This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Personalized Warfarin Dosing by Genomics and Computational Intelligence (NCT00872079), a na na study. The primary outcome is Patient Genomics.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00872079 |
| Phase | NA |
| Condition | Venous Thrombosis, Atrial Fibrillation, Myocardial Infarction |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 175 |
| Arms in the primary outcome | n/a |
| Lead sponsor | US Department of Veterans Affairs |
| Results posted | Yes |
2. Clinical Question
Population
The record concerns people receiving warfarin anticoagulation and lists venous thrombosis, atrial fibrillation, and myocardial infarction as conditions. The listed enrollment is 175. The registry description refers to collecting genotype information from up to 300 people receiving warfarin. It does not report a more detailed population definition, eligibility criteria, or the characteristics of participants contributing to the posted outcome.
Intervention
The recorded intervention is Genomics, classified as a device. The broader study description proposes using historical warfarin dosing information and genotype information to develop a computer model for predicting drug effects and exploring possible doses. The record does not report a completed assessment of the model's predictive performance or a comparison of dosing guided by the model with another approach.
Comparator
No like-for-like control comparison is recorded. Allocation is listed as NA, and the study model is single group. Although the arm description refers to a randomized clinical trial as an aim, the registry's listed design does not establish that a randomized comparison was conducted. A comparator group and comparative outcome results are not reported in the registry record.
Primary question
The recorded primary outcome is Patient Genomics at baseline: the number of participants whose CYP2C9 and VKORC1 genotypes were determined during Aim 2. This is a data-collection outcome. It does not measure how accurately a dosing model predicts response, whether model-guided dosing changes clinical outcomes, or whether one dosing strategy performs better than another. The number of participants with these genotypes determined is not reported in the registry record.
3. Trial Design
The registry identifies NCT00872079 as a terminated study sponsored by the US Department of Veterans Affairs. The recorded start is 2008-09 and the primary completion is 2011-09. Enrollment is listed as 175. The phase is NA, allocation is NA, masking is none, and the model is single group. These fields describe the registered study record; they do not establish that every planned activity was completed.
The study description sets out several aims: collect historical warfarin dosing data at the VA, collect genotype information from up to 300 people receiving anticoagulation, develop a computer model using those sources, and conduct a randomized clinical trial. The recorded intervention is Genomics, classified as a device. These planned aims are broader than the single-group design recorded in the study fields. The registry record does not explain whether the aims were revised, how far each aim progressed, or whether a randomized trial component was conducted.
That distinction matters when interpreting the record. The aim description is not evidence that a randomized comparison occurred. With allocation listed as NA and a single-group model, the recorded study does not support reading the outcome as a comparison of a model-guided strategy against a control strategy. The status is terminated, but the reason for termination is not reported in the registry record. The record also does not report the number enrolled at each aim, the number completing any activity, or participant flow through data collection and model development.
The posted primary outcome is a baseline count related to CYP2C9 and VKORC1 genotyping. It is not a reported measure of dosing accuracy, time in a therapeutic range, clinical events, or a treatment effect. No analysis results are listed. Accordingly, the design description supports an account of the study's stated aims and registered structure, but not a claim about how the model performed or what clinical outcomes followed.
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: Participants were not enrolled into the randomized clinical trial for Aim 4 due to lack of funding.
Overall Study
| Stage | Genomics |
|---|---|
| STARTED | 175 |
| COMPLETED | 175 |
| NOT COMPLETED | 0 |
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.
| Characteristic | Unit | Genomics |
|---|---|---|
| Participants analysed | 175 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 50 |
| Age, Categorical: >=65 years | Participants | 125 |
| Sex: Female, Male: Female | Participants | 10 |
| Sex: Female, Male: Male | Participants | 165 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 1 |
| Race (NIH/OMB): Black or African American | Participants | 17 |
| Race (NIH/OMB): White | Participants | 157 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Patient Genomics, measured over Baseline.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary outcome is titled Patient Genomics. Its unit is participants, its parameter is a number, and its timeframe is baseline. The description specifies that during Aim 2, investigators determined participant genotypes for CYP2C9 and VKORC1. In plain terms, the endpoint is intended to count participants with these genotypes determined.
