THE BIOHACKING REFERENCE

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Compare study populations, methods, findings and limitations, or place editorial topics side by side.

Compare the studies.

Wrist-worn heart rate versus ECG, in three historical adult cohorts.

Look at who was studied, how readings were collected and what each result can support. These studies use different cohorts, devices and sampling procedures; no pooled estimate or present-day device ranking is offered.

Showing all three studies. Selection and export controls become available when JavaScript loads.

Study identity

Participants and protocol

Population

Shcherbina et al., 2017

60 healthy adults; convenience recruitment with diversity selection.

Pasadyn et al., 2019

50 healthy athletic adults, age 18–56; 68% male, 76% White.

Etiwy et al., 2019; erratum 2020

80 adults in cardiac rehabilitation; mean age 62, 19% female.

Independent unit

Shcherbina et al., 2017

Participant; 80 tests are not 80 independent people.

Pasadyn et al., 2019

Participant; 25 participants per wrist model.

Etiwy et al., 2019; erratum 2020

Participant; repeated time points are not additional patients.

Study design

Shcherbina et al., 2017

Laboratory criterion validation; two device batches; fixed activity sequence.

Pasadyn et al., 2019

Prospective laboratory validation; randomized device and wrist assignment.

Etiwy et al., 2019; erratum 2020

Prospective criterion validation; randomized wrist-device allocation.

Historical devices

Shcherbina et al., 2017
  • Apple Watch (generation unspecified)
  • Basis Peak v1
  • Fitbit Surge
  • Microsoft Band v1
  • Mio Alpha 2
  • PulseOn
  • Samsung Gear S2
Pasadyn et al., 2019
  • Apple Watch III
  • Fitbit “Iconic” (source spelling; model identity unresolved)
  • Garmin Vivosmart HR
  • TomTom Spark 3
Etiwy et al., 2019; erratum 2020
  • Apple Watch (generation unspecified)
  • Fitbit Blaze
  • Garmin Forerunner 235
  • TomTom Spark Cardio

ECG comparator

Shcherbina et al., 2017

Concurrent 12-lead ECG, Quark CPET.

Pasadyn et al., 2019

Three-lead ECG, Quinton Q-tel RMS; trained visual reading.

Etiwy et al., 2019; erratum 2020

Torso limb-lead ECG, Quinton Q-tel RMS; cardiologist-supervised visual reading.

Activity and sampling

Shcherbina et al., 2017

Walking, running, cycling; final minute per stage, device-specific extraction.

Pasadyn et al., 2019

Six treadmill speeds, readings after two minutes; handrail gripping during roughly five-second observation.

Etiwy et al., 2019; erratum 2020

Individually prescribed treadmill/cycle exercise; readings at 3, 5, 7 minutes.

Measures and reported findings

Measured endpoints

Shcherbina et al., 2017

Relative error; repeated-measures modeling; selected Results only.

Pasadyn et al., 2019

Concordance, paired differences, Bland–Altman; mixed model for repeated observations.

Etiwy et al., 2019; erratum 2020

ECG-minus-device differences, absolute differences, concordance, Bland–Altman.

Supported finding

Shcherbina et al., 2017

Selected Results report less heart-rate error during cycling than walking in this protocol.

Pasadyn et al., 2019

Authors report declining wrist-device agreement at faster treadmill speeds.

Etiwy et al., 2019; erratum 2020

Fitbit treadmill mean signed difference was 0.5 bpm but mean absolute difference 8.2 bpm (Table 2); near-zero bias can coexist with individual error.

Quantitative restrictions

Shcherbina et al., 2017

No accuracy percentages reproduced: walking threshold text is internally inconsistent; supplements and broader notice reconciliation remain pending.

Pasadyn et al., 2019

Rendered concordance decimals are malformed; exact coefficients and device ranking withheld pending figure/publisher reconciliation.

Etiwy et al., 2019; erratum 2020

Descriptive paired readings, not an exercise prescription or participant-level confidence interval.

