"Answers in Hours" A Randomized Controlled Trial Using Microbiome Metagenomics for Bile Duct Cultures: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for "Answers in Hours" A Randomized Controlled Trial Using Microbiome Metagenomics for Bile Duct Cultures (NCT05523154), a randomized na study. The primary outcome is Number of Participants With Surgical Site Infections.

2. Clinical Question

The registry describes a randomized comparison focused on surgical site infections after surgery for pancreatic tumors. Its stated rationale is that bacteria found in bile at the time of surgery may also be identified in a later surgical site infection. The trial therefore evaluated whether adding nanopore sequencing to bile testing could provide information relevant to earlier detection of bacteriobilia and the prevention or management of infections. These aims describe the question motivating the study; they are not themselves evidence that sequencing changed infection outcomes.

The posted primary result is a count of participants with a surgical site infection, rather than a time-to-event measure or a measure of how quickly a test returned a result. The secondary outcome listed in the registry is timeliness of sample analysis. The posted results do not include a statistical analysis comparing the arms, so the clinical question can be described, but a quantified comparative effect cannot be read from an inferential result.

3. Trial Design

This was a randomized, parallel-group trial with no masking recorded. It compared two approaches to testing bile samples collected during standard-of-care surgery. Arm I received biospecimen collection and routine testing. Arm II received biospecimen collection, nanopore sequencing, and routine testing. Thus, the contrast was the addition of nanopore sequencing to routine testing, not sequencing instead of routine testing.

The registry records enrollment of 8 participants: 3.0 in Arm I and 5.0 in Arm II. The study status is terminated. The recorded study start was 2023-01-19, and the primary completion date was 2023-09-12. The reason for termination is not reported in the registry record. The registry does not report why the arm sizes differed, whether enrollment ended as planned, or details of the randomization sequence and allocation process.

The primary outcome was the number of participants with surgical site infections, assessed for up to 90 days. A secondary outcome was timeliness of sample analysis. The record lists 4 outcome measures, but a complete description of all posted measures is not available. The study is not assigned a phase; the phase field is listed as NA.

The small enrollment and terminated status are important context for reading the results. The registry records counts in each arm, but no comparative analysis is posted. Design features such as the randomization method, any planned interim analyses, the intended enrollment target, and the rationale for that target are not reported in the registry record. The design can therefore be summarized as randomized and parallel, while more detailed trial-conduct and planning questions remain unanswered.

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: This study evaluated the clinical use of Oxford Nanopore Sequencing in characterizing biliary microbial contamination in patients undergoing pancreatic head resection (total pancreatectomy, pancreaticoduodenectomy) surgery. Following enrollment, stratified randomization was performed using surgery type as a stratification factor. Patients that did not complete surgery were, therefore, removed from the study prior to assignment to a study group. assignment to a study group was dependent

Overall Study

Analysis population for the primary outcome, as defined in the registry: To determine whether the use of rapid Oxford Nanopore sequencing technology reduced rates of surgical site infections we compared the number of patients diagnosed with a surgical site infection in Arm II compared to the number of patients diagnosed with a surgical site infection in Arm I.

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 Participants With Surgical Site Infections, measured over Up to 90 days.

The primary endpoint counts participants diagnosed with a surgical site infection, abbreviated SSI, during follow-up of up to 90 days. The registry says SSI was classified using American College of Surgeons National Surgical Quality Improvement Program definitions. Evaluation could include physical examination, laboratory testing, and imaging such as computed tomography and ultrasound. The follow-up description also notes clinical visits and further assessment according to the course of recovery and clinical need.

This endpoint is used because the stated trial question concerns whether adding nanopore sequencing to bile testing is associated with differences in subsequent surgical site infections. A participant count gives a direct summary of how many people in each arm met the registry’s SSI definition. It does not, by itself, describe infection severity, timing, duration, or the test’s turnaround time. Timeliness of sample analysis is listed separately as a secondary outcome.

