The HMO Research Network (HMORN) Virtual Data Warehouse (VDW) is a public, non-proprietary, research-focused data model implemented at 17 health care systems across the United States. The HMORN has created a governance structure and specified policies concerning the VDW’s content, development, implementation, and quality assurance. Data extracted from the VDW have been used by thousands of studies published in peer-reviewed journal articles. Advances in software supporting care delivery and claims processing and the availability of new data sources have greatly expanded the data available for research, but substantially increased the complexity of data management. The VDW data model incorporates software and data advances to ensure that comprehensive, up-to-date data of known quality are available for research. VDW governance works to accommodate new data and system complexities. This article highlights the HMORN VDW data model, its governance principles, data content, and quality assurance procedures. Our goal is to share the VDW data model and its operations to those wishing to implement a distributed interoperable health care data system.

Health Affairs, 31, no.9 (2012):2094-2104 doi: 10.1377/hlthaff.2011.0686 The online version of this article, along with updated information and services, is available at

BackgroundDiagnostic test sets are a valuable research tool that contributes importantly to the validity and reliability of studies that assess agreement in breast pathology. In order to fully understand the strengths and weaknesses of any agreement and reliability study, however, the methods should be fully reported. In this paper we provide a step-by-step description of the methods used to create four complex test sets for a study of diagnostic agreement among pathologists interpreting breast biopsy specimens. We use the newly developed Guidelines for Reporting Reliability and Agreement Studies (GRRAS) as a basis to report these methods.MethodsBreast tissue biopsies were selected from the National Cancer Institute-funded Breast Cancer Surveillance Consortium sites. We used a random sampling stratified according to woman’s age (40–49 vs. ≥50), parenchymal breast density (low vs. high) and interpretation of the original pathologist. A 3-member panel of expert breast pathologists first independently interpreted each case using five primary diagnostic categories (non-proliferative changes, proliferative changes without atypia, atypical ductal hyperplasia, ductal carcinoma in situ, and invasive carcinoma). When the experts did not unanimously agree on a case diagnosis a modified Delphi method was used to determine the reference standard consensus diagnosis. The final test cases were stratified and randomly assigned into one of four unique test sets.ConclusionsWe found GRRAS recommendations to be very useful in reporting diagnostic test set development and recommend inclusion of two additional criteria: 1) characterizing the study population and 2) describing the methods for reference diagnosis, when applicable.

PURPOSEThe patient-centered medical home (PCMH) is being rapidly deployed in many settings to strengthen US primary care, improve quality, and control costs; however, evidence supporting this transformation is still lacking. We describe the Group Health experience in attempting to replicate the effects on health care use seen in a PCMH prototype clinic via a systemwide spread using Lean as the change strategy. METHODSWe used an interrupted time series analysis with a patient-month unit of analysis over a 4-year period that included baseline, implementation, and stabilization periods for 412,943 patients. To account for secular trends across these periods, we compared changes in use of face-to-face primary care visits, emergency department visits, and inpatient admissions with those of a nonequivalent comparison group of patients served by community network practices. RESULTSAfter accounting for secular trends among network patients, patients empaneled to the PCMH clinics had 5.1% and 6.7% declines in primary care offi ce visits in early and later stabilization years, respectively, after the implementation year. This trend was accompanied by a 123% increase in the use of secure electronic message threads and a 20% increase in telephone encounters. Declines were also seen in emergency department visits at 1 and 2 years (13.7% and 18.5%) compared with what would be expected based on secular trends in network practices. No statistically signifi cant changes were found for hospital admissions.CONCLUSIONS The Group Health experience shows it is possible to reduce emergency department use with PCMH transformation across a diverse set of clinics using a clear change strategy (Lean) and suffi cient resources and supports.Ann Fam Med 2013;11:S19-S26. doi:10.1370/afm.1476. INTRODUCTIONO n the basis of convincing evidence that strong primary care is associated with lower costs and improved quality of care, 1 there is a rapid move to implement the patient-centered medical home (PCMH) across the United States in various settings including independent practices, integrated delivery systems, community health centers, and large government systems. [2][3][4][5] Although these demonstration initiatives share the PCMH guiding principles, 6 they differ considerably with respect to their settings, organizational structures, payer participation, intervention components, and implementation strategies. 2,7 Early results are promising, 8,9 but more extensive and rigorous evaluations are needed. [8][9][10][11] As substantial infrastructure investments are often required to build medical home capabilities, 12 policy makers and health plan leaders are particularly interested in whether and when adoption of this model results in overall cost savings. Since 2006, Group Health Cooperative, a large nonprofi t, consumer-governed, integrated health insurance and care delivery system in the Pacifi c Northwest, has pioneered the medical home redesign. In contrast to small independent practices in the United States, Group Health has traditi...