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 Study Will Test the Theory That Training With the Facial-Flex Exercise Device Will Improve Snoring in Patients (NCT01554904), a na na study. The primary outcome is Snore Index.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01554904 |
| Phase | NA |
| Condition | Primary Snoring, Sleep Apnea |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 18 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Facial Concepts, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The registry describes people with primary snoring or very mild sleep apnea as the intended population. The listed conditions are Primary Snoring and Sleep Apnea. The primary outcome description focuses on subjects completing six weeks of training and Home Sleep Test # 2. Detailed eligibility criteria, including how primary snoring or very mild sleep apnea was established, are not reported in the registry record.
Intervention
Participants trained with the Facial-Flex facial exercise device. The brief summary describes a six-week training period. The registry identifies Facial-Flex as a device and describes it as an FDA approved Class I device for facial muscle laxity; that device description is not evidence about its effect on snoring in this study. Training frequency, session duration, adherence expectations, and other procedural details are not reported in the registry record.
Comparator
There was no separate control group in the single-group design. The registry describes a comparison between snoring measurements at baseline and after six weeks of training. This is a within-group before-and-after comparison, not a randomized comparison with an untreated or alternative-treatment group. Allocation is listed as NA, and the registry identifies no masking.
Primary question
The primary question was whether the mean Snore Index changed from baseline to after six weeks of facial muscle training. The Snore Index is defined as snores per hour of monitoring. The registry states that the pre-treatment and post-treatment values would be compared, but the actual values and estimated change are not reported in the registry record. The record therefore describes the question and measurement plan, but does not establish the direction or size of any observed change.
3. Trial Design
This was a completed, single-group study of the Facial-Flex device, sponsored by Facial Concepts, Inc. The registry lists an enrollment of 18 and identifies the intervention as a device. The study began in 2012-02, had primary completion in 2012-12, and is marked COMPLETED. The study phase is listed as NA. The intended population in the brief summary was patients with primary snoring or very mild sleep apnea.
The stated intervention period was six weeks of training. For the primary outcome, the registry describes comparing a baseline measurement with a measurement after six weeks. It characterizes the primary measure as a mean continuous outcome and identifies standard deviation as the dispersion measure. The outcome population is described as subjects completing six weeks of training and Home Sleep Test # 2. The record does not report how many participants contributed usable measurements at both time points.
The design has no parallel control group: the model is SINGLE GROUP, and allocation is listed as NA. Masking is listed as NONE. Consequently, the planned comparison is change over time among people receiving the device, rather than a contrast between independently assigned treatment groups. Changes during follow-up cannot be separated from the effects of the intervention using this design alone.
Apnea-Hypopnea Index (AHI) is listed as a secondary outcome. The registry identifies two outcome measures and two analyses, but details of the secondary measure's timing, analysis, and results are not reported in the registry record. The registry also does not report a protocol-level statistical analysis plan, eligibility details, training adherence results, or reasons for any missing follow-up measurements.
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.
Before assignment: The inclusion and exclusion criteria and study protocol were discussed with potential subjects. Subjects who desired to participate and met criteria signed an informed consent.
Overall Study
| Stage | Facial-Flex |
|---|---|
| STARTED | 18 |
| Home Sleep Study 1 | 18 |
| Start 6 Weeks of Facial Training | 17 |
| Complete 6 Weeks of Facial Training | 14 |
| Home Sleep Study 2 | 14 |
| COMPLETED | 14 |
| NOT COMPLETED | 4 |
Reasons for not completing this period:
| Reason | Facial-Flex |
|---|---|
| Withdrawal by Subject | 3 |
| Had sleep apnea on Home Study 1 | 1 |
Analysis population for the primary outcome, as defined in the registry: Subjects completing 6 weeks of training and Home Sleep Test # 2
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.
Population: Number completing study
| Characteristic | Unit | Facial-Flex |
|---|---|---|
| Participants analysed | 14 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 13 |
| Age, Categorical: >=65 years | Participants | 1 |
| Age Continuous | years | 50.1 (SD 15.4) |
| Sex: Female, Male: Female | Participants | 10 |
| Sex: Female, Male: Male | Participants | 4 |
| Region of Enrollment: United States | participants | 14 |
6. Primary Endpoint
The registry lists the primary outcome as Snore Index, measured over baseline and after 6 weeks of facial muscle training.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | snores per hour of monitoring |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the Snore Index, defined as the number of snores per hour of monitoring. The registry describes measuring it at baseline and after six weeks of facial muscle training, then comparing the pre-treatment and post-treatment values. The planned summary is a mean, with standard deviation as the stated measure of dispersion. The outcome population is described as subjects completing the training period and Home Sleep Test # 2.
