Sex and gender aspects on intensive care : access, intensity and outcome

Abstract

There is an underlying assumption in society that critically ill patients are admitted to an intensive care unit (ICU) based on their illness severity coupled with their comorbidities, and that other variables are irrelevant. It is therefore troublesome to not fully understand the sex discrepancy in the ICU-population; the gender distribution in intensive care units is consistently found to be around 60% men and 40% women. We sought to elucidate the reasons for this discrepancy by constructing five different studies, covering the entire chain from admittance to the ICU until 90 days post intensive care. The overall aim for this thesis is to investigate if there are differences in allocation of intensive care resources depending on whether the patient is a man or a woman.

The first two studies aimed at investigating gender differences in the afferent arm, i.e., the access to the ICU. This was done using surveys with fictive patient cases, where the respondent was to decide whether the patient in each case described was in need of ICU care or not. We concluded that in a blinded survey we could not see any differences in admittance to the ICU depending on whether the patient was a man or a woman. Study III is a retrospective cohort study with 8,598 adult patients admitted between 2006 and 2016 to the ICU at Karolinska University Hospital in Stockholm, Sweden. This study explored differences in the efferent arm, i.e., sex- and gender-based differences in discharge from the ICU and mortality after intensive care. We found that women had a higher probability of being discharged from the ICU. There were no differences in 30- or 90-day mortality. In Study IV we used the same cohort as in study III. In this retrospective cohort study, we explored care provided within the ICU, specifically different ICU-typical items, for example mechanical ventilation, vasoactive and inotropic treatment. We concluded that differences in the level of intensive care provided to men and women exist. Given equal severity of illness, men receive more intensive care. Finally, in study V, we investigated differences between men and women regarding care provided in the ICU as well as long-term outcome for all ICU-treated patients with COVID- 19 during the spring of 2020 in Sweden. Male sex was significantly associated with mortality. Additionally, age, COPD/asthma, immune deficiency, malignancy, SAPS 3 and admission month were associated with mortality. In this nationwide study of ICU patients with COVID- 19 we concluded that men were at higher risk of poor long-term outcome compared to women.