Background: The provision of adult critical-care facilities is not based on a rational or scientific assessment of need. We aimed to define the numbers of adult critical-care beds required for a population of 500000.
Methods: In five hospitals in Wales, UK, we classified patients who might be suitable for critical care in intensive-care or high-dependency units. On every 12th day for 1 calendar year, we counted the numbers of such patients admitted in a defined geographical population. A panel of ten intensivists made consensus decisions about whether individual patients were in the appropriate unit. The data were used to predict the numbers of beds and units required for the population.
Findings: 4058 patients were suitable for critical care, of whom 3028 lived in the study area. 56.4% were in general wards, 22.3% in high-dependency units, and 21.3% in intensive-care units. The mean risk of death was 22.0% and the in-hospital death rate 17.3%. According to the masked consensus, 41.3% of patients required high-dependency beds and 21.5% intensive-care beds. Mean risk of death increased from general wards (14.7%) to high-dependency units (19.2%) to intensive care (37.0%). Based on the consensus decisions, the average daily requirement of intensive-care beds was 21 and of high-dependency beds 43; to meet needs 95% of times required 30 and 55 beds, respectively, in a single critical-care unit.
Interpretation: We estimated, scientifically, numbers of adult critical-care beds required to meet population needs. Studies are necessary periodically to track changes in admissions requiring critical care.