{ "scope": "Three included primary studies, one retained and two newly read; source details are not claims about present-day devices.", "studies": [ { "id": "S1", "citation": "Shcherbina et al., 2017", "title": "Accuracy in Wrist-Worn, Sensor-Based Measurements of Heart Rate and Energy Expenditure in a Diverse Cohort", "pmid": "28538708", "pmcid": "PMC5491979", "doi": "10.3390/jpm7020003", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC5491979/", "population": "60 healthy adults; convenience recruitment with diversity selection.", "independentUnit": "Participant; 80 tests are not 80 independent people.", "design": "Laboratory criterion validation; two device batches; fixed activity sequence.", "devices": [ "Apple Watch (generation unspecified)", "Basis Peak v1", "Fitbit Surge", "Microsoft Band v1", "Mio Alpha 2", "PulseOn", "Samsung Gear S2" ], "comparator": "Concurrent 12-lead ECG, Quark CPET.", "sampling": "Walking, running, cycling; final minute per stage, device-specific extraction.", "endpoints": "Relative error; repeated-measures modeling; selected Results only.", "calibrationAndVersion": "Manufacturer instructions; no independently verified calibration or firmware versions.", "biasConcerns": "Convenience selection; excluded malfunctioning device; device-specific acquisition; missing-data exclusion in PCA.", "supportedFinding": "Selected Results report less heart-rate error during cycling than walking in this protocol.", "quantitativeRestriction": "No accuracy percentages reproduced: walking threshold text is internally inconsistent; supplements and broader notice reconciliation remain pending.", "access": "Retained Methods 151–228 and selected Results 229–247; native current PMC challenge and PubMed footer.", "evidenceRefs": [ "historical rawPointers in provenance-manifest.json; original captures October 31, hash rechecked November 7" ], "notice": "Exact DOI search found publisher notes; notes request returned 429. No notice clearance.", "registry": "No registry body inspected.", "reviewStatus": "Concerns and unresolved checks; no low-bias designation." }, { "id": "S2", "citation": "Pasadyn et al., 2019", "title": "Accuracy of commercially available heart rate monitors in athletes: a prospective study", "pmid": "31555543", "pmcid": "PMC6732081", "doi": "10.21037/cdt.2019.06.05", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC6732081/", "population": "50 healthy athletic adults, age 18–56; 68% male, 76% White.", "independentUnit": "Participant; 25 participants per wrist model.", "design": "Prospective laboratory validation; randomized device and wrist assignment.", "devices": [ "Apple Watch III", "Fitbit “Iconic” (source spelling; model identity unresolved)", "Garmin Vivosmart HR", "TomTom Spark 3" ], "comparator": "Three-lead ECG, Quinton Q-tel RMS; trained visual reading.", "sampling": "Six treadmill speeds, readings after two minutes; handrail gripping during roughly five-second observation.", "endpoints": "Concordance, paired differences, Bland–Altman; mixed model for repeated observations.", "calibrationAndVersion": "Placement described; proprietary algorithms and firmware not verified.", "biasConcerns": "Selected fit volunteers; altered arm motion; visual timing; missingness/registry agreement not established.", "supportedFinding": "Authors report declining wrist-device agreement at faster treadmill speeds.", "quantitativeRestriction": "Rendered concordance decimals are malformed; exact coefficients and device ranking withheld pending figure/publisher reconciliation.", "access": "Main Methods/statistics 135–197, Results 199–216 and limitations 223–225 read.", "evidenceRefs": [ "native-03-block-0:135–225", "native-05-block-27:177–251" ], "notice": "PubMed identity matched; exact DOI notice search found no identity-matched notice. Bounded screen only.", "registry": "NCT03612063 reported by paper; direct registry returned shell, so prespecification unverified.", "reviewStatus": "Concerns and unresolved checks; no low-bias designation." }, { "id": "S3", "citation": "Etiwy et al., 2019; erratum 2020", "title": "Accuracy of wearable heart rate monitors in cardiac rehabilitation", "pmid": "31275816", "pmcid": "PMC6603497", "doi": "10.21037/cdt.2019.04.08", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC6603497/", "population": "80 adults in cardiac rehabilitation; mean age 62, 19% female.", "independentUnit": "Participant; repeated time points are not additional patients.", "design": "Prospective criterion validation; randomized wrist-device allocation.", "devices": [ "Apple Watch (generation unspecified)", "Fitbit Blaze", "Garmin Forerunner 235", "TomTom Spark Cardio" ], "comparator": "Torso limb-lead ECG, Quinton Q-tel RMS; cardiologist-supervised visual reading.", "sampling": "Individually prescribed treadmill/cycle exercise; readings at 3, 5, 7 minutes.", "endpoints": "ECG-minus-device differences, absolute differences, concordance, Bland–Altman.", "calibrationAndVersion": "Electrode preparation and wrist placement described; firmware/calibration not independently verified.", "biasConcerns": "Visual timing; model-specific missing displays; selected single-center cohort; limited subgroup precision.", "supportedFinding": "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.", "quantitativeRestriction": "Descriptive paired readings, not an exercise prescription or participant-level confidence interval.", "access": "Main Methods 175–204, Results 206–317, limitations 335–338 read.", "evidenceRefs": [ "native-07-block-0:175–204", "native-08-block-20:275–299", "native-09-block-2:335–338", "native-06-block-2:152–164" ], "notice": "Identified erratum read: corrects coauthor name to Zade Akras; no numerical change in that notice.", "registry": "NCT03182439 reported by paper; registry shell prevents prespecification check.", "reviewStatus": "Concerns and unresolved checks; no low-bias designation." } ] }