The DETOUR 2 Clinical Trial: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for The DETOUR 2 Clinical Trial (NCT03119233), a na na study. The primary outcome is Primary Patency.

2. Clinical Question

The registry record describes a prospective investigation of the DETOUR System in people with Peripheral Arterial Disease. Its central question was whether the device-based approach could be used for percutaneous femoropopliteal bypass and how primary patency was assessed at 12 months. The primary endpoint defined patency using a peak systolic velocity ratio (PSVR) ≤2.5 from duplex ultrasound (DUS), together with no clinically-driven re-intervention within the stented segment.

This is a single-group study, not a randomized comparison. The registry description refers to comparison with performance goals, but the numerical goal and the result of that comparison are not reported in the registry record. The record therefore does not support a direct estimate of how outcomes compare with a concurrent control group. It also does not provide enough detail to determine which participants were included in the primary endpoint analysis or how missing endpoint assessments were handled.

3. Trial Design

DETOUR 2 is identified as a prospective, single-arm, multi-center, international clinical investigation of the DETOUR System. The registry lists 202 participants enrolled and marks the study as completed. The recorded start date is 2017-12-13, and the primary completion date is 2021-12-22. The sponsor is Endologix. The phase is listed as NA.

The model is single group, allocation is listed as NA, and masking is none. These design features mean the registry record does not describe random assignment between the DETOUR System and a concurrent control treatment. The arm description says the investigation evaluates the system compared with performance goals. However, the value of the performance goal, its source, and the statistical procedure used for that comparison are not reported in the registry record. A performance-goal comparison should not be read as equivalent to a randomized, like-for-like comparison.

The brief description says the investigation evaluates the safety and effectiveness of the PQ Bypass System for percutaneous femoropopliteal bypass. The intervention list names the DETOUR System as a device. The registry also identifies stent graft separation and migration, separation and migration assessed by 12-month X-ray, and stent graft fracture assessed by 12-month X-ray among the secondary outcomes. These listings describe topics assessed, but do not establish what the results were.

Five outcome measures and two analyses are listed in the registry record. More detailed information about the analysis populations, follow-up procedures, handling of withdrawals, and the prespecified statistical analysis plan is not reported in the registry record. The primary endpoint is defined at 12 months, but the number of participants with an evaluable assessment at that time is not reported in the registry record. The enrollment figure alone does not show how many participants contributed data to each outcome.

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: The DETOUR 2 study enrolled subjects at 32 US and 4 OUS sites 'All Subjects' (n=202 enrolled)

Overall Study

Analysis population for the primary outcome, as defined in the registry: Number at Risk/Total Number of Events

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 Primary Patency, measured over 12 months.

The primary endpoint is primary patency at 12 months. The registry defines it using two conditions: a peak systolic velocity ratio (PSVR) ≤2.5 on duplex ultrasound (DUS), and no clinically-driven re-intervention within the stented segment. The endpoint is expressed as a percentage of participants, and the registry describes its population measure as the number at risk and total number of events.

In general, a composite endpoint combines multiple criteria into one outcome. For this endpoint, meeting the patency definition requires the ultrasound criterion and the absence of the specified re-intervention. Such a definition can bring an imaging measure and a clinically relevant subsequent procedure into the same outcome, but interpretation depends on knowing how each component was assessed and how missing assessments were treated. Those details are not reported in the registry record.

Patency is used as a measure of whether the treated segment remains open according to the stated imaging and re-intervention criteria. The threshold and assessment window are part of the endpoint definition, not a result. The actual percentage meeting the definition, its 95% confidence interval, and the number assessed at 12 months are not reported in the registry record. Consequently, the endpoint description alone cannot establish the observed level of patency or its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes the primary endpoint as a percentage of participants and identifies a 95% confidence interval as the dispersion measure. It also lists the endpoint parameter as NUMBER and describes the population in terms of participants at risk and total events. The observed percentage, confidence interval limits, and endpoint counts are not reported in the registry record. The methodological implications can therefore be explained, but the trial’s numerical primary result cannot be interpreted from this record.

What does a confidence interval communicate?

In general, a confidence interval expresses the statistical uncertainty around an estimate under a specified method and its assumptions. For a percentage, it helps show how compatible the data are with a range of underlying values. It is not a guarantee that the true value lies in the interval, and it does not by itself address sources of bias such as missing outcome data, selection, or limitations in measurement. The registry names a 95% confidence interval for primary patency, but does not report its limits or the method used to calculate it.

The width of an interval is relevant to interpretation. Greater precision is generally reflected by a narrower interval, while less precision is reflected by a wider one. Precision depends in part on the amount of usable information and the analysis method. Enrollment is not a substitute for the endpoint denominator: not all enrolled participants necessarily have an observed assessment for a given outcome. The number at risk and endpoint-specific analysis population are not reported in the registry record.

How should a percentage endpoint be understood?

