This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Performance of Masimo INVSENSOR00057 in Detecting Atrial Fibrillation (Afib) (NCT05472012), a na na study. The primary outcome is Sensitivity of INVSENSOR00057 Atrial Fibrillation (Afib) Detection Function.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05472012 |
| Phase | NA |
| Condition | Atrial Fibrillation |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 139 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Masimo Corporation |
| Results posted | Yes |
2. Clinical Question
Population
The study enrolled 139 subjects for a validation study of atrial fibrillation detection. The registry record says 23 subjects were excluded from data analysis under protocol criteria. Those criteria included unreadable waveforms from the reference or test ECG, as judged by medical personnel. The record also begins describing subjects who appeared to have atrial fibrillation at enrollment, but does not give a complete account of that criterion.
Intervention
Subjects participating in data collection received the noninvasive INVSENSOR00057 device. The study evaluated its atrial fibrillation detection function using ECG measurements.
Comparator
Measurements from INVSENSOR00057 were compared with data collected using an FDA-cleared ECG monitor. This is a reference-device comparison within a single-group study, not a randomized comparison between treatment groups.
Primary question
The primary endpoint was the sensitivity of the INVSENSOR00057 atrial fibrillation detection function, expressed as a percentage of true positives. It asks how often the device's detection function identifies atrial fibrillation when the reference monitor indicates atrial fibrillation. The registry record does not report the sensitivity result.
3. Trial Design
This was a completed, single-group device study sponsored by Masimo Corporation. The registry lists an enrollment of 139 and identifies INVSENSOR00057 as the study device. Subjects who enrolled in the test group and participated in data collection received the noninvasive device. Its ECG measurements were compared with results from an FDA-cleared ECG monitor.
The registry lists no allocation and no masking. The study is therefore not described as a randomized or masked comparison. The design should be read as an evaluation of device performance against a reference monitor, rather than as a comparison of two independently assigned groups. The registry does not describe a separate control arm.
The study started on 2022-07-25, reached primary completion on 2023-12-16, and is marked completed. Its phase is listed as NA. The record lists atrial fibrillation as the condition and describes the purpose as validating the device's performance in detecting atrial fibrillation.
The primary endpoint's timeframe is 1-5 hours. The record lists 2 outcome measures, but the details of the other measure are not reported in the registry record. No analysis is listed in the registry record. The protocol, the rationale for the enrollment target, and details about how ECG recordings were matched and assessed are not reported in the registry record. These omissions limit how fully the study's operational design and analysis can be reconstructed from the registration alone.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | INVSENSOR00057 |
|---|---|
| STARTED | 139 |
| COMPLETED | 139 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: A total of 23 subjects were excluded from the data analysis based on the protocol criteria. This included individuals whose reference or test ECG did not provide readable waveforms, as determined by medical personnel, and those who appeared to have atrial fibrillation (Afib) at enrollment but provided waveforms that were inconsistent with an Afib diagnosis.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | INVSENSOR00057 |
|---|---|---|
| Participants analysed | 139 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 20 |
| Age, Categorical: >=65 years | Participants | 119 |
| Sex: Female, Male: Female | Participants | 65 |
| Sex: Female, Male: Male | Participants | 74 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 4 |
| Race (NIH/OMB): White | Participants | 134 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Sensitivity of INVSENSOR00057 Atrial Fibrillation (Afib) Detection Function, measured over 1-5 hours.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | % of true positive |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the sensitivity of the INVSENSOR00057 atrial fibrillation detection function, measured as a percentage of true positives. Sensitivity describes the proportion of cases identified by a test among cases that are positive according to a reference method. In this study, the reference was an FDA-cleared ECG monitor, and the device's ECG measurements were compared with the reference data. This endpoint focuses on detection of atrial fibrillation identified by the reference, rather than on all possible ways device readings might agree or disagree.
As general statistical context, sensitivity is useful when the question is whether a detection function recognizes reference-positive cases. It does not, by itself, describe how often a positive device result is correct when the reference is negative, or how often negative cases are correctly classified. Those are different performance characteristics and require their own definitions and results.
The registry specifies a timeframe of 1-5 hours and describes the endpoint as a number, with units of percent of true positive. It does not report the observed sensitivity, its uncertainty, or the number of reference-positive cases used in the calculation. Without those details, the endpoint definition can be explained, but the magnitude and precision of device performance cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a device-validation question: how sensitive the INVSENSOR00057 atrial fibrillation detection function was relative to an FDA-cleared ECG monitor. It identifies sensitivity as the primary endpoint and gives the measurement timeframe as 1-5 hours. However, it does not report a sensitivity value. Consequently, the posted registry information does not establish how often the device detected reference-positive cases, nor how precise that estimate was.
