# Hospitalisations and length of stays in women with endometriosis: a data linkage prospective cohort study

## TL;DR

Women with endometriosis are hospitalized more often than those without, and their hospital stays increase after diagnosis, showing the condition's impact on healthcare use.

## Contribution

This is the first longitudinal study to examine hospital admissions and lengths of stay before and after endometriosis diagnosis.

## Key findings

- Women with endometriosis had 2.11 times more hospital admissions per year than those without.
- Post-diagnosis, women had 1.52 times more hospitalizations and 1.81 times more days in hospital compared to pre-diagnosis.
- Women with endometriosis were more likely to be discharged on the same day of admission.

## Abstract

Women with endometriosis have more hospitalisations compared to those without the condition. However, no longitudinal study has examined hospital admission rates and lengths of stay before and after diagnosis. We examined all-cause hospital admissions and lengths of stay among women with, versus without, endometriosis, and before, versus after, diagnosis.

This study included 13,501 women of reproductive age, born in 1973–78. The Australian Longitudinal Study on Women's Health survey data linked to administrative health records was used to identify women with endometriosis. Hospital admission rates and length of stays were examined using hospital records of patients admitted up to 2022. Analysis was conducted using mixed-effects zero-inflated negative binomial models.

Women with endometriosis were more likely to be admitted to hospitals compared to those without the condition, with an adjusted incidence rate ratio (IRR) of 2.11 (95% CI: 1.83–2.43) for admissions per year. However, they had shorter hospital stays (IRR: 0.90; 0.81–0.99) for days per year and were more often discharged on the same day (odds ratio: 1.27; 1.20–1.33). Post-diagnosis, women experienced more hospitalisations and more days in hospital compared to their pre-diagnosis (IRR: 1.52; 1.22–1.88) and (IRR: 1.81; 1.53–2.14), respectively. Consistent findings were found for women with surgically confirmed or clinically suspected endometriosis.

The higher number of hospitalisations among women with endometriosis, compared to those without, highlights the substantial burden of the condition on healthcare utilisation. The persistent frequent hospitalisations and longer stays post-diagnosis indicate recurrent endometriosis, posing significant management challenges.

The Australian Longitudinal Study on Women's Health is funded by the Australian Government 10.13039/501100003921Department of Health and Aged Care. GDM and GWM are Australian 10.13039/501100000925National Health and Medical Research Council Leadership Fellows (GNT2009577 and GNT1177194).