The registry explains how snoring was operationalized. A nasal pressure cannula connected to a sensitive pressure transducer records the nasal pressure waveform. Snoring is detected as a fine, high-frequency oscillation superimposed on that waveform, and each breath with vibration is counted as a snore. An automated scoring algorithm in the Sleep Scout device identifies breaths with snoring. The description states that the same snore threshold was used for baseline and follow-up sleep studies, with the aim of limiting technologist bias in detecting snores.
Expressing the count relative to monitoring time makes the endpoint a rate rather than a raw count, which can support comparison across monitoring periods of different duration. In general, an objective, consistently applied measurement rule can improve reproducibility. It does not, by itself, establish that the recorded change is caused by training or that the measurement captures every aspect of snoring that matters to participants. The actual baseline and follow-up means, standard deviations, and estimated change are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a specific primary outcome and a planned baseline-to-follow-up comparison, but it does not report the observed Snore Index values or an estimated change. Without those results, the direction, size, and precision of the outcome cannot be assessed from the record. The completed status indicates that the study is marked completed; it does not supply the missing outcome findings.
The design is important when interpreting any within-group change that might be reported elsewhere. Each participant's follow-up measurement is compared with a baseline measurement, but there is no separate control group in this study. A change over time could reflect the intervention, but a before-and-after comparison alone cannot distinguish an intervention effect from other explanations, such as natural fluctuation, changes in measurement conditions, or changes in participant behavior. These are general considerations for uncontrolled pre-post designs, not reported events in this trial.
The endpoint is a rate of detected snores per hour of monitoring, based on an automated scoring rule applied to nasal pressure recordings. Consistent thresholds at both assessments support comparability of the measurement procedure as described in the registry. However, the registry does not report the actual recordings, the variability of the observed values, or the completeness of paired measurements. It also does not report whether the analysis accounted for repeated measurements within participants.
The stated endpoint population is subjects completing six weeks of training and Home Sleep Test # 2. That wording makes follow-up completion relevant to interpretation, but the number with usable baseline and follow-up values, and the handling of missing measurements, are not reported in the registry record. It is therefore not possible to judge from this record whether the reported endpoint population, if results were available, would represent everyone enrolled.
AHI is identified as a secondary outcome, but its result and analysis details are not reported in the registry record. No conclusion about that measure can be drawn from its listing alone. Likewise, the record does not provide an estimated treatment effect, confidence interval, p-value, or other inferential result for the primary outcome. General statistical interpretation requires both an estimate and a measure of uncertainty; neither is available for the Snore Index in the registry information.
These limitations do not show that the intervention had no effect. They mean that the registry record, as described, does not report the evidence needed to quantify or judge a change. Any interpretation should distinguish the study's stated objective and measurement method from outcome evidence that is not reported in the registry record.
9. Statistical Methods Explained
The registry frames the primary endpoint as a continuous measurement summarized by a mean and standard deviation. These summaries answer different questions. The mean describes the average Snore Index in the measured group; the standard deviation describes how spread out individual measurements are around that average. Neither summary alone describes the precision of an estimated change. The registry record does not report the primary endpoint values or an uncertainty interval.
What does a baseline-to-follow-up comparison estimate?
In general, a before-and-after analysis can focus on the change within each participant, then summarize those individual changes. This approach recognizes that baseline and follow-up observations from the same person are related. It differs from treating the two sets of measurements as independent groups. The registry says that pre-treatment and post-treatment values will be compared, but the specific statistical procedure is not reported in the registry record. It is not possible to determine whether the analysis used paired changes, a model for repeated measurements, or another method.
For a paired analysis, the precision of the average change depends on the variability of individual changes, not only on the separate standard deviations at each time point. The association between baseline and follow-up values matters because measurements from the same participant can move together. In general, a confidence interval for an estimated change describes a range of values compatible with the data and the method's assumptions. A narrower interval indicates greater precision than a wider one, but an interval does not resolve limitations in study design or measurement. No estimated change or confidence interval is reported in the registry record.
What does the measurement process contribute?
The registry describes a defined signal-processing approach: a nasal pressure cannula and pressure transducer capture the waveform, and an automated algorithm detects breaths with vibration under a common snore threshold at baseline and follow-up. In general, use of a consistent detection rule can reduce differences caused by changes in scoring practice. It cannot rule out every source of measurement error, and it does not show whether the measure is sensitive to all clinically relevant aspects of snoring. The actual measurement reliability in this study is not reported in the registry record.