The distinction between an endpoint definition and an endpoint result is essential. A stated sensitivity endpoint tells readers what the investigators intended to measure. It does not establish the measured performance. Interpretation would ordinarily require the observed estimate and information about the cases contributing to its denominator. Those details are not reported in the registry record. No confidence interval or other measure of uncertainty is listed, so the precision of any estimate cannot be judged.
The study enrolled 139 subjects, and the record states that 23 were excluded from data analysis based on protocol criteria. The criteria included cases where medical personnel determined that the reference or test ECG did not contain readable waveforms. The record also begins describing people who appeared to have atrial fibrillation at enrollment, but does not fully describe that criterion. Exclusions matter because sensitivity is based on reference-positive cases that can be evaluated. The total enrollment alone does not reveal how many usable ECG pairs or reference-positive cases remained.
The design is single-group and unmasked, with device readings compared against an FDA-cleared ECG monitor. This design addresses agreement or detection performance relative to that reference; it is not a randomized treatment comparison. The registry lists no allocation and no analyses. These design details do not substitute for endpoint results, and the record does not describe the statistical procedure used to estimate sensitivity.
The adverse-event counts are also separate from the performance endpoint. The record lists no serious adverse events among 139 at risk and one event in the other adverse-event count among 139 at risk. It lists no deaths. These counts do not indicate diagnostic sensitivity and should not be used to infer it.
Overall, the registry supports a description of the intended validation question, study structure, enrollment, exclusions, timeframe, and reported event counts. It does not support a numerical conclusion about sensitivity, the accuracy of individual classifications, or the precision of device performance. The missing result is not evidence of either high or low performance; it leaves the primary statistical question unanswered in the registry record.
9. Statistical Methods Explained
What sensitivity measures
As general statistical context, sensitivity is a conditional proportion: among cases that the reference method classifies as positive, it measures the share that the test also identifies as positive. For this study, the positive condition is atrial fibrillation, the test is INVSENSOR00057's detection function, and the reference is an FDA-cleared ECG monitor. The endpoint is expressed as a percentage of true positives. The registry record does not state the observed percentage or the number of reference-positive observations used to calculate it.
Sensitivity is only one aspect of classification performance. It does not describe false-positive results among reference-negative cases, nor does it give an overall agreement rate. Those questions require distinct measures and denominators. The registry's primary endpoint is specifically sensitivity, so it should not be interpreted as a complete account of every kind of device error.
Why the reference method matters
As general statistical context, a diagnostic-performance estimate depends on how the reference classification is defined and applied. The registry identifies an FDA-cleared ECG monitor as the comparator and says device measurements were compared with data collected using that monitor. It does not report the detailed adjudication process, how recordings were paired, or how disagreements were resolved. Without those details, readers cannot assess the practical influence of reference interpretation on the endpoint.
Reference-based sensitivity is an estimate of performance relative to the selected reference. It is not automatically a measure of an underlying truth independent of that reference. The registry record does not report whether the reference readings were reviewed independently or whether readers were blinded to device results. Masking is listed as none, but further procedural detail is not reported.
Exclusions and the analysis set
The registry states that 23 subjects were excluded from data analysis based on protocol criteria. It names unreadable waveforms from either the reference or test ECG, as determined by medical personnel, as part of the reason. The record also starts to describe subjects who appeared to have atrial fibrillation at enrollment, but the condition attached to that description is incomplete. The full exclusion criteria and the number remaining in the endpoint analysis are not reported in the registry record.
As general statistical context, excluding unreadable recordings can be necessary when a measurement cannot be classified. At the same time, exclusions affect which participants contribute to an estimate. If unusable recordings differ systematically from usable ones, the analyzed set may not represent all enrolled subjects in the same way. Assessing that possibility would require details on excluded cases and reasons, which are not fully in the registry record. The enrollment count should therefore not be mistaken for the number included in the sensitivity calculation.
Uncertainty and precision
As general statistical context, an estimate is more informative when accompanied by an interval describing its statistical uncertainty. A confidence interval represents a range of values compatible with the data under a specified method and assumptions; it is not a guarantee that the true value lies in that interval. For sensitivity, precision depends on the number of reference-positive cases available, not simply on overall enrollment. The registry does not report a confidence interval, a standard error, or the reference-positive denominator, so the precision of the primary endpoint cannot be evaluated.
