BinaxNOW for Evaluating Children for Infection With SARS-CoV-2 (COVID-19): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for BinaxNOW for Evaluating Children for Infection With SARS-CoV-2 (COVID-19) (NCT05087524), a na na study. The primary outcome is Number of Tests Taken Per Participant.

2. Clinical Question

3. Trial Design

The registry record describes NCT05087524, titled “BinaxNOW for Evaluating Children for Infection With SARS-CoV-2 (COVID-19).” Its official title refers to feasibility and specificity of BinaxNOW for diagnosis and surveillance of SARS-CoV-2 in schoolchildren. The listed sponsor is the University of Wisconsin, Madison. The study began on 2021-01-09, had a primary completion date of 2021-04-08, and has a status of terminated.

The design is single-group, with allocation and masking listed as not applicable and none, respectively. The intervention is the BinaxNOW Ag Card, described as a diagnostic test. The arm description identifies BinaxNOW Surveillance and says participants agreed to nasal swab sampling for diagnosis or screening, with research staff obtaining samples in the school setting. No randomized control group or like-for-like comparison is described.

The brief summary describes an intended enrollment of 240 students and 80 teachers in the Madison Metropolitan School District, with participation expected to last up to 8 weeks. The registry record lists enrollment of 65. These entries describe different enrollment figures, but the record does not explain their relationship or give a reason for the termination status. The reason for termination is not reported in the registry record.

The primary outcome is the number of tests taken per participant over up to 8 weeks, summarized as a mean with standard deviation. The record lists two outcome measures, but details for the other measure are not reported in the registry record. It lists no analysis records. Thus, the design and planned primary measure can be described, but the record does not provide numerical findings for the primary outcome or a reported analysis of those findings.

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 Number of Tests Taken Per Participant, measured over up to 8 weeks.

The primary endpoint is the number of tests taken per participant during up to 8 weeks. The registry record specifies a mean as the summary measure and standard deviation as the measure of dispersion. Its description says that greater than 1 test per participant is an indicator of compliance with repeat surveillance testing. The endpoint therefore focuses on feasibility of repeated testing: whether participants took part in testing beyond an initial test, as reflected in the number of tests recorded for each person.

General: A mean describes the average across participants, while a standard deviation describes how spread out individual values are around that average. Reporting both can convey the overall testing level and variation between participants. For a measure based on counts, the mean alone does not reveal whether testing was fairly consistent or concentrated among a subset of participants; the standard deviation adds information about dispersion, but does not show the full distribution.

The registry record does not report the mean or standard deviation for this endpoint. It also does not report the number of participants with more than one test or the distribution of individual testing counts. The endpoint is not itself a measure of sensitivity, specificity, or diagnostic agreement. Although specificity appears in the official title, the primary endpoint described in the record measures testing activity, not the accuracy of test results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the primary summary measure represent?

The registry record specifies a mean number of tests per participant and a standard deviation. General: The mean condenses participant-level values into an average, while the standard deviation describes how much those values vary around the average. Together they can give a compact account of testing volume and dispersion. They do not, by themselves, show the pattern of individual values, identify why participants had different counts, or describe whether testing occurred at regular intervals.

The outcome is a count of tests, but the record specifies a continuous-outcome summary. General: Count data take discrete values, and their distribution can be uneven or concentrated at particular values. A mean and standard deviation can still summarize counts, but interpretation depends on the observed distribution and the purpose of the summary. The registry record does not report the actual distribution, the mean, or the standard deviation, so no conclusion about the shape or variability of the data can be drawn.

What does the greater-than-one criterion mean?

The outcome description says that greater than 1 test per participant indicates compliance with repeat surveillance testing. This is the registry’s stated interpretation of the endpoint, not a reported finding. General: A threshold can make an operational measure easier to interpret by distinguishing participants who had repeat tests from those who did not. However, reducing testing counts to a threshold discards information about the number of tests beyond that threshold and does not describe timing. The record does not report how many participants met this criterion.

What is known about the analysis?

The record lists zero analysis records. It gives the endpoint type and intended summary statistics, but does not report an analysis method, an estimated mean, a standard deviation, a confidence interval, or a statistical test. It also does not report whether any adjustment or subgroup analysis was planned or conducted. These details are not reported in the registry record. The absence of a listed analysis means that the endpoint definition should not be mistaken for an analysis result.