In the posted results, Arm I has 1.0 participant with an SSI among 3.0 participants, and Arm II has 2.0 participants with an SSI among 5.0 participants. These are the observed arm counts. The registry does not post an inferential comparison, confidence interval, or adjusted effect estimate for this endpoint. Consequently, the counts describe this enrolled group but do not establish the precision of an arm-to-arm difference or how well that difference would represent a broader patient population.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is binary at the participant level: each participant either was or was not diagnosed with a surgical site infection during the specified follow-up. The registry reports the number with an event, not a modeled risk estimate. Arm I records 1.0 event participant among 3.0 participants, and Arm II records 2.0 among 5.0. Those are descriptive counts, not an inferential comparison.

What would an analysis compare?

In general, a two-arm analysis of a binary outcome compares the probability or proportion of participants with an event between groups. Common approaches can estimate a difference, ratio, or odds-based contrast, and can attach a confidence interval or test of a specified null hypothesis. Each approach has assumptions and can behave differently when event counts and group sizes are small. This is general statistical context; the registry does not report which method, if any, was planned for this endpoint.

Here, no analysis is posted for the two-arm binary comparison, and the available comparison is identified as not estimable. There is therefore no reported treatment-effect estimate to explain, no confidence interval to interpret, and no p-value to characterize. The absence of these statistics should not be mistaken for a finding of no difference. It means the registry record does not provide an inferential result for this comparison.

What does a confidence interval add?

In general, a confidence interval expresses the uncertainty in an estimated effect under a statistical procedure. Its width is influenced by the amount of information in the data, including the number of participants and events, as well as the method and assumptions used. An interval around an effect can show which values are compatible with the observed data under that procedure. It is not a guarantee that the true effect lies in the interval, and it does not resolve limitations in study conduct or measurement. No confidence interval is reported for this trial’s primary comparison.

With only 8 participants enrolled and few primary events recorded, the data provide limited information for precise estimation. This is a qualitative statement about the amount of information, not a newly calculated measure of precision. The arm sizes are also unequal. Randomization is recorded, but details of the randomization process are not reported in the registry record. A randomized design aims to make groups comparable on average, but it cannot ensure balance in every small realized sample.

Why distinguish observed results from planning?

A sample-size calculation is a planning exercise that asks how many participants might be needed under chosen assumptions. The planning illustrations on the page are based on the observed effect and use a two-sided significance level of 0.05, equal allocation, and a normal approximation. They describe participants per arm for a specified power under those assumptions, rather than the number actually observed. The registry’s own sample-size assumptions and justification are not reported in the registry record. Planning illustrations are not observed power and cannot retrospectively establish what the trial could detect.

The stated planning approach also describes effects as fractions of the observed effect. This makes the illustration dependent on the observed estimate, which in a very small study may itself be imprecise. Such calculations are useful only as conditional scenarios. They are not evidence that a future study will reproduce the same effect, nor do they substitute for a prespecified design rationale.

Does over-dispersion apply?

In general, over-dispersion refers to variation greater than a statistical model expects. It is particularly relevant to some count outcomes, where a simple model may underestimate variability if observations vary more than assumed. The primary endpoint is recorded as participants with an event, a binary outcome, not as a rate of repeated events. The registry does not report a model for the endpoint or an over-dispersion assessment. Over-dispersion should therefore not be presented as a feature demonstrated by these results.

What can be inferred from randomization?

Random allocation is recorded, and the trial is described as parallel-group. In general, randomization supports a comparison by reducing systematic allocation differences, especially when the study is adequately conducted and analyzed according to its design. It does not automatically remove uncertainty from a small sample, correct missing outcomes, or guarantee masking. Masking is listed as none. The registry does not report a detailed allocation procedure, an analysis population, or whether an intention-to-treat analysis was used.

