Results Summary

What was the project about?

Patients get care at different places, such as doctors’ offices, hospitals, and pharmacies. Linking patients’ data from these places can help researchers get complete information for each patient for use in studying patient health.

Researchers can use two types of methods to help link patient records based on personal data like names and dates of birth. The first type, known as deterministic, is simpler to use. The second type, known as probabilistic, uses complex computer programs that take longer to work and haven’t been studied as much. But when errors exist in the data, probabilistic methods may work better.

In this project, the research team wanted to learn more about the accuracy of deterministic and probabilistic methods for linking patient records.

What did the research team do?

The research team used four data sets of linked records:

  • Newborn screening registry records linked to hospital and clinic health records
  • Patient records from different hospitals
  • Patient records from public health registries
  • Patient death records linked to health records

The research team manually reviewed some records from each data set to check if they were linked correctly. Using only the records that were linked correctly, the team created four reference data sets.

Then, the research team used each linkage method to link individual patient records from the reference data sets one more time. The team compared the linkage results from each method to the reference data sets to see which method was more accurate.

Patients, a patient representative, and other community members helped design the study.

What were the results?

Overall, the probabilistic method was more accurate than the deterministic method. It led to better accuracy in all four data sets.

What were the limits of the project?

The research team didn’t check if one method worked better than the other across different racial and ethnic groups.

Future research could look at how the methods work with records from patients of different racial and ethnic backgrounds.

How can people use the results?

Researchers can use probabilistic linkage methods to link patient records.

Final Research Report

View this project's final research report.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study. 

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments.   

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following: 

  • The reviewers noted that while this methods-focused project was executed well, the report was hard to follow and contained a number of concepts and statistical approaches that would not be known to the average scientific audience. The researchers revised their report to include more summaries and examples to better describe the research to scientists who were not experts in this field.  
  • The reviewers requested additional information on the engagement activities for this highly technical project. In particular, they asked the researchers to provide more detail about the focus groups they employed to better understand the aspects of privacy-preserving record linkage (PPRL) that patients found most concerning and most important, and to help develop educational materials that could inform other patients about PPRL. The researchers added details about the topics discussed at the focus groups and how they used the findings from these groups.  

Conflict of Interest Disclosures

Project Information

Shaun Grannis, MD, MS
Indiana University
Advancing Privacy-Preserving Record Linkage Methods in the Context of Real-World Data Networks & HIE

Key Dates

November 2017
April 2023

Study Registration Information


Has Results
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Last updated: April 15, 2024