Patient-Directed Antimicrobial Duration in Acute Uncomplicated Pyelonephritis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Patient-Directed Antimicrobial Duration in Acute Uncomplicated Pyelonephritis (NCT06127160), a randomized phase 4 study. The primary outcome is Feasibility of Completing All Clinical Trial Activities and Follow-up.

2. Clinical Question

The clinical question is therefore primarily about feasibility and safety of conducting a larger randomized trial, rather than about establishing a definitive comparative treatment effect. The registry describes randomized, double-masked, parallel-group allocation. Enrollment is recorded as 39, while the brief summary describes an intention to randomize 40 female patients. The posted primary outcome records 17 participants in the Fixed Duration Treatment arm and 16 in the PDAD arm. These registry entries describe the recorded outcomes; they do not establish why the arm counts differ from the enrollment figure or the summary’s intended number.

3. Trial Design

The registry identifies NCT06127160 as a completed, randomized, double-masked, parallel-group Phase 4 pilot trial. The brief summary describes a comparison of standard-duration therapy with patient-directed antimicrobial duration in female patients with acute uncomplicated pyelonephritis. The posted arm labels are Fixed Duration Treatment and Patient-directed Antimicrobial Duration (PDAD). The intervention list names cephalexin and cephalexin or placebo, but more detailed dosing and treatment procedures are not reported in the registry record.

The stated objectives are to assess feasibility and safety of conducting a full-scale multicenter randomized controlled trial. The primary outcome concerns completion of study activities and follow-up through 90 days. Secondary outcomes include sustained clinical cure, sustained microbiological cure, clinical cure at the end of treatment, microbiological cure at the end of treatment, and additional health care visits for a urinary tract infection complaint. The registry lists six outcome measures overall and five posted secondary outcomes.

Enrollment is recorded as 39. The brief summary says the study will randomize 40 female patients, so the record distinguishes the intended figure in its summary from the enrollment field. The primary outcome entries use arm counts of 17 and 16. Other outcome and safety entries use different counts. The reasons for these differences are not reported in the registry record, and the figures should be read in the context of the specific outcome entry rather than treated as interchangeable analysis populations.

The registry records the study as completed, with a start date of 2024-06-04 and primary completion date of 2025-08-29. It names Brett A Faine as sponsor. The record does not report the detailed allocation procedure, masking procedures, treatment duration, or a protocol-level statistical analysis plan. Those details cannot be inferred from the design labels alone.

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 Feasibility of Completing All Clinical Trial Activities and Follow-up, measured over 90 days.

The primary endpoint is described as the percentage of participants who complete all study activities and follow-up through 90 days. It is a feasibility measure: it asks whether participants can remain engaged with the trial procedures and follow-up, rather than directly measuring a clinical treatment benefit. Feasibility outcomes are useful in pilot research because they can identify whether the procedures needed for a larger trial are workable and where additional planning may be needed.

The registry presents the outcome as a count of participants. It records 17 in the Fixed Duration Treatment arm and 16 in the PDAD arm, with a reported risk difference of 0.0, confidence interval from 0.0 to 0.0, and p = 1.0. This is the registry’s posted summary of the primary outcome. The description refers to a percentage, but no percentage values are listed in the arm results. The registry record does not report a separate threshold for what would constitute adequate feasibility, or a target completion rate against which the observed outcome should be judged.

Completion through 90 days is not the same as sustained clinical cure, microbiological cure, or the absence of adverse events. Those outcomes address different questions and are reported separately. The primary measure is relevant to whether trial follow-up was completed; it should not be interpreted as a stand-alone measure of treatment efficacy or as a complete account of participant experience.

7. Results Posted in the Registry

• Patient-directed Antimicrobial Duration (PDAD): 100.0% (16/16) versus 100.0% (17/17) on control; risk difference 0.0 percentage points (95% CI 0.0 to 0.0), risk ratio 1.00 (1.00–1.00); unadjusted two-proportion z-test p = n/a.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Sustained Clinical Cure

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Patient-directed Antimicrobial Duration (PDAD): 94.1% (16/17) versus 82.4% (14/17) on control; risk difference 11.8 percentage points (95% CI -9.5 to 33.1), risk ratio 1.14 (0.89–1.47); unadjusted two-proportion z-test p = 0.287.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Patient-directed Antimicrobial Duration (PDAD) and the control. The interval gives the range of effects that remain compatible with the data.

