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 Efficacy and Safety of Low-dose Ticagrelor (NCT03381742), a non-randomized phase 2, phase 3 study. The primary outcome is ADP-induced Inhibition of Platelet Aggregation.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03381742 |
| Phase | Phase 2, Phase 3 |
| Condition | Coronary Artery Disease |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 3043 |
| Arms in the primary outcome | n/a |
| Lead sponsor | First Affiliated Hospital of Harbin Medical University |
| Results posted | Yes |
2. Clinical Question
The registry record describes a study of different ticagrelor regimens compared with clopidogrel in patients with coronary artery disease. Its primary question concerns platelet function: how ADP-induced inhibition of platelet aggregation differed among the listed treatment groups after treatment.
Population
Patients with coronary artery disease. The registry’s brief summary discusses the need to evaluate low-dose ticagrelor in Chinese patients with coronary heart disease, but the primary endpoint’s population field is blank. Further eligibility details are not reported in the registry record.
Intervention
The listed ticagrelor regimens are 45mg bidpo., 90mg qdpo., and 90mg bidpo. The registry gives no additional treatment-duration or adherence results in the record.
Comparator
The comparison regimen is clopidogrel 75mg qdpo. The study is marked non-randomized, so treatment groups should not be assumed to be interchangeable at baseline or to form a like-for-like control comparison.
Primary question
What was the ADP-induced inhibition of platelet aggregation, measured as a percentage, in each regimen group? The endpoint was summarized as a median with an inter-quartile range and assessed up to 5 days. Group estimates and a between-group analysis are not reported in the registry record.
The registry also names outcomes concerning ADP-induced platelet-fibrin clot strength, high on-treatment platelet reactivity, cardiovascular events, and new-onset dyspnea. These are relevant to the study’s broader assessment, but the record does not provide their group results or a complete account of how each outcome was analyzed.
3. Trial Design
The registry identifies the study as a retrospective multicenter study and lists its official title as “Efficacy and Safety of Different Ticagrelor Regimens Versus Clopidogrel in Patients With Coronary Artery Disease: a Retrospective Multicenter Study (SUPERIOR).” It is marked completed, with a total enrollment of 3043. The listed condition is coronary artery disease, and the listed sponsor is First Affiliated Hospital of Harbin Medical University.
Allocation is recorded as non-randomized, masking as single, and the model as parallel. The phase field lists PHASE2 and PHASE3. The record does not describe the method used to assign treatment, the identity of the masked party, or the reason for listing both phases. Those details are not reported in the registry record.
Four treatment groups are named: ticagrelor 45mg bidpo., ticagrelor 90mg qdpo., ticagrelor 90mg bidpo., and clopidogrel 75mg qdpo. The registry describes each arm as intended to observe efficacy and safety in people with coronary artery disease. Because allocation was non-randomized, differences between groups may reflect differences in the people receiving each regimen as well as treatment-related differences. The registry’s own warning says the arms are not a like-for-like control comparison.
The recorded study start was 2017-12-13, and primary completion was 2018-12-13. These dates describe the registry record’s study timeline; they do not establish when every participant entered or completed follow-up. Detailed eligibility criteria, recruitment procedures, duration of follow-up, center-level information, and the process used to form the groups are not reported in the registry record.
The registry identifies a primary platelet-function endpoint and several secondary outcomes, but lists zero analyses. It does not report the statistical analysis plan, adjusted comparisons, or outcome estimates. The study design can therefore be described from its registry classifications and arm labels, but its comparative findings cannot be reconstructed from those details alone.
