Explaining variations in inpatient length of stay in the National Health Service.

This paper seeks to explain variations in acute inpatient length of stay in the National Health Service in England. A model is proposed in which the length of stay is allowed to vary according to patient characteristics, the local supply of NHS care. the local pressure on NHS resources, other non-NHS health care supply factors, and local policy effects. Length of stay data are obtained from the 1991/1992 Hospital Episode Statistics. They are standardized for age, sex and broad specialty group, and are aggregated to the level of small areas with populations of about 10,000. Explanatory variables include socio-economic data from the 1991 Census of Population, health status data, waiting time data, measures of access to inpatient and GP services, and measures of local private health care provision. The paper finds that variability in length of stay is greatest in the over-65 age group. The most important determinants of variations in length of stay are access to NHS hospitals, access to private hospitals, waiting times for elective surgery, indicators of poverty, and indicators of the availability of informal care.