INVSENSOR00013 Respiratory Rate Clinical Performance Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for INVSENSOR00013 Respiratory Rate Clinical Performance Study (NCT03440619), a na na study. The primary outcome is RRp Arms of Sensor Accuracy.

2. Clinical Question

This is a measurement-performance question, rather than a question about whether a treatment changes a health outcome. The target is agreement between a device measurement and a reference measurement. Agreement is summarized using the size of the differences between paired measurements, with both their average direction and their variability contributing to Arms.

The setting matters to interpretation. The registry record describes a healthy study population and a single test group, not a randomized comparison of treatment groups. It therefore does not establish comparative performance against a concurrent control arm. Although the study summary names additional comparison approaches, the primary outcome description identifies RRef as the reference for the specified Arms calculation. Numerical results for that calculation are not reported in the registry record, so the degree of agreement cannot be quantified from the record.

3. Trial Design

This completed prospective study evaluated the INVSENSOR00013 device in healthy participants. The registry record lists Masimo Corporation as the sponsor, an enrollment of 28, and study dates from 2018-02-06 to 2018-02-14. The primary outcome timeframe is 1-5 hours. The record lists the phase and allocation as NA, masking as NONE, and the model as SINGLE GROUP.

All subjects were assigned to the INVSENSOR00013 Test group and received the investigational device. There is no separate control arm described. In this design, comparisons for the primary outcome are between device readings and reference readings, rather than between groups assigned to different interventions. A measurement reference is not equivalent to a randomized control group: the two readings are paired measurement methods, and the study asks how closely they agree.

The study summary describes the objective as comparing RRp performance with respiratory rate measured by capnography (RRref), Masimo’s RAM technology, and manual annotation. The primary outcome description is narrower: it defines Arms by subtracting the respiratory-rate reference (RRef) from the INVSENSOR00013 RRp measurement across samples. Whether additional comparisons were prespecified as formal outcomes or analyses is not reported in the registry record.

The registry record marks the study COMPLETED. It does not report the protocol’s rationale for the enrollment target, detailed eligibility criteria, measurement schedule, or operational procedures for collecting paired readings. It also does not report whether all enrolled participants contributed to the primary endpoint. These details affect how representative the observed measurements would be and how precisely they would characterize device performance, but they cannot be inferred from the design labels 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

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.

6. Primary Endpoint

The registry lists the primary outcome as RRp Arms of Sensor Accuracy, measured over 1-5 hours.

The primary outcome is titled “RRp Arms of Sensor Accuracy” and is measured in respiration per minute (RPM). It summarizes the difference between the INVSENSOR00013 device’s noninvasive respiratory-rate measurement by pleth (RRp) and the respiratory-rate reference (RRef). The outcome description says the reference value is subtracted from the device value for a number of samples. The average of these differences is the bias; their standard deviation is the precision; and Arms is the square root of the sum of the squared bias and squared precision.

As a general statistical interpretation, bias describes the average direction and size of measurement error, while precision describes how much the differences vary around their average. Combining both components yields a single summary of overall discrepancy. A measure of this kind is useful because a small average difference alone could conceal substantial variation across paired measurements. Conversely, low variation does not by itself rule out a consistent offset.

Arms is therefore an accuracy summary, not a direct measure of clinical benefit or a treatment effect. Its interpretation depends on the reference method, the measurement conditions, the sampled readings, and the population in which measurements were taken. The registry record defines the calculation but does not report the numerical Arms result, its uncertainty, or the number of paired samples included. The observed size and precision of the device-reference differences are consequently not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint uses paired measurement differences. For each sample, the device’s RRp value is compared with RRef, as specified in the outcome description. The direction of subtraction matters: the reference is subtracted from the device value. Positive and negative differences therefore represent opposite directions of discrepancy. The registry record defines this calculation but does not report the paired values or the resulting summary statistics.

What do bias and precision describe?

As a general statistical explanation, bias is the average of the paired differences. It indicates whether device values tend, on average, to be higher or lower than the reference values. Precision, as defined in this record, is the standard deviation of those differences. It describes how widely individual differences vary around their average. These concepts answer related but distinct questions: bias concerns a systematic offset, while precision concerns dispersion.

A small bias does not necessarily imply close agreement for individual measurements. Differences can average near zero while varying substantially in both directions. Similarly, measurements can be tightly clustered yet remain consistently offset from the reference. This is why the endpoint combines the squared bias and squared precision rather than relying on the average difference alone.

How is Arms constructed?

The registry describes Arms as the square root of the sum of the squares of bias and precision. As a general interpretation, squaring prevents positive and negative components from cancelling when they are combined; taking the square root returns the summary to the measurement scale. Arms is thus a single overall measure that reflects both systematic discrepancy and variation. It is expressed in respiration per minute (RPM), the unit listed for the primary outcome.