In general, a binary percentage represents the share of an analysis population that meets a defined event or outcome criterion. Interpretation requires both the numerator and the denominator, along with a clear definition of what qualifies and the time period over which it is assessed. Here, the criterion is primary patency at 12 months, based on PSVR ≤2.5 from DUS and no clinically-driven re-intervention within the stented segment. The actual number meeting this definition and the number evaluated are not reported in the registry record.

The stated definition combines an imaging threshold with a clinical event criterion. General statistical practice treats the endpoint definition as essential to reproducibility: different thresholds, assessment schedules, or rules for missing measurements can change which participants count as having the outcome. The registry record does not report details about image assessment, adjudication, or the treatment of missing or indeterminate measurements.

What does a single-group design permit?

In general, a single-group study can describe outcomes among participants who receive an intervention, subject to the study’s population and measurement procedures. Without a concurrent randomized comparison group, it cannot isolate the intervention’s effect from other explanations for the observed outcomes. The DETOUR 2 arm description refers to performance goals, but the registry does not report their numerical values, their basis, or the analysis used to compare outcomes with them. Such a benchmark comparison is not interchangeable with a randomized treatment contrast.

Allocation is listed as NA and masking as none. These labels do not supply further details about outcome assessment or potential sources of bias. The registry does not report whether endpoint assessors were independent, whether any outcome review was blinded, or whether other steps were used to reduce measurement or ascertainment bias. Those details should not be inferred from the design labels.

What can be said about planning illustrations?

In general, sample-size planning uses assumptions about the outcome, the effect to detect, the significance level, allocation, and the statistical method. Planning values describe a hypothetical study design; they are not results from the completed trial and should not be called observed power. The planning assumptions associated with the posted illustrations specify 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. The stated planning method distinguishes time-to-event illustrations, which use a total event count under the Schoenfeld approach, from other illustrations, which use participants per arm.

These assumptions are explicitly described as a planning illustration computed from the observed effect, not as the trial’s own design. They do not establish that DETOUR 2 was designed with those assumptions, and the registry record does not report its sample-size justification. Since this investigation is single-group, an equal-allocation two-arm illustration is not a description of its allocation. No numerical planning values or observed primary effect are reported in the registry record.

Why do analysis details matter?

In general, analysis choices determine how observations are converted into estimates and how uncertainty is quantified. For repeated or clustered data, for example, methods need to reflect dependence among observations; for event counts, over-dispersion can make a simple model understate uncertainty when variability exceeds the model assumption. These are general considerations, not claims about methods used in this trial. The registry record does not report enough detail to determine whether these issues applied or how they were addressed. The named endpoint, confidence level, and study design do not by themselves identify the statistical procedures used.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures and two analyses. It identifies primary patency at 12 months as the primary endpoint and lists secondary outcomes involving stent graft separation and migration, including X-ray assessment at 12 months, and stent graft fracture by 12-month X-ray. The registry record does not report a multiplicity strategy, such as a hierarchy among outcomes or an adjustment to account for multiple statistical tests. It also does not report which analyses correspond to which outcomes.

In general, testing multiple outcomes can increase the chance of obtaining at least one apparently notable result by chance if each is treated as an independent confirmatory test. A prespecified testing strategy can clarify which analyses are confirmatory and how interpretation should account for multiple comparisons. Without the analysis plan and reported results, it is not possible to determine how multiplicity was handled or what role each analysis played.

Missing-data handling is also not reported in the registry record. The primary endpoint is defined at 12 months, but the number of participants assessed at that time, the reasons for missing assessments, and the method used to handle missing or unevaluable observations are not reported. General statistical interpretation of a percentage endpoint depends on knowing its denominator and whether participants without an observed outcome were excluded, counted under a specified rule, or addressed through another method.

The analysis populations are not described in sufficient detail to determine whether the results were based on all enrolled participants, participants who received the intervention, or another defined group. No interim-analysis plan or stopping rule is reported in the registry record. These absences do not establish that such procedures were or were not used; they mean the record does not report them.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 3% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: vascular stent occlusion (12.9%), peripheral artery stenosis (6.9%), vascular stent stenosis (5.4%), intermittent claudication (5.4%), peripheral artery occlusion (4.5%).

The registry reports 130 affected among 202 at risk for serious adverse events and 142 affected among 202 at risk for other adverse events. It also reports 14 deaths. These are aggregate safety figures. The registry record does not report the timing of the events, their causes, their seriousness criteria, their relationship to the device, or whether deaths occurred during a particular follow-up period.

The listed serious adverse-event terms are vascular stent occlusion, 12.9%; peripheral artery stenosis, 6.9%; vascular stent stenosis, 5.4%; intermittent claudication, 5.4%; peripheral artery occlusion, 4.5%; and peripheral ischaemia, 4.5%. The record does not explain the denominator or counting rule for these term-specific percentages. They should therefore be understood as registry-listed percentages, not converted into counts or assumed to represent separate groups of participants. Event terms can overlap within a participant, and the record does not clarify whether overlap occurred.

