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 Low-Cost, Portable Flexible Nasopharyngoscope in Head & Neck Cancers in Low Resource Settings - Optimization Phase (NCT04905134), a non-randomized na study. The primary outcome is Number of Participant Exams in Which Providers Reported the FNS (Flexible Nasopharyngoscope) is Easy to Use.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04905134 |
| Phase | NA |
| Condition | Head and Neck Cancer, Oral Cancer |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 53 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Duke University |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns patients being evaluated for head and neck cancers, including oral cancer, and providers conducting the examinations. The primary outcome applies only to providers who conducted exams. The registry record lists enrollment of 53.
Intervention
The device of interest is a low-cost, portable flexible nasopharyngoscope prototype, abbreviated FNS. Patients were evaluated using the prototype, and providers used it during exams.
Comparator
The stated comparator is the standard-of-care (SOC) nasopharyngoscope. The registry describes patient evaluations using the SOC scope and frames the device assessment as a comparison with standard care.
Primary question
In participant exams conducted by providers, how often did providers report that the FNS was easy to use? The outcome is described as a count of exams, with provider ratings recorded on a five-point scale.
The study aims to develop and evaluate a portable scope for use in settings with limited resources. It considers ease of use, image quality, and perceived pain, and the stated ultimate goal is to compare ease of use between the FNS and the device used in standard care. The record also lists image-quality outcomes for both scopes, adverse events following flexible-scope use, and comparative pain or discomfort.
This is an assessment of device use and examination experience, not a randomized treatment comparison. The primary question is specifically about provider reports for exams using the prototype. It does not, by itself, ask whether the scope changes cancer outcomes or establishes diagnostic accuracy. The registry record does not report the primary outcome result, so the frequency of provider reports that the FNS was easy to use cannot be stated from the record.
3. Trial Design
NCT04905134 is titled an optimization-phase study of a low-cost, portable flexible nasopharyngoscope for head and neck cancers in low-resource settings. Its official title describes a partnership to establish a practice-based network for assessing head and neck cancers using the device. Duke University is listed as sponsor. The phase is recorded as NA, the status is completed, and the registry lists a start date of 2023-07-31 and a primary completion date of 2023-09-22.
The design is listed as nonrandomized, with a parallel model and no masking. The record lists enrollment of 53. It describes patients evaluated using the flexible prototype and patients evaluated using the standard-of-care nasopharyngoscope, as well as providers using the prototype. This structure allows the record to describe experiences with the devices, but nonrandom allocation does not ensure that the groups are comparable. The registry specifically flags that the arms are not a like-for-like control comparison.
The intervention is a device, named Nasopharyngoscope. The record's brief summary says that the prototype is to be compared with the SOC endoscope in terms of ease of use, image quality, and perceived pain. However, the arm descriptions are blank, and the registry record does not describe how patients or providers were assigned to device use, whether the same providers or patients used both scopes, or how the comparison was conducted in practice. Those details should not be inferred from the parallel-model label.
The primary outcome is provider-reported ease of use for participant exams, measured over a timeframe of up to 15 minutes. The listed primary population is providers who conducted exams. The record lists five outcome measures overall and one analysis entry, but it does not report the primary result or detailed statistical methods. The nonrandomized design and incomplete outcome reporting limit what can be concluded about comparative performance.
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 providers who conducted the exams (n = 9) were not considered enrolled.
Exam With Standard Nasopharyngoscope
| Stage | SOC Nasopharyngoscope Examination of the Upper Aerodigestive Tract |
|---|---|
| STARTED | 53 |
| COMPLETED | 50 |
| NOT COMPLETED | 3 |
Reasons for not completing this period:
| Reason | SOC Nasopharyngoscope Examination of the Upper Aerodigestive Tract |
|---|---|
| Study device not available | 2 |
| Withdrawal by Subject | 1 |
Exam With Study Nasopharyngoscope
| Stage | SOC Nasopharyngoscope Examination of the Upper Aerodigestive Tract |
|---|---|
| STARTED | 50 |
| COMPLETED | 50 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Only applicable to the providers who conducted the exams.
