A Trial for the Safety and Effectiveness of a Novel Antimicrobial-Coated Foley Catheter for Reduction of CAUTI.: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Trial for the Safety and Effectiveness of a Novel Antimicrobial-Coated Foley Catheter for Reduction of CAUTI. (NCT01681511), a randomized na study. The primary outcome is Number of Subjects Affected, During Treatment and Follow-up Time Periods, by a Catheter Associated Urinary Tract Infection (CAUTI) Event After First CAUTI Event..

2. Clinical Question

This was framed as a pilot rather than as a definitive test of a treatment effect. Its stated objective was to assess recruitment feasibility and gather information about CAUTI timing and rates that could help estimate the numbers needed for a pivotal study. The record does not report whether recruitment feasibility was achieved or provide a result for the primary question.

3. Trial Design

The registry identifies NCT01681511 as a randomized, parallel trial with single masking. It lists the phase as NA. Single masking is recorded, but the registry record does not identify which participants or study personnel were masked. It also does not report the allocation ratio, the randomization procedure, or the operational details of masking.

The two arms used Foley catheter devices for urinary bladder catheterization: the ICET™ TIC Foley Catheter and the BARD® LUBRI-SIL® IC Foley Catheter. The registered enrollment is 100. This is the registry’s enrollment figure, not a reported count of participants who were enrolled, treated, or included in an analysis. The record does not report actual recruitment or the number of participants assessed in each analysis population.

The study’s stated primary objective was to demonstrate the feasibility of recruiting eligible patients for assessing CAUTI timing and rates according to an agreed case definition, with the aim of better estimating the numbers needed for a pivotal study. The registry lists urinary tract infection as the condition and identifies two secondary outcomes: the proportion of subjects with symptomatic urinary tract infection and the proportion with asymptomatic bacteremic urinary tract infection.

The listed start was 2012-05 and primary completion was 2013-01. The status is terminated. The registry record does not state why the trial was terminated or describe whether the planned enrollment or follow-up was completed. It lists five outcome measures and zero analyses. The absence of analyses in the registry means that comparative estimates and statistical tests are not reported in this 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: As of Study Termination: 100 Sbj signed Informed Consent, 95 Sbj RND Definitions: Safety Pop=Any Sbj receiving treatment after RND Evaluable Pop=All RND Sbj successfully CZD ≥ 72±24 hours w/out systemic (post-op) antibiotic for CZD/non-CZD related reasons. CZD=catheterized or catheter, Pop=Population, RND=Randomized, Sbj=Subject

Overall Study

Reasons for not completing this period:

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: Overall Number of Baseline Participants (95 participants) includes 4 individuals who were randomized, but not treated.

6. Primary Endpoint

The registry lists the primary outcome as Number of Subjects Affected, During Treatment and Follow-up Time Periods, by a Catheter Associated Urinary Tract Infection (CAUTI) Event After First CAUTI Event., measured over up to 30th day from the time of catheterization.

The primary endpoint is registered as the number of subjects affected during treatment and follow-up by a CAUTI event after the first CAUTI event. Its unit is participants, and the record classifies the outcome parameter as a number. The wording therefore concerns affected subjects, rather than a rate per unit of catheter time. However, the phrase after the first CAUTI event leaves the precise counting rule unclear; the registry record does not explain how events occurring after an initial event were to be counted or how the endpoint related to recurrent events.

The stated timeframe is up to the 30th day from catheterization. Follow-up is described as continuing until that limit, withdrawal, or hospital discharge, whichever came first, and also includes 48 hours after catheter removal. The registry does not explain how these stopping conditions were reconciled for participants who reached more than one of them.

