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Multicenter Study
. 2012 Nov-Dec;19(6):965-72.
doi: 10.1136/amiajnl-2011-000782. Epub 2012 Jul 3.

Patient characteristics associated with venous thromboembolic events: a cohort study using pooled electronic health record data

David C Kaelber  1 , Wendy Foster, Jason Gilder, Thomas E Love, Anil K Jain
Affiliations
Multicenter Study

Patient characteristics associated with venous thromboembolic events: a cohort study using pooled electronic health record data

David C Kaelber et al. J Am Med Inform Assoc. 2012 Nov-Dec.

Abstract

Objective: To demonstrate the potential of de-identified clinical data from multiple healthcare systems using different electronic health records (EHR) to be efficiently used for very large retrospective cohort studies.

Materials and methods: Data of 959 030 patients, pooled from multiple different healthcare systems with distinct EHR, were obtained. Data were standardized and normalized using common ontologies, searchable through a HIPAA-compliant, patient de-identified web application (Explore; Explorys Inc). Patients were 26 years or older seen in multiple healthcare systems from 1999 to 2011 with data from EHR.

Results: Comparing obese, tall subjects with normal body mass index, short subjects, the venous thromboembolic events (VTE) OR was 1.83 (95% CI 1.76 to 1.91) for women and 1.21 (1.10 to 1.32) for men. Weight had more effect then height on VTE. Compared with Caucasian, Hispanic/Latino subjects had a much lower risk of VTE (female OR 0.47, 0.41 to 0.55; male OR 0.24, 0.20 to 0.28) and African-Americans a substantially higher risk (female OR 1.83, 1.76 to 1.91; male OR 1.58, 1.50 to 1.66). This 13-year retrospective study of almost one million patients was performed over approximately 125 h in 11 weeks, part time by the five authors.

Discussion: As research informatics tools develop and more clinical data become available in EHR, it is important to study and understand unique opportunities for clinical research informatics to transform the scale and resources needed to perform certain types of clinical research.

Conclusions: With the right clinical research informatics tools and EHR data, some types of very large cohort studies can be completed with minimal resources.

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Conflict of interest statement

Competing interests: DCK is the Chief Medical Informatics Officer of the MetroHealth System, which is an early participant in the Explorys network. Neither DCK nor the MetroHealth System has any direct financial ties to Explorys Inc. In exchange for contributing de-identified data to the Explorys network, the MetroHealth System receives access to the Explorys Population Explorer tool, which was used to conduct this study. JG and WF are Explorys employees who participated in this research and did not receive additional compensation for this study. AJ is the Senior-Vice President and Chief Medical Information Officer of Explorys Inc. and in addition to receiving salary, holds a financial interest in Explorys Inc. TL has no financial ties to Explorys Inc. None of the authors received funding directly to support this study.

Figures

Figure 1
Figure 1
High level schematic of clinical information system (including electronic health records) integration through Explorys, Inc. HDG, health data gateway; LOINC, logical observation identifiers names and codes; SNOMED, systematized nomenclature for medicine. Figure used with permission from Explorys, Inc.
See this image and copyright information in PMC

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References

    1. Jha AK, DesRoches CM, Campbell EG, et al. Use of electronic health records in U.S. hospitals. N Engl J Med 2009;360:1628–38 - PubMed
    1. DesRoches CM, Campbell EG, Rao SR, et al. Electronic health records in ambulatory care—a national survey of physicians. N Engl J Med 2008;359:50–60 - PubMed
    1. Blumenthal D, Tavenner M. The “meaningful use” regulation for electronic health records. N Engl J Med 2010;363:501–4 - PubMed
    1. Embi PJ, Payne PR, Kaufman SE, et al. Identifying challenges and opportunities in clinical research informatics: analysis of a facilitated discussion at the 2006 AMIA Annual Symposium. AMIA Annu Symp Proc 2007:221–5 - PMC - PubMed
    1. United States Congress Health Insurance Portability and Accountably Act of 1996. 104th Congress, 1st Session. Public Law 104-191. Washington: GPO, 1996. Print.

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