Sex-Based Disparities in Venous Thromboembolism Sociodemographics and Outcomes: A National Inpatient Sample (NIS)-Based Analysis

Background: Venous thromboembolism (VTE) contributes to significant morbidity, mortality, and socioeconomic burden. Though male sex is a known risk factor for recurrent VTE, there is a paucity of literature regarding sex-based sociodemographic differences as well as differences in VTE outcomes including hospital length of stay and mortality rates.

Methods: We conducted a retrospective analysis from the National Inpatient Sample (NIS) database from 2012-2013. Inclusion criteria were age 18 years and older and primary discharge diagnosis of VTE Sociodemographic features and medical comorbidities were analyzed, as were hospital length of stay and in-hospital mortality rates.

Results: 107,896 patients in the NIS, representing a national estimate of 539,480 patients hospitalized for VTE between 2012 and 2013, met inclusion criteria. 53% were female and 47% were male. Mean age was 63 years and on average women were older than men (65 years versus 62 years, p<0.001). There were significant differences between men and women with respect to race, primary insurance payor, and VTE location as well as medical comorbidities (Table 1). Median overall length of stay (LOS) was 4 days and in-hospital mortality rates were 2.1%. Female sex was associated with a small but significantly longer hospital LOS (RR 1.04, CI 1.03-1.05, p<0.001) which was also seen in subgroup analyses of lower extremity DVT (RR 1.05, CI 1.03-1.06, p<0.001) and pulmonary embolism (RR 1.03, CI 1.02-1.05, p<0.001) but not upper extremity (RR 1.04, CI 0.96-1.12, p=0.36). There were no significant sex-based differences in in-hospital mortality (2.2% in women versus 2.1% in men, p=0.15). In a multivariate model correcting for sociodemographic differences and medical comorbidities, there were no significant differences between women and men with respect to hospital LOS or in-hospital mortality (Table 2).

Conclusion: We used data from the NIS to study a large number of patients hospitalized for VTE, and identified several sex-based disparities in sociodemographic factors and location of VTE. However, in a multivariable analysis correcting for these factors, sex was not associated with significant differences in hospital LOS or inpatient mortality rates.