...
JSON format does not allow to specify or control order of attributes. Despite of that, as most JSON engines allow to control the order of attributes it is strongly recommended to follow the attribute order specified in details. The reason for that is that due to a possible large size of Dataset-JSON files, following the specified order will enable a software using steaming approaches to read the file to work in an efficient and fast way.
Dataset-JSON must contain only one dataset per file.
Top Level Attributes
At the top level of Dataset-JSON object, there are technical attributes and two main optional attributes: clinicalData and referenceData, corresponding to Dataset-XML elements. At least 1 of the main attributes must be provided. Subject data is stored in clinicalData and non-subject data is stored in referenceData.
| Attribute | Usage | Description | Attribute order | fileOID | Required |
|---|
| A unique identifier for this file. | 1 | creationDateTime | Required | Time of creation of the file containing the document. | 1 |
| datasetJSONVersion | Required | Version of Dataset-JSON standard | 2 |
| fileOID | Optional | A unique identifier for this file. | 3 |
| asOfDateTime | RequiredOptional | The date/time at which the source database was queried in order to create this document. | 3 | datasetJSONVersion | Required | Version of Dataset-JSON standard | 4 |
| originator | Optional | The organization that generated the ODM Dataset-JSON file. | 5 |
| sourceSystem | Optional | The computer system or database management system that is the source of the information in this file. | 6 |
| sourceSystemVersion | Optional | The version of the "SourceSystemsourceSystem" above. | 7 |
| clinicalData | OptionalSee | ODM definition for study OID (STUDYOID)Contains datasets for clinical data across multiple subjects. | 8 |
| referenceData | OptionalSee | ODM definition for metadata version OID (METADATAVERSIONOID)Contains datasets for non-subject data domains. | 9 |
| Code Block |
|---|
|
{
"fileOIDcreationDateTime": "www.sponsor.xyz.org.project123.final",2023-03-22T11:53:27",
"creationDateTimedatasetJSONVersion": "2023-03-22T11:53:271.0.0",
"fileOID": "www.sponsor.xyz.org.project123.final",
"asOfDateTime": "2023-02-15T10:23:15",
"originator": "Sponsor XYZ",
"sourceSystem": "Software ABC",
"sourceSystemVersion": "1.0.0",
"datasetJSONVersion": "",
"clinicalData": { ... },
"referenceData": { ... }
} |
...
Both clinicalData and referenceData have the same structure. Each of these attributes contains study and metadata OIDs, optional reference to the metadata file and an object describing an item group (dataset). The following attributes are defined on this level.
| Attribute | Requirement | Description | Attribute order |
|---|
| studyOID | RequiredOptional | See ODM definition for study OID (STUDYOIDODM/Study/@OID). | 1 |
| metaDataVersionOID | RequiredOptional | See ODM definition for metadata version OID (METADATAVERSIONOIDODM/Study/MetaDataVersion/@OID). | 2 |
| metaDataRef | Optional | URL for a metadata file the describing the data. | 3 |
| itemGroupData | Required | Object containing dataset information | 4 |
...
itemGroupData is an object with a single attribute corresponding to an individual dataset. There must be only one dataset per Dataset-JSON file. The attribute name is OID of a described dataset, which must be the same as the OID of the corresponding itemGroup itemGroupDef in the Define-XML file.
| Code Block |
|---|
|
"itemGroupData": {
"IG.DM": { ... }
}
|
The dataset description contains basic information about the dataset itself and its items.
| Attribute | Requirement | Description | Attribute order |
|---|
| records | Required | The total number of records in a dataset | 1 |
| name | Required | Dataset name | 2 |
label | Required | Dataset description | 3 |
| items | Required | Basic information about variables | 4 |
| itemData | Required | Dataset data | 5 |
| Code Block |
|---|
|
"IG.DM": {
"records": 100,
"name": "DM",
"label": "Demographics",
"items": [ ... ],
"itemData": [ ... ]
} |
items is an array of basic information about dataset variables. The order of the elements in the array must be the same as the order of variables in the described dataset. The first element always describes the Record Identifier (ITEMGROUPDATASEQ).
| Attribute | Requirement | Description | Attribute order |
|---|
| OID | Required | OID of a variable (must correspond to the variable OID in the Define-XML file) | 1 |
| name | Required | Variable name | 2 |
label | Required | Variable description | 3 |
| type | Required | Type of the variable |
(i.e., | . Allowed values: "string", "integer", "decimal", "float", "double", "boolean" |
; see | . See ODM types for details |
)| . | 4 |
| length | Optional | Variable length | 5 |
| displayFormat | Optional | Display format supports data visualization of numeric float and date values. | 6 |
| keySequence | Optional | Indicates that this item is a key variable in the dataset structure. It also provides an ordering for the keys. | 7 |
| Code Block |
|---|
|
"items": [
{
"OID": "ITEMGROUPDATASEQ",
"name": "ITEMGROUPDATASEQ",
"label": "Record identifier",
"type": "integer",
},
{
"OID": "IT.DM.STUDYID",
"name": "STUDYID",
"label": "Study Identifier",
"type": "string",
"length": 12,
"keySequence": "1",
},
...
] |
itemData is an array of records with variables values. Each record itself is also represented as an array of variables values. The first value is a unique sequence number for each record in the dataset.
| Code Block |
|---|
|
"itemData": {[
[1, "MyStudy", "001", "DM", 56],
[2, "MyStudy", "002", "DM", 26],
}
...
] |
Missing values are represented by null in the case of numeric variables, and an empty string in case of character variables: [1, "MyStudy", "", "DM", null]
The following is a full example of a Dataset-JSON file:
| Code Block |
|---|
|
{
"fileOID "creationDateTime": "2023-03-22T11:53:27",
"datasetJSONVersion": "www1.sponsor.org.project123.final0.0",
"creationDateTimefileOID": "2023-03-22T11:53:27www.sponsor.org.project123.final",
"asOfDateTime": "2023-02-15T10:23:15",
"originator": "Sponsor XYZ",
"sourceSystem": "Software ABC",
"sourceSystemVersion": "1.2.3",
"datasetJSONVersion": "1.0.0",
"clinicalData": {
"studyOID": "xxx",
"metaDataVersionOID": "xxx",
"metaDataRef": "https://metadata.location.org/api.link",
"itemGroupData": {
"IG.DM": {
"records": 600,
"name": "DM",
"label": "Demographics",
"items": [
{"OID": "ITEMGROUPDATASEQ", "name": "ITEMGROUPDATASEQ", "label": "Record identifier", "type": "integer"},
{"OID": "IT.STUDYID", "name": "STUDYID", "label": "Study identifier", "type": "string", "length": 7, "keySequence": 1},
{"OID": "IT.USUBJID", "name": "USUBJID", "label": "Unique Subject Identifier", "type": "string", "length": 3, "keySequence": 2},
{"OID": "IT.DOMAIN", "name": "DOMAIN", "label": "Domain Identifier", "type": "string", "length": 2},
{"OID": "IT.AGE", "name": "AGE", "label": "Subject Age", "type": "integer", "length": 2}
],
"itemData": [
[1, "MyStudy", "001", "DM", 56],
[2, "MyStudy", "002", "DM", 26],
...
]
}
}
},
} |
The TypeScript model representation and the JSON schema for Dataset-JSON version 1.0 can be found at https://github.com/cdisc-org/DataExchange-DatasetJson.