SPOTFIRE Sore Throat (ST) Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for SPOTFIRE Sore Throat (ST) Study (NCT06713642), a na na study. The primary outcome is Aim 2 Clinical Outcome: Summary of Test Results.

2. Clinical Question

This is a descriptive clinical question rather than a treatment-effect question. The registry describes evaluation of the settings and patient groups in which urgent-care clinicians see potential benefit, alongside test performance and user satisfaction. Those aims do not, by themselves, establish that testing changes care or improves health outcomes. Because there is no like-for-like control group, comparisons between participants who receive different test results would not constitute a randomized estimate of what would have happened without the test.

The record lists the condition as infective pharyngitis and says participants may be on study for up to approximately 25 minutes. It does not report the clinical criteria used to identify the eligible patient groups, the reference method used to assess test performance, or a specific clinical outcome beyond the stated count summary. Those details are not reported in the registry record.

3. Trial Design

The SPOTFIRE ST TITUS study is registered as a completed, single-group study sponsored by the University of Wisconsin, Madison. Its phase is listed as NA. Allocation is also listed as NA, and masking is NONE. The registry describes the intervention as the SPOTFIRE ST System, classified as a device, and identifies one eligible-participant group. There is no randomized comparator arm described.

The registry lists enrollment as 200. The arm description says a maximum of 200 patients would be enrolled, drawn from the top 3-4 patient groups that providers identified through a survey as potentially benefiting most from the test. The record does not report how those patient groups were selected in practice, or whether the enrolled participants were distributed evenly among them.

The study start date is 2024-12-02, the primary completion date is 2025-03-31, and the status is COMPLETED. The brief description says participation could last up to approximately 25 minutes; the primary outcome timeframe is up to 20 minutes. These are registry descriptions of the study schedule, not evidence about how long each participant actually remained in the study.

A single-group design can describe the distribution of observations within the group and can be useful for documenting implementation or test results. It does not, on its own, separate an intervention effect from other influences. Since no randomized comparison is described, the arms are not a like-for-like control comparison. The registry record does not report further design details such as recruitment procedures, eligibility criteria, or a statistical analysis plan.

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: 371 participants were screened for enrollment into the study, 232 were found eligible, and 200 enrolled. Most participants declined enrollment because they were not interested or feeling too sick to participate.

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 Aim 2 Clinical Outcome: Summary of Test Results, measured over up to 20 minutes.

The primary endpoint is titled Aim 2 Clinical Outcome: Summary of Test Results. It is measured in participants and described as SPOTFIRE ST results by count, with a timeframe of up to 20 minutes. In practical terms, this endpoint is intended to show how many participants fall into the recorded test-result categories. The registry record does not list those categories or the resulting counts, so the result distribution itself is not reported in the registry record.

Counts are useful for describing what was observed in a study group. When the relevant denominator and category definitions are available, counts can also support a clear account of the frequency of each result. The denominator matters: a count without a clearly defined eligible or tested population cannot be interpreted as a rate or proportion. The record lists enrollment as 200, but the posted primary outcome description does not give result counts or an analysis population linked to those counts.

This endpoint is not a direct measure of patient health benefit. A test-result summary can describe test output, but does not establish accuracy without a stated reference standard and an appropriate comparison. Nor does it show whether results changed clinical decisions or patient outcomes. Those details are not reported in the registry record. The endpoint is therefore best read as a planned descriptive account of test results, rather than as a comparative estimate of diagnostic or clinical benefit.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a count outcome describe?

For a count outcome, the analysis records how many participants have a particular result or event. A count is a direct description of observed cases, but its interpretation depends on the population to which it refers. A denominator identifies how many participants could have contributed to that count. If the denominator or the analysis population is unclear, a count alone should not be treated as a proportion, risk, or rate. The primary endpoint in this study is described as test results by count, but the result categories, observed counts, and analysis denominator are not reported in the registry record.

Why does study design matter?

General statistical principle: a randomized comparison can help balance measured and unmeasured factors between groups, supporting a causal comparison when the trial is appropriately conducted and analyzed. A single-group study does not create that comparison. Its descriptive results concern the participants observed under the study conditions; they do not establish what would have happened to those same participants under another approach. Here the registry lists a single-group model, allocation NA, and masking NONE. There is no randomized control group described, so the study is not suited to estimate a comparative treatment effect from its design alone.

What is needed to assess a diagnostic test?

