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 Ticagrelor Versus Clopidogrel in Type 2 Diabetic Patients (NCT01823510), a randomized phase 4 study. The primary outcome is Thrombus Formation.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01823510 |
| Phase | Phase 4 |
| Condition | Type-2 Diabetes Mellitus, Coronary Artery Disease |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | Single |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Juan J Badimon |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns patients with type-2 diabetes and coronary artery disease. The registry record lists an enrollment of 20. It does not give further eligibility criteria or describe the characteristics of the enrolled participants.
Intervention
Ticagrelor was given with aspirin as a loading dose, followed by daily dosing for 5 to 7 days. The study description says both treatments were given separately to all subjects, with specialized blood tests taken before dosing, at two time-points after the loading dose, and after the last daily dose.
Comparator
The comparison was clopidogrel with aspirin, also given as a loading dose followed by daily dosing for 5 to 7 days. The study used a crossover model, so participants received both treatment regimens. The registry record does not report the treatment sequence or any washout period.
Primary question
The stated purpose was to determine whether ticagrelor plus aspirin is more effective than clopidogrel plus aspirin in patients with type-2 diabetes. The primary outcome was thrombus formation in the Badimon Perfusion Chamber, described as an ex vivo model of thrombosis under high shear. It was measured as a percentage of baseline size, with the registry specifying a mean and standard error and a timeframe of up to 7 days. No comparative result for this outcome is reported in the registry record.
3. Trial Design
The registry record describes a Phase 4, randomized, single-masked, crossover study. It lists an enrollment of 20 and a completed status. The stated start was 2013-07, and primary completion was 2016-05-10. The sponsor is Juan J Badimon. These details describe the registered study, but do not establish how many participants completed each treatment period or contributed to any particular outcome.
The crossover design means each participant was intended to receive both treatment regimens separately: ticagrelor plus aspirin and clopidogrel plus aspirin. Each regimen included a loading dose followed by daily dosing for 5 to 7 days. The study description says blood tests were planned before the loading dose, at two time-points after it, and after the final daily dose. This repeated assessment fits a design that compares treatment responses within participants as well as across treatment conditions.
Randomization is recorded, but the registry record does not report the randomized treatment sequences, how the randomization was conducted, or whether treatment order was balanced. The meaning of single masking is not specified, so the identity of the masked group cannot be established from the record. A washout period, adherence procedures, and handling of treatment-period effects are not reported in the registry record.
The listed conditions are type-2 diabetes mellitus and coronary artery disease. The primary outcome is thrombus formation in an ex vivo high-shear model; secondary outcomes include platelet reactivity, P2Y12 Reaction Unit (PRU), and Platelet Reactivity Index (PRI). The record lists four outcome measures and zero analyses. It therefore describes the intended design and measurements, but does not supply a reported treatment-effect analysis.
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.
Days 1-7
| Stage | Tica-Clop | Clop-Tica |
|---|---|---|
| STARTED | 10 | 10 |
| COMPLETED | 10 | 10 |
| NOT COMPLETED | 0 | 0 |
Days 8-21
| Stage | Tica-Clop | Clop-Tica |
|---|---|---|
| STARTED | 10 | 10 |
| COMPLETED | 10 | 10 |
| NOT COMPLETED | 0 | 0 |
Days 22-28
| Stage | Tica-Clop | Clop-Tica |
|---|---|---|
| STARTED | 10 | 10 |
| COMPLETED | 10 | 10 |
| NOT COMPLETED | 0 | 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 | Type 2 Diabetic Patients |
|---|---|---|
| Participants analysed | 20 | |
| Age, Continuous | years | 57.2 (SD 8.3) |
| Sex: Female, Male: Female | Participants | 8 |
| Sex: Female, Male: Male | Participants | 12 |
| Body Mass Index (BMI) | kg/m^2 | 30.9 (SD 4.5) |
| Diabetes, type-2 | Participants | 20 |
| Hypertension | Participants | 17 |
| Hypercholesterolemia | Participants | 19 |
| Smoking | Participants | 3 |
6. Primary Endpoint
The registry lists the primary outcome as Thrombus Formation, measured over up to 7 days.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Error |
| Unit | percentage of baseline size |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is thrombus formation measured in the Badimon Perfusion Chamber, which the registry describes as an ex vivo model of thrombosis under high shear. The outcome is expressed as a percentage of baseline size. The registry specifies a mean as the summary measure, standard error as its dispersion measure, and a timeframe of up to 7 days.
