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 Urease Breath Test for Rapid Characterization of Pneumonia (NCT03100760), a non-randomized phase not stated study. The primary outcome is Adverse Events.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03100760 |
| Phase | Phase not stated |
| Condition | Pneumonia, Bacterial |
| Allocation | Non-Randomized |
| Design model | Single Group |
| Masking | Single |
| Enrollment | 75 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of New Mexico |
| Results posted | Yes |
2. Clinical Question
Population
Patients presenting to the emergency department with clinical suspicion for bacterial pneumonia and a plan for either outpatient or inpatient treatment. The registry record lists enrollment 75 but does not report further demographic or eligibility details in the material described.
Intervention
A ¹³C-urea breath test. The cohort descriptions state that baseline breath samples were collected, up to 6, followed by nebulization of ¹³C-urea solution. The test was evaluated for detecting urease-producing bacteria.
Comparator
There is no randomized control group. The registry describes outpatient and inpatient treatment cohorts, but these are not a like-for-like control comparison. The record does not report a separate comparator intervention.
Primary question
The primary endpoint counts participants with adverse events within 24-48 hours of the breath test. The listed secondary outcomes concern exhaled ¹³CO₂, relationships with bacterial RNAseq counts and pneumonia severity measures, and diagnostic-performance criteria. Results for those secondary outcomes are not reported in the registry record.
3. Trial Design
This is a Phase 1, open-label evaluation of a ¹³C-urea breath test in patients diagnosed with pneumonia in the emergency department. The intervention is listed as a device. The registry identifies the allocation as non-randomized and the model as single group; it does not describe a randomized comparison. Although outpatient and inpatient treatment cohorts are named, treatment setting is not an assigned control intervention in the registry record reported.
The cohort descriptions concern patients with clinical suspicion for bacterial pneumonia and a plan for outpatient or inpatient treatment. Both descriptions specify baseline breath-sample collection, up to 6, followed by complete nebulization of the ¹³C-urea solution. The description available for each cohort is truncated after the nebulization procedure, so further test procedures are not reported in the registry record.
The registry lists enrollment 75, identifies the condition as bacterial pneumonia, and names the University of New Mexico as sponsor. The recorded start date is 2017-05-01, the primary completion date is 2020-06-04, and the status is completed. The masking field says single, but who was masked is not reported in the registry record. The record also does not report a detailed protocol, recruitment flow, or a statistical analysis plan.
Because allocation was non-randomized and the model is single group, differences between the outpatient and inpatient cohorts should not be interpreted as treatment effects. The registry itself flags that the arms are not a like-for-like control comparison. The main available result in the registry record is a count-based safety outcome; results for the diagnostic aims are not reported in the registry record.
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: All subjects provided written informed consent prior to participation. Subjects were screened for eligibility, including medical history, vital signs, and ability to perform breath sampling. No randomization was performed; subjects were assigned to outpatient or inpatient cohorts based on clinical treatment plan.
Overall Study
| Stage | Outpatient Treatment Cohort (Cohort A) | Inpatient Treatment Cohort (Cohort B) |
|---|---|---|
| STARTED | 15 | 60 |
| COMPLETED | 15 | 60 |
| NOT COMPLETED | 0 | 0 |
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: All participants who enrolled and completed breath testing are included in the baseline analysis population. No exclusions were made. Participant totals reflect completion at both study sites.