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: Participants who completed the study are included.
| Characteristic | Unit | SOC Nasopharyngoscope Examination of the Upper Aerodigestive Tract |
|---|---|---|
| Participants analysed | 50 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 25 |
| Age, Categorical: >=65 years | Participants | 25 |
| Sex: Female, Male: Female | Participants | 18 |
| Sex: Female, Male: Male | Participants | 32 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 46 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 4 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 2 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 10 |
| Race (NIH/OMB): White | Participants | 35 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 3 |
| Region of Enrollment: United States | participants | 50 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participant Exams in Which Providers Reported the FNS (Flexible Nasopharyngoscope) is Easy to Use, measured over up to 15 minutes.
| Element | Registry entry |
|---|---|
| Result type | Count Of Units |
| Measure of spread | not applicable |
| Unit | Participant exams |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of participant exams in which providers reported that the flexible nasopharyngoscope was easy to use. The record says the assessment uses a five-point scale: 1 is Very hard, 2 is Harder, 3 is Same, 4 is Easier, and 5 is Very Easy. The timeframe is up to 15 minutes, and the endpoint applies only to providers who conducted the exams.
This outcome is relevant to an optimization study because a device intended for use in resource-limited settings needs to be workable for the providers performing examinations. A count of exams associated with positive ease-of-use reports can describe the observed experience in the study, subject to clear reporting of the scale and the rule used to classify a report as easy. The registry record does not specify a cutpoint for converting the five scale responses into the endpoint count. It also does not report the count or the distribution of ratings.
The measure captures provider perception, not objective diagnostic performance. It does not establish whether the scope detects disease accurately, changes clinical decisions, or improves patient outcomes. The listed secondary outcomes separately address image quality, adverse events, and patient-reported pain or discomfort. Those outcomes provide different kinds of information and should not be treated as interchangeable with provider-reported ease of use. Without the posted primary result and its analysis details, the endpoint's observed magnitude and precision cannot be assessed.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a completed optimization-phase device study with a nonrandomized, parallel design and no masking. Its primary outcome focuses on provider reports of ease of use during exams with the flexible nasopharyngoscope. The study's stated aim is to evaluate a portable, lower-cost scope in head and neck cancer assessment in low-resource settings and to compare it with the standard-of-care device.
The central interpretive limitation is that the primary outcome result is not reported in the registry record. The record gives the scale and the unit of measurement, but not the number of exams rated as easy to use, the rating distribution, or an estimate of uncertainty. Consequently, it is not possible to quantify the observed provider experience or judge how precisely it was estimated. The record also does not report the results for the listed image-quality, adverse-event, or pain outcomes, apart from the serious and other adverse-event figures for the SOC examination group described separately.
Even if comparative results are available elsewhere, a nonrandomized design requires cautious interpretation. Device groups may differ in ways related to use or rating, and the record does not give enough information about assignment or repeated use to assess those possibilities. The listed arms are not a like-for-like control comparison. A comparison of ratings therefore would not automatically isolate an effect of the scope itself.
The primary outcome is subjective and provider-reported. Such an outcome can be useful for assessing usability, but its meaning depends on how the response scale was administered and how the endpoint count was defined. The registry record does not report a threshold distinguishing an easy rating from other ratings. Nor does it describe whether providers were trained on each scope or whether ratings were collected in a way that reduced expectation effects.
The record's completed status and enrollment figure describe study administration, not evidence of a favorable or unfavorable result. No conclusion about comparative ease of use, image quality, pain, diagnostic accuracy, or clinical benefit follows from those details alone. Interpretation should remain limited to the outcomes actually posted, with attention to the design and the missing analysis details. In this record, the primary result and its precision are not reported, so the stated research question remains unanswered by the registry entry.