Clinical Cure Rate at the End of Treatment

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Patient-directed Antimicrobial Duration (PDAD): 100.0% (17/17) versus 88.2% (15/17) on control; risk difference 11.8 percentage points (95% CI -3.6 to 27.1), risk ratio 1.13 (0.95–1.35); unadjusted two-proportion z-test p = 0.145.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Patient-directed Antimicrobial Duration (PDAD) and the control. The interval gives the range of effects that remain compatible with the data.

Microbiological Cure Rate at End of Treatment Defined as Defined as the Bacterial Pathogen Found at Trial Entry is Reduced to Fewer Than 10^3 Cfu/mL and no New Pathogen >10^3 Cfu/mL,

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Patient-directed Antimicrobial Duration (PDAD): 64.7% (11/17) versus 41.2% (7/17) on control; risk difference 23.5 percentage points (95% CI -9.1 to 56.1), risk ratio 1.57 (0.81–3.06); unadjusted two-proportion z-test p = 0.169.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Patient-directed Antimicrobial Duration (PDAD) and the control. The interval gives the range of effects that remain compatible with the data.

The secondary endpoints cover distinct dimensions and time points: sustained clinical response, clinical cure at the end of treatment, microbiological response at the end of treatment, and additional health care visits for a urinary tract infection complaint. The posted secondary results do not all have the same denominator or follow-up timing. Those differences matter because outcomes measured in different ways or at different times should not be treated as interchangeable evidence of a single underlying effect.

Across the posted comparative estimates, the point estimates for the clinical and microbiological cure outcomes lean toward PDAD. However, the confidence intervals for the risk differences include zero, so the results remain compatible with no group difference as well as with differences in either direction. This pattern is exploratory and does not turn the primary feasibility outcome into an efficacy finding. The primary result asks about completion of study activities and follow-up; the secondary endpoints ask about clinical or microbiological status.

Unadjusted secondary results carry less weight because several outcomes are examined and the registry record does not report a multiplicity adjustment, outcome hierarchy, or detailed analysis plan. General: when many comparisons are considered, a result that looks noteworthy can arise by chance even if there is no true effect. Prespecification and appropriate multiplicity methods can help distinguish confirmatory conclusions from exploratory observations, but their use cannot be assumed.

The registry does not report analyses for the secondary outcomes in its analyses listing. It also does not explain missing data, outcome ascertainment procedures, or reasons for varying denominators. These omissions limit the extent to which the secondary pattern can be interpreted as a coherent, planned comparative analysis. The outcomes can help identify topics for a future study, but they should not be used to make a definitive claim about treatment benefit or harm.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Sustained Clinical Cure
• Sustained Microbiological Cure Defined as the Bacterial Pathogen Found at Trial Entry is Reduced to Fewer Than 10^3 Cfu/mL and no New Pathogen >10^3 Cfu/mL,
• Clinical Cure Rate at the End of Treatment
• Microbiological Cure Rate at End of Treatment Defined as Defined as the Bacterial Pathogen Found at Trial Entry is Reduced to Fewer Than 10^3 Cfu/mL and no New Pathogen >10^3 Cfu/mL,
• Additional Health Care Visits With the Chief Complaint of Urinary Tract Infection

9. Statistical Interpretation

10. Statistical Methods Explained

Several statistical ideas help interpret the registry results. General explanations below describe how these methods are ordinarily understood; they do not imply that a particular method was used unless the registry record says so.

What does a risk difference describe?

A risk difference compares the proportion of participants with an outcome in one group with the proportion in another group. A value of 0.0 indicates that the recorded proportions are equal in the comparison as posted. Positive and negative values indicate differences in opposite directions according to the order of the comparison. The primary result is reported as a risk difference of 0.0. Secondary risk differences are also posted for several binary outcomes.

For the primary outcome, the registry lists counts rather than percentages in the arm results, even though the outcome description refers to a percentage. The comparison reports a risk difference of 0.0, but the record does not explain the calculation details or the population used to construct the comparison. Statistical interpretation should therefore stay close to the stated result and avoid treating the displayed count and comparison as a fully documented analysis.

What does a confidence interval communicate?

