Context

When comparing sleep data between Oura and Apple Health sources, users may notice significant differences in sleep metrics such as time in bed, latency, and sleep stages, even when the Apple Health data originally came from Oura.

Answer

The differences between Oura and Apple Health sleep data are expected due to how each data source is processed:

Oura Data Direct Source:

• Sleep metrics are received directly from Oura's API

• Includes pre-calculated sleep session metrics using Oura's proprietary algorithms

• Maintains complete session context and structure

Apple Health Data:

• Apple HealthKit receives individual sleep stage samples rather than complete sessions

• Sleep data loses some context during translation to Apple HealthKit's format

• Vital computes its own summary metrics from these individual samples (indicated by the presence of vital_computed_properties field)

• The reconstruction of sleep sessions from individual samples may result in different calculations compared to the original Oura data

For more detailed analysis of sleep data, users can reference the Sleep Cycle endpoint here and events here, which contain the fine-grained sleep segment data that can be compared to the samples in the Apple Health app's "Show All Data" view.