ODEN Trial: Option vs. Denali IVC Filters: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for ODEN Trial: Option vs. Denali IVC Filters (NCT02201277), a randomized na study. The primary outcome is IVC: Filter Penetration.

2. Clinical Question

The registry describes a prospective randomized comparison of the relative safety of the Option and Denali filters. Its stated hypothesis was that there would be no significant difference in efficacy and complication rate between the filters. The main endpoint focused on filter penetration: imaging was to be used to identify penetration through the inferior vena cava wall, including penetration greater than 3 mm. The description also says the number of days since placement at imaging timepoints and the number of struts or hooks with penetration would be recorded.

The clinical context in the registry is prevention of clot migration from the legs to the lungs among patients who cannot take blood thinners. It also describes filter follow-up and removal when medically appropriate as an aim of the research. The primary endpoint, however, is a filter-complication measure, not a direct measure of clot prevention or other clinical benefit. The registry record does not report results for every aim in enough detail to determine how follow-up and removal were carried out.

3. Trial Design

ODEN is identified in the registry as a prospective randomized, parallel-group trial comparing the Denali and Option Elite inferior vena cava filters. The record lists single masking. It does not identify who was masked, and further details of the randomization procedure are not reported in the registry record. The phase is listed as not applicable.

The registry lists enrollment of 45. The outcome entries show 24 participants in the Denali group and 20 in the Option group. These group counts do not account for the full enrollment listed in the record; the record does not explain the difference. It also does not report how many people were screened, excluded, withdrew, or were included in each analysis population.

The trial started on 2014-05-27 and has a primary completion date of 2018-04-13. Its status is terminated. The reason for termination and whether termination affected recruitment, follow-up, or analysis are not reported in the registry record. The registry identifies the University of California, San Francisco as sponsor.

The primary endpoint concerns the number of participants with inferior vena cava filter penetration, assessed using imaging. The stated timeframe runs from one day after filter insertion through up to 3 years. The description says investigators would encourage imaging follow-up and removal at 30 days, while also reviewing available CT and X-ray images that clearly show the filter and vessel walls. The registry also lists secondary outcomes involving clot, migration, tilt, fracture, follow-up, and removal. Details of allocation concealment, a formal statistical analysis plan, and the sample-size justification are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: patients consented to the trial and needing a temporary ivc filter

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: 45 participants signed consent forms in the trial however one was withdrawn from the Option group due to physician's choice and in the Denali group one participant had two filters placed at different times.

6. Primary Endpoint

The registry lists the primary outcome as IVC: Filter Penetration, measured over in dwelling time in 1 day after filter insertion up to 3 years..

The primary endpoint is the number of participants with inferior vena cava filter penetration. The registry describes identifying penetration through the vessel wall using imaging, with the endpoint definition specifying penetration greater than 3 mm. The timeframe is described as beginning one day after filter insertion and continuing through up to 3 years. The endpoint description also mentions recording the number of days since placement at imaging timepoints and the number of filter struts or hooks with penetration.

This kind of endpoint is used to track a device complication that can be assessed from images. In general, imaging-based assessment can identify structural findings without relying only on symptoms or clinical examination. But interpretation depends on how imaging is obtained, which images are available, how often participants are assessed, and how findings are defined and adjudicated. The registry description says available CT and X-ray images would be reviewed, but it does not report how many participants had imaging, whether image review was blinded, or how missing imaging was handled.

The posted primary outcome entries list 24.0 participants for Denali and 20.0 for Option, against group sizes of 24.0 and 20.0. The accompanying comparison represents both groups as having an event probability of 1.0 and reports a risk difference of 0.0. In contrast, the adverse-event listing gives 0.0% for filter penetration at the stated threshold and for all CTs with penetration. The registry record does not explain this apparent inconsistency, so these entries should not be treated as an unambiguous account of the primary endpoint without clarification.

7. Results Posted in the Registry

• Option: 100.0% (20/20) versus 100.0% (24/24) 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.

IVC Filter Clot

• 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:
  • Option: 10.0% (2/20) versus 8.3% (2/24) on control; risk difference 1.7 percentage points (95% CI -15.5 to 18.8), risk ratio 1.20 (0.19–7.77); unadjusted two-proportion z-test p = 0.848.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Option and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists secondary outcomes covering filter clot, migration, tilt, fracture, penetration on imaging, and follow-up and prompt filter removal. The posted secondary clot comparison is based on 2.0 participants with an event in each group. The other listed secondary endpoints are not all accompanied by interpretable numerical results in the registry record summarized for these outcomes. The overall secondary evidence is therefore incomplete, and it cannot provide a consistent, fully quantified cross-check of the primary comparison.

