Impact of Sex- and Gender-Related Factors on Length of Stay Following Non-ST-Segment-Elevation Myocardial Infarction: A Multicountry Analysis

Abstract

Background Gender-related factors are psycho-socio-cultural characteristics and are associated with adverse clinical outcomes in acute myocardial infarction, independent of sex. Whether sex- and gender-related factors contribute to the substantial heterogeneity in hospital length of stay (LOS) among patients with non-ST-segment-elevation myocardial infarction remains unknown. Methods and Results This observational cohort study combined and analyzed data from the GENESIS-PRAXY (Gender and Sex Determinants of Cardiovascular Disease: From Bench to Beyond Premature Acute Coronary Syndrome study), EVA (Endocrine Vascular Disease Approach study), and VIRGO (Variation in Recovery: Role of Gender on Outcomes of Young AMI [Acute Myocardial Infarction] Patients study) cohorts of adults hospitalized across Canada, the United States, Switzerland, Italy, Spain, and Australia for non-ST-segment-elevation myocardial infarction. In total, 5219 participants were assessed for eligibility. Sixty-three patients were excluded for missing LOS, and 2938 were excluded because of no non-ST-segment-elevation myocardial infarction diagnosis. In total, 2218 participants were analyzed (66% women; mean±SD age, 48.5±7.9 years; 67.8% in the United States). Individuals with longer LOS (51%) were more likely to be White race, were more likely to have diabetes, hypertension, and a lower income, and were less likely to be employed and have completed secondary education. No univariate association between sex and LOS was observed. In the adjusted multivariable model, age (0.62 d/10 y; P<0.001), unemployment (0.63 days; P=0.01), and some of countries included relative to Canada (Italy, 4.1 days; Spain, 1.7 days; and the United States, -1.0 days; all P<0.001) were independently associated with longer LOS. Medical history mediated the effect of employment on LOS. No interaction between sex and employment was observed. Longer LOS was associated with increased 12-month all-cause mortality. Conclusions Older age, unemployment, and country of hospitalization were independent predictors of LOS, regardless of sex. Individuals employed with non-ST-segment-elevation myocardial infarction were more likely to experience shorter LOS. Sociocultural factors represent a potential target for improvement in health care expenditure and resource allocation.

Keywords: acute myocardial infarction; employment; gender; length of stay; sex.

Figure 1. Flowchart of cohort selection for patients with non–ST‐segment–elevation myocardial infarction (NSTEMI) and recorded length of stay.

EVA indicates Endocrine Vascular Disease Approach study; GENESIS‐PRAXY, Gender and Sex Determinants of Cardiovascular Disease: From Bench to Beyond Premature Acute Coronary Syndrome study; STEMI, ST‐segment–elevation myocardial infarction; and VIRGO, Variation in Recovery: Role of Gender on Outcomes of Young AMI [Acute Myocardial Infarction] Patients study.

Figure 2. Distribution of length of stay overall and by sex in patients with non–ST‐segment–elevation myocardial infarction.

Figure 3. Forest plot of the multivariate linear regression model, including sex‐ and gender‐related factors.

All CIs are indicated on the right‐hand side with associated P values. Sex is reported as “female sex,” age in years, level of education as “education level higher than high school,” income as “low income,” employment as “being employed,” low social as “low social support,” married as “being married,” and country as “country relative to Canada.” Gender‐related factors include level of education, income, employed, and married. Sex refers to sex assigned at birth.