This measure fits the data-gathering aim described in the record. Genotype information was intended to contribute to a computer model alongside historical warfarin dosing information. Counting participants with genotypes determined can describe whether this particular input was collected. It does not, by itself, assess the quality or completeness of genotyping, the model's predictive accuracy, or whether incorporating genotype information changes a dose decision or a clinical outcome.
The outcome is recorded at baseline, not as a change over follow-up. Although the registry lists one outcome measure, it does not report a participant count for this endpoint. Therefore, the record does not establish how many participants had CYP2C9 and VKORC1 genotypes determined. It also does not report a result that could be interpreted as a comparison between groups. The endpoint's relevance is to documenting the intended collection of genetic information, rather than evaluating a clinical benefit or harm.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record supports a narrow interpretation. It describes an effort to collect warfarin dosing and genotype information, develop a computer model, and pursue a randomized clinical trial as one of its aims. The registered design, however, is single group, with allocation listed as NA and no masking. The primary outcome is a baseline count of participants with CYP2C9 and VKORC1 genotypes determined. These details identify the kind of work the record describes, but do not provide an estimate of model performance or a comparative clinical effect.
No primary outcome result is reported in the registry record. The number of participants with genotypes determined is therefore unknown from this record. There are also no analyses listed. Without a posted outcome count or analysis, it is not possible to assess the amount of genetic information collected, quantify uncertainty around that count, or determine whether the outcome met a prespecified target. The record does not give a target for this outcome.
The enrollment figure of 175 is a registered study-level figure; it should not be treated as the denominator for the primary outcome without a reported analysis population. The description separately refers to genotype information from up to 300 people. The record does not reconcile these figures or indicate how many people contributed to the genotype outcome. It would be inappropriate to infer completion, missingness, or a response rate from them.
The arm description mentions a randomized clinical trial, but that statement appears within the listed aims. It does not override the registered single-group model and NA allocation, nor does it establish that a randomized comparison produced results. A treatment effect, uncertainty interval, or test comparing dosing strategies is not reported in the registry record. No conclusion about comparative effectiveness can be drawn from the posted information.
General statistical interpretation: a point estimate describes the observed value of an outcome in the analyzed population; a confidence interval describes uncertainty around an estimate under its statistical assumptions. Neither can be interpreted when the relevant result and analysis are absent. Likewise, a p-value would require a specified hypothesis and an analysis result. No such result is reported.
The registry also records a terminated status. This indicates the recorded status, but does not explain the reason or establish which planned activities were completed. The status alone is not a statistical result. It cannot be used to infer that the model was unsuccessful, that data collection stopped at a particular point, or that a treatment strategy did or did not have an effect. The defensible interpretation is limited to the design and outcome description actually recorded, with the primary result and comparative findings not reported in the registry record.
9. Statistical Methods Explained
The registry record lists one primary outcome and zero analyses. It does not report an inferential statistical method for that outcome, an analysis population, an estimate, an uncertainty interval, or a hypothesis test. The methods discussion must therefore distinguish the recorded endpoint from statistical procedures that might be used in general. No particular procedure should be attributed to this study unless the registry record reports it.
What does a participant count describe?
The endpoint is a number of participants whose CYP2C9 and VKORC1 genotypes were determined during Aim 2. A count is descriptive: it reports how many individuals meet the recorded outcome definition. Interpreting a count also requires knowing who was eligible for that outcome, who had data assessed, and whether any observations were missing. Those denominators and participant-level details are not reported in the registry record. As a result, the listed enrollment cannot automatically serve as the denominator for an outcome proportion.
General explanation: a count and a proportion answer different questions. A count states the number of observations meeting a definition. A proportion relates that count to a defined denominator. A proportion is meaningful only when the denominator and the way participants entered the analysis are clear. The registry supplies neither a primary outcome count nor a corresponding analysis population, so no proportion can be interpreted from the record.
What can a single-group design establish?
The registered model is single group and allocation is NA. A single-group description can document measurements within a group, but it does not itself provide a concurrent control group for estimating a between-group contrast. The aim description mentions conducting a randomized clinical trial, yet the registry's design fields do not record a randomized allocation. Whether that aim was carried out is not reported in the registry record. Thus, no randomization-based comparison or treatment-effect estimate should be inferred from the aim statement alone.