General statistical principle: diagnostic performance is assessed by relating test classifications to a reference standard that represents the condition of interest. The result categories and reference classification must be defined, and the counts in the relevant combinations must be available. Measures such as sensitivity and specificity depend on those paired classifications; a summary of test outputs alone is not enough to derive them. The registry record does not report a reference standard, the classification rules, or the counts needed for such measures. It therefore supports no numerical accuracy assessment.

How should uncertainty be considered?

General statistical principle: an estimate is more informative when accompanied by a measure of uncertainty. A confidence interval gives a range of values compatible with the observed data under the specified statistical model and assumptions. It is not a guarantee that the true value lies within the interval, and it does not address bias from selection, measurement, or design. The posted record does not report an estimate or interval for the primary outcome. The enrollment listing alone cannot replace either, because the observed outcome distribution and the participants included in its analysis are not reported.

What does over-dispersion mean?

General statistical principle: over-dispersion occurs when observed variability is greater than a statistical model assumes. If a model underestimates variability, its uncertainty intervals can be too narrow and its tests can appear more conclusive than warranted. This concept is relevant to some count models, but the registry record does not report a count-model specification or data with which to assess over-dispersion. It should not be assumed that a particular model was used.

What can be inferred from the planning illustration?

The record describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. For time-to-event tables, the described output is total events; for other outcomes, it is participants per arm. These are planning assumptions, not observed study results and not evidence of observed power. The registry record does not report the illustration's numerical outputs here, and this single-group study does not have the equal-allocation two-arm design described by those assumptions. The illustration should not be mistaken for the study's own sample-size justification, which is not reported in the registry record.

What does the analysis listing establish?

The record lists 0 analyses. That registry entry does not explain whether analyses were conducted outside the registry, whether results were submitted, or what model would be appropriate for the data. It also does not identify an estimand, adjustment variables, subgroup methods, or a method for handling repeated or incomplete observations. Those details are not reported in the registry record. Statistical interpretation should not fill those gaps by assuming an analysis plan.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 26 outcome measures, while the analysis listing reports 0 analyses. A large collection of outcomes can raise multiplicity concerns when several hypotheses are tested: even if each test uses a conventional significance threshold, conducting many tests can increase the chance of at least one apparently notable result by chance. General statistical approaches include prespecifying a small set of primary questions, adjusting for multiple testing, or treating secondary findings as exploratory. The registry record does not report whether any such approach was planned or used. The number of outcome measures alone does not establish that multiple statistical tests were performed.

The record identifies a primary outcome titled Summary of Test Results, but it does not provide an analysis plan, a hierarchy of outcomes, or a multiplicity procedure. It is therefore not possible to determine how the primary outcome was distinguished from other measures in analysis or interpretation. Specific methods are not reported in the registry record.

Missing-data handling is also not reported in the registry record. The record does not state whether any participants lacked a test result, how incomplete observations were handled, or which participants were included in the primary analysis. Enrollment listed as 200 does not establish that every enrolled participant contributed to every outcome. In general, missingness can affect estimates when the participants with observed data differ systematically from those without observed data. The extent and direction of any such effect cannot be evaluated without details of missingness and the analysis population.

The record likewise does not describe an intention-to-treat population, a per-protocol population, or another analysis set. Those populations are not reported in the registry record. These omissions limit reproducibility and make it difficult to judge whether the posted endpoint description corresponds to all enrolled participants or a subset.

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's adverse-event fields list the eligible SPOTFIRE ST Participants group with 200 at risk. The serious adverse-event count is 0, the other adverse-event count is 0, and deaths are listed as 0. These figures describe what is recorded in the registry fields; they should not be read as proof that the intervention has no safety risks.

An at-risk count identifies the group size associated with the registry's adverse-event reporting fields. It does not by itself clarify how adverse events were solicited, defined, monitored, or verified. The record does not report those procedures, the observation period used for safety assessment, or further detail about event classification. Those details are not reported in the registry record.

A zero recorded count can occur when no event is observed or when no event is entered in the reported category, but the registry fields alone do not explain the circumstances. Safety interpretation also depends on the completeness of follow-up and the ability to detect and report events. The listed counts should therefore be read as registry-reported counts for this study group, not as a general assurance about safety or a comparison with another test or care strategy.

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

The registry record describes a completed study intended to evaluate provider-identified target populations, implementation, test performance, potential utility, and provider and patient satisfaction for SPOTFIRE ST in urgent care. It identifies a single-group design and a primary endpoint that counts test results. Those features indicate a descriptive evaluation of test use and recorded outputs, rather than a randomized comparison of competing strategies.

