Epidemiology of admissions to 11 stand-alone high-dependency care units in the UK

High-dependency care units (HDUs) are a focus of research to optimize critical care resource allocation. HDUs provide a level of care between the general ward and the intensive care unit (ICU). However, few data report on the case mix and outcomes of patients in these units.

Retrospective observational cohort study of patients admitted to 11 stand-alone HDUs in the UK from 2008 to 2011. We stratified patients by location prior to HDU admission and location on discharge from HDU, and we summarized the case mix, transitions of care, and mortality.

Of 9008 patients admitted to 11 stand-alone HDUs, 56.5% were male and the mean age was 62.7 ± 17.9 years. The majority of patients admitted to HDUs were non-surgical (59.3%), with 22.4 and 20.1% admitted from the ICU and general ward, respectively; 41.3% were admitted from the operating room or recovery suite. The median length of stay in HDU was 1.8 days (IQR 0.9-3.5) and in-HDU mortality was 5.1%. Among HDU survivors (n = 8551), 8.5% were discharged to an ICU, 80.9% to a general ward, and 10.6% to other care areas. For patients admitted to HDU from an ICU, only 5.8% were readmitted to ICU. Hospital mortality for the HDU population was 14.8%; for patients discharged to an ICU, hospital mortality was 43.6%.

In a sample of 11 stand-alone HDUs in the UK, patients are from many different hospital locations. Hospital mortality for patients requiring HDU care is high, particularly for patients who require transfer to an ICU.