| Characteristic | Unit | Outpatient Treatment Cohort (Cohort A) | Inpatient Treatment Cohort (Cohort B) | Total |
|---|---|---|---|---|
| Participants analysed | 15 | 60 | 75 | |
| Age, Continuous | Years | 45 (SD 14) | 60 (SD 14.6) | 54 (SD 14) |
| Sex: Female, Male: Female | Participants | 9 | 28 | 37 |
| Sex: Female, Male: Male | Participants | 6 | 32 | 38 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 5 | 5 |
| Race (NIH/OMB): Asian | Participants | 0 | 1 | 1 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 1 | 1 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 15 | 15 |
| Race (NIH/OMB): White | Participants | 0 | 34 | 34 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 4 | 4 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 15 | 15 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 0 | 42 | 42 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 3 | 3 |
| Region of Enrollment: United States | Participants | 15 | 60 | 75 |
6. Primary Endpoint
The registry lists the primary outcome as Adverse Events, measured over Within 24-48 hours of breath test.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with adverse events within 24-48 hours of the breath test. It is a count of participants affected, not a count of separate event episodes. The registry defines an adverse event broadly as an untoward medical occurrence associated with drug use, whether or not considered drug related. The intervention is listed as a device, and the record does not explain this wording or provide further endpoint adjudication details.
Counting affected participants provides a direct description of how many people in each cohort had a recorded event during the stated observation window. For a small early-phase evaluation, such safety monitoring can describe events observed around use of the test. These counts do not, by themselves, establish that the test caused an event or that no risk exists. The registry does not report event severity beyond the separate serious-event counts, event descriptions, or a comparison with an untreated or randomized control group.
The primary endpoint is distinct from the listed secondary outcomes, which address exhaled ¹³CO₂ and potential diagnostic relationships or criteria. Those outcomes could address test behavior or diagnostic performance, but their results are not reported in the registry record. Thus the available primary endpoint results speak to reported adverse-event counts in the stated time window, not to sensitivity, specificity, predictive values, or clinical benefit.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary outcome is a participant count for adverse events recorded within 24-48 hours of the breath test. In the Outpatient Treatment Cohort (Cohort A), serious adverse events affected 0 of 15 participants at risk, and other adverse events affected 5 of 15. In the Inpatient Treatment Cohort (Cohort B), serious adverse events affected 0 of 60 participants at risk, and other adverse events affected 0 of 60. Deaths were recorded as 0 in each cohort.
These observations describe what was recorded in the cohorts; they do not establish whether the breath test caused or prevented an event. The study was non-randomized and single group, and the registry explicitly cautions that the cohorts are not a like-for-like control comparison. The cohort counts therefore should not be read as a controlled estimate of a difference attributable to outpatient versus inpatient care, or to the test itself.
The serious-event counts are zero in both cohorts, but zero observed serious events is not proof that serious events cannot occur. The precision of a count depends on how many participants were observed and on the event frequency. No confidence intervals or other uncertainty estimates for these counts are reported in the registry record. A confidence interval, in general, expresses the range of values compatible with observed data under a statistical method; without one, the precision of the event estimates cannot be read directly from the record.
The 5 other adverse events recorded in the outpatient cohort are not characterized by event term, severity, duration, or relatedness in the registry record. The registry also does not report corresponding narratives or explain how events were classified. Consequently, the counts cannot show what those events were or whether investigators considered them related to the breath test. In the inpatient cohort, no other adverse events were recorded among the participants at risk, but this is an observation in that cohort, not evidence that such events are impossible.
The study's stated objective concerns detection of urease-producing bacteria. The secondary outcomes include measures of exhaled ¹³CO₂, correlation criteria involving bacterial RNAseq counts and pneumonia severity measures, and sensitivity, specificity, positive predictive value, and negative predictive value criteria. None of their results are included in the registry record. The available adverse-event counts therefore cannot answer whether the breath test identified pathogens accurately or how its readings related to disease severity.
In short, the registry reports a limited safety description over the stated observation window. It does not provide the diagnostic results or enough statistical detail to quantify uncertainty, establish causality, or support comparisons between the treatment cohorts.
9. Statistical Methods Explained
The registry presents a count endpoint: participants with an adverse event. A participant count records whether a person experienced an event during the outcome window; it is not the same as counting every event episode. The stated timeframe is within 24-48 hours of the breath test. Results are separated for the outpatient and inpatient treatment cohorts and distinguish serious from other adverse events.
What does a count endpoint show?
