Effects of hospitals' structural clinical integration on efficiency and patient outcome.

The objective of this study was to examine the relationships among structural clinical integration, average total charge, and adverse patient outcomes. The conceptual framework of this study is based on Donabedian's triadic model for outcomes research on structure, process, and outcome. Retrospective data were obtained from multiple sources: (1) the American Hospital Association (AHA) annual survey in 1997; (2) the Area Resource File (ARF) data set in 1997; (3) the Dorenfest IHDS + database (version 2); and (4) the National Inpatient Sample (NIS) data set in 1997. A cross-sectional study design was used. Outcomes indicators were risk-adjusted with logistic regression, and the Medicare case-mix index was used for the risk-adjustment of the efficiency indicator. LISREL (LInear Structural RELationship) was used to test the hypotheses that structural clinical integration is negatively related to average total charge, and that average total charge is positively related to adverse patient outcomes. The risk-adjustment models were successful in discriminating the patients who suffered adverse events. Significant associations were found between structural clinical integration and average total charge per admission, between average total charge per admission and surgical complication, and between surgical complication and in-hospital death. However, the implementation of structural clinical integration did not show the expected reduction in total charge per admission. This study confirms Donabedian's model for outcomes research. However, the study found that hospitals with highly integrated structures showed no immediate financial benefit. Structural clinical integration has only an indirect effect on patient care outcomes.