Reading scope and unresolved checks

Text accessed

Shcherbina et al., 2017

Retained Methods 151–228 and selected Results 229–247; native current PMC challenge and PubMed footer.

Pasadyn et al., 2019

Main Methods/statistics 135–197, Results 199–216 and limitations 223–225 read.

Etiwy et al., 2019; erratum 2020

Main Methods 175–204, Results 206–317, limitations 335–338 read.

Correction and notice assessment

Shcherbina et al., 2017

Exact DOI search found publisher notes; notes request returned 429. No notice clearance.

Pasadyn et al., 2019

PubMed identity matched; exact DOI notice search found no identity-matched notice. Bounded screen only.

Etiwy et al., 2019; erratum 2020

Identified erratum read: corrects coauthor name to Zade Akras; no numerical change in that notice.

Registry assessment

Shcherbina et al., 2017

No registry body inspected.

Pasadyn et al., 2019

NCT03612063 reported by paper; direct registry returned shell, so prespecification unverified.

Etiwy et al., 2019; erratum 2020

NCT03182439 reported by paper; registry shell prevents prespecification check.

Calibration and version limits

Shcherbina et al., 2017

Manufacturer instructions; no independently verified calibration or firmware versions.

Pasadyn et al., 2019

Placement described; proprietary algorithms and firmware not verified.

Etiwy et al., 2019; erratum 2020

Electrode preparation and wrist placement described; firmware/calibration not independently verified.

Bias concerns

Shcherbina et al., 2017

Convenience selection; excluded malfunctioning device; device-specific acquisition; missing-data exclusion in PCA.

Pasadyn et al., 2019

Selected fit volunteers; altered arm motion; visual timing; missingness/registry agreement not established.

Etiwy et al., 2019; erratum 2020

Visual timing; model-specific missing displays; selected single-center cohort; limited subgroup precision.

Review conclusion

Shcherbina et al., 2017

Concerns and unresolved checks; no low-bias designation.

Pasadyn et al., 2019

Concerns and unresolved checks; no low-bias designation.

Etiwy et al., 2019; erratum 2020

Concerns and unresolved checks; no low-bias designation.

Exact evidence locators

Shcherbina et al., 2017
  • historical rawPointers in provenance-manifest.json; original captures October 31, hash rechecked November 7
Pasadyn et al., 2019
  • native-03-block-0:135–225
  • native-05-block-27:177–251
Etiwy et al., 2019; erratum 2020
  • native-07-block-0:175–204
  • native-08-block-20:275–299
  • native-09-block-2:335–338
  • native-06-block-2:152–164

Record provenance

As recorded in the complete synthesis: Three included primary studies, one retained and two newly read; source details are not claims about present-day devices.

The comparison retains original study-record text. These file hashes identify the complete canonical artifacts, not a new appraisal or a hash of only the selected rows. Raw publisher bodies remain outside this site’s repository.

  • studies.jsonSHA-256 c5216f51890b07c41af5663942a5c941db888fa0004ce49194bb4dca3ce8842d
  • protocol.jsonSHA-256 845bba5c4201644be9e3a7bff69d07e04631be41a44e2d27428d2c29570d7950
  • claim-map.jsonSHA-256 8b20c1ac234a13e8c91a76e9317b28049412367e733c75e9352ee5cdb141638f
  • provenance-manifest.jsonSHA-256 f1c19b16e5c243d6cbb6a499193fa0c639debbe105af84247d028050b8f3a617
  • release-bindings.jsonSHA-256 fe7c6fad05b1c640c40187c0cbc96666fa2ba6e76b69955d45834802d36114d8
  • receipts/synthesis-review.jsonSHA-256 5b10ab96f50c09295ab94168602cf001aca3af4d740f2ae2e2e92f40789fd8f2
  • receipts/synthesis-integration-addendum.jsonSHA-256 84538aa2868110f3ab7ad8e50bfcd389d3b266d6562c321c437b1be275e1b157

Comparison Studio

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