Electronic health records (EHRs), administrative claims databases, and other patient data are important sources of healthcare information that can be used for research. However, they live in separate systems, which means researchers typically can’t easily combine insights to understand a complete picture of the patient experience. These sources also contain sensitive information that must be protected. To address this challenge, PCORnet leaders have embraced a technique called privacy-preserving record linkage (PPRL) to link records from different databases while protecting the privacy of patients.

But why should patients care about PPRL? Here are five key ways the implementation of PPRL in PCORnet will bring meaningful benefits to patients:

1. Maintaining the highest protection of patient privacy: PPRL uses unique codes, such as numbers, to represent sensitive data. This ensures that patients can rest easy knowing that linking these data sources will not compromise to their confidential data, given that data is anonymized and de-identified before it is ever used in research.
2. Improved data accuracy: PPRL helps to improve the accuracy of patient data by matching records across different databases, eliminating duplicates and ensuring that the most up-to-date information is used in research. For patients, that means that results from research powered by PCORnet will be even more reliable than they are to date.
3. Findings that more fully reflect the population: PPRL enables PCORnet researchers to access a larger and more diverse set of patient data, leading to more comprehensive and robust research findings. Patients should feel confident that research results hold true for people who share their race, ethnicity or background. PPRL helps capture that diversity.
4. Better decision making: PPRL helps to improve decision making by providing a more complete picture of patients’ health experiences, as data from multiple sources can be linked and analyzed. As a result, gaps in our understanding are reduced, leading to more comprehensive assessments and informed care choices.
5. A gateway to precision healthcare: PPRL helps researchers tap into much broader data so we can understand the nuance across different populations and settings. When that nuanced data is combined with sophisticated analytic models, it can help us deliver healthcare in a very precise and personalized way. That means clinicians can potentially diagnose patients earlier, tailor therapies to the individual and better manage chronic conditions.

“As patients, we know our lived experience is so much richer and more diverse than what is depicted in a single electronic health record,” said Greg Merritt, patient partner for PCORnet. “I am really excited about the promise of PPRL to unlock some of that rich detail so that clinicians can partner with patients like me, do research that will protect my privacy, ask meaningful research questions, and ultimately, find the course of treatment that is actually for me—not just my EHR.”

Want to learn more about PPRL in PCORnet? Check out this recent article.

Two recent manuscripts published in the journal BMC Research Notes and JAMIA describe the framework and implementation of a new method of connecting patient data across disparate healthcare ecosystems in PCORnet while maintaining the highest levels of privacy and security. Privacy-preserving record linkage, or PPRL, connects electronic health records (EHRs) and administrative claims databases, unlocking the ability to fill important gaps in data, while still making sure the private information of the individual stays protected.

“There’s a growing appreciation for the fact that traditional health systems are not the only places where important information about our overall health resides,” said Tom Carton, who co-led the PPRL Implementation Workgroup for PCORnet. “PPRL is a method that allows us to fill these gaps in data while maintaining the highest privacy standards so we can better understand what is driving good or bad health outcomes.”

How PPRL works

PPRL has been used as an encryption technique since the 1990s in the computer science community, but only recently has it made the jump to healthcare. The method involves a technique called hashing to create an irreversible and unique code (such as a number) given a set of inputs, like patient demographics or first and last names. These codes allow researchers to link patient records across data sources in a way that is compliant with HIPAA, the Health Insurance Portability and Accountability Act. As a result, users of PCORnet can now assign a universal patient identifier code across multiple datasets from PCORnet Partner Networks without compromising any personal information.

“PPRL is going to bring tremendous value by solving two key problems that currently plague large-scale research,” said Keith Marsolo, co-lead of the PPRL Implementation Workgroup for PCORnet. “First, it will allow users to flag and de-duplicate records across multiple datasets, meaning that people who get care from multiple health systems in the same geography will be more accurately counted. And second, it will allow us to much more easily link EHRs and claims data sets across PCORnet, providing a more complete picture of patients’ health experiences.”

The current state of PPRL in PCORnet

The PCORnet PPRL Implementation Workgroup successfully demonstrated the ability to use PPRL to identify overlap across approximately 170 million patient records accessible via PCORnet; they also created a de-duplicated summary of demographic and clinical characteristics for patients from 61 Partner Networks. This project, which was one of the largest linkage efforts of its kind in the U.S., enables current and future studies—including several PCORnet rare disease studies—to benefit from connected insights across EHR claims, and patient reported data.

“This is an exciting advance for researchers and patients alike,” said Marsolo. “With PPRL in place, meaningful research can proceed uninhibited by gaps in understanding with zero sacrifice to patient privacy and security. It’s a win-win.”