General: a confidence interval describes a range of values compatible with a statistical estimate under the assumptions of the analysis method. It communicates uncertainty more directly than a point estimate alone. A wide interval indicates that the data are compatible with a broad range of effects; an interval that includes zero for a risk difference is compatible with no difference as well as with values on either side of zero. A confidence interval is not a guarantee that the true effect lies within its limits.

The primary comparison is reported with both limits at 0.0. Secondary risk-difference intervals extend across zero. The primary interval’s identical limits do not provide a visible range of uncertainty, so readers should not interpret that display as proof of exact equality. The registry record does not report the statistical procedure used to obtain it.

How should p-values be read?

General: a p-value describes how unusual data at least as incompatible with a specified null hypothesis would be under that hypothesis and the assumptions of the test. It is not the probability that the null hypothesis is true, nor is it a measure of clinical importance. A large p-value does not demonstrate that two strategies are equivalent. A small p-value does not by itself establish that an observed difference is important or reliable.

The primary comparison has p = 1.0. Secondary p-values are described as unadjusted where they are posted. The registry record does not identify the tests used, their assumptions, or a threshold for interpreting the p-values. They should be read alongside the estimated effects and confidence intervals, not in isolation.

Why do pilot results have limited precision?

General: estimates from small studies can be sensitive to the outcomes of a small number of participants. Binary outcomes are especially difficult to estimate precisely when the number of participants with or without an event is limited. A pilot study can still describe procedures and produce preliminary estimates, but those estimates may be unstable and should not be treated as though they came from a definitive comparative trial.

The registry calls this a pilot study and gives enrollment as 39. The posted outcome denominators vary, and the reasons are not reported in the registry record. The record does not state a formal sample-size justification for the trial. In particular, the planning illustrations associated with some secondary outcomes are not the study’s original design calculations.

What do the sample-size illustrations mean?

General: a sample-size calculation estimates how many participants might be needed to detect a specified effect under stated assumptions. These calculations depend on the chosen effect, significance level, power, allocation, outcome frequency, and statistical method. They are planning tools, not evidence that a trial had a particular probability of finding a result after it was conducted. They are not observed power.

The posted planning assumptions specify a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The illustrations use the observed effect or stated fractions of that effect. For sustained clinical cure, the planning entries list 117 participants per arm for 80% power at 100% of the observed effect, and 231 participants per arm for 80% power at 75% of the observed effect. For microbiological cure at the end of treatment, the corresponding entries are 70 participants per arm and 125 participants per arm. These are planning illustrations based on the observed results, not observed trial enrollment requirements and not the trial’s own design justification.

General: planning from an observed effect can be optimistic when the pilot estimate is unusually large or variable. Using a smaller fraction of the observed effect illustrates how sample-size needs can change when a more conservative effect is selected. The registry’s assumptions should be kept in view when considering these values; they do not substitute for a protocol-based design calculation.

What does an unadjusted comparison leave out?

General: an unadjusted comparison generally presents a group contrast without accounting for other variables or applying an adjustment for multiple outcome testing. This can be a straightforward descriptive comparison, but it may not match a prespecified primary analysis. With multiple outcomes, repeated testing can increase the chance that at least one result appears noteworthy by chance. Adjustment methods and an analysis hierarchy can address that issue, but the registry record does not report such methods for these results.

The record lists zero analyses in the analyses count, and does not describe a statistical analysis plan. The posted comparisons can still be read descriptively, but their status as sponsor-reported or protocol-specified analyses cannot be established from the record. No recalculated comparison is needed to interpret the posted estimates, and there is no reported discrepancy that would displace the registry’s stated comparison.

11. Confidence Intervals and Precision

Precision concerns how narrowly an estimate is bounded by its uncertainty. For the primary completion outcome, the registry reports a risk difference of 0.0 and a confidence interval from 0.0 to 0.0. Because the limits are identical, the displayed interval does not show a range around the estimate. This is the value recorded, but it does not justify a claim that the true difference is known exactly. The registry record does not report the method or analysis details needed to assess why this interval has no width.

The secondary outcomes provide a different picture of precision. The posted confidence intervals for the risk differences in sustained clinical cure, clinical cure at the end of treatment, and microbiological cure at the end of treatment all include zero. They also extend to values on both sides of zero, so the data are compatible with no difference and with effects in either direction. The width of an interval indicates how much uncertainty remains, but does not tell whether an effect is clinically important without a relevant clinical threshold.