The analysis should also be distinguished from the endpoint’s clinical ascertainment. The registry describes SSI classification and possible assessments, but it does not report whether outcome assessors were blinded or how disagreements were handled. Those details matter for evaluating the consistency of outcome classification, but cannot be inferred from the endpoint description alone. The posted figures should consequently be treated as registry-reported counts, not as the output of a fully documented statistical analysis.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Arm I (Biospecimen Collection, Routine Testing)", "Arm II (Biospecimen, Nanopore Sequencing, Routine ")
n      <- c(3, 5)
events <- c(1, 2)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Arm I (Biospecimen Collection, Routine Testing)  3  1  33.3  0.8  90.6  6.1  79.2  6.8  80.6
ARM  Arm II (Biospecimen, Nanopore Sequencing, Routine   5  2  40.0  5.3  85.3  11.8  76.9  11.8  77.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and a secondary outcome of timeliness of sample analysis. It also records 4 outcome measures. The posted record does not describe a multiplicity strategy for handling more than one outcome or multiple comparisons. It is not reported in the registry record whether a hierarchy, adjustment, or other prespecified approach was planned. Since no inferential analyses are posted, there are no reported p-values whose interpretation can be adjusted or evaluated for multiplicity.

Missing-data handling is also not reported in the registry record. The available arm sizes and primary counts are presented, but there is no account of participants with missing endpoint assessments, withdrawals, exclusions after randomization, or imputation. The registry does not state whether every randomized participant was included in the primary analysis or define an analysis population. It would therefore be inappropriate to assume an intention-to-treat, per-protocol, or complete-case analysis.

The follow-up description gives a period of up to 90 days and describes clinical review and assessment procedures. It does not provide a participant-level account of follow-up completion or explain how outcomes were handled when follow-up was incomplete. These details affect interpretation because a count of recorded events is most informative when the completeness and consistency of outcome ascertainment are clear.

Additional analysis details—including a prespecified statistical plan, adjustment variables, interim analyses, and handling of protocol deviations—are not reported in the registry record. The record therefore supports a description of the endpoint and observed counts, but not a reconstruction of the planned analysis or its population.

12. 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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: bactereremia (66.7%), arterial injury (33.3%), fatigue (33.3%), hematoma (33.3%), intraabdominal hemorrhage (33.3%).

The serious adverse event figures are separate from the primary surgical site infection endpoint. The registry records serious adverse events affecting 3 participants in Arm I, where 3 were at risk, and 3 participants in Arm II, where 5 were at risk. Deaths are recorded as 0 in each arm. These are the posted serious-event summaries; they should not be treated as a comparison of treatment-related risk without further information.

The listed serious adverse event terms include Bactereremia at 66.7%, and Arterial injury, Fatigue, Hematoma, Intraabdominal hemorrhage, and Cholangitis at 33.3% each. The registry does not clarify in this record whether participants could contribute more than one event term or how these percentages relate to overlapping events. The terms are reproduced as posted and should not be assumed to be mutually exclusive categories.

All participants in Arm I are listed as having an other adverse event, as are all participants in Arm II. These figures describe the registry’s adverse-event reporting and do not establish causation. The available record does not provide enough detail to determine attribution, duration, severity grading beyond the serious designation, or the relationship of each event to surgery, testing, or the intervention. Serious adverse event summaries should also not be substituted for the primary SSI counts, which are reported separately.

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

This trial’s posted primary result is a count of participants diagnosed with surgical site infections: 1.0 in Arm I and 2.0 in Arm II. The registry records 3.0 participants in Arm I and 5.0 in Arm II. Those observations describe the enrolled participants; they do not by themselves establish a reliable difference between the testing approaches.

The study asked whether nanopore sequencing added to routine bile testing could be relevant to earlier detection of bacteria in bile and surgical site infections. The primary endpoint addresses diagnosed SSI, while timeliness of sample analysis is listed as a secondary outcome. No posted results for timeliness are included. Thus, the record does not establish whether sequencing shortened analysis time, and the SSI counts cannot answer that separate question.

The record also does not establish that adding sequencing prevented infections, caused infections, or changed clinical care. No comparative estimate, confidence interval, or p-value is posted for the primary endpoint. The study’s terminated status and enrollment of 8 participants further limit what can be learned from the counts. The reason for termination is not reported in the registry record.

These findings should not be interpreted as evidence for or against clinical use. They are a small set of registry-reported observations in a randomized study, without a reported inferential comparison or full account of missing data and analysis populations. The appropriate reading is descriptive: the registry records the specified counts, while the magnitude and precision of any underlying difference remain unreported.