In general, a clinically defined endpoint makes the question measurable by specifying what event is counted and over what period. CAUTI timing and frequency were relevant to the pilot’s stated aim of informing a later study’s planning. But no primary endpoint counts, comparison, uncertainty estimates, or test results are reported in the registry record. The secondary infection outcomes do not fill that gap for the registered primary endpoint.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry gives basic design labels, endpoint wording, a follow-up description, and criteria for an evaluable population. It does not report the statistical analysis methods used for the primary endpoint. The distinction matters: an endpoint description defines what investigators intended to measure, while an analysis method explains how observations were converted into an estimate and how uncertainty was assessed. The record does not provide that latter information.

What does randomization tell the reader?

Randomization assigns participants to study arms by chance rather than by a clinician’s or participant’s choice. In general, this can help make the groups comparable at the point of assignment, including with respect to factors that were not measured. It does not guarantee that groups will be balanced in a small study, nor does it resolve bias arising after assignment, such as incomplete follow-up or differences in endpoint assessment. The registry identifies the study as randomized but does not describe the random sequence method, allocation concealment, or allocation ratio. The equal allocation mentioned in the planning assumptions is an assumption for a planning illustration, not a reported description of the trial’s actual allocation.

What does the parallel design mean?

In a parallel-group trial, participants are assigned to one arm and compared with participants assigned to another arm. Here the two listed arms correspond to the ICET™ TIC Foley Catheter and the BARD® LUBRI-SIL® IC Foley Catheter. The record does not report whether participants switched devices, how device exposure was recorded, or how departures from assigned treatment were handled in the analysis. Those details should not be inferred from the parallel design label.

How should the masking label be read?

The record says single masking. In general, masking can reduce the influence of expectations on care or assessment, depending on who is masked and how it is implemented. The registry does not specify who was masked, which procedures maintained masking, or whether masking was successful. No particular participant, clinician, assessor, or analyst should be assumed to have been masked on the basis of the label alone.

What do the endpoint and follow-up rules imply?

The registered primary outcome is a count of affected subjects, with a stated period extending up to the 30th day from catheterization and follow-up stopping conditions involving withdrawal or hospital discharge, as well as a period after catheter removal. In general, a participant-level count differs from an event rate: a count records how many people meet an endpoint, whereas an event rate also requires a time-at-risk denominator. The record does not state that the primary endpoint was analyzed as a rate or provide an analysis accounting for different observation times. The wording about events after the first CAUTI event is not explained further.

The registry’s evaluable population description refers to all randomized subjects successfully CZD and remaining on the CZD for 48 ± 24 hours or more without systemic postoperative antibiotics for CZD or non-CZD reasons. The term CZD is not defined in the registry record. It further states that subjects receiving an intercurrent course of systemic antibiotics lasting more than 24 hours, other than surgical prophylaxis, were considered non-evaluable in effectiveness-endpoint analyses using the evaluable population. In general, excluding participants from an evaluable analysis can make the analysis population differ from the randomized population. The record does not report how many participants met these criteria or whether other analysis populations were used.

What can be said about statistical precision?

In general, a confidence interval describes a range of values compatible with the observed data under a specified statistical model. A narrower interval indicates greater precision under that model, while a wider interval indicates less precision. No confidence interval or underlying primary endpoint result is reported in the registry record, so precision cannot be assessed for the CAUTI comparison. A p-value, also not reported, would address compatibility with a statistical null model; it would not by itself describe the size or clinical importance of an effect.

The record describes planning illustrations using a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation, with the effect to detect expressed as a stated fraction of the observed effect. It also describes total-event planning for time-to-event outcomes using the Schoenfeld method and participants per arm for other outcomes. These are planning assumptions, not evidence that the trial used those methods in its analysis. No corresponding planning estimates or observed primary effect are reported in the record. Planning illustrations are not observed power and cannot substitute for reported outcome estimates.

