Breast cancer treatment across health care systems: Linking electronic medical records and state registry data to enable outcomes research

Abstract

Background Understanding of cancer outcomes is limited by data fragmentation. We analyzed the information yielded by integrating breast cancer data from three sources: electronic medical records (EMRs) of two healthcare systems and the state registry. Methods We extracted diagnostic test and treatment data from EMRs of all breast cancer patients treated from 2000–2010 in two independent California institutions: a community-based practice (Palo Alto Medical Foundation) and an academic medical center (Stanford University). We incorporated records from the population-based California Cancer Registry (CCR), and then linked EMR-CCR datasets of Community and University patients. Results We initially identified 8210 University patients and 5770 Community patients; linked datasets revealed a 16% patient overlap, yielding 12,109 unique patients. The proportion of all Community patients, but not University patients, treated at both institutions increased with worsening cancer prognostic factors. Before linking datasets, Community patients appeared to receive less intervention than University patients (mastectomy: 37.6% versus 43.2%; chemotherapy: 35% versus 41.7%; magnetic resonance imaging (MRI): 10% versus 29.3%; genetic testing: 2.5% versus 9.2%). Linked Community and University datasets revealed that patients treated at both institutions received substantially more intervention (mastectomy: 55.8%; chemotherapy: 47.2%; MRI: 38.9%; genetic testing: 10.9%; p<0.001 for each three-way institutional comparison). Conclusion Data linkage identified 16% of patients who were treated in two healthcare systems and who, despite comparable prognostic factors, received far more intensive treatment than others. By integrating complementary data from EMRs and population-based registries, we obtained a more comprehensive understanding of breast cancer care and factors that drive treatment utilization.

Use of and Mortality After Bilateral Mastectomy Compared With Other Surgical Treatments for Breast Cancer in California, 1998-2011

“…By contrast, patterns of bilateral mastectomy use suggest that affluent non-Hispanic white women, women of high SES, or both seek more aggressive preventive care, consistent with reported associations between greater use of expensive diagnostic tests (such as breast MRI and genetic testing) and bilateral mastectomy within this patient subgroup. 4,31 …”

“…Proposed explanations include the increasing use of highly sensitive breast magnetic resonance imaging, with increases in anxiety-producing recall and biopsy rates that may drive patients to undergo preventive surgery, 6,31,32 and the dissemination of genetic testing, which facilitates identification of high-risk patients who benefit from bilateral mastectomy. 7,8,33 Although fear of cancer recurrence may prompt the decision for bilateral mastectomy, such fear usually exceeds the estimated risk.…”

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“…Our work was motivated by a previously published study investigating choices in breast cancer care [13]. This dataset was created from electronic medical records of two independent institutions: an academic medical center and a large multi-site community practice with data sources from institutional and state cancer registries.…”

Evaluation of Relational and NoSQL Approaches for Cohort Identification from Heterogeneous Data Sources in the National Sleep Research Resource

“…It is important for clinical trial recruitment [2], outcomes research [3] and other research studies [4,5]. However, the process of identifying patient cohorts can be challenging and expensive when the patient data come from heterogeneous sources.…”