General: An estimate summarizes the data, while an uncertainty measure communicates how precisely that estimate is determined under an analysis method. A confidence interval can be useful for showing uncertainty around a mean, but its interpretation depends on the design, the data, and assumptions used to calculate it. No interval or other uncertainty estimate for the primary measure is reported in the registry record. No recalculated result can be described from the posted information.

Why does the single-group design matter?

The study is listed as single-group, with allocation not applicable and masking none. The record does not describe a randomized control group. General: A single-group design can describe what happened among participants who took part, but it does not directly estimate a contrast with an alternative approach. Such a contrast requires a suitable comparison and a defined analysis. Here, the primary endpoint is a participant-level testing count, and no comparator group is listed. The endpoint can therefore address testing activity in the surveillance group, but it cannot establish a relative effect between groups.

The stated sample-size illustration assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effects expressed as fractions of an observed effect. Those assumptions are not a description of the listed single-group design. The registry record does not report an observed effect on which to base such an illustration. General: Sample-size calculations based on an effect and a test’s assumptions are planning illustrations; they are not observed power and do not replace the analysis of collected data. The record does not report a study-specific sample-size justification.

What can dispersion and repeated observations tell us?

General: Participants may contribute different numbers of repeated tests, so an average can conceal variation in participation. The standard deviation is a summary of spread, but it does not reveal whether variation reflects a few high counts, broadly different testing patterns, or other features. Repeated measurements within a participant are also related observations rather than independent people. If an analysis uses each test as a separate observation, the relationship among observations from the same person can affect uncertainty estimates. The registry record does not describe such an analysis, and no method for handling repeated observations is reported.

Over-dispersion is a general concern for count outcomes when observed variability exceeds what a chosen statistical model expects. A model that underestimates variability can produce uncertainty estimates that are too narrow. That concept is relevant when selecting a model for count data, but the registry record does not identify a count model or provide data that would allow assessment of dispersion. The reported intention to summarize with a mean and standard deviation should not be taken as evidence that a particular model was used.

What is absent from the statistical record?

There are no listed analysis records, and numerical results for the primary endpoint are not reported in the registry record. The exact analysis population, handling of missing test counts, treatment of participants with incomplete follow-up, and any sensitivity analyses are not reported in the registry record. General: Missing-data methods matter when not all planned measurements are observed, because the analysis can depend on why values are missing and on the assumptions used to address them. Without details on completeness or the analysis population, neither missingness nor its statistical handling can be evaluated.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("BinaxNOW Surveillance")
n   <- c(65)
m   <- c(5.11)
sp  <- c(2.56)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  BinaxNOW Surveillance  65  5.110  2.560  4.476  5.744

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists two outcome measures and zero analysis records. The primary endpoint is described as the number of tests taken per participant, but details and results for the other measure are not reported in the registry record. No multiplicity plan is reported in the registry record, including whether the outcomes were treated as co-primary, whether any hierarchy was specified, or whether adjustments were planned for multiple statistical tests.

General: Multiplicity arises when several outcomes, comparisons, or statistical tests are considered. Without a plan, repeated testing can increase the chance of finding an apparently notable result by chance. Adjustments and outcome hierarchies are possible approaches, but their appropriateness depends on the study’s objectives and analysis plan. Since no analyses or multiplicity methods are listed, the registry record does not permit assessment of how this issue was addressed.

The registry record does not report the analysis population or a missing-data method. It does not state how participants with incomplete testing records, missed visits, or other unavailable measurements were handled. These details are not reported in the registry record. General: Missingness can affect a summary if participants with observed measurements differ from those without them. The direction and extent of any effect depend on the pattern and reasons for missing data, which cannot be inferred from the endpoint definition alone.

The record describes an expected study duration of up to 8 weeks, but does not report completeness of follow-up or the number of tests observed for each participant. It also does not report interim analyses or stopping rules. The termination status alone does not identify a statistical reason for ending the study. These design and analysis details are not reported in the registry record, so no claims about their role in the results are warranted.

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

The registry record defines a feasibility endpoint based on the number of tests taken per participant, with greater than 1 test per participant identified as an indicator of compliance with repeat surveillance testing. It also describes a school-based sampling setting and a single BinaxNOW Surveillance group. These details clarify the question the endpoint was intended to address, but they do not show the level of testing completed or how much participation varied.

Numerical results for the primary endpoint are not reported in the registry record. The record therefore does not establish the average number of tests per participant, the standard deviation, or the proportion of participants who had repeat tests. It does not quantify the precision of any endpoint estimate. The study’s terminated status and listed enrollment of 65 do not, on their own, explain the outcome data or the reason for termination.

