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 par-ticipating 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 be-ing investigated. The PSOCS data set includes more than 1,100 variables re-lated to each patient and more than 300 variables related to provider-specific and facility-specific characteristics. This massive data set presents a formida-ble 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 subhy-potheses, 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 ac-tions (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.