Secondary outcomes can help describe other aspects of device performance, but they do not automatically resolve uncertainty in a primary endpoint. In this trial, the primary outcome entries conflict with the adverse-event listing for penetration, and the available clot comparison has a wide interval. The secondary endpoints consequently add context about the range of outcomes considered, but they do not establish a clear overall pattern that settles the primary reporting question.

In general, multiple endpoints create multiplicity: the more comparisons examined, the greater the chance that at least one result may appear unusual by chance. Statistical adjustment or a prespecified hierarchy can address some multiplicity concerns, but the registry record does not report whether any such approach was planned or used. The secondary clot p-value is explicitly unadjusted. It should be treated as exploratory rather than as a stand-alone confirmatory finding, particularly because the registry does not report a complete statistical analysis plan or the adjustment strategy across outcomes.

The secondary outcomes also differ in how they are measured. Some concern imaging findings, while others concern follow-up or removal. In general, differences in assessment schedules, available imaging, and definitions can make results across endpoints difficult to compare directly. The registry description supplies some intended procedures but does not report enough detail on completed assessments and missing observations to establish whether all secondary outcomes had comparable ascertainment.

Accordingly, the secondary information is best read as supplementary descriptive evidence. It does not remove the need to clarify the primary endpoint entries, and unadjusted secondary results carry less weight than a clearly defined, prespecified primary analysis.

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

• Computerized Tomography (CT) Studies With IVC Penetration
• Number of Participants With IVC Filter Migration
• IVC Filter Tilt
• IVC Filter Fracture
• IVC Filter Clot
• IVC Filter Improved Patient Follow Up and Prompt Filter Removal
• IVC Filter Improved Patient Follow Up and Prompt Filter Removal: Number of Days

9. Statistical Interpretation

10. Statistical Methods Explained

For a binary endpoint, each participant is classified as having or not having the event under the endpoint definition. A group event probability describes the proportion of participants with the event, while a risk difference expresses the difference between the two group probabilities. In general, a risk difference of zero means the estimated probabilities are equal in the observed data; it does not prove that the underlying probabilities are identical.

The primary comparison in the registry reports probabilities of 1.0 for both groups and a risk difference of 0.0, with limits of 0.0 and 0.0. These entries follow from the primary outcome counts as posted, but conflict with the adverse-event listing of 0.0% for penetration measures. The record does not reconcile the two accounts. This means readers should distinguish what the comparison fields report from a verified clinical interpretation of how many participants experienced penetration.

A confidence interval describes a range of values compatible with the data under the assumptions of the method used. In general, a narrow interval indicates greater precision, while a wide interval indicates that the estimate is uncertain. A confidence interval that includes zero for a risk difference does not, by itself, prove that there is no difference; it can reflect uncertainty as well as a small observed difference. The primary interval is reported as exactly 0.0 to 0.0, but its relevance is limited by the unresolved inconsistency in the endpoint entries and by the lack of reported details about the analysis.

The registry lists a two-sided t-test for superiority and a one-sided t-test for equivalence, each with a p-value of 1.0. A p-value measures how unusual the data would be under a specified null hypothesis and the assumptions of the test. In general, it is not the probability that the null hypothesis is true, nor does it measure the size or clinical importance of a difference. The record does not provide test statistics, degrees of freedom, analysis inputs, or enough detail to assess how the t-tests were applied to this participant-count endpoint.

Equivalence is a distinct statistical claim from failure to find a statistically significant difference. In general, an equivalence analysis asks whether the plausible difference lies within prespecified bounds that are considered acceptably small. Those bounds are called an equivalence margin. The registry labels one analysis as equivalence but does not report a margin or a confidence interval for that analysis. A one-sided p-value of 1.0 is therefore not sufficient to establish equivalence from the registry record.

The secondary clot endpoint is also binary. The posted counts are 2.0 participants with an event among 24.0 in the Denali group and 2.0 among 20.0 in the Option group. The recalculated risk difference is 0.017, with a confidence interval from -0.155 to 0.189 and an unadjusted p-value of 0.848. A relative risk compares the event probabilities as a ratio, while an odds ratio compares event odds. Such relative measures can be unstable when event counts are sparse. The interval for the risk difference is wide enough to include differences in either direction, so the point estimate should not be read as precise evidence of a group difference.

