HealthKit provides a central repository for health and fitness data on iPhone and Apple Watch. Data may be entered manually by the user, or programmatically by the iPhone, Apple Watch, or other apps connected to consumer health devices using Bluetooth. With the user’s permission, apps communicate with the HealthKit data store to access those data. HealthKit data is requested by status/post when the app is running in the background. As such, requested data will upload to REDCap soon after they are collected, regardless of a user’s interaction with the app. With our platform, investigators request HealthKit data through commands issued in REDCap field annotations:


Once initiated, the app will continuously receive and upload the requested metric from HealthKit. REDCap Events containing Data Collection Instruments calling for HealthKit data should be configured as repeating events. Data collection can be terminated by a stop command:


a)    Active Data Collection
Certain types of data require the user’s interaction with Apple’s Health app or third-party apps associated with a connected consumer health device. An example of data collection requiring user interaction is a user-initiated blood pressure reading using a Bluetooth-connected cuff. The following are the active data collection measurements implemented by our platform:

(1)    mindfulSession
(2)    respiratoryRate
(3)    bodyTemperature
(4)    bloodPressureDiastolic
(5)    bloodPressureSystolic
(6)    bodyMass

b)    Passive Data Collection
Some HealthKit data, in certain circumstances, are collected automatically without a user’s interaction with an app or device. Passive data collection measurements implemented by our platform include:

(1)    heartRate
(2)    stepCount
(3)    flightsClimbed
(4)    restingHeartRate
(5)    heartRateVariabilitySDNN
(6)    numberOfTimesFallen
(7)    walkingHeartRateAverage
(8)    oxygenSaturation
(9)    walkingStepLength
(10)     walkingSpeed
(11)     stairAscentSpeed
(12)     stairDescentSpeed
(13)     walkingAsymmetryPercentage
(14)     walkingDoubleSupportPercentage
(15)     appleStandTime
(16)     appleExerciseTime
(17)     sixMinuteWalkTestDistance
(18)     workout