, p = 0.6), location (substernal: female 82% vs. male 80%; p = 0.2), radiation (female 27% vs. male 26%; p = 0.3), and most associated symptoms. Men had more cardiac risk factors (mean 1.5 vs 1.4; p < 0.001), more abnormal ECGs (59% vs. 48%; p < 0.001), and a higher TIMI risk score (p < 0.001). With respect to the main outcome, men received more cardiac catheterizations (12.6% vs. 6.0%; odds ratio [OR], 2.25; 95% confidence interval [CI] = 1.88 to 2.70) and more stress tests (14.7% vs. 12.3%; OR, 1.22; 95% CI = 1.05 to 1.42). After adjustment for age, race, cardiac risk factors, ECG, and TIMI risk score, men still received more cardiac catheterizations (adjusted OR, 1.72; 95% CI = 1.40 to 2.11) and stress tests (adjusted OR, 1.16; 95% CI = 1.01 to 1.33). Models adjusting for acute myocardial infarction or death, high-risk initial clinical impression, or emergency department disposition found similar results for increased likelihood of cardiac catheterization in men but no difference in stress testing between men and women. Conclusions: Female patients with potential ACS receive fewer cardiac catheterizations than male patients, even when presenting complaint, history, ECG, and diagnosis are taken into account. The gender bias cannot be explained by differences in presentation or clinical course.