The combined summary does not show which component accounts for the observed discrepancy. If an Arms result were available, separate bias and precision estimates would help explain whether it reflects a consistent shift, variable readings, or both. The registry record does not report those component estimates, so that decomposition is unavailable.

Why do paired measurements matter?

As a general statistical principle, agreement analyses use readings taken under corresponding conditions so that the difference is meaningful for each paired observation. The registry outcome description refers to subtracting the reference measurement from the device measurement across samples. It does not report the number of pairs, the process for matching device and reference readings, or whether repeated samples came from the same participants. Such information is important for evaluating data quality and the independence assumptions used in uncertainty calculations.

When observations are repeated within a participant, they may be correlated. General statistical methods can account for that clustering when estimating uncertainty. Treating correlated readings as independent can make an analysis appear more precise than the data warrant. Whether the study had repeated readings, and how any within-participant correlation was handled, is not reported in the registry record.

What uncertainty information is available?

A point estimate alone would describe the observed sample but not show how uncertain the estimate is. As a general explanation, a confidence interval combines information about the estimate and its sampling variability, under the assumptions of the analysis. The registry record does not report a confidence interval, standard error, or other uncertainty measure for Arms. It also does not report a statistical analysis entry, despite listing the primary outcome measure.

The record describes the outcome timeframe as 1-5 hours, but does not say how that window relates to sample selection, aggregation, or participant-level summaries. It does not identify whether the primary analysis would aggregate all readings, summarize readings within each participant before combining participants, or use another approach. Those choices can affect the weighting of participants and the interpretation of the estimate. The analysis method is not reported in the registry record.

What can sample-size planning say?

As a general concept, a sample-size calculation depends on assumptions about the target effect, variability, significance level, allocation, and analysis. The registry record contains a description of planning illustrations based on fractions of an observed effect and specifies general assumptions for those illustrations. It does not report an actual numerical illustration or a trial-specific sample-size justification. Such planning figures, when available, describe hypothetical design requirements; they are not observed outcomes and are not a substitute for an analysis of the collected data.

Because the primary outcome result is not reported, the observed effect needed for an effect-based planning illustration is not available in the registry record. No planning estimate can be interpreted as observed power or as evidence that the study could detect a particular level of agreement. The record also does not state a clinically or technically acceptable Arms threshold, which would be needed to relate the magnitude of a result to a prespecified performance criterion.

Overall, the statistical definition is sufficiently clear to explain what the endpoint is intended to summarize. The numerical inputs, result, uncertainty, and analysis details needed to judge the estimate are not reported in the registry record. General statistical concepts clarify what those elements would mean, but they cannot fill in absent study results.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure and zero analysis entries. The primary outcome is the Arms summary for RRp compared with RRef. The study summary also names comparisons with capnography, Masimo’s RAM technology, and manual annotation. The record does not specify whether these were additional formal outcomes, secondary analyses, or descriptive comparisons, so the full set of planned statistical tests is not reported in the registry record.

Multiplicity arises when several outcomes, comparisons, time points, or analytical choices are examined. As a general statistical principle, conducting many tests can increase the chance of a nominally notable result occurring by chance, unless the analysis plan accounts for that multiplicity or the findings are interpreted accordingly. The registry record does not report a multiplicity adjustment, a hierarchy of outcomes, or a prespecified testing strategy. It is not possible to conclude from the number of listed outcome measures alone that multiplicity was absent.

Missing-data handling and analysis populations are also not described. The record does not state how unusable readings, incomplete paired measurements, protocol deviations, or participant withdrawals were handled. It does not identify a population definition for the primary analysis or report the number of participants and paired samples contributing to the outcome. The listed enrollment of 28 should therefore not be read as a confirmed analysis denominator.

These omissions limit assessment of whether the reported analysis, if any, followed a prespecified plan and whether missing measurements could have influenced the result. The statistical analysis plan, multiplicity approach, missing-data procedures, and analysis populations are not reported in the registry record.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry record lists the INVSENSOR00013 Sensor group with 28 participants at risk for serious adverse events and 0 affected. It also lists 28 at risk for other adverse events and 0 affected. Deaths are listed as 0. No serious adverse event terms are listed.

These counts describe what is recorded for the group; they do not provide detail on event definitions, surveillance procedures, duration of follow-up, or completeness of reporting. The outcome timeframe for the primary measurement is 1-5 hours, but the adverse-event follow-up period is not reported in the registry record. The counts also do not show whether participants experienced symptoms or events that were not classified under the reported categories.

As a general statistical caution, a zero count in a study group does not prove that an event cannot occur. It means no events were recorded in the specified category for the listed group and period, as represented in the registry record. Without further safety definitions and follow-up details, these figures should not be extended beyond that record. They are safety counts, not a comparative safety estimate, because the study has no separate control group.