In general, over-dispersion arises when outcome variability exceeds what a chosen model expects. It can make standard errors too small if ignored, leading to intervals that appear more precise than warranted. The registry does not report a model for the primary endpoint, a dispersion parameter, or a method for addressing over-dispersion. It is therefore not possible to assess whether this issue applied or how it was handled.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures, including the primary CAUTI endpoint and secondary outcomes for symptomatic urinary tract infection and asymptomatic bacteremic urinary tract infection. It lists zero analyses. No analysis results are reported for these outcomes, and the record does not describe a multiplicity strategy, such as whether testing of multiple outcomes was adjusted or treated as exploratory. Without a reported analysis plan or results, the chance of false-positive findings across multiple tests cannot be assessed. The presence of several outcome measures does not establish that each was formally tested.

Missing-data handling is not reported in the registry record. There is no description of how investigators handled participants with incomplete follow-up, missing endpoint assessments, withdrawal, or discharge before the end of the stated follow-up. The endpoint description names withdrawal and hospital discharge as stopping conditions, but does not explain how observations accrued before those points entered the analysis or whether any imputation was planned.

The evaluable population definition includes criteria related to remaining on the CZD and systemic antibiotic use. Subjects with an intercurrent systemic antibiotic course lasting more than 24 hours, other than surgical prophylaxis, were considered non-evaluable in effectiveness analyses using that population. The record does not state how many participants were excluded on this basis, whether a randomized-population analysis was also conducted, or how any differences between analysis populations were handled. It uses the term CZD without defining it.

In general, an analysis restricted to evaluable participants answers a different question from an analysis that includes all randomized participants, because post-randomization exclusions can alter the groups being compared. The record does not provide enough information to determine which population underlies any estimate; it reports no such estimate.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

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: acute myocardial infarction (2.2%), myocardial iscaemia (2.2%), extradural haematoma (2.2%), thalamic infarction (2.2%), pulmonary embolism (2.2%).

The registry lists serious adverse-event counts for both arms. For the BARD® LUBRI-SIL® IC Foley Catheter, 3 were affected and 45 were at risk. For the ICET™ TIC Foley Catheter, 0 were affected and 46 were at risk. For other adverse events, the listed figures are 39 affected and 45 at risk for the BARD® arm, and 40 affected and 46 at risk for the ICET™ arm. These are the record’s counts; no formal statistical comparison or uncertainty estimate is reported.

The serious-event terms listed are acute myocardial infarction, myocardial iscaemia, extradural haematoma, thalamic infarction, and pulmonary embolism, each reported as 2.2%. The registry does not give further detail in this record about the timing, event-level counting, or how those percentages relate to the arm-level counts. They should not be interpreted as comparative risks between devices.

Deaths are listed as null for both groups. This means death counts are not reported in the registry record; it should not be read as a reported count of zero. Adverse-event counts alone also do not establish causation, particularly without details of ascertainment, exposure, follow-up, and clinical context. These figures describe the recorded safety information but do not support a conclusion about relative safety.

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

The registry record establishes that a randomized, parallel comparison of two Foley catheter devices was registered and that the trial status is terminated. It describes a pilot objective centered on recruitment feasibility and on assessing CAUTI timing and rates to inform planning for a pivotal study. It also specifies a primary endpoint and follow-up framework. These details define the question the trial set out to address.

What the record does not establish is the comparative primary outcome. No CAUTI counts by arm, effect estimate, confidence interval, or p-value are reported. No analyses are listed. The registered enrollment of 100 is not a result and does not show how many participants were actually enrolled or analyzed. The absence of results in this registry record does not establish that there were no events, that the devices had equal outcomes, or that one device had better outcomes.

The serious and other adverse-event counts give limited descriptive information, but the record does not report a formal comparative safety analysis. In particular, deaths are not reported as counts, and the serious-event term percentages lack context needed for a direct arm-to-arm interpretation. The reason for termination and the extent of completed follow-up are also not reported.

In general, a pilot study may inform whether recruitment and measurement procedures are feasible and may help plan a later study. It is not automatically designed or analyzed to provide a precise treatment-effect estimate. Here, the registry describes that intended role, but does not report whether the feasibility aims were met or provide the outcome data needed to judge comparative effects. The most defensible reading is therefore that the record documents a study question and design, alongside limited safety counts, while leaving the primary comparative result unresolved.

