Getty Images

What to Look for in Application Programming Interfaces?

Interoperability, increased detail, accuracy, and timeliness are critical for application programming interface (API) developers and consumers.

Although EHR adoption is becoming more widespread throughout the healthcare industry, interoperability and patient data sharing still pose significant challenges to providers. To address those challenges, the healthcare industry can adopt application programming interfaces (APIs) that other industries, such as finance and travel, have already implemented.

APIs are utilized each and every day by individuals around the world.

APIs allow travel services to compare flights from separate airlines without the user visiting each website. Also, each time an individual checks the weather on her phone or sends a direct message, she is utilizing an API.   

In March 2020, the Office of the National Coordinator for Health Information Technology (ONC) deployed its most current phase of the 21st Century Cures Act, the interoperability rule.

While the ONC final rule aims to eliminate information blocking, it also requests that healthcare providers and health IT developers promote patient data access by way of third-party applications and APIs.

“The ONC interoperability rules will advance interoperability so that patients and clinicians have greater access to data,” Ben Moscovitch, project director of health information technology at Pew Charitable Trusts, said in an interview with EHRIntelligence.

“The ONC got the API portions right. That's because the elements of the final rule will standardize API. Specifically, ONC requires that API use FHIR Release 4, which is the newest version of the FHIR Standard. The rules will also create implementation guides for FHIR.”

ONC proposed to adopt the HL7 Fast Healthcare Interoperability Resources (FHIR) standard as a foundational standard and requested comment on four options to determine the best version of FHIR to adopt. In the end, ONC adopted FHIR Release 4.

“The advantage in the API enabled app world is the patients have their data, then they decide if they want it to be used for research or other purposes they may want, as opposed to finding an efficient way for patients to consent for data to be used by researchers,” explained ONC in a 2020 API report.


Although APIs can be valuable, health IT experts still face integration and usability challenges. Thus, standardized methods to improve patient data exchange through separate health IT systems and mobile apps are a necessity.

“If standard APIs were broadly adopted in health care, patients could access and compile their data from multiple providers while clinicians could process complicated information and make care recommendations,” Moscovitch said in January 2021. “APIs would also offer other benefits, such as facilitating the exchange of clinical data among health care providers.”

Along with reducing the amount of time that consumers spend obtaining their respective data, anonymous healthcare stakeholders noted four key characteristics that app developers should focus on in a 2020 ONC report:

  • Interoperability
  • Detail
  • Accuracy
  • Timeliness

Respondents said developers need to combine data from claims, consumers, and EHRs to standardize this data to make it interoperable.

“In the future, participants can be the conduit [for all data sources] and there will be one comprehensive record,” said an anonymous stakeholder.

Next, developers should provide detailed and educational information for users to maintain interest in the application.

“The information in your patient portal is like a ‘connect-the-dots,’ where you don’t know what it is,” explained a stakeholder. “Notes fill in the context and promote trust and deepen relationships with providers.”

In order to maintain trust between the consumer, provider, and developer, the data needs to be accurate and free from errors.

“In a lab, the microphone is 90% predictive of Parkinson’s, but in the real world, your dog is barking,” clarified an anonymous respondent. “For a thermometer reading of 101 degrees, it’s not the value but the trend that can matter.”

Lastly, real-time data provides more value than a regular hospital visit. The data needs to be updated consistently to uphold actionability and meaningfulness.

“I looked at Apple Health, and I can see my weight and blood pressure, but I have more access to blood pressure from my home health devices, as compared to the readings from my twice-a-year doctor’s appointments,” an anonymous respondent said.

Standardization, such as using the FHIR standard, could ensure easier API usability and access.

“FHIR can offer access to individual pieces of information—such as a list of medications—instead of a broader document containing more data, some of which might be unnecessary or patients may not wish to share,” Moscovitch said.


Patient access to data, patient data exchange, and integrating clinical decision support (CDS) tools for prescribing antibiotics are the leading API adoption benefits.

API adoption can give patients access to data. Patients can utilize APIs to track and manage their healthcare outside of the doctor’s office on their smartphone or computer.

Prior research revealed that when a patient could access her data, she reported great benefits. Those benefits were more salient among older people with lower educational attainment and lower English language proficiency. Patient access to data can engage the patient to ask further questions and process more information.

APIs can allow clinicians to pick and choose the needed or important patient information to exchange, rather than sending full clinical history

“Through FHIR, health care providers could send individual—or modular—pieces of data to one another,” Moscovitch explained. “For example, providers could send patients’ medication lists or their most recent care plans, instead of a broader document containing more data, some of which might be unnecessary or sensitive.”

Using APIs, providers can integrate applications into the EHR to give users a broader range of CDS tools that would allow the user to pick one that works best.

“Applications in use cited by interviewees helped with pediatric growth monitoring, diagnosing and managing pulmonary emboli, and forecasting for immunizations,” explained Moscovitch. “These applications can synthesize years of patient data in useful ways, transforming the health record from simply an information repository into a dynamic technology that offers benefits beyond the base system.”


Pew partnered with RTI International, a research institute, to further examine and assess current and future API uses by talking to health IT professionals.

The stakeholders said they most commonly utilized APIs for patient access and CDS. Some respondents even said they have not utilized APIs for other use cases, such as patient data exchange.

Next, Pew learned health IT vendors differ on the permitted data elements for patient data exchange. This variance impacts the type and amount of patient information that clinicians can exchange.  

For example, providers, EHR vendors, and third-party app developers don’t always include terms and conditions. Documents they exchange also do not always include critical details, such as costs, according to the respondents.

Last, the respondents said API use could improve by permitting EHR data entry, integrating applications into clinician workflow, and applying standardized data elements.

“Increased use of APIs—particularly those based on common adopted and consistently deployed standards—has the potential to make health care more efficient, lead to better care coordination, and give providers and patients additional tools to access information and ensure high-quality, efficient, safe, and value-based care,” Moscovitch concluded.

“Yet obstacles remain, such as some hospital hesitation to grant patient access to data, lack of bidirectional data exchange, confusion around the process of implementing APIs, and potentially prohibitive fee structures.”

Due to the spread of COVID-19, the 2015 edition health IT certification criteria updates and the new standardized API functionality dates are now required by December 31, 2022.

Next Steps

Dig Deeper on Interoperability in healthcare

Cloud Computing
Mobile Computing