A count is an intuitive summary of observed events, but it is tied to the number of people observed and the period of observation. A count alone does not describe the full uncertainty around an event frequency. Statistical reporting may pair counts with estimates and confidence intervals, but confidence intervals for the safety results are not reported in the registry record. In general, a confidence interval communicates the uncertainty of an estimate under the chosen method; it does not guarantee that the interval contains the true value.
The phrase “participants at risk” identifies the cohort denominator associated with the reported event count. It should not be confused with an estimate of risk attributable to the device. Establishing attribution would require a suitable comparison and analysis, neither of which is reported for these counts. The broad event definition also means the listed count does not itself indicate seriousness, causality, or clinical importance. Serious events are presented separately from other events, but event descriptions and relatedness assessments are not reported in the registry record.
Why does the design matter?
The registry identifies non-randomized allocation and a single-group model. Random allocation, in general, can help create comparable groups for estimating intervention effects; it is not part of the design. The outpatient and inpatient cohorts reflect different planned treatment settings, and the record cautions that they are not a like-for-like control comparison. Differences in observed counts across these cohorts therefore cannot be treated as an unconfounded estimate of a test effect. No control group receiving a different test or no test is reported.
The open-label designation means the trial is not described as fully masked. The registry's masking field says single, but it does not identify who was masked. The record does not report whether event assessment was blinded or whether a prespecified process was used to judge event relatedness. These details matter because awareness of treatment or cohort status can affect event reporting or classification.
What statistical analysis is reported?
The registry lists 12 outcome measures and 0 analyses in the registry record. The primary result is expressed as participant counts. Inferential tests, adjusted estimates, confidence intervals, and a detailed statistical analysis plan are not reported in the registry record. Their absence means the reader cannot assess a formal hypothesis test or a model-based estimate from this record. No analysis should be inferred from the descriptive counts alone.
General statistical considerations for binary event outcomes include accounting for the number of participants observed and the possibility that estimates from small cohorts are imprecise. If outcomes are sparse, standard approximations may perform poorly; exact or other suitable methods may be considered in a prespecified analysis. This is general methodological context, not a claim about methods used in this trial. The registry does not identify a method for uncertainty estimation or describe any adjustment for cohort characteristics.
How should planning illustrations be read?
The stated planning framework describes a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. For non-time-to-event outcomes, the stated convention is participants per arm; time-to-event illustrations use a total event count. Such calculations are planning illustrations, not observed power and not a description of this trial's design. The record does not report a trial-specific sample-size justification, and numerical planning results are not reported in the registry record.
For this trial, the non-randomized, single-group design is materially different from the equal-allocation two-arm assumptions in that generic planning framework. A hypothetical planning calculation based on those assumptions should not be read as evidence that the study was designed to detect a particular effect or as an estimate of the probability that a result is true. The registry does not report interim analyses, a prespecified statistical plan, or details of how missing observations were handled.
What remains unreported?
The registry entries do not describe a participant flow, analysis populations, missing outcome data, event adjudication, or methods for the secondary diagnostic outcomes. They also do not report the planned reference standard for confirming urease-producing pathogens or any diagnostic accuracy estimates. These omissions prevent assessment of how the listed diagnostic criteria were operationalized and whether the posted counts represent all enrolled participants or a defined analysis set. The interpretation should therefore remain limited to the registry's reported cohort-level safety counts and the design information recorded.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 12 outcome measures, including the primary adverse-event endpoint and secondary measures concerning exhaled ¹³CO₂, correlations with bacterial RNAseq counts and pneumonia severity measures, and diagnostic-performance criteria. The registry entries list 0 analyses. No multiplicity strategy, such as a hierarchy among secondary outcomes or an adjustment for multiple statistical tests, is reported in the registry record. Without results and a stated analysis plan, it is not possible to determine which outcomes were formally tested or how any multiple comparisons were handled.