In general, an ex vivo assay measures a biological response outside the body using a sample collected from a participant. A high-shear setting represents a particular flow condition for assessing thrombus formation; it is not itself a clinical event or a direct measure of a participant’s health outcome. The assay can be used to compare how platelet-related responses vary under the tested conditions. Its meaning depends on how measurements were collected and analyzed, as well as the relationship between the assay and outcomes of clinical interest. The registry record does not report such a relationship.
Expressing the outcome as a percentage of baseline makes the measurement relative to the baseline value. The record does not specify the exact calculation used for that expression or provide endpoint values. Although the primary outcome is identified, the registry data do not report a treatment comparison, an effect estimate, or its uncertainty. The outcome description alone therefore explains what was intended to be measured, not what the study found.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the study question and primary outcome, but the information available for interpretation stops short of reporting results. It lists zero analyses and does not provide mean thrombus-formation values, a treatment contrast, a confidence interval, or a significance test. No claim about the direction, size, or precision of a difference between regimens can be made from the outcome description alone.
The endpoint is a continuous measurement summarized as a mean with standard error. In general, a mean describes the central value of a set of measurements, while a standard error describes the precision of an estimated mean. A standard error is not a description of the spread of individual participants’ measurements. Neither measure is reported numerically for this endpoint in the registry record, so the variability and precision of the study’s observed outcome cannot be assessed.
The crossover structure is relevant to how a treatment contrast would ordinarily be interpreted. General statistical reasoning for crossover studies emphasizes comparisons within participants, while also considering treatment order, period effects, and whether effects from an earlier treatment could persist into a later period. These are design considerations, not evidence that such effects occurred in this study. The registry record does not report the sequence, washout, or analysis approach needed to evaluate them.
The registry lists secondary measurements related to platelet reactivity, including PRU and PRI, but does not give their results or analyses. The existence of multiple outcomes or time points can complicate interpretation if comparisons are selected after results are known. The record does not report an outcome hierarchy, a multiplicity adjustment, or which comparisons were planned for inference.
For the primary outcome, the registry data indicate that several categories or time points were not reduced to a single comparison. That leaves no single estimate to interpret. The completed status means the study is registered as completed; it does not substitute for numerical results. The findings and their precision are not reported in the registry record, so the record cannot establish whether observed assay responses differed between the treatment regimens.
9. Statistical Methods Explained
The registered design combines randomization with a crossover model. In general, randomization is intended to reduce systematic differences in treatment assignment, while a crossover allows each participant to receive each treatment condition. When outcomes are measured under both conditions, within-participant comparisons can account for stable characteristics shared by the same participant. This general advantage depends on suitable conduct and analysis; it does not show that a particular treatment effect was found.
What does crossover require analysts to consider?
General crossover analysis must distinguish treatment effects from possible period effects, treatment-order effects, and carryover. A period effect is a change associated with when a measurement occurs rather than with treatment. Carryover refers to an effect of an earlier treatment that may influence measurements during a later treatment period. Treatment sequence matters because the order in which regimens are received can affect interpretation. These considerations are especially relevant when outcomes are measured after dosing over a short period. The registry record does not report the sequence, washout interval, or statistical handling of these issues, so their influence cannot be assessed.
The record describes single masking but does not say who was masked or how masking was maintained. This limits what can be concluded about protection from expectations or measurement-related bias. The registry record also does not report adherence, protocol deviations, withdrawals, or the number of participants contributing measurements at each assessment.
What do the endpoint summaries mean?
The primary outcome is continuous and is described using a mean and standard error. In general, a mean gives a central summary of measurements. A standard error indicates the precision of an estimated mean and tends to be smaller when the estimate is more precise. It should not be read as the range of participant responses or as the standard deviation of individual observations. Because no outcome values or standard errors are reported in the registry record, none of these quantities can be interpreted for this study.
In general, a confidence interval presents a range of effect estimates compatible with the data and the method used to construct it. It communicates uncertainty about an estimated contrast, not the probability that a particular treatment effect is true. No confidence interval for the treatment comparison is reported in the registry record. Likewise, no test statistic or p-value for the primary comparison is reported.
Why can over-dispersion matter?