A percentage by itself would also need its underlying denominator for context. For instance, the same point estimate can have different precision depending on how many eligible positive cases contributed. No observed percentage is reported in this registry record, and no denominator for the endpoint is listed. It is therefore not possible to reconstruct or independently assess the sensitivity estimate from the record.
Planning illustrations are not trial results
As general statistical context, sample-size planning explores how many participants might be needed under specified assumptions. The stated planning approach uses a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. Such planning illustrations are not observed outcomes, and they are not observed power. The study itself is described as single-group, so the equal-allocation assumption in a planning illustration should not be mistaken for the design actually used.
The registry record does not report the observed primary endpoint needed to assess illustrations based on a fraction of the observed effect. Nor does it report a protocol-based sample-size justification. No sample-size result can therefore establish what this study was designed to detect or how its achieved precision compared with a planned target.
What the analysis record establishes
The registry lists 2 outcome measures and no analyses. It specifies the primary endpoint's name, unit, and timeframe, but does not report an analysis method or numerical result. In statistical interpretation, a method description explains how an estimate was calculated, while a result gives the estimate and often its uncertainty. Neither a detailed method nor a sensitivity result is available in the registry record. The endpoint definition and the design can be described, but a quantitative performance conclusion cannot be drawn from them alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 2 outcome measures, identifies sensitivity of the atrial fibrillation detection function as the primary outcome, and lists no analyses. The other outcome measure's definition and results are not reported in the registry record. There is no description of how multiple outcomes were prioritized in analysis, whether any multiplicity adjustment was planned, or whether additional subgroup or secondary analyses were conducted.
As general statistical context, when multiple hypotheses are tested, the chance of at least one apparently notable result can rise unless the analysis plan accounts for multiplicity. This concern depends on what was tested and how results were interpreted. The registry record does not describe such testing or any adjustment, so readers cannot determine whether multiplicity was relevant to the reported analyses.
The record says 23 subjects were excluded from data analysis under protocol criteria. Unreadable reference or test ECG waveforms, as judged by medical personnel, were among the reasons. It also begins to describe subjects who appeared to have atrial fibrillation at enrollment, but does not give a complete description of that criterion. The total number contributing to the primary endpoint, the handling of missing or unreadable recordings, and the analysis population definition are not reported in the registry record.
As general statistical context, missingness can affect interpretation when the chance that a measurement is unavailable is related to the subject's condition or measurement characteristics. No missing-data method or assessment is described. The record also does not report an interim-analysis plan or a statistical analysis plan. These absences prevent a detailed appraisal of analytic choices; they do not show that a particular method was or was not used outside what is recorded.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| INVSENSOR00057 | 0 | 139 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| INVSENSOR00057 | 0 of 139 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| INVSENSOR00057 | 1 of 139 |
Most frequent non-serious adverse event terms
| Event term | Organ system | INVSENSOR00057 |
|---|---|---|
| Arm Cramp | Injury, poisoning and procedural complications | 1 of 139 |
The registry lists 139 subjects at risk for serious adverse events in the INVSENSOR00057 group and 0 with a serious adverse event. For the other adverse-event count, it lists 139 at risk and 1 affected. Deaths are listed as 0. No serious adverse-event terms are listed.
These are event counts recorded for the study, not a comparison between randomized groups. The study has a single-group design, and the record provides no like-for-like control group. The count of 1 in the other adverse-event category is not accompanied by a description of the event in the registry record, so its nature and relationship to the device cannot be assessed from the listed information.
As general statistical context, observing no serious events in a study does not establish that the underlying risk is zero. Event counts also do not assess device detection performance, which is addressed by the sensitivity endpoint. The registry does not provide detailed event narratives or additional safety analyses, so these figures should be read as the recorded counts rather than as a complete safety profile.
12. What the Result Does, and Does Not, Mean
The registry record establishes that this completed study was designed to evaluate the atrial fibrillation detection performance of INVSENSOR00057 relative to an FDA-cleared ECG monitor. It specifies sensitivity as the primary endpoint, gives a timeframe of 1-5 hours, and reports enrollment of 139 subjects. It also reports that 23 subjects were excluded from data analysis based on protocol criteria, including unreadable reference or test ECG waveforms.
Those details describe the study question and some features of the dataset, but they do not answer the primary question. The observed sensitivity is not reported in the registry record. The number of reference-positive cases used in analysis, an uncertainty interval, and details of the endpoint analysis are also not reported. It is therefore not possible to judge the magnitude or precision of detection performance from this record.