Missing-data methods are not reported in the registry record. The registry entries do not say whether any outcome observations were unavailable, how missing breath samples or assessments were handled, or whether participants were excluded from an analysis. Analysis populations are also not reported: there is no description of an intention-to-treat, per-protocol, or safety population. The participant counts at risk are presented for each cohort, but the record does not provide a participant flow or explain how those denominators were determined.
These are important limits on interpretation. Missingness can affect estimates if the likelihood of an unavailable measurement is related to an outcome or participant characteristics. Multiplicity can also make isolated findings among many outcomes harder to interpret. These are general statistical considerations, not claims that missing data or multiplicity problems occurred in this trial. The registry record does not provide the information needed to evaluate either issue for the diagnostic outcomes.
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 |
|---|---|---|---|
| Outpatient Treatment Cohort (Cohort A) | 0 | 15 | 0.0% |
| Inpatient Treatment Cohort (Cohort B) | 0 | 60 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Outpatient Treatment Cohort (Cohort A) | 0 of 15 |
| Inpatient Treatment Cohort (Cohort B) | 0 of 60 |
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 |
|---|---|
| Outpatient Treatment Cohort (Cohort A) | 5 of 15 |
| Inpatient Treatment Cohort (Cohort B) | 0 of 60 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Outpatient Treatment Cohort (Cohort A) | Inpatient Treatment Cohort (Cohort B) |
|---|---|---|---|
| Coughing | Respiratory, thoracic and mediastinal disorders | 3 of 15 | 0 of 60 |
| Nausea | Gastrointestinal disorders | 1 of 15 | 0 of 60 |
| Syncope | Cardiac disorders | 1 of 15 | 0 of 60 |
For serious adverse events, the registry records 0 affected participants among 15 at risk in the outpatient cohort and 0 among 60 at risk in the inpatient cohort. Deaths are recorded as 0 in each cohort. For other adverse events, the outpatient cohort has 5 affected participants among 15 at risk, while the inpatient cohort has 0 among 60 at risk. These are observed participant counts within the stated window of 24-48 hours after the breath test.
The serious-event figures should be read as no serious events recorded in these cohorts during the specified observation period, not as proof that the test has no serious risks. The registry entries do not provide uncertainty intervals, event descriptions, relatedness judgments, or follow-up beyond the stated timeframe. The 5 other adverse events in the outpatient cohort are not described further, so their nature and clinical importance cannot be assessed from the registry record.
Because the trial is non-randomized and does not provide a like-for-like control comparison, these counts cannot establish causation or compare safety reliably between treatment settings. They are a descriptive account of the reported safety results.
12. What the Result Does, and Does Not, Mean
The result supports a narrow descriptive statement: the registry reports serious and other adverse-event counts for the outpatient and inpatient cohorts within 24-48 hours of the breath test. It records no serious adverse events or deaths in either cohort, and reports 5 participants with other adverse events in the outpatient cohort and 0 in the inpatient cohort. These counts characterize what was recorded, not why an event occurred.
The result does not establish that the breath test caused an adverse event, prevented one, or is free from risk. There is no randomized control group in the design described, and the registry cautions that the outpatient and inpatient cohorts are not like-for-like controls. The counts do not justify a causal comparison between settings. The record also does not describe event types or relatedness, which limits interpretation of the other adverse events.
The registry's scientific question extends beyond safety to detection of urease-producing bacteria. Listed secondary outcomes address exhaled ¹³CO₂, correlation with bacterial RNAseq counts and pneumonia severity measures, and diagnostic criteria for sensitivity, specificity, and predictive values. Results for these outcomes are not reported in the registry record. Thus the available safety counts cannot establish diagnostic accuracy, an association with severity, or clinical usefulness.
Precision is also difficult to judge. No confidence intervals or inferential analyses for the adverse-event counts are reported. In general, a confidence interval helps convey uncertainty around an estimate, while a hypothesis test addresses compatibility with a specified statistical model; neither should be inferred from descriptive counts alone. The record does not report enough information to assess missing observations, analysis populations, or any adjustment for multiple outcomes.
