Higher in-hospital mortality in female patients following coronary artery bypass surgery: a population-based study

Susan B. Jaglal
Jack V. Tu
C. David Naylor
Provincial Adult Cardiac Care Network of Ontario
(Steering Committee Members: Alnoor Abdulla, Glenn Bartlett, Donald Beanlands, Robert Chisholm, Martin Goldbach, Neil McKenzie, Christopher Morgan, John Pym, Hugh Scully, William Shragge, James Swan)

Clinical Epidemiology Unit, Sunnybrook Health Sciences Centre, Institute for Clinical Evaluative Sciences in Ontario, Department of Preventive Medicine and Biostatistics, University of Toronto, Toronto, Ontario, and Division of Health Policy Research and Education, Harvard University, Boston, Massachusetts

(Original manuscript submitted 17/3/94; received in revised form 14/9/94; accepted 20/9/94)

Abstract

This study examined the relationship between gender and in-hospital mortality using data from patients undergoing coronary artery bypass surgery (CABS) in the province of Ontario. All patients who underwent CABS between April 1, 1991 and March 31, 1992 at the 9 cardiac surgery institutions were included for study (n = 5,175). The unadjusted in-hospital mortality rate was 3.3% and was higher among females (5.3%) than males (2.8%). Using logistic regression analysis to adjust for several predictors of in-hospital mortatity the odds ratio estimate (OR) for female sex was 1.55 and was statistically significant (95% confidence interval (CI) 1.09 to 2.20). Women experienced rates of in-hospital mortality that are 1.6 times greater than males following bypass surgery after case-mix adjustment for age, anatomical disease severity, anginal class, and comorbid conditions. Severe unstable angina had the greatest potential contribution to in-hospital mortality (OR = 7.51, 95% CI = 3.71-15.23) and was more prevalent in women, indicating that excess mortality may be due to delayed diagnosis in women.

Clin Invest Med 1995; 18 (2): 99-107

Table of contents: CIM vol. 18, no. 2