12. What the Result Does, and Does Not, Mean

The record establishes that a prospective, single-group study evaluated INVSENSOR00013 in healthy participants, with a listed enrollment of 28 and a primary outcome based on comparison of RRp with RRef. It specifies how the endpoint is calculated: the average paired difference is bias, the standard deviation of the differences is precision, and Arms combines those components. This allows the measurement question and intended summary to be understood.

The record does not report the numerical primary outcome result, its component estimates, or uncertainty. It therefore does not show how large the measurement differences were, how variable they were, or how precisely agreement was estimated. No conclusion about the observed degree of accuracy can be drawn from the endpoint definition alone. A stated calculation method is not itself evidence of a particular result.

The design also sets boundaries on interpretation. A single test group with a reference measurement is suitable for describing a device-reference comparison, but it is not a randomized comparison of interventions. The population is described as healthy, and the registry record does not report how performance might vary in other populations or settings. The study summary mentions additional comparison approaches, but numerical results for them are not reported in the registry record.

As a general distinction, measurement agreement and clinical usefulness are different questions. An accuracy summary can describe discrepancy relative to a reference, but interpretation for a particular purpose would also depend on an appropriate performance threshold and the intended measurement context. No such threshold is reported in the registry record. The available information supports describing the study’s design and endpoint, not asserting that the device meets a standard or produces a particular clinical benefit.

The adverse-event record lists zero serious events, zero other events, and zero deaths for the listed group. These are recorded counts, not evidence of comparative safety or proof that events are impossible. Taken together, the record supplies design and endpoint definitions but lacks the results required to quantify device performance.

13. Why This Trial Matters Statistically

This study illustrates a common statistical distinction in clinical measurement research: evaluating agreement is not the same as comparing treatments. The device reading is compared with a reference reading, and the target is the size and structure of their differences. A single-group design can address that measurement question without a randomized treatment control, but it cannot answer questions that require a contrast between intervention groups.

The endpoint also highlights why a single summary can benefit from component interpretation. Arms combines bias and precision, so it captures systematic offset as well as variability. Reporting the components and uncertainty would help readers understand what drives the overall measure and how much confidence to place in it. The registry record defines the metric but does not report those results.

Registry records can therefore be informative about what a study set out to measure while remaining insufficient for judging its findings. Here, the population, device, measurement reference, endpoint definition, and listed enrollment are recorded. The numerical endpoint result, analysis details, analysis population, and uncertainty are not reported in the registry record. That distinction helps keep conclusions anchored to what is actually documented.

The design and reporting gaps are statistically important rather than merely administrative. The number of usable paired readings, the handling of repeated observations, and the missing-data strategy affect how an estimate should be interpreted. Likewise, a prespecified accuracy threshold is needed to evaluate whether a result meets an intended criterion. Without those elements and the result itself, a reader can understand the analysis target but cannot assess its empirical performance.

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 registry record gives limited detail for evaluating the study beyond its stated design and outcome definition. The population is described only as healthy; more specific eligibility criteria and participant characteristics are not reported in the registry record. The record lists enrollment of 28 but does not report the number with evaluable paired measurements or explain whether any enrolled participants were excluded from the primary analysis.

The outcome is defined using samples of device and reference readings, but the number of samples and the method for pairing or selecting them are not reported in the registry record. The record does not clarify how many readings came from each participant, whether readings were repeated, or how any correlation among repeated measurements was handled. These issues bear on the estimate’s weighting and uncertainty.

The registry record does not provide a numerical Arms result, bias, precision, confidence interval, or analysis entry. The statistical analysis plan, missing-data procedures, analysis population, and approach to additional comparisons are also not reported. The study summary names capnography, RAM technology, and manual annotation, while the primary outcome description specifies RRef; results for the other named comparisons are not reported in the registry record.

Finally, the record does not state an acceptable performance threshold, detailed measurement procedures, or adverse-event follow-up duration. The study is listed as single-group, and the findings cannot be interpreted as a randomized comparison. These limitations mean the record supports a description of the intended measurement assessment, but not a detailed appraisal of observed accuracy or broader generalizability.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: INVSENSOR00013 Respiratory Rate Clinical Performance Study — NCT03440619.
• Registry record last updated 2019-04-23; status last verified 2019-04.
• Results first posted 2019-04-23.
• 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.

18. Record Summary

NCT03440619 is the registry record for the completed INVSENSOR00013 Respiratory Rate Clinical Performance Study, sponsored by Masimo Corporation. It describes a prospective, single-group study in healthy participants, with 28 enrolled and study dates from 2018-02-06 to 2018-02-14. Participants received the INVSENSOR00013 investigational device; masking is listed as NONE and allocation as NA.

The primary outcome is RRp Arms of Sensor Accuracy, measured in respiration per minute, with a timeframe of 1-5 hours. Its definition combines the average and standard deviation of differences between device readings and RRef. The record reports no analysis entries or numerical primary outcome result. Serious adverse events, other adverse events, and deaths are recorded as 0 for the listed group.