Multiple hospital admissions in a calendar year.

Hospital in-patient workload is routinely measured as episodes of care. We report on the extent to which counts of episodes of care differ from counts of patients treated in different specialties and in different age groups. Linked records of hospital care in a population of 1.9 million people, collected over an 11-year period (1976-1986), were analysed. The all-ages multiple admission ratio (the number of admissions per 100 people admitted in the same specialty and year) varied between specialties from 102 to 171. Medical specialties tended to have higher ratios than surgical ones. The influence of age on multiple admission ratios varied between specialties, although in general the ratios increased with increasing age. There were progressive but small increases in multiple admission ratios over the period studied in a number of specialties but, by and large, stability over time was more striking than any change. The information presented could be used to estimate person-based admission rates from available episode-based data where the former are not available. This should be helpful both in managing hospital resources and in purchasing care on behalf of resident populations. Purchasers in particular should be aware of numbers of people being treated as well as the numbers of episodes of care provided.