Long-Term Outcome After Intensive Care for COVID-19

Differences Between Men and Women -- A Nationwide Cohort Study

Erik Zettersten; Lars Engerström; Max Bell; Gabriella Jäderling; Johan Mårtensson; Linda Block; Emma Larsson

Disclosures

Crit Care. 2021;25(86) 

In This Article

Abstract and Introduction

Abstract

Background: Questions remain about long-term outcome for COVID-19 patients in general, and differences between men and women in particular given the fact that men seem to suffer a more dramatic course of the disease. We therefore analysed outcome beyond 90 days in ICU patients with COVID-19, with special focus on differences between men and women.

Methods: We identified all patient ≥ 18 years with COVID-19 admitted between March 6 and June 30, 2020, in the Swedish Intensive Care Registry. Patients were followed until death or study end-point October 22, 2020. Association with patient sex and mortality, in addition to clinical variables, was estimated using Cox regression. We also performed a logistic regression model estimating factors associated with 90-day mortality.

Results: In total, 2354 patients with COVID-19 were included. Four patients were still in the ICU at study end-point. Median follow-up time was 183 days. Mortality at 90-days was 26.9%, 23.4% in women and 28.2% in men. After 90 days until end of follow-up, only 11 deaths occurred. On multivariable Cox regression analysis, male sex (HR 1.28, 95% CI 1.06–1.54) remained significantly associated with mortality even after adjustments. Additionally, age, COPD/asthma, immune deficiency, malignancy, SAPS3 and admission month were associated with mortality. The logistic regression model of 90-day mortality showed almost identical results.

Conclusions: In this nationwide study of ICU patients with COVID-19, men were at higher risk of poor long-term outcome compared to their female counterparts. The underlying mechanisms for these differences are not fully understood and warrant further studies.

Introduction

We have not yet seen the end of the Coronavirus disease (COVID-19) pandemic. As of November 17, 2020, there were more than 55 million global cases and more than one million people have died.[1] In late 2020, many countries reported anew increasing number of patients with COVID-19, leading to reintroduction of restrictions including country- or region-wide lockdowns. The emergence of COVID-19 has induced an enormous global need for intensive care services, leading to rapid expansion of intensive care unit (ICU) resources. Understanding of outcomes in COVID-19 patents admitted to ICU is not complete as the current literature to a large extent is based on small patient cohorts and a large variation in follow-up intervals.[2,3] In addition, many studies are hampered by the fact that many patients still remain in ICU at study endpoint as excluding patients still in ICU when calculating mortality most likely introduces a skewness in the results.

It is by now apparent that men are suffering a more dramatic course of COVID-19 compared to women, and the underlying explanations for these are insufficiently understood. The number of COVID-19 cases appears to be equally distributed between men and women,[4] but there are more men than women hospitalized following COVID-19 and more men are treated in the ICU.[5–7] Questions remain about associations of sex with outcome beyond 30 days after ICU admission, after adjusting for age, comorbidities and other clinically relevant confounders. Analysis of comprehensive population data including detailed baseline characteristics, clinical course and minimal loss to follow-up are needed in order to increase clinicians' knowledge of patient groups at high risk for poor outcome after intensive care treatment. In this nationwide cohort study, we therefore aimed to analyse long-term outcome beyond 90 days in critically ill patients with COVID-19, with special focus on differences between men and women. We also present data on demographics, baseline comorbidities and process of care.

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