A cross-sectional retrospective analysis of the regionalization of complex surgery

BACKGROUND: The Veterans Health Administration (VHA) system has assigned a surgical complexity level to each of its medical centers by specifying requirements to perform standard, intermediate or complex surgical procedures. No study to similarly describe the patterns of relative surgical complexity among a population of United States (U.S) civilian hospitals has been completed. METHODS: Design: single year, retrospective, cross-sectional. Setting/Participants: the study used Florida Inpatient Discharge Data from short-term acute hospitals for calendar year 2009. Two hundred hospitals with 2,542,920 discharges were organized into four quartiles (Q 1, 2, 3, 4) based on the number of complex procedures per hospital. The VHA surgical complexity matrix was applied to assign relative complexity to each procedure. The Clinical Classification Software (CCS) system assigned complex procedures to clinically meaningful groups. For outcome comparisons, propensity score matching methods adjusted for the surgical procedure, age, gender, race, comorbidities, mechanical ventilator use and type of admission. Main Outcome Measures: in-hospital mortality and length-of-stay (LOS). RESULTS: Only 5.2% of all inpatient discharges involve a complex procedure. The highest volume complex procedure hospitals (Q4) have 49.8% of all discharges but 70.1% of all complex procedures. In the 133,436 discharges with a primary complex procedure, 374 separate specific procedures are identified, only about one third of which are performed in the lowest volume complex procedure (Q1) hospitals. Complex operations of the digestive, respiratory, integumentary and musculoskeletal systems are the least concentrated and proportionately more likely to occur in the lower volume hospitals. Operations of the cardiovascular system and certain technology dependent miscellaneous diagnostic and therapeutic procedures are the most concentrated in high volume hospitals. Organ transplants are only done in Q4 hospitals. There were no significant differences in in-hospital mortality rates and the longest lengths of stay were found in higher volume hospitals. CONCLUSIONS: Complex surgery in Florida is effectively regionalized so that small volume hospitals operating within the range of complex procedures appropriate to their capabilities provide no increased risk of post surgical mortality.