How much should be paid for specialised treatment?

English health policy has moved towards establishing specialist multi-disciplinary teams to care for patients suffering rare or particularly complex conditions. But the healthcare resource groups (HRGs), which form the basis of the prospective payment system for hospitals, do not explicitly account for specialist treatment. There is a risk, then, that hospitals in which specialist teams are based might be financially disadvantaged if patients requiring specialised care are more expensive to treat than others allocated to the same HRG. To assess this we estimate the additional costs associated with receipt of specialised care. We analyse costs for 12,154,599 patients treated in 163 English hospitals in fiscal year 2008/09 according to the type of specialised care received, if any. We account for the distributional features of patient cost data, and estimate ordinary least squares and generalised linear regression models with random effects to isolate what influence the hospital itself has on costs. We find that, for nineteen types of specialised care, patients do not have higher costs than others allocated to the same HRG. However, costs are higher if a patient has cancer, spinal, neurosciences, cystic fibrosis, children's, rheumatology, colorectal or orthopaedic specialised services. Hospitals might be paid a surcharge for providing these forms of specialised care. We also find substantial variation in the average cost of treatment across the hospital sector, due neither to the provision of specialised care nor to other characteristics of each hospital's patients.