KnowYourPrime Evidence Registry
Permanent, citable records of how strong the published evidence is for specific claims about wearable health metrics. Each finding has a fixed ID, a rating set by a fixed rule, the studies behind it and a dated version history.
Findings
Showing all 25 findings
| ID | Finding | Measurement | Rating | Version | Reviewed |
|---|---|---|---|---|---|
| KYP-ER-0001 | Smartwatch Blood Oxygen (SpO2) Accuracy Against Arterial Blood (SaO2) | Blood oxygen (SpO2) | Uncertain | 1.1 | October 25, 2026 |
| KYP-ER-0002 | Pulse Oximeter Accuracy and Skin Tone | Blood oxygen (SpO2) | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0003 | Wearable HRV Accuracy Against ECG | Heart rate variability (HRV) | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0004 | Chest Strap HRV Accuracy Against ECG | Heart rate variability (HRV) | Established | 1.0 | October 24, 2026 |
| KYP-ER-0005 | Readiness and Recovery Score Validity | Readiness and recovery scores | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0006 | Work Stress and HRV | Heart rate variability (HRV) | Emerging | 1.0 | October 24, 2026 |
| KYP-ER-0007 | Wearable Sleep Tracking Accuracy Against a Sleep Lab | Sleep | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0008 | Under-Mattress Sleep Sensor Accuracy | Sleep | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0009 | Wearable Heart Rate Accuracy | Heart rate | Established | 1.0 | October 24, 2026 |
| KYP-ER-0010 | Wearable Calorie and Energy Expenditure Accuracy | Calories (energy expenditure) | Uncertain | 1.1 | October 24, 2026 |
| KYP-ER-0011 | Wearable VO2 Max Estimate Accuracy | VO2 max (cardio fitness) | Emerging | 1.0 | October 24, 2026 |
| KYP-ER-0012 | Do Activity Trackers Make People More Active? | Physical activity | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0013 | Overnight HRV Drop Before an Infection | Heart rate variability (HRV) | Emerging | 1.0 | October 24, 2026 |
| KYP-ER-0014 | Normal HRV Range by Age | Heart rate variability (HRV) | Established | 1.0 | October 24, 2026 |
| KYP-ER-0015 | VO2 Max by Age and Sex: US Reference Standards | VO2 max (cardio fitness) | Established | 1.1 | October 24, 2026 |
| KYP-ER-0016 | Wearable Sleep Stage Accuracy | Sleep | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0017 | Can Blood Oxygen Monitoring Rule Out Sleep Apnea? | Blood oxygen (SpO2) | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0018 | Smartwatch Blood Oxygen Accuracy at Altitude | Blood oxygen (SpO2) | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0019 | Blood Oxygen Readings With Poor Circulation | Blood oxygen (SpO2) | Uncertain | 1.2 | October 24, 2026 |
| KYP-ER-0020 | Accuracy of Smartwatches With a Built-In Blood Pressure Cuff | Blood pressure | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0021 | Cuffless Blood Pressure Accuracy at Night | Blood pressure | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0022 | Do Calibrated Cuffless Blood Pressure Readings Track Real Changes? | Blood pressure | Uncertain | 1.0 | October 24, 2026 |
| KYP-ER-0023 | Apple Watch Blood Oxygen Accuracy Against Medical Devices | Blood oxygen (SpO2) | Uncertain | 1.2 | October 27, 2026 |
| KYP-ER-0024 | Oura Ring HRV Accuracy Against ECG | Heart rate variability (HRV) | Established | 1.0 | October 24, 2026 |
| KYP-ER-0025 | Apple Watch HRV Accuracy Against ECG and Chest Straps | Heart rate variability (HRV) | Uncertain | 1.0 | October 24, 2026 |
What a finding is
A finding is one question about a wearable measurement, such as whether a smartwatch blood oxygen reading matches arterial blood, rated against every study KnowYourPrime has scored for it. The record states the question, the rating, a plain answer, the key numbers, what the finding does and does not cover, its limitations and the full list of studies with their roles. The long-form analysis behind each finding sits on its research desk, linked from the finding; the Registry is the citable record of where that analysis stands.
How ratings are set
Each study is assigned a role for the claim: an anchor the rating can rest on, a supporting study, a conflicting study or a null result. A fixed rule turns those roles into one of five ratings, so the same evidence always produces the same rating. The rule and its version are shown on every finding.
- EstablishedStrong, consistent evidence supports the claim.
- EmergingEvidence currently favors the claim, but more confirmation is needed.
- UncertainEvidence is conflicting, inconsistent, or difficult to interpret.
- InsufficientToo little evidence exists to reach a conclusion.
- UnsupportedExisting evidence does not support the claim.
The full rule is set out in the methodology and how KnowYourPrime interprets evidence.
Versions, review dates and corrections
A finding always carries the current rating on its research desk. When the evidence moves the rating, the finding gets a new major version (2.0, 3.0); when its text is revised, a new minor version (1.1, 1.2). Each version is dated and says what changed, and earlier versions stay listed. Errors are corrected the same way, as a new dated version, and can be reported to corrections@knowyourprime.com.
How to cite a finding
KnowYourPrime Evidence Registry, Finding [ID], version [version], reviewed [date]. [URL]
Every finding prints its own completed citation line, and the same line appears in its JSON and Markdown versions. Cite the page URL, not the JSON or Markdown file.