[The public-private mix in hospital care in the Lombardy region]

1) to compare complexity and severity of the case-mix in the public and private sector, overall and across individual hospitals, and to examine their relative efficiency, by contrasting DRG and/or stage specific average length of stay (ALOS); 2) to assess the impact of a new contractual scheme based on a preassigned number of beddays for a restricted list of specific conditions.

Discharge data on 940.670 admissions to 101 public hospitals and 185.161 admissions to 55 private hospitals in the Regione Lombardia in 1990, assigned to HCFA-DRGs, 8th version and to stages and substages of principal and unrelated diagnostic categories, based on Disease Staging.

The spread of the case-mix is higher in the private sector, which also shows a higher concentration of admissions across hospital for specific medical and surgical conditions. The proportion of more advanced stages of disease is higher in the public sector, for most of the most frequent diagnostic categories. Obstetric care, including abortion, is the largest single public sector activity, while it is virtually not existent in the private sector. Elective surgical procedures, including ENT, cataract and varicose veins surgery make up a substantial proportion of the private hospitals' case load. DRGs-specific ALOS is longer in public hospitals for the most frequent surgical DRGs, mainly due to their preoperative LOS. The net impact of the proposed contractual scheme will save substantial proportion of beddays for most of the conditions considered, except cataract and varicose veins surgery.