Because the endpoint is a rate per hour of monitoring, the interpretation depends on both the number of detected snores and the monitoring duration. Rate-based measures are useful when observation time may differ, but the record does not report monitoring durations or data-quality information. No further calculation can be made from the endpoint definition alone.
How should a confidence interval or p-value be read?
In general, a confidence interval conveys uncertainty around an estimate under a specified statistical model. A p-value addresses how compatible the observed data are with a specified null hypothesis under the analysis assumptions; it is not the probability that the intervention works, nor a measure of effect size. These quantities should be interpreted alongside the estimated change, the design, and the quality and completeness of the data. The registry information does not report a confidence interval, p-value, or formal statistical test for the primary outcome.
The record's sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two hypothetical arms, and a normal approximation. They do not establish that the actual trial used that design: the study itself is single-group. They also do not establish the study's original sample-size justification or observed power. Details of the actual design-stage calculation are not reported in the registry record. A planning illustration is a statement about hypothetical future design assumptions, not evidence that the completed study had adequate precision.
Why can over-dispersion matter?
In general, count outcomes can be more variable than a simple statistical model expects. When the spread of counts exceeds the model's assumptions, standard errors may be too small if that extra variability is ignored. The Snore Index is expressed as a rate derived from counts, but the registry identifies the endpoint as continuous and does not report the model used to analyze it. There is no basis in the registry record to say whether over-dispersion was present or how it was handled. This is a general consideration, not a finding about this study.
What can be inferred from the design?
A single-group pre-post comparison can describe the observed trajectory in participants with measurements at both times. In general, it cannot by itself identify the causal effect that would be estimated by comparing outcomes under intervention and an appropriate control condition. Regression to the mean, natural variation, changes in behavior, and other time-related influences are possible explanations for change in an uncontrolled study; the registry does not report whether any of these occurred. The absence of a control group is a design limitation, not a statistical adjustment that can be repaired by a more elaborate analysis alone.
Important analysis details remain unreported in the registry record: the method used for the primary comparison, the handling of missing values, the analysis population, any adjustment for baseline values, and the uncertainty estimates. Without those details and the outcome results, a numerical statistical interpretation is not possible.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies the Snore Index as the primary outcome and Apnea-Hypopnea Index (AHI) as a secondary outcome. It also indicates two outcome measures and two analyses. Reporting more than one outcome can raise a multiplicity question: when several outcomes or statistical tests are considered, the chance of at least one apparently unusual result can increase. In general, a prespecified hierarchy or adjustment can address this concern, but the registry record does not report a multiplicity strategy or whether any adjustment was used.
The record describes the primary outcome population as subjects completing six weeks of training and Home Sleep Test # 2. It does not report how many participants had complete data for both assessments, how missing measurements were handled, or whether all enrolled participants were included in any analysis. It also does not report a prespecified analysis population such as an intention-to-treat or completer population. The endpoint wording suggests that completion is relevant to the primary measure, but it does not establish the full analysis procedure.
In general, excluding participants without follow-up measurements can affect how representative an analysis is if missingness is related to outcomes or participant characteristics. Methods such as imputation or likelihood-based analyses rely on assumptions that need to be stated and evaluated. No missing-data method or reason for missingness is reported in the registry record, so the extent and potential impact of missing data cannot be assessed.
These omissions matter because outcome multiplicity and incomplete follow-up affect the interpretation of estimates and their uncertainty. They do not establish that an analysis was inappropriate; they leave these aspects undocumented in the registry record.
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 |
|---|---|---|---|
| Facial-Flex | 0 | 17 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Facial-Flex | 0 of 18 |
The safety figures list 0 serious adverse events among 17 participants at risk in the Facial-Flex group. The other adverse-event figures list 0 affected among 18 at risk. These are the recorded counts for the categories shown, and the registry lists no serious adverse-event terms. They should not be read as a complete description of every possible symptom or event unless the registry's reporting definitions and collection procedures are also known.
The serious-event denominator differs from the denominator shown for other adverse events. The registry record does not explain the difference, so it should not be interpreted as evidence about why participants may or may not have been included in each category. The death count is null, which means it is not reported in the registry record; it is not equivalent to a recorded count of zero.
In general, zero recorded events does not prove that an event is impossible or that a device is free of risk. Rare events may not appear in a small study, and safety interpretation also depends on follow-up duration, event definitions, and how actively events were collected. Those details are not reported in the registry record. The figures describe what is recorded in the safety summary, not a comprehensive estimate of risk.
12. What the Result Does, and Does Not, Mean
The registry record establishes that this completed study was designed to examine the Snore Index before and after six weeks of Facial-Flex training in a single group. It also describes a standardized automated approach to detecting snores from nasal pressure recordings. These details clarify what the primary question was and how the outcome was intended to be measured.