The appropriate reading is therefore limited: the posted data offer a short-window descriptive safety account from an early-phase evaluation. They do not demonstrate a treatment effect, establish a causal safety profile, or answer the diagnostic-performance questions listed in the registry.
13. Why This Trial Matters Statistically
This trial is statistically notable because it combines a diagnostic technology evaluation with an early-phase safety endpoint in an emergency-department population described as having clinical suspicion for bacterial pneumonia. The registry's stated objective is detection of urease-producing bacteria using a ¹³C-urea breath test. The primary outcome, however, is a count of participants with adverse events within 24-48 hours. Keeping these questions distinct is essential: safety counts do not measure diagnostic accuracy.
The design information also illustrates why a comparator matters. The registry identifies a non-randomized, single-group model and explicitly warns that the outpatient and inpatient cohorts are not like-for-like controls. Their observed counts can be described separately, but they cannot be treated as a randomized estimate of the effect of the device or of treatment setting. This is a useful example of how design labels shape the claims that can be made from results.
The secondary outcomes list potential ways to examine test readings, including correlations with bacterial RNAseq counts and pneumonia severity measures, as well as sensitivity, specificity, and predictive-value criteria. Yet the registry entries do not include those results. A list of intended outcomes is not evidence that a test met those criteria, and the available safety findings cannot substitute for diagnostic validation.
Finally, the record highlights the role of complete statistical reporting. Outcome counts are informative, but confidence intervals, analysis populations, missing-data handling, and multiplicity methods would help readers judge uncertainty and analytic choices. Those details are not reported in the registry record. The study therefore offers a clear teaching case in separating observed counts, design-based inference, and unanswered diagnostic questions.
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 cohort descriptions are truncated after the breath-test procedure, so the registry record does not report all test procedures or follow-up details. The primary endpoint has a stated window of 24-48 hours, but longer-term safety follow-up is not described in the registry record. The adverse-event definition refers to an occurrence associated with drug use even though the intervention is listed as a device; the record does not explain this wording.
Adverse events are reported as participant counts, with serious events separated from other events. Event terms, severity details for other events, duration, relatedness assessments, and adjudication procedures are not reported in the registry record. No confidence intervals or other uncertainty estimates are given for the safety counts. This limits assessment of their precision.
The design is non-randomized and identified as single group. Although outpatient and inpatient cohorts are reported, the registry warns that they are not like-for-like control arms. The record does not describe a comparator group or adjustment for differences between cohorts. No causal effect of the breath test can therefore be derived from these cohort counts.
The registry entries do not report results for the secondary diagnostic outcomes, the reference standard used to confirm urease-producing pathogens, or the analysis methods for correlations and accuracy criteria. The statistical analysis plan, analysis populations, missing-data handling, and multiplicity approach are also not reported in the registry record. These omissions leave the main diagnostic objective unresolved in the posted information.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Urease Breath Test for Rapid Characterization of Pneumonia — NCT03100760.
- Registry record last updated 2025-07-14; status last verified 2025-06.
- Results first posted 2025-07-14.
- 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
NCT03100760 is a completed Phase 1, open-label evaluation of a ¹³C-urea breath test for detecting urease-producing bacteria in patients diagnosed with pneumonia in the emergency department. The registry identifies the allocation as non-randomized and the model as single group. It describes outpatient and inpatient treatment cohorts and lists enrollment 75.
The primary outcome is the number of participants with adverse events within 24-48 hours of the test. The registry reports 0 serious adverse events among 15 at risk and 5 other adverse events among 15 at risk in the outpatient cohort; in the inpatient cohort, it reports 0 serious and 0 other adverse events among 60 at risk. Deaths are recorded as 0 in each cohort.
The record lists diagnostic and correlation outcomes but does not report their results in the registry record. It also does not report confidence intervals, a detailed statistical plan, missing-data methods, or analysis populations. The safety counts are descriptive and do not establish causation or diagnostic performance.