The trial is described as a pilot and enrollment is recorded as 39. Outcome-specific denominators differ, and the record does not explain those differences. Together, the pilot setting and the outcome-specific counts counsel against treating the point estimates as stable or highly precise. The registry record does not report a prespecified clinically meaningful difference, equivalence margin, or formal precision target for the primary endpoint.

Confidence intervals and p-values answer related but different questions. A p-value alone does not communicate the range of effect sizes compatible with the analysis. For interpretation, the estimate, its interval, the endpoint definition, and the study’s stated feasibility objective should be considered together. The displayed precision is not a basis for concluding that clinically relevant differences have been ruled out.

12. Multiplicity, Missing Data and Analysis Populations

The registry record lists multiple outcome measures, including a primary feasibility endpoint and several secondary clinical and microbiological endpoints. It does not report a statistical analysis plan identifying an outcome hierarchy, specifying which comparisons were confirmatory, or describing a correction for multiple testing. Without that information, the secondary comparisons are best treated as exploratory. General: examining several outcomes creates more opportunities for apparently unusual results, so unadjusted p-values should not be interpreted as if each were the only test conducted.

The record does not report how missing outcome data were handled, whether any imputation was used, or whether sensitivity analyses were conducted. It also does not specify the analysis population for each outcome, such as whether analyses followed randomized assignment regardless of treatment received. These details are not reported in the registry record and cannot be inferred from the arm labels or the posted results.

The counts differ across the primary outcome, secondary outcomes, and safety reporting. The primary endpoint records 17 participants in the Fixed Duration Treatment arm and 16 in the PDAD arm. Some secondary outcomes use 17 in each arm, while the safety entries list 19 and 20 at risk. The registry record does not explain these differences. They may reflect different outcome-specific reporting sets, but the reasons are not reported, so no explanation should be assumed.

The brief summary describes an intention to randomize 40 female patients, whereas enrollment is recorded as 39. This distinction is part of the registry record; it does not by itself explain the outcome-specific denominators or establish who was included in any analysis. The record lists zero analyses in its analyses count. It does not report whether any interim analyses, protocol deviations, exclusions, or missing-data assessments occurred. These gaps limit reproducibility and make it difficult to assess how the posted comparisons relate to the original statistical plan.

13. 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.

Most frequent non-serious adverse event terms

The safety entries report no serious adverse events in either arm: the number affected is 0 among 19 at risk in Fixed Duration Treatment and 0 among 20 at risk in PDAD. The registry also records 7 other adverse events in each arm. No deaths are reported in either arm. These are the posted counts and should be read within their listed safety groups, whose numbers at risk differ from those in the primary outcome entries.

Zero recorded serious adverse events in these groups means that none are listed in the registry results for this trial. It does not demonstrate that the risk of serious events is zero, or establish that the strategies have identical safety profiles. A pilot trial with limited enrollment cannot characterize uncommon events reliably. The registry record does not provide further detail about the nature, timing, severity, or relatedness of the other adverse events, and no serious adverse event terms are listed.

The safety counts are descriptive. They do not replace a comparative safety analysis or establish causation. The registry’s stated objective includes assessing safety as part of trial feasibility, but the posted figures should be interpreted as event reporting from this study rather than as a complete assessment of safety in a broader population.

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

The results describe what was recorded in a completed pilot trial comparing fixed-duration treatment with patient-directed antimicrobial duration. The primary outcome concerns completion of study activities and follow-up through 90 days. Its posted comparison reports the same result in the two arms, with a risk difference of 0.0 and a confidence interval from 0.0 to 0.0. The registry’s outcome description refers to a percentage, while the results present counts, and the record does not explain the calculation details behind the comparison.

This result does not establish that the treatment strategies are equivalent. A finding of no observed difference is not the same as evidence that any clinically meaningful difference has been excluded. The registry does not report an equivalence or noninferiority margin, nor does it provide the protocol-level analysis information needed to make that kind of conclusion.

The secondary outcomes provide preliminary information about clinical and microbiological results at specified follow-up times. Their intervals include no difference, and the comparisons are unadjusted where p-values are reported. They should be regarded as exploratory rather than definitive. Similarly, the safety entries record no serious adverse events and some other adverse events, but these data do not rule out uncommon harms or establish comparative safety.

