Common Configuration

Many features of Synthea^TM are configurable using a settings file. The settings file uses a simple format with one setting per line as shown below:

# this is a comment
exporter.ccda.export = false
exporter.fhir.export = true
exporter.fhir_stu3.export = false
exporter.fhir_dstu2.export = false

Synthea includes a default configuration file (which developers can find at ./src/main/resources/synthea.properties). Each default setting can be individually overridden using a local settings file that is passed to Synthea when it is run. For users of the basic setup:

java -jar synthea-with-dependencies.jar -c path/to/settings/file

For those using the developer setup:

./run_synthea -c path/to/settings/file

Summary of Commonly-Used Configuration Options

Export Formats

Setting Name	Valid Values	Default	Description
exporter.ccda.export	true/false	false	Change this setting to true to enable exporting patients in CCDA format.
exporter.fhir.export	true/false	true	Change this setting to false to disable exporting patients in FHIR R4 format.
exporter.fhir.use_us_core_ig	true/false	false	US Core Implementation Guide for FHIR R4
exporter.fhir.us_core_version	version number	5.0.1	Version of the US Core IG to use, if enabled above. See HL7 FHIR for list of supported versions
exporter.fhir_stu3.export	true/false	false	Change this setting to true to enable exporting patients in FHIR STU3 format.
exporter.fhir_dstu2.export	true/false	false	Change this setting to true to enable exporting patients in FHIR DSTU2 format.
exporter.hospital.fhir.export	true/false	true	Change this setting to false to disable exporting hospital information in FHIR R4 format.
exporter.hospital.fhir_stu3.export	true/false	false	Change this setting to true to enable exporting hospital information in FHIR STU3 format.
exporter.hospital.fhir_dstu2.export	true/false	false	Change this setting to true to enable exporting hospital information in FHIR DSTU2 format.
exporter.text.export	true/false	false	Change this setting to true to enable exporting patients in a simple text-based format.
exporter.csv.export	true/false	false	Change this setting to true to enable exporting patient data in a comma-separated value format. See the CSV File Data Dictionary.
exporter.csv.append_mode	true/false	false	Change this setting to true to enable append mode for the CSV exporter, where all new runs will be appended onto the existing CSV records, rather than overwriting the files. For instance, this could be used to help produce a single set of CSVs spanning patients across multiple states, since only one state can be run at a time.
exporter.csv.folder_per_run	true/false	false	Change this setting to true to enable exporting CSVs in a separate subfolder per run of Synthea. Currently the CSVs get reset each time, so if you want to keep a run you have to specifically copy it off somewhere else. This option makes CSVs more like other export formats in that files will persist until manually deleted. Note that this setting will supersede exporter.csv.append_mode if both are true

Other Export Settings

Setting Name	Valid Values	Default	Description
exporter.years_of_history	Whole number	10	The number of years of patient history to include in patient records. For example, if set to 5, then all patient history older than 5 years old (from the time you execute the program) will not be included in the exported records. Note that conditions and medications that are currently active will still be exported, regardless of this setting. Set this to 0 to keep all history in the patient record.
exporter.baseDirectory	Folder paths	./output/	This is the base folder in which all patient records will be exported. Files will be exported to subfolders based on their type. (For example FHIR records will be stored in the /fhir/ subfolder under this folder.
exporter.subfolders_by_id_substring	true/false	false	If true, patient records will be grouped into subfolders based on their UUID, which is a randomly generated unique identifer. This reduces the number of files in any single folder, and ensures a roughly even distribution of files among folders. However there is no correlation between files in any given folder as the IDs are random.
exporter.use_uuid_filenames	true/false	false	If true, patient records will have filenames based only on their UUID. If false, patient records will have filenames including the patient's name. This is mostly intended as a debugging feature - if watching the terminal as patients are generating, this makes it easier to find the record once it is generated.

Generation Settings

Setting Name	Valid Values	Default	Description
generate.default_population	Whole numbers	./output/	This is the number of living patients (population size) that Synthea will generate. Synthea will generate patients until the number of living patients reaches this value.
generate.database_type	file, in-memory, or none	none	⚠️ This setting no longer exists, and only functions for some legacy versions of Synthea. ⚠️ Using the file or in-memory database will cause dramatic performance impacts (generation will be extremely slow) and require significant storage. If enabled, this database can be used to track various metrics, which can be used to produce various reports. If these reports are not desired (the default), the database should be disabled to improve runtime performance. Alternatively, if it is desirable to persist this data across runs, use the file option to save data to a persistent database file (./database.mv.db, which can be accessed using the h2 database client). But beware of file as the size of the database can grow VERY large.

Other Settings

Synthea^TM contains a number of configurable options relating to the world, human vital signs, risk levels, etc. These have been pre-seeded with values based on US and Massachusetts data, with citations for these values where possible. See Default Demographic Data. Users generally will not want to modify these unless trying to simulate a specific result or trying to adapt Synthea^TM to another geographic or geopolitical location (in which case they should see the series of wiki pages under Other Areas starting with Demographics for Other Areas.

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