The record does not report the primary test-result counts, their categories, or estimates of test performance. As a result, the posted information does not establish how the test performed in the enrolled group or how precisely any result frequency was estimated. The record also does not report a reference standard or a comparative group. It cannot support a claim that the test is more accurate or beneficial than another approach, or that using it changes patient outcomes.

The provider survey is described as the way to identify the top 3-4 patient groups considered most likely to benefit. That description reflects the study's approach to selecting target groups; it does not establish clinical benefit for those groups. The criteria and survey findings are not reported in the registry record.

Similarly, study completion and an enrollment listing of 200 do not by themselves establish that the planned outcomes were fully analyzed or that every participant contributed to every measure. The registry does not report the analysis populations, missing-data procedures, or numerical primary results. The appropriate conclusion is limited to what the record describes: a completed single-group evaluation was registered, but the posted record lacks the outcome details needed to judge the test-result distribution, its precision, or clinical consequences.

13. Why This Trial Matters Statistically

This study raises statistical questions that are important when a diagnostic device is evaluated in routine-care settings. A test's observed output is only the start of an evaluation: readers also need to know how result categories were defined, what population was tested, how a reference standard was applied, and how uncertainty was quantified. Without these elements, counts can be difficult to interpret beyond their descriptive role.

The provider-informed selection of target groups is also relevant. It links the study's intended population to clinicians' views about where testing may be useful. Statistically, however, a selected group may not represent all urgent-care patients with pharyngitis. Generalizability depends on how those groups and participants were chosen and on how closely later users' populations resemble them. The registry record does not report enough detail to assess that issue.

The single-group design makes the distinction between description and comparison especially important. Counts from a group can help characterize use, but they cannot isolate a causal effect of testing without a suitable comparison. This matters when interpreting terms such as potential utility: potential is an aim to investigate, not a demonstrated patient benefit.

Finally, the registry lists many outcome measures but no analyses. Transparent reporting of prespecified outcomes, analysis populations, missing observations, and uncertainty would help readers distinguish primary evidence from exploratory findings. Those details are not reported in the registry record. The study's statistical importance therefore lies in the questions it poses about measurement, population selection, and interpretation, as well as in the need for complete results reporting.

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.

A central limitation of the available record is that it describes the primary endpoint but does not report its numerical results. The test-result categories, observed counts, and precision estimates are not reported in the registry record. This prevents assessment of the primary outcome itself.

The single-group design has no randomized control comparison. It can describe observations among participants in the study, but cannot establish a comparative effect or show what would have occurred under an alternative testing strategy. The registry does not report a reference standard, so diagnostic accuracy cannot be evaluated from the record. The provider survey used to identify target patient groups is mentioned, but its questions, response pattern, and selection criteria are not reported in the registry record.

Other details needed to assess validity and applicability are also missing. Eligibility criteria, recruitment procedures, analysis populations, missing-data handling, statistical methods, and confidence intervals are not reported in the registry record. The record lists 26 outcome measures and 0 analyses, but does not clarify which measures were completed or how they were analyzed. The adverse-event fields report zero counts, but methods for event monitoring and the safety observation period are not described.

These are limitations of what can be evaluated from the registry record; they do not establish that the study did not collect or analyze additional information. The posted details are insufficient to assess selection effects, measurement quality, generalizability, or the precision of the clinical findings.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: SPOTFIRE Sore Throat (ST) Study — NCT06713642.
• Registry record last updated 2026-03-23; status last verified 2026-03.
• Results first posted 2026-03-23.
• 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

The SPOTFIRE Sore Throat study, NCT06713642, is listed as COMPLETED and sponsored by the University of Wisconsin, Madison. It is a single-group device study of the SPOTFIRE ST System in urgent care, with no masking and no randomized comparison described. The registry lists enrollment as 200 and identifies infective pharyngitis as the condition.

The primary outcome is a count summary of SPOTFIRE ST results, with a timeframe of up to 20 minutes. The study description includes evaluation of implementation, test performance, potential utility, and provider and patient satisfaction. The record lists 26 outcome measures and 0 analyses. Numerical primary results, analysis methods, missing-data handling, and a reference standard are not reported in the registry record. Adverse-event fields list 0 serious adverse events, 0 other adverse events, and 0 deaths.