“Network of networks (NN)” model for achieving NHIN and SHINs

The very need for the NN model is the belief that these networks can evolve independently yet be able to interconnect and interoperate. Just like the internet has basic constructs such as DNS, IP addressing etc at its core for achieving the NoN model, any NHIN should have similar set of basic constructs and open services to achieve the true goal of NN.

Any network of networks model needs to be built on the most fundamental architectural principle of separating physical layout of the network from the logical constructs that define the network. Physical network layout describes the physical characteristics such as how the servers, the IP network gear such as routers, VPN devices and IP firewalls that are components of this network are laid out. A Logical network is created by logically grouping a set of physical nodes and applying a set of technical policies to that group.  Various network services are associated with the different logical networks.

As an example, several RHIOs can each create a logical network and includes a national lab that has one physical node on the network. As an illustration, all SHINs are logical networks that includes all of the physical nodes in a given state as well as nodes that are national in scope however they participate in some role in a given state. Example of a national node would be Labcorp, which serves multiple states across the nation. Stony Brook University Hospital is an example of a node that has statewide scope. The SHIN for New York state should include nodes such as SBUH and Labcorp. The way to achieve that is to let each entity have its how physical servers yet allow these physical servers to be adminstratively grouped in a logical network called the SHIN - New York.

Ultimately, the NHIN is a logical collection of statewide networks i.e. the SHINs.

The concept of separation of physical layout from logical networks is the single most powerful concept in order to achieve the NHIN and SHINs. By using this construct the architecture is able to support the myriad of requirements that the NHIN and the SHINs bring forth. This is a truly path breaking model.

Figure: Each Physical Node in the bottom is a peer to the other physical nodes on the network. Each node provides a set of services. Each service can participate in one or more logical networks. This is the most fundamental principle by which the entire SHIN is constructed.

Illustrative Use Cases

The following examples illustrate various use cases that a network that complies with the above architecture can support.

Example 1: Physician accessing longitudinal clinical summary for a patient across the provider network.

Physical Nodes: Physician Practice (PP) Node; Other PP Nodes; Other Hospital Nodes

Services:  Master Patient Index; Peer to peer secure record location service (RLS)

Logical Network: Regional Health Information Network (e.g. e-Health Network of Long Island Network) owned and operated by RHIO

Example 2: Patient getting a copy of her lab test result from physician

Physical Nodes:  Physician Practice (PP) Node; PHR Node

Services:  Patient Generated Index; Peer to peer secure record transfer

Logical Network: SHIN-New York PHR owned and operated by RHIOs and NY State (as an example)

Example 3: Public Health getting a pseudo-anonymized lab result that tested positive for a reportable condition

Physical Nodes:  Lab Node; Universal Public Health (PH) Node (State level Department of Health)

Services:  Lab Result Public Health monitoring service; Peer to peer secure record transfer

Logical Network:  Suffolk RHIO operated RHIN; NY DOH operated PHIN

Article author: Prem Urali, CEO and CTO, HealthUnity Corp