General explanation: a comparative effect requires a clearly defined contrast, such as outcomes under one strategy versus outcomes under another, together with an analysis appropriate to the design. A confidence interval around that contrast would express the uncertainty in the estimated difference under the model's assumptions. Since no contrast or result is reported, there is no comparative estimate to interpret.
What do the planning assumptions mean?
The record includes planning assumptions for sample-size illustrations: two-sided significance level 0.05, equal allocation between two arms, and a normal approximation. The stated effect to detect is a fraction of an observed effect. The record specifies that non-time-to-event illustrations are expressed as participants per arm, while time-to-event illustrations use a total event count. These are planning assumptions, not evidence that the actual study used two arms or followed that allocation. They do not establish the trial's own design or sample-size justification; that justification is not reported in the registry record.
General explanation: a sample-size illustration depends on assumptions about the effect to detect, variability, significance level, allocation, and analysis method. Changing an assumption can change the planning result. Such a calculation is not an observed outcome and is not observed power. Power is a design concept based on assumed conditions; it does not show whether a completed study produced a reliable result. No specific sample-size illustration result is reported in the registry record, and none can substitute for an observed primary outcome or a treatment-effect estimate.
Why do outcome definitions and analysis populations matter?
The endpoint description identifies genotypes and a baseline timeframe, but it does not explain how a participant was counted if one genotype result was unavailable, whether both results were required, or how incomplete records were handled. Those operational details are not reported in the registry record. A clear rule matters because different rules can produce different counts, even when the underlying data are unchanged.
General explanation: an analysis population defines which participants contribute to a particular estimate. For a descriptive count, readers need to know whose records were assessed and how missing observations were treated. For a randomized comparison, analysis populations can also affect how participants are assigned to groups for analysis. Here, no analysis population or missing-data method is reported, and the record does not report a randomized comparison result.
The record provides no basis for judging the precision of the primary outcome or the robustness of an analysis. It also does not report interim analyses, adjustment for multiple outcomes or tests, or a statistical analysis plan. Those omissions should be treated as unknown rather than filled in with assumptions. The result is a statistical account limited to the registered outcome definition and study design, not a reconstruction of analyses that are absent from the record.
10. Multiplicity, Missing Data and Analysis Populations
The record lists one primary outcome measure and zero analyses. It does not report a statistical analysis plan, interim analyses, or procedures for addressing multiplicity. Since no analysis results are listed, there is no set of reported tests or estimates from which to evaluate whether multiple comparisons affected interpretation. The outcome count itself is not reported in the registry record.
General explanation: multiplicity arises when several outcomes, comparisons, subgroups, or repeated tests are considered. If multiple opportunities to declare a result are assessed without an appropriate plan, the chance of a misleading positive finding can increase. A prespecified analysis plan can clarify which outcomes and comparisons are primary and how additional analyses will be interpreted. The registry record does not report such a plan, so no adjustment strategy can be attributed to this study.
Missing-data handling is also not reported in the registry record. The endpoint description does not specify how unavailable genotype results or incomplete participant records were treated, and the record does not identify the analysis population for the outcome. The enrollment figure cannot be assumed to equal the number assessed for genotyping. The description's reference to collecting genotype information from up to 300 people does not resolve the number with outcome data.
General explanation: missingness can affect both the denominator and the interpretation of a result. The consequences depend on why information is missing and on the analysis method. Without counts of missing observations and a stated approach to them, readers cannot assess whether the reported participants represent everyone intended for assessment. In this record, there is no posted outcome analysis to assess. The reason for termination is also not reported, and should not be inferred from the status alone.
11. What the Result Does, and Does Not, Mean
The record documents a study intended to combine warfarin dosing information and genetic information in developing a computer model. It identifies CYP2C9 and VKORC1 genotype determination at baseline as the primary outcome. This makes the endpoint relevant to whether a planned source of model input was collected, but it is not a direct test of whether the model predicts drug effects accurately.
The record does not report the number of participants with genotypes determined, the model's performance, or results from a randomized comparison. It therefore does not show whether model-guided dosing changed dosing decisions or clinical outcomes. Nor does it support a conclusion about comparative benefits or harms. The registry's mention of a randomized clinical trial as an aim is not itself evidence that a randomized trial was conducted or analyzed.