The sample-size figures accompanying the secondary comparison are planning illustrations based on the observed effect, not the trial's design justification and not observed power. The stated assumptions are a two-sided significance level of 0.05, equal allocation, and a normal approximation. The illustration gives participants per arm for 80% power and participants per arm for 90% power at 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect. These figures describe hypothetical planning under those assumptions; they do not change what the trial observed. The registry record does not report its own sample-size justification.

In general, over-dispersion matters when observed variability exceeds what a statistical model assumes. A model that underestimates variability can produce intervals that are too narrow and tests that are too optimistic. The posted outcomes are participant counts for binary endpoints, and the registry does not report an over-dispersion assessment or a model-based analysis requiring such an adjustment. More broadly, the absence of a detailed statistical analysis plan makes it difficult to assess endpoint definitions, model choices, and whether the posted analyses followed prespecified methods.

The analysis populations are not reported in the registry record. It is therefore unclear whether the posted outcomes include all randomized participants, only participants with available imaging, or another subset. The handling of missing outcomes, incomplete follow-up, and participants who did not receive their assigned filter is also not reported. These issues matter because an imaging-based endpoint can depend on whether follow-up images are available and interpretable.

11. Confidence Intervals and Precision

The primary comparison reports a risk difference of 0.0, with a confidence interval from 0.0 to 0.0. The displayed interval is maximally narrow, but it should not be read as proof of exact equality between the filters. The primary group values indicate an event in every participant, while the adverse-event listing reports 0.0% for penetration measures. The registry does not explain that inconsistency or report enough analysis detail to establish how the primary interval was obtained. Its apparent precision therefore cannot be interpreted independently of the unresolved reporting issue.

For the secondary clot endpoint, the recalculated risk difference is 0.017, with a confidence interval from -0.155 to 0.189. The interval includes zero and extends to differences in either direction. In general, this means the observed estimate is not precise enough to distinguish a small difference from a meaningfully larger difference under the assumptions of the calculation. The group counts are 2.0 events among 24.0 participants and 2.0 among 20.0 participants, so the estimate is based on few observed events.

The registry reports no confidence interval for its two primary t-test analyses. For the secondary endpoint, the posted comparison includes intervals for relative measures as well as the risk difference; wide intervals around relative measures are also consistent with substantial uncertainty. Confidence intervals describe statistical uncertainty under a method and its assumptions. They do not account automatically for missing data, selective reporting, endpoint misclassification, or differences in follow-up.

Precision is not the same as importance. In general, an interval can be statistically informative while still not answering whether an observed difference matters clinically; that requires context and prespecified interpretation criteria. The registry does not report an equivalence margin, a clinically important difference threshold, or a primary confidence interval from the sponsor's own analysis. The termination status and unreported analysis populations add context that the intervals alone cannot resolve.

12. Analyses Reported by the Sponsor

The registry reports a two-sided t-test for the primary comparison with a p-value of 1.0 and a one-sided t-test labelled as an equivalence analysis with a p-value of 1.0. It does not report the estimated effect, a confidence interval, or further test details for either analysis. The record does not identify these entries more specifically as a sponsor analysis, so they are best described as the analyses posted in the registry.

The posted primary comparison also gives equal event probabilities of 1.0 and a risk difference of 0.0, with a confidence interval from 0.0 to 0.0. Those values are consistent with the primary outcome counts as entered, but not with the adverse-event listing reporting 0.0% for penetration measures. The registry record does not clarify the mismatch. The recalculated comparison should therefore be read as a direct summary of the posted counts, not as an independent resolution of what the primary endpoint counts represent.

For the secondary clot endpoint, the recalculated unadjusted comparison is based on 2.0 events in each group and gives a risk difference of 0.017, a confidence interval from -0.155 to 0.189, and an unadjusted p-value of 0.848. No corresponding sponsor analysis is posted for this secondary endpoint. In general, a recalculation from summary counts is a simple unadjusted comparison and may not reproduce an analysis using participant-level data or prespecified adjustments. The registry does not report such additional methods for the clot outcome.

