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Augmenting the National Hospital Care Survey (NHCS) Data through Linkages with Administrative Records: A Project

Leverage the Power of Administrative Data Resources and Accelerate Integration of Multiple Data Sources to Support Program Evaluation and Public Health Surveillance
  • Centers for Disease Control and Prevention (CDC)
Start Date
  • 6/1/2019
  • Linking of Clinical and Other Data for Research


STATUS: Active Project


The National Hospital Care Survey (NHCS), conducted by the National Center for Health Statistics (NCHS), is designed to provide accurate and reliable health care statistics, describing national patterns of health care delivery in hospital-based settings, including prevalence of conditions, health status of patients, and health services utilization. The NHCS collects patient-level identifiers which enables linkage of patient episodes of care within hospital inpatient and outpatient settings to other administrative data sources, providing a more complete picture of patient care. Previously funded OS-PCORTF projects have linked the NHCS to death certificate information collected from the National Death Index (NDI), creating a new unique data resource to support the study of post hospitalization mortality outcomes in more than 3.2 million patients.

This project will expand on previously funded OS-PCORTF projects that increased the capacity of the NHCS to support a wide range of OS-PCORTF research objectives. This project will link the 2016 NHCS with Medicare Fee-for-Service claims data collected from Centers for Medicare & Medicaid Services (CMS) and federal housing assistance program data collected from the U.S. Department of Housing and Urban Development (HUD). The files will include unique patient identifiers, which will make it possible to link together information on mortality, health care service utilization, prescription drug use, facility based patient health assessments, and receipt of federal housing with a given patient’s hospital administrative claims and electronic health records (EHRs). The linkage between the NHCS to CMS and HUD data sources will expand data capacity to support research studies focused on a wide range of patient health outcomes including initiatives targeting opioid use and mental health care services, efficacy of treatment protocols and drugs, medical interventions and drugs, health outcomes associated with different types of post-acute care services, and disparities in efficacy by critical and previously unexamined subpopulations. The linked data sources will allow researchers to examine the role of federal social support programs in health outcomes, treatment efficacy for persons with stable housing, with the ability to focus on specific subpopulations, including persons with substance use disorders.


The project focused on the following four objectives

  • Conduct a patient-level record linkage of the 2016 NHCS hospital administrative claims and EHR data to 2016/2017 CMS Medicare claims data.

  • Conduct a patient-level record linkage of the 2016 NHCS hospital administrative claims and EHR data to the 2016/2017 HUD administrative records on federal housing program participation.

  • Refine probabilistic matching algorithms and disseminate detailed statistical methodology report to support high quality future data linkage activities within and beyond the patient-centered outcomes research (PCOR) community.

  • Create research files and user guidance documents to support PCOR researchers in using the new NHCS linked data resources. The linked data sets will be available through the NCHS Research Data Center and the documentation be made available via NCHS website.

  • Disseminate tools and training data, and lessons learned to stimulate the application of these methods to a wider array of use cases by PCOR researchers.