General statistical models often rely on assumptions about how variable observations are. Over-dispersion occurs when observed variability exceeds what a model assumes. If unaccounted for, it can make standard errors too small and confidence intervals too narrow. The primary endpoint is described as a continuous mean, and the record does not specify a model or report a dispersion assessment. Over-dispersion is therefore a general modeling consideration, not a reported feature of this study.
What can be said about planning calculations?
The registry’s planning note describes illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It also describes detecting stated fractions of the observed effect. These are planning assumptions, not evidence of the study’s original sample-size justification or its analysis plan. The record does not report the trial’s own sample-size justification. It also does not give a numerical observed effect in the registry record for interpretation, so no planning result can be assessed. Any such planning illustration is not observed power.
In general, a sample-size calculation asks how many participants may be needed under specified assumptions about an effect and variability. A planning estimate is conditional on those assumptions and should not be interpreted as a measure of the probability that a completed study has detected an effect. Since the record does not report an effect estimate or its variability, the assumptions cannot be checked against the study’s observed data.
How should multiple outcomes be handled?
The record identifies a primary endpoint and secondary measures, but it does not report a statistical analysis plan, a prespecified hierarchy among outcomes, or adjustment for multiple comparisons. In general, testing many outcomes or time points can increase the chance of finding an apparently notable result by chance. A prespecified approach can help make clear which comparisons are confirmatory and how uncertainty is interpreted. The absence of a reported plan does not establish that no plan existed; it means the approach is not reported in the registry record.
Overall, the available methodological details establish the broad design and outcome summaries, but not the analysis used to estimate treatment effects. The registry record does not report the analysis population, model specification, missing-data procedure, or treatment of period and sequence effects. These omissions prevent an assessment of whether the analysis matched the crossover design and planned measurements.
10. Multiplicity, Missing Data and Analysis Populations
The record lists a primary outcome, secondary platelet-reactivity outcomes, four outcome measures, and zero analyses. It does not describe a prespecified hierarchy among outcomes, identify a primary comparison at each time point, or report whether statistical adjustment for multiple comparisons was planned or used. Because the primary outcome includes multiple categories or time points, the record does not reduce it to a single comparison. The results needed to assess multiplicity are not reported in the registry record.
In general, examining multiple outcomes or time points creates more opportunities for apparently notable findings to arise by chance. A prespecified analysis plan can identify which comparisons are central and whether an adjustment is appropriate. No such plan is reported. This absence should not be interpreted as proof that investigators did not have a plan; its status is simply not reported in the registry record.
Missing-data details are also not reported. The record does not state whether measurements were missing, why any might be missing, or how missing values were handled. It does not specify the analysis population, such as which participants or treatment periods would be included in an endpoint analysis. In a crossover design, this information matters because outcome availability may differ across periods or assessments. Without those details and numerical results, the effect of missing observations on the comparison cannot be evaluated.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Ticagrelor + Aspirin | 0 | 20 | 0.0% |
| Clopidrogel + Aspirin | 0 | 20 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Ticagrelor + Aspirin | 0 of 20 |
| Clopidrogel + Aspirin | 0 of 20 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Ticagrelor + Aspirin | 0 of 20 |
| Clopidrogel + Aspirin | 0 of 20 |
The registry reports separate safety entries for ticagrelor plus aspirin and clopidogrel plus aspirin. Each entry lists 20 at risk for serious adverse events and 20 at risk for other adverse events. Both entries report zero serious adverse events, zero other adverse events, and zero deaths. These are the figures recorded for the treatment groups; they are not a substitute for a detailed safety analysis.
In general, a zero count in a registry entry means that no events are recorded in that entry. It does not establish that an event is impossible or that risk is absent. The record does not provide event narratives, follow-up details, severity categories beyond the reported groupings, or an explanation of how adverse events were collected. It also does not report whether safety comparisons were statistically analyzed. Because this is a crossover study and participants received both regimens, group entries should not be read as evidence about separate, non-overlapping sets of participants.
The reported counts describe what is entered in the registry, not a broad conclusion about comparative safety. The record’s completed status does not add information beyond the recorded counts.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, single-masked crossover study was registered to compare ticagrelor plus aspirin with clopidogrel plus aspirin in patients with type-2 diabetes. It identifies thrombus formation in an ex vivo high-shear model as the primary outcome and lists platelet-reactivity measures as secondary outcomes. It also records enrollment of 20 and a completed status.