9. Statistical Methods Explained
The registry record supplies a design label and an outcome definition, but little detail about the statistical analysis. The distinctions below explain how the listed measures are generally interpreted and identify information needed to assess results. They are general statistical explanations, not descriptions of unreported procedures.
What does a count endpoint represent?
A count records how many units meet a stated condition. Here the unit is a participant exam, and the primary title refers to exams in which providers reported the FNS was easy to use. A count is meaningful only alongside a clear definition of the condition being counted and the number of exams eligible to be counted. The record describes the rating scale but does not specify the threshold used to classify responses as easy, report the observed count, or provide the eligible-exam denominator. Therefore, no rate or proportion can be interpreted from this record.
Counts can be analyzed using methods designed for count outcomes, but the choice depends on how the data were generated, their distribution, and the study design. A simple count model may be unsuitable if observations vary more than its assumptions allow; over-dispersion means that the variability is greater than the model expects. In that situation, uncertainty can be understated if a model fails to account for the extra variation. This is a general consideration, not evidence that over-dispersion occurred in this study. The registry record does not report a model, a dispersion assessment, or an adjusted estimate.
How should the five-point scale be read?
The scale runs from Very hard through Very Easy, with intermediate labels of Harder, Same, and Easier. It is an ordered response scale: the labels have an order, but the distance between neighboring responses is not necessarily equal. A summary that treats scale steps as equal distances would rely on an additional assumption. Reporting the response distribution can preserve the distinctions among categories; a count based on a threshold instead requires the threshold to be explicit. The registry record gives the labels but does not report the rating distribution or a classification rule for the primary count.
Provider ratings are also subjective measurements. Their interpretation can be affected by familiarity, expectations, and the context in which the rating is collected. These are general issues for usability assessments. The record does not describe provider training, the order of device use, rating procedures, or steps taken to reduce potential influence from expectations. With no masking listed, users and assessors should not be presumed unaware of which device was used.
What does the nonrandomized design imply?
Random allocation is not listed; the registry classifies allocation as nonrandomized. In general, random assignment can balance measured and unmeasured characteristics on average, while nonrandom assignment may leave differences between groups. Comparisons in nonrandomized studies can be affected by those differences, including differences in who uses each device or in the circumstances of an exam. The registry explicitly warns that the arms are not a like-for-like control comparison. The record does not describe an adjustment strategy or the variables, if any, used in an adjusted analysis.
The parallel model indicates that the registry classifies the study as having parallel groups, but does not establish whether a given provider or patient contributed observations to more than one device group. Repeated observations from the same person are statistically related; treating related observations as independent can produce misleading uncertainty. The record does not report the relationship between observations or how any repeated measurements were handled. That information matters for interpreting standard errors and confidence intervals in a comparison.
What would uncertainty estimates add?
A confidence interval is a range of values compatible with the observed data under a specified statistical method. It conveys precision as well as the direction and scale of an estimate. A narrow interval indicates greater precision than a wide interval, while neither alone establishes practical importance. The registry record does not report a primary estimate or confidence interval, so the precision of the provider-reported outcome cannot be assessed. A p-value, if reported, would address compatibility with a specified null model; it would not replace an effect estimate or convey the size of the observed difference.
The planning illustrations associated with this record are described as calculations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They are illustrations for planning, not observed power. The stated fraction of the observed effect is the effect assumed for each planning scenario. The assumptions do not establish that the original study was designed with those values, and the registry record does not report a sample-size justification for the trial. Since the observed primary effect is not reported in the registry record, the numerical planning outputs cannot be interpreted from the record alone.
These planning assumptions also need to be considered against the actual design. Equal allocation between two arms is an assumption for the illustration, while the registry describes multiple patient and provider arm labels and a nonrandomized design. The record does not report enough detail to establish how the illustration's assumed comparison maps to the study's observations. A planning calculation cannot correct limitations in allocation, outcome definition, or missing results.
