Differences in Length of Stay Between Public Hospitals, Treatment Centres and Private Providers : Selection or Efficiency?

We investigate differences in patients' length of stay between National Health Service (NHS) public hospitals, public treatment centres and private treatment centres that provide elective (non-emergency) hip replacement to publicly-funded patients. We find that private treatment centres and public treatment centres have on average respectively 40% and 18% shorter length of stay compared to NHS public hospitals, even after controlling for differences in age, gender, number and type of diagnosis, deprivation and geographical variation. We therefore interpret such differences as due to efficiency as opposed to selection (treatment of less complex cases). Quantile regression suggests that the proportionate differences between different provider types are larger at the higher conditional quantiles of length of stay compared to the lower ones