Relationships between patient-related risk factors, processes, structures, and outcomes of cardiac surgical care. Conceptual models.

The processes, Structures, and Outcomes of Care in Cardiac Surgery (PSOCS) study involves data collection on a comprehensive array of patient risk factors, processes, structures, and short-term outcomes of care at 14 participating Veterans Administration medical centers. This article summarizes the PSOCS conceptual models that serve as the theoretical framework for analyzing the hypothesized risk-process-structure-outcome relationships being investigated. The PSOCS data set includes more than 1,100 variables related to each patient and more than 300 variables related to provider-specific and facility-specific characteristics. This massive data set presents a formidable analytic challenge. The conceptual modeling process involved four-steps: 1) establishing a vision of the general conceptual model defining the overall risk-process-structure-outcome relationships, 2) developing specific hypotheses or subhypotheses, 3) visualizing a hierarchical set of dimensions and subdimensions, and 4) uniquely assigning each variable collected in the study to a dimension or subdimension for purposes of testing the study's primary hypotheses. A multidisciplinary team participated in this modeling process. The goal of the conceptual modeling process is to identify clearly the actions (ie, the changes in either processes or structures that are linked to risk-adjusted patient outcomes) that can be taken by clinicians, management, and policymakers to improve the quality of cardiac surgical care.