AIMS To estimate the nature and quantity of clinical experience available for trainees in paediatrics or general practice in acute general hospitals of differing sizes in the UK. To discuss implications for training and service configuration taking account of current Royal College recommendations (a minimum of 1800 acute contacts each year and ideally covering a population of 450 000 to 500 000 people).

RESULTS Small units (1800 or less acute referrals a year) provide adequate exposure to common conditions such as gastroenteritis (157 per annum) and asthma (171 per annum) but encounter serious or unusual disease rarely. When modelled for units serving larger populations, numbers of such disorders remain small. For example, about 0.5% of admissions require intensive care to the level of ventilatory support. Medium size units offer a wide range of experience but differ little from those serving the population of 500 000 proposed as being optimal for training. This standard is not justified by the evidence in this review. Closing or amalgamating units on the scale necessary to achieve this ideal would be impractical as only five hospitals in England have a paediatric workload equivalent to this population; it would also raise issues of access and equity.