The endpoint is about testing activity rather than diagnostic accuracy. Despite the reference to specificity in the official title, no specificity or sensitivity estimate is reported in the registry record. The endpoint also does not compare BinaxNOW with another testing strategy, because the design is single-group and no like-for-like comparator is listed.

General: Feasibility measures can describe whether a study procedure was carried out and how participants engaged with it. They are distinct from measures of diagnostic performance and from comparisons of clinical outcomes. A result on testing frequency, even if available, would need to be interpreted according to the study’s setting and design; it would not alone establish accuracy or comparative benefit. In this record, the absence of numerical endpoint results limits interpretation further: the planned measure can be described, but its observed value and precision cannot be assessed.

13. Why This Trial Matters Statistically

This study raises a practical statistical question about repeated surveillance: how to describe participation when the planned activity involves multiple tests per person. The primary endpoint uses a test count for each participant and identifies greater than 1 test per participant as an indicator of compliance with repeat testing. That makes the endpoint relevant to feasibility, while keeping it distinct from diagnostic accuracy.

General: Repeated testing creates data with more than one observation potentially associated with the same person. An overall mean can describe testing volume, but it may conceal variation in how often different participants were tested. A standard deviation adds information about spread, though it does not reveal the full distribution or the timing of tests. These statistical distinctions are important when evaluating a surveillance process, because averages and participant-level patterns answer different questions.

The record also illustrates why the design and the endpoint must be read together. A single-group study can describe activity within its surveillance group, but it does not provide a like-for-like estimate of how that activity compares with another approach. The title’s reference to specificity does not change the nature of the listed primary endpoint, which concerns test counts.

There is an important limit to what can be learned from this registry entry: the primary endpoint’s numerical results and analysis are not reported. The record lists enrollment of 65 and a terminated status, while the brief summary describes intended enrollment of 240 students and 80 teachers. The reason for that status and the relationship between the enrollment figures are not reported. Without outcome estimates, the statistical value lies in clarifying the intended measure and the information needed to interpret it, not in drawing a quantitative conclusion about feasibility.

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 main limitation for statistical interpretation is that the registry record does not report numerical results for the primary endpoint. It specifies the mean and standard deviation as intended summaries, but gives neither value. It also does not report participant-level test counts or the number of participants who had greater than 1 test. The measure’s observed level and variability therefore cannot be evaluated.

The record lists zero analysis records. It does not describe an analysis population, missing-data handling, confidence intervals, statistical tests, or sensitivity analyses. These details are not reported in the registry record. Without them, the analysis process and precision of any estimate cannot be assessed.

The design is single-group, with no like-for-like comparator. Consequently, the listed primary measure is not a comparative estimate. The study title refers to specificity, but the primary endpoint is a count of tests taken; diagnostic accuracy results are not reported in the registry record.

The registry record lists enrollment of 65, while its brief summary describes an intended enrollment of 240 students and 80 teachers. It does not explain the relationship between these figures, identify the reason for termination, or describe whether the recorded enrollment represents the full analysis population. The expected duration is up to 8 weeks, but completeness of follow-up and the amount of testing observed are not reported.

The record lists two outcome measures, but details for the other measure and any multiplicity approach are not reported in the registry record. It also does not report the rationale for the sample size or a study-specific statistical plan. These omissions limit conclusions about analysis choices and the scope of the results; they do not establish why information is absent or why the study ended.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: BinaxNOW for Evaluating Children for Infection With SARS-CoV-2 (COVID-19) — NCT05087524.
• Registry record last updated 2022-01-28; status last verified 2022-01.
• Results first posted 2022-01-28.
• 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

NCT05087524 is a terminated, single-group study of the BinaxNOW Ag Card for SARS-CoV-2 diagnosis or surveillance in a school setting. The listed sponsor is the University of Wisconsin, Madison. The study began on 2021-01-09 and had a primary completion date of 2021-04-08. The registry record lists enrollment of 65; the brief summary describes an intended enrollment of 240 students and 80 teachers, with participation expected to last up to 8 weeks.

The primary endpoint is the number of tests taken per participant, summarized as a mean and standard deviation. The registry description treats greater than 1 test per participant as an indicator of compliance with repeat surveillance testing. No analysis records are listed, and numerical results for the primary endpoint are not reported in the registry record. The reason for termination, the relationship between the enrollment figures, and diagnostic accuracy results are also not reported in the registry record.