Overall, the record permits a description of the intended endpoint and design, but not an independent reconstruction of the analysis. The statistical model, handling of dependence, adjustment, uncertainty estimates, and decision rules are not reported in the registry record. Results should be interpreted only with those limits in view, and the absence of a reported primary result precludes an effect estimate or precision assessment.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists five outcome measures: the primary provider-reported ease-of-use count and secondary measures addressing image quality for the SOC scope, image quality for the flexible scope, adverse events following flexible-scope use, and comparative pain or discomfort. When multiple outcomes are examined, the possibility of chance findings across analyses can increase. A prespecified hierarchy or multiplicity adjustment can help clarify which outcomes are confirmatory and how evidence across outcomes should be interpreted. The registry record does not report a multiplicity plan or explain how outcome priority was handled beyond identifying the primary measure.
One analysis entry is listed, but that fact does not describe the statistical plan. The record does not report whether there were subgroup analyses, interim analyses, outcome transformations, or adjustments for multiple comparisons. Those details are not reported in the registry record and should not be inferred from the number of analysis entries.
The registry record also does not report the amount or pattern of missing outcome data, how missing ratings were handled, or the analysis population used for each endpoint. Missing ratings can matter if their occurrence is related to the device or the provider's experience. Without denominators and missing-data methods, a reported count or rating distribution would be difficult to interpret fully. No imputation or complete-case approach can be assumed.
The primary endpoint applies only to providers who conducted exams, but the record does not specify the number of providers, the number of exams eligible for rating, or whether all eligible exams contributed to the analysis. These details are needed to understand the precision and scope of the endpoint. The registry record does not report them.
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 |
|---|---|---|---|
| SOC Nasopharyngoscope Examination of the Upper Aerodigestive Tract | 0 | 53 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| SOC Nasopharyngoscope Examination of the Upper Aerodigestive Tract | 0 of 53 |
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 |
|---|---|
| SOC Nasopharyngoscope Examination of the Upper Aerodigestive Tract | 0 of 53 |
For the SOC Nasopharyngoscope Examination of the Upper Aerodigestive Tract, the registry lists 53 at risk, 0 serious adverse events, 0 other adverse events, and 0 deaths. These figures describe the SOC examination group. They should not be read as safety results for the flexible prototype: the secondary outcome list includes adverse events following flexible-scope use, but its result is not reported in the registry record.
A zero count means that no events of the listed type were recorded in the stated group. It does not demonstrate that an event is impossible or that risk is absent. The amount of uncertainty around a zero count depends on the observation process and follow-up, which the registry record does not detail. The record also does not give event definitions or information about how events were collected and attributed.
The listed adverse-event figures are not a comparative estimate of safety between scopes. The study is nonrandomized, and the registry warns that the arms are not a like-for-like control comparison. Without comparable outcome results and information on follow-up, exposure, and ascertainment, the group figures cannot establish a relative safety difference. The flexible-scope adverse-event result is not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The study addresses a practical device question: whether a portable flexible nasopharyngoscope can be evaluated for use in head and neck cancer assessment in low-resource settings. Its primary measure focuses on provider-reported ease of use during exams. The record also names image quality, patient pain or discomfort, and adverse events as outcomes of interest. These measures address usability and examination experience, not the full clinical performance of a diagnostic device.
The registry record does not report the primary outcome result. It therefore does not establish how many exams were rated as easy to use, how the ratings were distributed, or how precisely the outcome was estimated. The record also does not report the results for image quality or comparative pain and discomfort. The SOC serious adverse-event figures do not substitute for the missing flexible-scope adverse-event result.
Even a positive usability result would not by itself demonstrate diagnostic accuracy, improved cancer detection, better patient outcomes, or equivalence to the standard-of-care scope. Those are different claims requiring appropriate outcomes and evidence. The registry record's stated aim is device evaluation and optimization; no conclusion about those broader clinical questions can be drawn from the information.