The brief summary frames the trial as a pilot to evaluate feasibility and safety for a full-scale multicenter randomized controlled trial. In that context, the posted findings can inform questions about follow-up, outcome measurement, analysis populations, and planning for further research. The registry record does not report the detailed design rationale, missing-data procedures, or analysis plan that would clarify how to use the results for a definitive trial.

These results do not support medical advice for an individual patient, and they should not be read as a recommendation for either strategy. They describe a particular trial and its registry-reported outcomes. Decisions about treatment require clinical context beyond these statistical findings.

15. Why This Trial Matters Statistically

This trial illustrates an important statistical distinction between feasibility and efficacy. The primary endpoint concerns completion of study activities and follow-up, which can help assess whether a larger study is workable. It is not itself a direct measure of comparative treatment benefit. Keeping that distinction clear prevents a pilot completion result from being overinterpreted as a clinical efficacy conclusion.

It also shows why endpoint definitions and analysis populations need to be explicit. The primary outcome description refers to a percentage, while the posted arm results are counts, and the outcome-specific denominators differ across the record. Without explanations of those differences, readers cannot fully reconstruct how each comparison was made. A later trial can address this by defining the population, endpoint, follow-up window, denominator, and missing-data approach in its protocol and analysis plan.

Another statistical lesson is that a point estimate and its uncertainty must be interpreted together. The primary comparison is reported with a confidence interval whose limits are identical, while secondary intervals include zero. Those displays do not demonstrate equivalence or rule out clinically important effects. For a larger study, a prespecified target effect and a clear precision objective would help make the results more informative.

Finally, unadjusted exploratory comparisons across several outcomes are useful for generating questions, but they do not carry the same evidential weight as a prespecified primary analysis. The registry record does not report a multiplicity strategy or detailed analysis plan. This makes transparent statistical planning particularly relevant when moving from a pilot to a confirmatory study.

16. 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 trial and analysis details unreported. It does not describe the duration of the fixed regimen, the patient-directed duration rules, the randomization procedure, or how masking was maintained. The intervention entries name cephalexin and cephalexin or placebo, but they do not establish the full treatment contrast or provide dosing instructions. As a result, the treatment strategies cannot be reconstructed in detail from the record alone.

There is also a difference between the enrollment figure of 39 and the brief summary’s stated intention to randomize 40 patients. The outcome entries use varying counts, including different arm counts for the primary outcome, secondary endpoints, and safety reporting. Reasons for those differences, including any missing outcome data or exclusions, are not reported in the registry record. The record does not specify analysis populations or whether participants were analyzed according to randomized assignment.

The primary result is presented as counts despite a description framed as a percentage, and its reported confidence interval has identical limits. The registry does not report the calculation method or enough detail to assess this presentation. No sponsor-reported analyses are listed in the analyses count, and the statistical analysis plan, multiplicity methods, and missing-data procedures are not reported.

The study is identified as a pilot and the posted enrollment is limited. The record does not report a formal sample-size justification for the trial. Planning illustrations based on observed secondary effects are not a substitute for the original design rationale, and they do not establish the precision or power of the completed trial. Together, these limitations make the findings descriptive and preliminary, especially for comparative clinical and safety conclusions.

17. Related Tutorials

18. Related Statistical Calculators

19. Sources

• ClinicalTrials.gov: Patient-Directed Antimicrobial Duration in Acute Uncomplicated Pyelonephritis — NCT06127160.
• Registry record last updated 2026-08-03; status last verified 2026-07.
• Results first posted 2026-08-03.
• 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.

20. Record Summary

NCT06127160, titled “Patient-Directed Antimicrobial Duration in Acute Uncomplicated Pyelonephritis,” is recorded as a completed Phase 4 randomized, double-masked, parallel-group pilot trial. The brief summary describes a comparison of standard-duration therapy with patient-directed antimicrobial duration in female patients with acute uncomplicated pyelonephritis. The stated objectives are to assess feasibility and safety for a full-scale multicenter trial.

Enrollment is recorded as 39. The primary endpoint concerns completion of all study activities and follow-up through 90 days. The posted comparison reports a risk difference of 0.0, a confidence interval from 0.0 to 0.0, and p = 1.0. Secondary clinical and microbiological outcomes and adverse-event counts are also recorded. The registry record does not report detailed analysis methods, missing-data handling, or a statistical analysis plan, which limits interpretation of the comparative results.