The study's single-group design and lack of masking should be kept in view. The comparison with an FDA-cleared ECG monitor is a reference-based performance assessment, not a randomized comparison of treatment strategies. The record does not supply detail on how readings were adjudicated, how incomplete recordings were handled, or how the endpoint analysis was conducted.
The adverse-event counts describe a different question from diagnostic sensitivity. The registry reports 0 serious adverse events among 139 at risk, 1 event in the other adverse-event count among 139 at risk, and 0 deaths. These counts cannot fill the gap in the performance result, and they do not by themselves establish a comprehensive safety profile.
As general statistical context, neither a study purpose nor a planned endpoint should be treated as a finding. A performance claim requires the actual endpoint estimate, the relevant denominator, and information about uncertainty and analysis. Without those, the registry record supports a description of what was evaluated, but not a conclusion about how well the device detected atrial fibrillation.
13. Why This Trial Matters Statistically
This trial matters statistically because it illustrates the difference between defining a diagnostic endpoint and reporting evidence about that endpoint. Sensitivity is a meaningful measure for asking how often a detection function identifies cases classified as positive by a reference monitor. Yet the endpoint definition alone cannot quantify performance. The registry identifies the comparison and the intended measure but does not report the sensitivity result or its precision.
It also highlights why the analysis population matters. Enrollment was 139, while 23 subjects were excluded from data analysis under protocol criteria. Some exclusions involved unreadable ECG waveforms. For a sensitivity analysis, the number of usable reference-positive cases is particularly important. The registry does not report that denominator, so the overall enrollment cannot be used to infer how much information supported the endpoint.
The single-group structure clarifies the scope of inference. This study evaluates device readings against a reference monitor; it is not a randomized comparison between treatment arms. The listed planning assumptions include equal allocation between two arms, but that planning framework should not be confused with the actual study design. Planning illustrations answer hypothetical design questions, not questions about the observed result.
Finally, the record shows why results and methods need to be reported together. The absence of a listed analysis, a numerical endpoint result, an uncertainty estimate, and a complete account of exclusions leaves important questions unresolved. This does not determine whether the device performed well or poorly. It defines what can and cannot be concluded statistically from the registry record.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The primary limitation for interpretation is that the registry does not report the observed sensitivity, its uncertainty, or the number of reference-positive cases contributing to the endpoint. As a result, the central performance question cannot be answered from the posted results. The endpoint definition and timeframe are recorded, but no numerical performance estimate is available.
The record reports 23 exclusions from data analysis among 139 enrolled subjects. It describes unreadable reference or test ECG waveforms as a reason and begins to mention subjects who appeared to have atrial fibrillation at enrollment, but the latter criterion is not fully described. The number analyzed and the complete exclusion rationale are not reported in the registry record. This makes it difficult to assess how exclusions shaped the endpoint population.
Additional details relevant to interpretation are not reported in the registry record, including the statistical analysis method, the approach to missing or unreadable data, the process for adjudicating ECG classifications, and the handling of disagreements between device and reference. The record lists no analyses and does not provide a statistical analysis plan or interim-analysis information.
The study is single-group and unmasked, with no randomized control comparison. It addresses performance relative to an FDA-cleared ECG monitor, but the record does not give enough procedural detail to assess the effect of reference interpretation or masking on the comparison. The phase is listed as NA, and the protocol-based rationale for enrollment is not reported.
Safety detail is also limited to aggregate counts: no serious adverse events, one event in the other adverse-event count, and no deaths. The event in the other category is not described. These limitations restrict conclusions to the design and counts recorded, rather than supporting a comprehensive assessment of performance or safety.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Performance of Masimo INVSENSOR00057 in Detecting Atrial Fibrillation (Afib) — NCT05472012.
- Registry record last updated 2025-05-22; status last verified 2025-05.
- Results first posted 2025-05-22.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry describes a completed, single-group study sponsored by Masimo Corporation to validate INVSENSOR00057 for atrial fibrillation detection. Enrollment was 139. Participants in data collection received the noninvasive device, and its ECG measurements were compared with results from an FDA-cleared ECG monitor. The study was unmasked, with no allocation listed.
The primary endpoint was sensitivity of the device's atrial fibrillation detection function, expressed as a percentage of true positives, with a timeframe of 1-5 hours. The record states that 23 subjects were excluded from data analysis under protocol criteria, including unreadable reference or test ECG waveforms. The sensitivity result and its precision are not reported in the registry record.
The record lists 2 outcome measures and no analyses. It reports 0 serious adverse events among 139 at risk, 1 event in the other adverse-event count among 139 at risk, and 0 deaths. The study started on 2022-07-25, reached primary completion on 2023-12-16, and is marked completed.