A CLOSER EXAMINATION OF SEX BIAS IN THE TREATMENT OF ISCHEMIC CARDIACDISEASE

Background. Past studies have conflicted regarding the existence of se x bias in the treatment of women with ischemic cardiac disease. This s tudy explored the effect of different analytic models on conclusions a bout sex bias. Methods. A retrospective analysis of medical records wa s performed on 787 patients evaluated for potential acute cardiac isch emia in the emergency departments of two nonteaching community hospita ls. The Acute Coronary Ischemia Time Insensitive Predictive Instrument (ACI-TIPI) was used to estimate the likelihood of ischemic disease. T he decisions to admit to hospital, not to admit to hospital, and to di scharge with diagnosis of myocardial infarction were the outcome varia bles. Results. Logistic regression models of increasing levels of deta il were applied and evaluated. Analysis using summary data (similar to discharge abstracts or claims data) revealed that patient sex affecte d admission decisions, but an analysis of clinically detailed data by hospital was required to reveal the nature of the effect. There was di sparity in admission decisions by sex at one hospital but not at the o ther. The odds ratio for admission (women vs men) was 0.546 (95% CI, 0 .33 to 0.91) at Hospital A, and 1.22 (95% CI, 0.72 to 2.05) at Hospita l B. This disparity appeared to be related to a high rate of admission (67%) among men with low (<10%) probability of acute ischemia. Conclu sions. Differences in treatment of suspected acute cardiac ischemia by sex may be a practice variation phenomenon rather than a uniform bias . When these differences occur, they may represent overtreatment of me n rather than inadequate treatment of women. Because summary or billin g datasets lack clinical detail, they are inadequate for the study of physician decision-making.