Regional variance in socioeconomic status among Dutch intensive care units: a nationwide cohort study of 588,568 ICU admissions

Background Low socioeconomic status (SES) is a known determinant for higher disease incidence and adverse health outcomes. However, the geographical distribution of SES and its impact on intensive care unit (ICU) populations remains unclear. This study aims to examine SES differences across Dutch acute care regions, hospital types, and patient characteristics and to build a national ICU cohort to improve comparisons of intensive care quality and identify potential health inequalities.Methods A nationwide cohort study was conducted, linking clinical data of the National Intensive Care Evaluation registry from all Dutch ICU admissions (2014-2022) with SES scores from Statistics Netherlands. The SES score was based on wealth, education, and employment component scores per household. SES distributions were compared across regions, hospital types and volumes, admission types, and number of chronic conditions.Results Of 623,838 eligible ICU admissions, 588,568 (94.3%) were successfully linked to SES scores. Differences in SES were observed between regions. The Southwest and Limburg regions showed the lowest mean SES, while Middle and Zwolle regions showed the highest. Lower SES was observed in admissions to non-academic hospitals, smaller volume hospitals, medical admissions, and patients with chronic conditions.Conclusion Despite the robust healthcare system, socioeconomic disparities were observed among Dutch ICUs and regions in this novel ICU cohort, highlighting the importance of considering SES when comparing ICUs. Our findings underscore the need for further research into the effects of SES on ICU outcomes within this and other cohorts, including studies in different countries. Additionally, these results suggest that incorporating SES into the ICU performance benchmarking is crucial for fair comparisons across diverse healthcare settings.