The discrepancy flag is false, so there is no stated conflict requiring the sponsor's own analysis to take precedence over a recalculation. Even so, the primary entries do not align on their face with the adverse-event listing. Clarification of the endpoint coding and analysis would be needed to understand the primary result fully. The registry record does not provide that clarification.

13. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary endpoint and multiple secondary outcomes, but does not report a multiplicity strategy. In general, multiplicity arises when several outcomes or comparisons are tested: even if no true effect exists, testing many hypotheses increases the chance of at least one apparently notable result. A prespecified hierarchy, adjustment procedure, or clear designation of exploratory analyses can help readers interpret a collection of tests. Whether any such plan was used is not reported in the registry record.

The secondary clot comparison gives an unadjusted p-value of 0.848. That value should not be interpreted as if it were a result from a family of tests with a known correction strategy. The registry does not report whether the analyses of migration, tilt, fracture, penetration, follow-up, and removal were adjusted for multiplicity, or how they were prioritized. Nor does it report a complete statistical analysis plan setting out which comparisons were confirmatory.

Missing-data methods are also not reported. The primary endpoint relies on imaging, and the description refers to review of available CT and X-ray images and encourages imaging follow-up. The record does not state how many participants had usable imaging, how missing or uninterpretable images were treated, or whether the outcome was assigned when a participant had no follow-up image. It also does not report the number of participants who completed each follow-up assessment.

The analysis populations are not reported in the registry record. It is not clear whether results were analyzed by randomized assignment, by filter received, or among participants with endpoint data. These distinctions can matter in randomized trials, particularly if participants did not receive their assigned device or were missing from follow-up. The record does not provide enough information to determine how such cases were handled.

Finally, the registry lists enrollment of 45 while the primary outcome groups contain 24.0 and 20.0 participants. The record does not reconcile the enrollment and group counts. The status is terminated, but the reason and its implications for enrollment, follow-up, or analysis are not reported. Together, these omissions limit assessment of whether the reported comparisons reflect the intended randomized population and a prespecified analytical approach.

14. 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

Serious events with the highest arm-level rate: filters with ivc penetration ≥ 3 mm (0.0%), all cts with ivc penetration (0.0%), filter fracture (0.0%), filter movement (0.0%), filter tilt > or = 15 deg. (0.0%).

The registry's serious adverse-event entries report 0 serious events among 24 participants at risk in the Denali group and 0 among 20 at risk in the Option group. Other adverse events are likewise listed as 0 in each group. Deaths are listed as 4 in the Denali group and 3 in the Option group. The record does not describe the causes of death, their timing, or whether they were considered related to a filter or to the trial intervention.

The adverse-event listing also gives 0.0% for several filter-related terms, including penetration at the stated threshold, all CTs with penetration, fracture, movement, and tilt. These entries are not aligned on their face with the primary outcome values, which list all participants as having the primary event. The registry does not explain the relationship between these entries.

In general, zero recorded events in a small group do not establish that an event cannot occur. The counts describe what was reported for the participants at risk; interpretation also depends on follow-up completeness, event definitions, and ascertainment. Those details are not fully reported. The death counts should be treated as all-cause figures as listed, not as evidence of a causal relationship with either filter.

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

The registry record describes a randomized comparison of two inferior vena cava filters among patients needing a temporary filter. Its primary endpoint concerns filter penetration assessed by imaging. The posted primary outcome entries produce equal group probabilities and a risk difference of 0.0, but the adverse-event listing reports 0.0% for penetration measures. Because the record does not explain this mismatch, the primary result cannot be given a straightforward clinical interpretation from the posted entries alone.

The secondary clot outcome records 2.0 events in each group. Its recalculated risk difference is 0.017, with a confidence interval from -0.155 to 0.189 and an unadjusted p-value of 0.848. This comparison is imprecise and does not establish that the groups are equivalent. The registry's equivalence-labelled analysis for the primary outcome also lacks a reported margin and supporting interval, so its p-value does not by itself demonstrate equivalence.

These results do not establish that one filter is safer, more effective, or equivalent to the other. Nor do the listed data answer whether the filters prevent clot migration or improve patient follow-up and prompt removal. The registry describes those aims, but the posted results do not provide a complete basis for interpreting them.

In general, a randomized design can support fair comparisons when allocation, follow-up, outcome definitions, and analyses are adequately implemented and reported. Here, the record does not report important details about analysis populations, missing imaging, multiplicity, or the reason for termination. The group counts also do not fully reconcile with the enrollment figure. Those limitations make the results less conclusive than a simple reading of a p-value or a zero event count might suggest.