General explanation: a data-collection outcome and a clinical outcome answer different questions. Documentation that a measurement was collected can establish that an input was available for development work. Demonstrating prediction quality requires evaluating predictions against an appropriate observed outcome. Assessing a strategy's effect requires a defined comparison and an analysis suited to the design. These are separate evidentiary steps; the presence of one does not establish the others.
The enrollment figure of 175 should be read as the registry's enrollment entry, not as the number with complete genotype data or as a denominator for the primary outcome. The record's separate reference to up to 300 people does not explain how many were enrolled in or contributed to each aim. Because the study is marked terminated and the reason is not reported, neither completion nor failure of a particular aim can be inferred from status alone.
In short, the posted information describes the rationale, intended activities, registered design, and outcome definition. It does not provide the primary outcome result or an estimate of treatment effect. Any stronger claim about model accuracy, patient outcomes, or comparative performance would go beyond what the registry record reports.
12. Why This Trial Matters Statistically
This study raises a useful statistical distinction between building a prediction tool and evaluating a treatment strategy. The stated aims move from collecting historical dosing information and genotype information to developing a computer model and conducting a randomized clinical trial. Each step calls for a different kind of evidence. A count of genotypes determined can describe data collection; it cannot, by itself, establish predictive accuracy or a clinical effect.
The registered endpoint is concrete and narrow: a baseline participant count related to CYP2C9 and VKORC1 genotypes. That specificity helps clarify what the primary outcome is meant to measure. At the same time, the missing result and absent analysis information limit what can be learned from the record. The number assessed, completeness of genotype data, and any relationship between collected information and model development are not reported in the registry record.
The design fields also matter. The registry lists a single-group model and allocation as NA, while the aims mention a randomized trial. Recognizing the difference between a planned activity and a recorded design prevents an aim statement from being mistaken for evidence of a comparative experiment. Without a documented comparison and its results, the record cannot answer whether a model-guided strategy differed from an alternative.
For biostatisticians and clinical researchers, the case illustrates why outcome definitions, analysis populations, and transparent results are essential. It also shows the limits of interpreting sample-size planning assumptions without a documented trial design and observed analyses. The record's termination status adds context but not an explanation. Statistically, the most reliable reading is disciplined: identify what was intended, distinguish it from what is documented, and leave unreported results unresolved.
13. 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 limitation is the absence of posted outcome results. Although the registry identifies a primary endpoint, it does not report the number of participants with CYP2C9 and VKORC1 genotypes determined. No analyses are listed, so there is no estimate, uncertainty interval, or statistical test to interpret. The record also does not report model validation or comparative clinical results.
The design information is limited. Allocation is NA, masking is none, and the model is single group. The arm description refers to a randomized clinical trial as an aim, but the registry does not say whether that activity was conducted. A control group, allocation procedure, and comparative analysis are not reported in the registry record. This prevents interpretation as a randomized treatment comparison.
The record does not specify participant eligibility criteria in detail, the outcome analysis population, the denominator for genotyping, or how incomplete genotype results were handled. It lists enrollment as 175, while the study description refers to genotype information from up to 300 people; the relationship between these figures is not explained. They should not be used to infer the number with complete outcome data.
The study is marked terminated, but the reason, timing, and consequences for each aim are not reported. The statistical analysis plan, sample-size justification, interim analyses, and multiplicity procedures are also not reported in the registry record. These gaps limit assessment of precision, missing-data risk, and selective analysis. They do not establish that any particular planned activity failed or succeeded; they leave those points unknown.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Personalized Warfarin Dosing by Genomics and Computational Intelligence — NCT00872079.
- Registry record last updated 2014-02-24; status last verified 2014-02.
- Results first posted 2014-02-24.
- 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.
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17. Record Summary
NCT00872079 is a terminated, single-group study sponsored by the US Department of Veterans Affairs. The record lists enrollment of 175, a start of 2008-09, primary completion of 2011-09, allocation as NA, and no masking. Its aims describe collecting historical warfarin dosing data, collecting genotype information from up to 300 people receiving warfarin, developing a computer model, and conducting a randomized clinical trial.
The primary outcome is a baseline count of participants with CYP2C9 and VKORC1 genotypes determined. The outcome result is not reported in the registry record, and zero analyses are listed. The record does not establish that a randomized comparison was conducted, nor does it report model performance or comparative clinical outcomes. The reason for termination, analysis population, and missing-data methods are not reported.