13. Why This Trial Matters Statistically

This trial matters statistically because it illustrates the difference between a registered research question and a reported analysis. The record identifies randomization, parallel arms, a primary CAUTI endpoint, a timeframe, and a pilot objective. Those details help readers understand what investigators intended to study. But without outcome counts, estimates, or analyses, the intended comparison cannot be evaluated statistically.

The pilot objective also highlights why feasibility work and efficacy estimation are not interchangeable. The stated aim was to assess recruitment feasibility and CAUTI timing and rates so that a later pivotal study could be planned. In general, feasibility information can help refine recruitment, endpoint definitions, follow-up procedures, and planning assumptions. It does not by itself establish a treatment effect. The registry record does not report the recruitment results or whether the pilot produced the information sought.

The primary endpoint wording raises a second statistical issue: clarity of measurement. It describes a number of subjects affected by CAUTI after the first CAUTI event, while the endpoint unit is participants. Without an explicit counting rule, it is difficult to know exactly how repeat events relate to the endpoint. Clear definitions matter because analysis depends on whether the target is people with an event, total events, or an event rate over time.

Finally, the record distinguishes a planned enrollment figure from results and gives evaluable-population criteria that could affect who enters an effectiveness analysis. Those distinctions matter when interpreting any trial: planned enrollment is not analyzed sample size, and post-randomization exclusions can change the population represented by an estimate. Since the record reports no analyses, these concerns cannot be resolved from the posted results.

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.

Several trial-specific limitations of interpretation follow from what is and is not reported in the registry record. The primary endpoint result is absent, and the record lists zero analyses. There are no CAUTI counts by arm, statistical estimates, uncertainty intervals, or tests. Consequently, neither the size nor precision of a comparative CAUTI effect can be assessed.

The endpoint description is not fully clear about the relation between affected subjects and events occurring after the first CAUTI event. It identifies participants as the unit but does not explain the counting rule for subsequent events. The stated follow-up includes a limit tied to the 30th day, withdrawal, hospital discharge, and a period after catheter removal, but the registry does not fully explain how those conditions were applied together. The record also does not report actual follow-up duration by arm.

The listed evaluable population depends on remaining on the CZD and antibiotic-use criteria, but CZD is not defined in the record. No counts are reported for participants who met or failed those criteria, and no details describe other analysis populations. The registry also does not report missing-data methods, multiplicity handling, or the statistical model used for the primary endpoint.

The registered enrollment is 100, but actual enrollment and analysis counts are not reported. The reason for termination, recruitment outcomes, and extent of endpoint ascertainment are also not reported. Safety information is limited to descriptive counts and selected event terms; deaths are not reported as counts, and no comparative safety analysis is given. These gaps limit interpretation of both the study’s feasibility objective and its clinical outcomes.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Trial for the Safety and Effectiveness of a Novel Antimicrobial-Coated Foley Catheter for Reduction of CAUTI. — NCT01681511.
• Registry record last updated 2014-04-28; status last verified 2014-04.
• Results first posted 2014-04-10.
• 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

NCT01681511 is a randomized, parallel, single-masked trial comparing the ICET™ TIC Foley Catheter with the BARD® LUBRI-SIL® IC Foley Catheter for urinary bladder catheterization. The registered enrollment is 100; the record does not report actual enrollment or analysis counts. The study is listed as terminated, with a start of 2012-05 and primary completion of 2013-01.

The stated pilot objective was to assess recruitment feasibility and CAUTI timing and rates to inform planning for a pivotal study. The primary endpoint concerns subjects affected by CAUTI during treatment and follow-up, with a timeframe up to the 30th day from catheterization. The registry lists five outcome measures and zero analyses. It does not report primary or secondary outcome results, the reason for termination, or statistical analysis methods. Serious adverse-event counts are reported by arm, but no comparative safety analysis is given.