The appropriate reading is therefore narrow: the registry contains comparisons of the two filters, but the primary endpoint entries are difficult to reconcile and the secondary comparison is uncertain. Additional clarification of the primary endpoint data and analysis would be needed for a firmer interpretation. No treatment recommendation follows from these registry entries.

16. Why This Trial Matters Statistically

This trial illustrates why the meaning of a result depends on more than its p-value. The primary comparison reports a risk difference of 0.0 and a confidence interval from 0.0 to 0.0, while the adverse-event listing reports no penetration events. Those entries are hard to reconcile with primary outcome values showing 24.0 participants out of 24.0 and 20.0 out of 20.0. A precise-looking result is not reassuring if the outcome coding or reporting cannot be understood.

It also demonstrates the difference between failing to identify a difference and demonstrating equivalence. The registry labels a one-sided analysis as equivalence, but does not report an equivalence margin. In general, equivalence requires defining in advance what range of differences would be acceptably small. A p-value of 1.0 without that context cannot establish that two devices have the same safety profile.

The secondary clot outcome shows how few events can leave a comparison uncertain. The point estimate is accompanied by a broad confidence interval that spans differences in both directions. This is a reminder that a non-significant p-value is not evidence that the true effects are identical, and that planning illustrations based on an observed effect are not a substitute for the trial's own design justification.

Finally, the registry lacks several details needed to interpret a randomized comparison: analysis populations, missing-data handling, multiplicity methods, and the reason for termination are not reported. A trial record is most useful when its endpoint definitions, participant flow, analysis choices, and estimates are all transparent. The uncertainties in this record show why careful statistical reading must attend to internal consistency and precision as well as nominal test results.

17. 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 limitations are specific to the information in this trial record. The most important is the apparent disagreement between the primary outcome entries and the adverse-event listing. The primary entries show 24.0 participants in the Denali group and 20.0 in the Option group, with a comparison representing probabilities of 1.0 in both groups. Yet the adverse-event listing reports 0.0% for filter penetration measures. The registry does not explain whether different definitions or data sources account for this difference.

The registry lists enrollment of 45, while the outcome groups contain 24.0 and 20.0 participants. The record does not explain the difference, and participant flow is not reported. As a result, it is unclear how many randomized participants contributed to each analysis and whether all enrolled participants were included.

The primary endpoint depends on imaging, and the description refers to available CT and X-ray studies. The record does not report imaging completion, image quality, blinded review, or handling of absent and uninterpretable scans. These details are relevant to whether penetration was assessed consistently between groups.

The trial is marked terminated, but the reason for termination is not reported. The registry also does not report a sample-size justification, a detailed statistical analysis plan, a multiplicity strategy, an equivalence margin, or the populations used for analysis. The sponsor's reported primary analyses contain p-values but no effect estimates or confidence intervals. The secondary clot comparison has few events and a wide interval.

These limitations do not establish that the trial was conducted improperly; they identify what cannot be assessed from the registry record. Resolving the primary outcome inconsistency and clarifying participant flow, imaging completeness, and analysis methods would be important for a more reliable interpretation.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: ODEN Trial: Option vs. Denali IVC Filters — NCT02201277.
• Registry record last updated 2019-09-12; status last verified 2019-08.
• Results first posted 2019-09-12.
• 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.

21. Record Summary

The ODEN trial is a prospective randomized, parallel-group comparison of Denali and Option Elite inferior vena cava filters. The registry lists enrollment of 45, single masking, and a terminated status. The primary endpoint is the number of participants with filter penetration assessed through imaging, with a stated timeframe from one day after insertion through up to 3 years.

The primary outcome entries list 24.0 participants in the Denali group and 20.0 in the Option group, and the posted comparison reports a risk difference of 0.0 with a confidence interval from 0.0 to 0.0. However, the adverse-event listing reports 0.0% for penetration measures, and the record does not reconcile these entries. For the secondary clot endpoint, 2.0 participants in each group had an event; the recalculated unadjusted comparison is imprecise.

The record does not report the reason for termination, analysis populations, missing-data methods, multiplicity strategy, or an equivalence margin. These gaps and the primary endpoint inconsistency limit the conclusions that can be drawn from the posted results.