bulk-match-provider

The Bulk Match Provider is an open-source reference implementation of the FHIR Bulk Match IG. Additionally, it offers a set of features designed to assist bulk match client developers. For instance, this server supports authentication-free usage, can simulate matches, and can proxy incoming match requests to external FHIR servers.

Installation

The Bulk Match Provider is available online but can also be installed locally. It requires NodeJS v20 or newer and a Unix-based OS such as macOS or Linux. We recommend using NVM for managing NodeJS versions.

To get the code and install it, follow these steps:

# Go to destination folder
cd /my/projects

# Get the source code
git clone https://github.com/smart-on-fhir/bulk-match-provider.git

# Go into the project root
cd bulk-match-provider

# auto-select node version (or make sure you are using NodeJS 20+ if you don't have NVM)
nvm use

# Install dependencies
npm i

# Start the server
npm start

Configuration

We use environment variables to configure the server. To create your own configuration, create a file named .env in the project root and declare your configuration variables there. Below is an example of all the supported variables along with their default values and comments. These variables are optional and only need to be used if you want to override their default values.

# Port number to run on. 0 means random port allocated by the OS
PORT=0

# Host or IP to listen on. "0.0.0.0" means the entire local network
HOST="0.0.0.0"

# Use this secret when signing our JWT tokens. Must be changed before running
# another instance.
SECRET="this is our patient matching secret"

# Max allowed access token lifetime in minutes
MAX_ACCESS_TOKEN_LIFETIME=60

# Keep jobs for how long (minutes since creation)
JOB_MAX_LIFETIME_MINUTES=60

# Check for old jobs once every ? minutes
JOB_CLEANUP_MINUTES=5

# MS to wait before matching each input patient. This is useful for slowing
# down matches to make them look more realistic, as well as to have a
# predictable durations while testing
JOB_THROTTLE=1000

# Throttle all http responses (mostly useful for development/testing)
THROTTLE=0

# If we reach this number more jobs cannot be started and clients will be
#  required to retry later after some jobs have (hopefully) completed
MAX_RUNNING_JOBS=100

After creating or updating the .env file, the server must be restarted to apply those changes.

Local Development

To run the server and the sample app locally, navigate to the project root folder and run:

nmp run dev

This command will:

• Delete previous builds of the sample app (if any)
• Start a hot reloading server for the app at http://localhost:3457/
• Start a reloading server for the backend at http://localhost:3456/. This one will also serve the app, but any changes in the app's source code will not be applied without refreshing the page. Note that your PORT environment variable will be ignored when running the dev script.

Matching

Patients can be matched either by identifier (SSN and MRN implemented), resulting in a "hard" match with 100% confidence, or by fuzzy matching a combination of parameters. The minimum required set of parameters to match includes name and birthDate, providing a confidence of 0.6 (60%). Additional matched parameters further increase the confidence score.

Comparing Names

1. We compare flattened versions of human names consisting of given and family name values concatenated with a space character.
2. Our comparison is case-insensitive.
3. We ignore the use, text, prefix, suffix, and period properties if present.
4. Both the input resource and the source Patient being compared can have multiple names. The match is successful only if there is one (or more) overlapping name between the two name arrays.

Note that having a matching name is not sufficient to match a patient; it needs to be combined with other matched properties.

Comparing DOB

We compare birth dates with a day precision, meaning that we consider two birth dates equal if they represent the same year, month, and day, ignoring the time part (if any). Note that in FHIR, the birthDate can also be loosely specified as YYYY or YYYY-MM. This means that, for example, we would match all of the following dates as equal: 2020, 2020-01, 2020-01-01, 2020-01-01T10:12:34.