In general, adverse-event counts describe what was recorded, not by themselves whether an intervention caused an event. Causal interpretation requires additional information about timing, clinical context, attribution, and comparison. Those details are not reported in the registry record, so the figures should be read descriptively rather than as evidence of causation.

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

The registry record establishes that DETOUR 2 was a completed, prospective, single-arm investigation of the DETOUR System and that primary patency at 12 months was its primary endpoint. The endpoint was defined using PSVR ≤2.5 on DUS and no clinically-driven re-intervention within the stented segment. The record also reports aggregate safety counts and several serious adverse-event terms with percentages.

The record does not report the numerical primary patency result, its 95% confidence interval, or the endpoint-specific numerator and denominator. It also does not report results for the named secondary outcomes. As a result, the record cannot show the observed level or precision of primary patency or whether a stated performance goal was met. The numerical performance goal and the method for comparing with it are not reported.

The single-group design does not provide a randomized control comparison. General statistical interpretation distinguishes a description of outcomes in a treated group from an estimate of what would have happened under an alternative treatment. Without a concurrent randomized comparator, any contrast with a performance goal depends on the validity and relevance of that benchmark; the registry record does not provide the details needed to assess it.

The reported adverse-event figures describe safety observations, but they do not establish that the device caused those events. The record does not report event timing, attribution, or detailed follow-up. Nor does it explain the denominator used for the listed serious-event percentages. Those limits matter when drawing conclusions from safety summaries.

These absences do not show that an endpoint was not measured or that an analysis was not performed; they indicate that the result or method is not reported in the registry record. Readers can use the record to understand the trial’s broad design, endpoint definition, and recorded safety counts, but not to infer an unreported efficacy estimate, causal effect, or comparison with an unstated goal.

13. Why This Trial Matters Statistically

DETOUR 2 illustrates an important distinction in clinical-trial interpretation: a clearly defined endpoint is not the same as a reported endpoint result. The registry specifies primary patency at 12 months using both an ultrasound threshold and a re-intervention criterion. Yet without the observed percentage, confidence interval, numerator, and denominator, the endpoint’s magnitude and precision cannot be assessed from the registry record.

The single-group design also makes the comparison framework central. The arm description refers to performance goals, but their numerical value and the analysis used to assess them are not reported. A performance goal is not a concurrent control group, and conclusions based on an external benchmark depend on its relevance and comparability. This distinction is essential when interpreting results from nonrandomized, single-arm investigations.

The record’s safety summaries further show why denominators and definitions matter. Aggregate counts are reported for serious and other adverse events, alongside death counts and term-specific percentages. Without the denominator for each listed percentage and information about overlap, timing, and attribution, those figures cannot be translated into a fuller account of participant-level risk or causation.

More generally, a confidence interval, analysis population, missing-data rule, and multiplicity plan all affect how endpoint results should be read. The registry record does not report several of these details, and it does not provide the primary outcome estimate. Recognizing what is specified and what remains unreported is therefore part of sound statistical interpretation, rather than a basis for filling gaps with assumptions.

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 principal interpretive limitation is that the registry record does not report the primary patency result, its 95% confidence interval, or its numerator and denominator. Although the endpoint is defined at 12 months, the number assessed and the handling of missing assessments are not reported. Enrollment of 202 does not establish the endpoint analysis population.

The study is single-group, with allocation listed as NA and masking as none. The description refers to performance goals, but the numerical goal and comparison method are not reported. There is no randomized control arm in the registry design, so the record does not provide a concurrent like-for-like comparison. The source and suitability of any external benchmark cannot be assessed from the registry information.

Detailed eligibility criteria, participant characteristics, intervention delivery details, endpoint assessment procedures, and analysis-population definitions are not reported in the registry record. Nor are the statistical analysis plan, multiplicity handling, interim analyses, or sample-size justification reported. These gaps limit assessment of bias, precision, generalizability, and the prespecification of analyses.

Safety information is also limited to aggregate counts and listed terms. The record does not report event timing, cause, relatedness, follow-up duration for safety, or the denominator for term-specific percentages. The reported figures therefore cannot establish causation or support additional participant-level calculations. The secondary outcome names identify what was assessed, but their numerical results are not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: The DETOUR 2 Clinical Trial — NCT03119233.
• Registry record last updated 2025-04-02; status last verified 2025-03.
• Results first posted 2025-04-02.
• 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

DETOUR 2 (NCT03119233) is listed as a completed, prospective, single-arm, multi-center, international clinical investigation sponsored by Endologix. The registry reports 202 participants enrolled, a start date of 2017-12-13, and a primary completion date of 2021-12-22. The intervention is the DETOUR System, and the condition is Peripheral Arterial Disease.

The primary endpoint is primary patency at 12 months, defined by PSVR ≤2.5 on DUS and no clinically-driven re-intervention within the stented segment. The primary result and confidence interval are not reported in the registry record. Safety figures include 130 affected among 202 at risk for serious adverse events, 142 affected among 202 at risk for other adverse events, and 14 deaths. The record also lists serious adverse-event terms with percentages, but does not explain their denominator or report timing and attribution details.