HealthKit Characteristics represent data that does not typically change over time, like date of birth.
One file will be created per type of data (e.g., "BloodType" and "DateOfBirth"). The file name will correspond to the type of data (e.g., "HealthKitV2Characteristics_BloodType_20211101-20211217" and "HealthKitV2Characteristics_DateOfBirth_20211101-20211217").
| Field | Description |
|---|---|
HealthKitCharacteristicKey |
A unique, auto-generated key for this characteristic. |
ParticipantIdentifier |
The identifier of the participant this task was for. Can be used to cross reference with Participants. |
Date |
The date the characteristic was recorded, in ISO 8601 format. Includes timezone offset information. |
Value |
The characteristic’s value. May be a date (in ISO 8601 format), a yes/no selection, a number or a text field. |
InsertedDate |
The creation date of the entry, in ISO 8601 format. Is always in UTC. |
ModifiedDate |
The date the entry was last modified, in ISO 8601 format. Is always in UTC. |
If a participant re-syncs their device, you may observe duplicate samples. HealthKit samples are immutable, so when doing data analysis, your team will need to remove any samples that have the same HealthKitCharacteristicKey and ParticipantIdentifier as another sample.
Sample CSV Export
HealthKitCharacteristicKey,ParticipantIdentifier,Date,Value,InsertedDate
8d5828fa-4f12-5cc7-bbb8-60f5b84993ac,256263d8-3ffc-eb11-aaae-0afb9334277d,2021-12-14T11:38:43-05:00,BPositive,2021-12-14T16:38:43Z
456c5a90-6031-5400-9123-de8e4a52dc71,a1098476-a16c-4ee9-802e-5153fed5c221,2021-11-22T14:48:06-05:00,BPositive,2021-11-22T19:48:06Z
ac70ee62-80a7-594d-aae8-86be48053965,e794c47e-438e-4d7b-9b24-99ce68c75300,2021-11-05T10:21:03-04:00,BPositive,2021-11-05T14:21:03Z
Sample JSON Export
{
"HealthKitCharacteristicKey":"8d5828fa-4f12-5cc7-bbb8-60f5b84993ac",
"ParticipantIdentifier":"256263d8-3ffc-eb11-aaae-0afb9334277d",
"Value":"BPositive",
"Date":"2021-12-14T11:38:43-05:00",
"InsertedDate":"2021-12-14T16:38:43Z"
}