The nonrandomized design further constrains comparative interpretation. Groups may differ in important ways, and the record does not describe allocation procedures or analytical adjustment. The warning that arms are not a like-for-like control comparison is especially relevant when interpreting any apparent difference. The completed status and enrollment figure do not resolve these evidentiary limitations.
In short, the registry establishes what the study intended to assess and how the primary scale was labeled, but it does not provide the primary result needed to answer the stated ease-of-use question. Any stronger conclusion would require outcome results, analysis details, and sufficient information about the comparison and observations.
13. Why This Trial Matters Statistically
Device usability is a statistical question as well as a practical one. A new examination tool may be assessed through provider ratings, patient experience, image quality, and safety observations, but each outcome captures a different aspect of use. Keeping those outcomes distinct prevents a favorable result on a subjective usability measure from being mistaken for evidence about diagnostic performance or patient benefit.
This record is also a useful example of why design labels matter. A parallel model does not make groups comparable when allocation is nonrandomized. The registry explicitly cautions that the arms are not a like-for-like control comparison. That warning should shape interpretation of any between-device contrast: observed differences may reflect group composition or examination circumstances as well as the device.
Outcome definitions and denominators are essential for count data. The primary endpoint describes a count of exams linked to provider reports, but the record does not state the threshold for classifying a rating as easy or give the result and eligible-exam denominator. Without these details, readers cannot determine the magnitude or precision of the measure. A scale's labels alone do not resolve how a count was constructed.
Finally, planning calculations and observed evidence serve different purposes. The record's described planning assumptions are not proof of observed power and do not replace a reported effect estimate with uncertainty. Since the primary result is not reported in the registry record, the key statistical question remains unresolved. Clear outcome reporting would be needed to judge what this optimization study found.
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 leaves important design and analysis details unspecified. The arm descriptions are blank, and the record does not explain how patients or providers were assigned to the prototype or SOC device, whether the same people used both scopes, or how exams were scheduled. These omissions limit understanding of how comparable the groups were and whether observations may be related.
The primary outcome is described as a count of exams where providers reported the FNS was easy to use, measured with a five-point scale. However, the record does not define the cutpoint that determines an easy report, give the number of eligible exams, or report the outcome value. It also does not report the scale's response distribution. The absence of these details prevents assessment of both the outcome construction and its precision.
The study is nonrandomized and unmasked. Those design features may matter for a subjective provider-rated outcome, and the registry cautions that the arms are not a like-for-like control comparison. The record does not describe provider familiarity, training, device-use order, outcome collection procedures, or analytical adjustments. Their influence cannot be determined from the record.
Additional limitations include the lack of reported statistical methods, missing-data handling, analysis populations, confidence intervals, and a sample-size justification. Results for the flexible-scope adverse-event measure, image quality, and pain or discomfort are not reported in the registry record. The available SOC safety counts do not fill those gaps. As a result, the record supports a description of the study's intent and design, but not a complete evaluation of its findings.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Low-Cost, Portable Flexible Nasopharyngoscope in Head & Neck Cancers in Low Resource Settings - Optimization Phase — NCT04905134.
- Registry record last updated 2024-09-19; status last verified 2024-08.
- Results first posted 2024-09-19.
- 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
NCT04905134 is a completed, nonrandomized, parallel-model device study sponsored by Duke University. The phase is listed as NA, masking as none, and enrollment as 53. The record lists a start date of 2023-07-31 and a primary completion date of 2023-09-22.
The study evaluates a low-cost portable flexible nasopharyngoscope prototype for head and neck cancer assessment in low-resource settings, with the SOC nasopharyngoscope as the intended comparator. The primary measure is a provider-reported ease-of-use count for participant exams, rated on a five-point scale over up to 15 minutes. Listed secondary outcomes address image quality, flexible-scope adverse events, and comparative pain or discomfort.
The primary result and the secondary outcome results are not reported in the registry record. The record reports 0 serious adverse events, 0 other adverse events, and 0 deaths among 53 at risk in the SOC examination group. The registry warns that the nonrandomized arms are not a like-for-like control comparison.