MedlinePlus Connect: 10 Years of Linking Electronic Health Records to Consumer Health Information

Guest post by Jennifer Jentsch, MLS, Project Manager, MedlinePlus Connect, National Library of Medicine

NLM is celebrating the 10^th anniversary of MedlinePlus Connect, a free service that links electronic health records (EHRs), patient portals, and other health IT systems to relevant, authoritative, and up-to-date health information from NLM’s MedlinePlus health information resource and other NIH websites. A look back over the past 10 years highlights opportunities that came together to create this successful NLM resource.

Development of MedlinePlus Connect

We know that having access to information empowers people. When it comes to a person’s health, information is fundamental in helping people learn about their conditions, medications, and treatment options, and helps them make more informed decisions about their health. We also know that to facilitate this understanding, health care professionals need to point the people they treat to trusted, accurate health information that is easy to understand. Quality information is an essential component of quality health care.

With the release of the MedlinePlus and MedlinePlus en español websites in the late 1990s, NLM quickly became a trusted source of quality online health information for the public. A decade later, a new health information need began to emerge. Health care providers were rapidly transitioning from paper health records to EHRs. The EHR system itself became a new platform for the delivery of health education, where both patients and providers could easily access explanatory resources about a diagnosis, medication or medical test. The sharing of trusted health information between provider and patient was migrating to an entirely electronic, yet personalized, environment.

In these emerging EHR systems, NLM saw an opportunity to leverage the rich resources of MedlinePlus and serve the public in a new way.   

The idea became reality with the launch of MedlinePlus Connect in 2010. NLM used the expertise of staff in data science, medical code systems, health data standards, and information technology to build this innovative service. The team created an Application Programming Interface (API) to seamlessly bring the rich consumer health resources of the MedlinePlus and MedlinePlus en español websites directly into EHRs. Tens of thousands of pages about diseases and conditions, medications and lab tests were now accessible for use in a new way. 

How It Works

MedlinePlus Connect is a free web application and web service that does not require registration to use. It works by accepting specific requests from EHR systems in a customized HTTPS format and responds with links to relevant information.

In the course of patient care, health care professionals assign medical codes for particular diagnoses, tests, procedures, and medications to the health records of patients. MedlinePlus Connect uses these codes to provide patient-specific health information to the EHR system.

As part of NLM’s commitment to health data standards, MedlinePlus Connect uses standard medical code systems like SNOMED and LOINC, and adheres to the Infobutton standard. To facilitate the connection with EHRs, NLM staff create “mappings” (or associations) between MedlinePlus content and standard medical coding systems used in EHRs. Today, MedlinePlus Connect supports half a dozen major code systems for diagnoses, medications, procedures, and medical tests, including ICD-9-CM, ICD-10-CM, SNOMED, and RxNorm.

MedlinePlus Connect Today and into the Future

Since its launch, MedlinePlus Connect has been employed by a wide array of users, including large and small EHR systems, health care networks and organizations, hospital systems, and mobile applications. The API has grown significantly in usage, in content, and in code mappings. (See our timeline infographic for important developments over the past 10 years.)

Today, MedlinePlus Connect provides a robust service that can easily respond to more than 171,000 medical codes with relevant health information.  In 2020, MedlinePlus Connect received 252 million code requests from external systems.

An exciting new initiative is the integration of consumer health information from other NIH Institutes and Centers (ICs). In 2018, MedlinePlus Connect piloted a collaboration with the National Institute of Diabetes and Digestive and Kidney Diseases. The success of this collaboration led to the participation of two additional NIH Institutes: the National Institute on Aging and the National Cancer Institute . NLM is working with other NIH ICs in this effort to expand the scope of content in MedlinePlus Connect.

The next major development will be the addition of Current Procedural Terminology (CPT®) codes from the American Medical Association to expand access to information about medical procedures.

As MedlinePlus Connect enters a new decade, we can’t help but reflect on how the goals behind the service remain very much the same as they were when this service launched:  to deliver health information to the public in new and innovative ways, to reduce barriers in information access, and to support quality health care everywhere.

Interested in learning how to implement MedlinePlus Connect?  Read our documentation and contact us with questions. Sign up for the MedlinePlus Connect email list to keep up with developments and exchange ideas with other users.