EHR Networks

Zus participates in two of the major national EHR networks - CommonWell Health Alliance and Carequality. These non-profit organizations facilitate the exchange of clinical information amongst participating healthcare providers, often implemented by their EHR. Collectively, these networks represent 75,000+ provider sites, 270M+ patients, and are connected to major EHRs such as Epic, Cerner, eClinicalWorks, Allscripts, athenahealth, and many others.

This page describes how Zus's connections to these networks function. For more information about pre-requisites to participate in exchange, see our Network Requirements section.

Record location on EHR networks

Our approach to record location varies based on how each network operates.

CommonWell

CommonWell maintains a central master person index (MPI) and that tracks which participants have registered a patient and routes requests to those participants when it receives a request matching the patient's demographics. When querying CommonWell, Zus relies on this MPI to find records.

Carequality

Carequality maintains a directory of endpoints with addresses for the contributing locations. Requesters querying Carequality are expected to already know where a patient has received care or make their best guess as to where the patient might have records. Zus does this in a variety of ways:

• We search in a radius around the patient's address and vary the radius we use based on regional density (tight for cities, broad for rural areas)
• We search across all known patient addresses, past and present, and expand as new ones are discovered.
• We always query network participants that act as gateways to other facilities
• We incorporate signal that a patient has received care at a specific location:
  • Facilities where the patient has been seen before, reinforced by national ADT data
  • Prescribing provider locations using nationwide medication data
  • Inbound requests from other network participants
• Based on customer input, we configure our record locator to target your referral partners and priority sites with every request

Missing records

Despite all of this targeting, you may still find yourself missing records for a particular patient or encounter. Common reasons for missing data include:

• A facility may not be listed on one of the national networks. In general, we see the most robust participation from large hospital systems and multispecialty groups. Smaller clinics and behavioral health providers tend to have lower participation rates depending on their EMRs and technology vendors
• A patient may have received care at a "restricted" department that requires a special consent on file in order to respond to queries. Responding facilities set their own rules about which departments and records require additional consents
• A patient may have opted out of record sharing altogether
• Facilities set their own rules and defaults for how much data they make available through the networks. A site may be defaulting to only respond with the last two years of data
• A facility might be transitioning EMRs or interoperability vendors
• (Less common) Zus may have failed to target a site where your patient received care. We are working continuously to close such gaps and give you more control over records requests.

Data from EHR networks

Data is exchanged on these networks in a document format. The vast majority of documents we retrieve are CCDAs, but we also handle PDFs and images. Zus stores the raw document, and also translates the underlying structured content into a rich set of FHIR resources. The resource types generated today are:

The underlying CDA documents are available through the following resource types:

• Binary
• DocumentReference
• Provenance