More broadly, the trial’s rationale raises a testable question about the relationship between bile microbiology, testing speed, and postoperative infection. The posted outcome information does not resolve that chain of questions. Any conclusion beyond the observed counts would require analyses and details not reported in the registry record.

14. Why This Trial Matters Statistically

This study is statistically informative as an example of the distinction between a randomized design and a precise, interpretable estimate. Randomization is recorded, but the trial enrolled 8 participants and is marked terminated. The primary event counts are available, yet the registry does not post an inferential comparison. A design label alone cannot supply the missing precision or analysis.

The outcome is clinically framed as a count of participants with surgical site infections, and the intervention adds a sequencing procedure to routine testing. That makes it important to separate the primary endpoint from the secondary question of timeliness. An intervention might generate information on a different timeline without that fact being represented by the infection count; conversely, infection counts do not tell readers how quickly samples were analyzed. The registry lists both kinds of question but does not post the secondary outcome values.

The record also illustrates why denominators and analysis details matter. The observed counts need to be read alongside the arm sizes, follow-up, and information about outcome ascertainment. With no reported confidence interval or analysis method, readers cannot evaluate the uncertainty of an estimated group contrast. With missing-data procedures and analysis populations not reported in the registry record, readers also cannot determine how the reported counts map to a prespecified analysis.

Finally, the planning illustrations are distinct from the trial’s evidence. They are conditional calculations based on stated assumptions, not proof of achieved power or a substitute for design documentation. For biostatisticians and clinical researchers, this record reinforces the value of transparent reporting of enrollment rationale, analysis plans, outcome completeness, and comparative estimates—even when the main result is necessarily descriptive.

15. 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 most immediate limitation is the limited enrollment: the registry records 8 participants, with 3.0 in Arm I and 5.0 in Arm II. The study is marked terminated, but the reason and circumstances of termination are not reported in the registry record. The available primary endpoint counts are therefore a small descriptive result rather than a precise comparative estimate.

No inferential analysis is posted for the primary comparison. The registry does not provide an effect estimate, confidence interval, p-value, or method used to compare the binary endpoint. The available comparison is recorded as not estimable. Without these details, readers cannot assess the uncertainty of a group difference or determine whether an analysis was prespecified.

The record does not report the randomization procedure, intended enrollment, sample-size justification, allocation concealment, or interim analyses. Masking is listed as none, and outcome assessor masking is not described. These omissions constrain assessment of study conduct and the potential for bias, without showing that any particular bias occurred.

Missing-data handling, the analysis population, protocol deviations, and completeness of follow-up are not reported in the registry record. The primary outcome has a follow-up period of up to 90 days, but participant-level completion is not detailed. The secondary outcome of timeliness of sample analysis is listed, while its results are not included in the posted information available for this account. Together, these limitations restrict interpretation to the reported event counts and prevent broader conclusions about test timing or comparative clinical outcomes.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: "Answers in Hours" A Randomized Controlled Trial Using Microbiome Metagenomics for Bile Duct Cultures — NCT05523154.
• Registry record last updated 2025-02-18; status last verified 2025-01.
• Results first posted 2025-02-18.
• 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.

19. Record Summary

The registry record describes NCT05523154, a randomized, parallel-group trial of bile testing in patients undergoing surgery for benign or malignant pancreatic tumors. Arm I received bile collection and routine testing; Arm II received bile collection, nanopore sequencing, and routine testing. Masking is listed as none. The study enrolled 8 participants and is marked terminated.

The primary endpoint was the number of participants with surgical site infections during follow-up of up to 90 days. The posted counts are 1.0 among 3.0 participants in Arm I and 2.0 among 5.0 in Arm II. No analysis is posted for this comparison, and no confidence interval or p-value is reported. Timeliness of sample analysis is listed as a secondary outcome, but results are not included.

The record includes serious adverse event summaries and records 0 deaths in each arm. The reason for termination, sample-size justification, missing-data procedures, and analysis population are not reported in the registry record. The posted evidence is therefore descriptive and does not quantify the precision of an arm-to-arm difference.