Heterogeneity among hospitals statewide in percentage shares of the annual growth of surgical caseloads of inpatient and outpatient major therapeutic procedures.

STUDY OBJECTIVE: Suppose that it were a generalizable finding, in both densely populated and rural states, that there is marked heterogeneity among hospitals in the percentage change in surgical caseload and/or in the total change in caseload. Then, individual hospitals should not simply rely on federal and state forecasts to infer their expected growth. Likewise, individual hospitals and their anesthesiology groups would best not rely on national or US regional surgical trends as causal reasons for local trends in caseload. We examined the potential utility of using state data on surgical caseload to predict local growth by using 6 years of data for surgical cases performed at hospitals in the States of Florida and Iowa.

DESIGN: Observational cohort study.

SETTING: 303 hospitals in Iowa and Florida.

MEASUREMENTS: Cases with major therapeutic procedures in 2010 or 2011 were compared pairwise by hospital with such cases in 2015 and 2016. Changes in counts of cases were decreases or increases, while study of growth set decreases equal to zero.

MAIN RESULTS: Hospitals in Iowa had slightly lesser percentage changes than did hospitals in Florida (Mann-Whitney P = 0.016). Hospitals in Iowa had greater variability among hospitals in the change in counts of cases with a major therapeutic procedure than did hospitals in Florida (P < 0.0001). The 10% of hospitals with the largest growths in counts of cases accounted for approximately half of the total growth in Iowa (70%) and Florida (54%). The large share of total growth attributable to the upper 10th percentile of hospitals was not caused solely by the hospitals having large percentage growths, based on there being weak correlation between growth and percentage growth, among the hospitals that grew (Iowa: Kendall's tau = 0.286 [SE 0.120]; Florida tau = 0.253 [SE 0.064]).

CONCLUSIONS: Even if the data from states or federal agencies reported growth in surgical cases, there is too much concentration of growth at a few hospitals for statewide growth rates to be useful for forecasting by individual hospitals and anesthesiology groups.