Those design details do not reveal the result of the comparison. No primary outcome values, treatment-effect estimate, uncertainty interval, or inferential analysis is reported in the registry record. The posted information therefore does not show whether the measured thrombus formation differed between regimens, how large any difference was, or how precisely it was estimated. No conclusion about benefit or lack of benefit follows from the absence of a reported estimate.
The endpoint is a laboratory measure, not a clinical event. In general, a change in an ex vivo assay may describe a biological response under the assay conditions, but interpreting its relevance to clinical outcomes requires evidence not reported. The registry record does not establish that an assay difference predicts an effect on clinical outcomes.
The safety entries record zero serious adverse events, zero other adverse events, and zero deaths in each treatment group. These counts are descriptive registry entries and do not demonstrate that risk is absent or establish a comparative safety result. The limited safety information does not include detailed event reporting or a statistical comparison.
Thus, the registry record supports a description of the question, design, measurements, and recorded safety counts. It does not support a conclusion about the primary treatment effect, its precision, or clinical implications. Those results are not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically notable for its crossover design and repeated biological measurements. In general, comparing treatment responses within the same participant can reduce the influence of stable differences between participants. That advantage must be considered alongside sequence, period, and carryover effects, which need to be addressed in both study conduct and analysis. The registry record does not report enough detail to determine how those considerations were handled.
The endpoint also illustrates the distinction between a measurement and an interpretation. Thrombus formation in a high-shear ex vivo model is a continuous laboratory outcome expressed relative to baseline. It can describe assay response, but the registry record does not establish how that response relates to clinical outcomes. Statistical precision and clinical meaning are separate questions, and neither can be resolved without reported estimates and relevant context.
The study lists a primary endpoint, secondary outcomes, and several categories or time points, yet reports zero analyses and no numerical outcome comparisons. This makes transparent reporting of the planned contrasts, analysis populations, missing-data handling, and multiplicity approach particularly important for readers seeking to interpret results. Those details are not reported in the registry record.
The safety entries provide recorded counts but no detailed safety analysis. Together, the design and reporting illustrate why a completed-study status is not equivalent to a reported result: an interpretable treatment comparison requires estimates, uncertainty, and enough methodological detail to understand how they were obtained.
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.
Important trial-specific details are absent from the registry record. It does not report participant eligibility criteria beyond the listed conditions, baseline characteristics, treatment sequence, washout period, adherence, withdrawals, or protocol deviations. These omissions limit assessment of how the crossover design was implemented and which participants contributed to each measurement.
The primary outcome is described as a mean with standard error and a timeframe of up to 7 days, but the record does not provide numerical outcome values or a single treatment comparison. It notes multiple categories or time points without reducing them to one comparison. No analysis model, effect estimate, confidence interval, significance test, or analysis population is reported. The secondary outcome results are also not reported in the registry record.
The record does not describe missing-data procedures, a multiplicity strategy, treatment of period or sequence effects, or any assessment of carryover. It does not specify who was masked under the single-masked design. These are unknowns in the registry record, not evidence that any particular procedure was absent from the study.
The safety entries report zero events in the listed categories, but offer limited detail about collection, follow-up, and event classification. Finally, the ex vivo endpoint is a laboratory measure; the registry record does not report evidence linking its measured response to clinical outcomes. Consequently, the registered design and safety counts cannot replace a full report of endpoint estimates, analysis methods, and uncertainty.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Ticagrelor Versus Clopidogrel in Type 2 Diabetic Patients — NCT01823510.
- Registry record last updated 2017-12-08; status last verified 2017-12.
- Results first posted 2017-09-01.
- 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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18. Record Summary
NCT01823510 is a completed Phase 4 randomized, single-masked crossover study sponsored by Juan J Badimon. It lists enrollment of 20 and concerns patients with type-2 diabetes and coronary artery disease. Participants were to receive ticagrelor plus aspirin and clopidogrel plus aspirin separately, each with a loading dose followed by daily dosing for 5 to 7 days.
The primary outcome was thrombus formation in the Badimon Perfusion Chamber, an ex vivo high-shear model, expressed as a percentage of baseline size and summarized as a mean with standard error. Secondary outcomes include platelet reactivity, PRU, and PRI. The registry lists four outcome measures and zero analyses. It reports no numerical primary or secondary outcome results, treatment-effect estimates, or inferential comparisons. Safety entries list zero serious adverse events, zero other adverse events, and zero deaths for each treatment group.