The record does not report the observed Snore Index values, the estimated change, or its uncertainty. It therefore does not show whether the measure increased, decreased, or stayed similar during follow-up, nor how precisely any change was estimated. The listing of an outcome is not itself a result. The same applies to the secondary AHI outcome, whose findings are not reported in the registry record.
Even if a before-and-after change were available, the single-group design would limit causal interpretation. Without a separate control group, changes over time cannot be attributed to the device alone. General alternative explanations include natural fluctuation, changes in behavior, and measurement variability. The study design can describe what happened in the observed group, but it cannot fully separate these influences from an intervention effect.
The record's safety figures show no recorded affected participants in the listed serious and other adverse-event categories, with different at-risk counts; the death count is not reported. These data should be interpreted within the limits of the available safety detail and follow-up information. They do not establish the absence of all possible adverse events.
Overall, the registry record documents a research question, a device intervention, and a planned outcome measurement. It does not provide the outcome evidence required to estimate the size or precision of a change in snoring. It cannot support a conclusion about whether training altered snoring or about the extent of any alteration.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of the distinction between a clearly defined measurement plan and a reported result. The registry describes the Snore Index in operational terms, specifies the monitoring-based rate, and states that a common automated detection threshold was used at baseline and follow-up. Such detail helps readers understand what the endpoint represents and what kind of comparison the study intended.
The design also makes the inferential boundary clear. A single-group pre-post comparison can examine change over time within participants, but it lacks a concurrent control group to help distinguish intervention-related change from other influences. Statistical methods can quantify uncertainty around an observed change, but they cannot make an uncontrolled comparison equivalent to a randomized control comparison.
The record also illustrates why analysis populations and missing data matter. The primary measure is described for participants completing training and Home Sleep Test # 2, yet the number with paired outcome measurements and the handling of missing observations are not reported. Without those details, readers cannot assess how complete the outcome data were or how the analyzed group relates to the enrolled group.
Finally, sample-size planning assumptions should be distinguished from the design and results of a completed study. The registry includes assumptions for a planning illustration, including a hypothetical two-arm setup, while the actual study is single-group. These assumptions do not demonstrate observed power or resolve the absence of reported outcome estimates. Statistical relevance lies in identifying what the design and record can support—and what remains unreported.
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 principal limitation for interpreting the primary outcome is that its observed values and estimated change are not reported in the registry record. There is no reported confidence interval or p-value for the Snore Index, so neither the direction nor precision of the outcome can be evaluated from the registry information.
The study is single-group and has no separate control condition. Any observed baseline-to-follow-up change would therefore be difficult to distinguish from other changes over time. The record lists masking as NONE. It describes automated snore scoring and a common threshold, which may limit some scorer-related variation, but it does not remove other potential sources of bias or measurement error.
The primary outcome is described for subjects completing six weeks of training and Home Sleep Test # 2. The number with complete measurements, reasons for missing follow-up, and the analysis population are not reported in the registry record. Adherence to training and details of the training regimen beyond the six-week period are also not reported. These omissions make it difficult to assess how the planned intervention was carried out and which participants contributed to the primary analysis.
Eligibility details are limited to the broad description of primary snoring or very mild sleep apnea and the listed conditions. The registry record does not report further diagnostic criteria or participant characteristics. The secondary outcome, AHI, is listed, but its result and analysis details are not reported. Multiplicity handling and the statistical method for the primary comparison are also not reported in the registry record.
These limitations are specific to the information recorded and should not be mistaken for proof that unreported procedures were absent. They mean that the registry record does not document enough information to evaluate the outcome effect, the analysis assumptions, or the completeness of follow-up in detail.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study Will Test the Theory That Training With the Facial-Flex Exercise Device Will Improve Snoring in Patients — NCT01554904.
- Registry record last updated 2013-05-01; status last verified 2013-04.
- Results first posted 2013-05-01.
- 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
NCT01554904 is a completed, single-group study sponsored by Facial Concepts, Inc. It evaluated six weeks of training with the Facial-Flex device in people described as having primary snoring or very mild sleep apnea. Enrollment is listed as 18; the study began in 2012-02 and primary completion was in 2012-12. Masking is listed as NONE.
The primary outcome was the mean Snore Index, measured as snores per hour of monitoring at baseline and after six weeks. AHI is listed as a secondary outcome. The registry describes automated snore detection and a common threshold for both assessments, but the actual outcome values and statistical results are not reported in the registry record. Safety figures list 0 serious adverse events among 17 at risk and 0 other adverse events among 18 at risk; the death count is not reported.