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
| Stage | Ticagrelor 45mg Bidpo. | Ticagrelor 90mg Bidpo. | Clopidogrel 75mg Qdpo. | Ticagrelor 90mg Qdpo. |
|---|---|---|---|---|
| STARTED | 525 | 501 | 1511 | 506 |
| COMPLETED | 525 | 501 | 1511 | 506 |
| NOT COMPLETED | 0 | 0 | 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 | Clopidogrel 75mg Qdpo. | Ticagrelor 90mg Bidpo. | Ticagrelor 45mg Bidpo. | Ticagrelor 90mg Qdpo. | Total |
|---|---|---|---|---|---|---|
| Participants analysed | 1511 | 501 | 525 | 506 | 3043 | |
| Age, Continuous | years | 63 (55 to 69) | 61 (52 to 67) | 62 (55 to 69) | 62 (55 to 68) | 62 (55 to 69) |
| Sex: Female, Male: Female | Participants | 532 | 159 | 201 | 237 | 1129 |
| Sex: Female, Male: Male | Participants | 979 | 342 | 324 | 269 | 1914 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 1511 | 501 | 525 | 506 | 3043 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 | 0 |
| Region of Enrollment: China | participants | 1511 | 501 | 525 | 506 | 3043 |
| Weight | kg | 70 (63 to 78) | 70 (62 to 78) | 70 (60 to 75) | 70 (60 to 75) | 70 (62 to 78) |
| smoking | Participants | 736 | 234 | 226 | 202 | 1398 |
| Hypertension | Participants | 879 | 243 | 332 | 287 | 1741 |
| diabetes mellitus | Participants | 426 | 126 | 161 | 117 | 830 |
| chronic kidney disease | Participants | 60 | 13 | 25 | 13 | 111 |
| percutaneous coronary intervention | Participants | 1056 | 326 | 241 | 179 | 1802 |
| coronary artery bypass grafting | Participants | 12 | 2 | 2 | 1 | 17 |
| total cholesterol | mmol/L | 4.2 (3.4 to 5.1) | 3.9 (2.6 to 5) | 4.3 (3.4 to 5.3) | 4.7 (3.8 to 5.7) | 4.24 (3.39 to 5.18) |
| triglyceride | mmol/L | 1.6 (1.2 to 2.4) | 1.9 (1.3 to 3.6) | 1.7 (1.2 to 2.7) | 1.6 (1.1 to 2.4) | 1.67 (1.17 to 2.57) |
| high density lipoprotein | mmol/L | 1.1 (0.9 to 1.3) | 1.1 (0.9 to 1.3) | 1.1 (1.0 to 1.3) | 1.2 (1 to 1.4) | 1.1 (0.93 to 1.3) |
6. Primary Endpoint
The registry lists the primary outcome as ADP-induced Inhibition of Platelet Aggregation, measured over up to 5 days.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | percentage of inhibition of platelet agg |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is ADP-induced inhibition of platelet aggregation, expressed as a percentage of inhibition of platelet aggregation. The registry describes testing with a Thromboelastography Hemostasis Analyzer and software. It states that the test used channels to assess platelet therapy effects through the arachidonic acid and ADP pathways, with this endpoint focused on the ADP pathway. Values can range from 0% - 100%, and higher values indicate greater platelet inhibition.
Blood collection was described as occurring after an overnight fast. For twice-daily regimens, samples were drawn 12 hours after the last study-drug dose; for once-daily regimens, they were drawn 24 hours after the last dose. The timeframe is listed as up to 5 days. The record also describes processing samples within two hours of collection according to a standard operating procedure.
Platelet-function measurements provide a laboratory measure of platelet inhibition. As a general statistical and clinical interpretation, such a measure is not itself the same as a clinical event outcome. A difference in a laboratory endpoint should not be treated as proof of a difference in cardiovascular events or other outcomes. The registry lists the primary endpoint’s summary format as a median and inter-quartile range, but does not report the actual group medians, inter-quartile ranges, or a comparative estimate. The amount and precision of any observed group difference therefore cannot be evaluated from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies the primary endpoint and its measurement scale, but it does not report the results needed to interpret the endpoint by treatment group. There are no listed medians or inter-quartile ranges for ADP-induced inhibition of platelet aggregation, and no reported estimate of a difference between regimens. Consequently, the direction, magnitude, and precision of any primary-endpoint contrast are not reported in the registry record.
The same limitation applies to the secondary outcomes. The registry names ADP-induced platelet-fibrin clot strength, high on-treatment platelet reactivity, cardiovascular events defined as cardiovascular death, new-onset myocardial infarction, or stroke, and new-onset dyspnea. It does not give their results by group. Although the registry lists six outcome measures, the full set of outcome descriptions and results is not reported in the registry record.
The study is explicitly marked non-randomized, and its registry warning says the arms are not a like-for-like control comparison. In a non-randomized study, treatment groups may differ in characteristics that influence both the choice of treatment and the outcome. As a general statistical point, those differences can confound an unadjusted comparison. Adjustment can sometimes address measured differences, but cannot automatically remove bias from unmeasured or poorly measured factors. The record does not report an adjusted analysis or enough detail to judge whether such differences were assessed.
The primary endpoint is a laboratory measure rather than a clinical event. As a general interpretation principle, a laboratory contrast alone does not establish a corresponding contrast in cardiovascular outcomes. The registry lists clinical events among secondary outcomes, but does not provide event counts or comparative estimates for them. The platelet endpoint and the clinical outcomes therefore cannot be treated as interchangeable evidence.
Nothing in the registry record supports a conclusion that one regimen is superior, equivalent, or more precisely estimated than another. No confidence intervals or p-values for the primary or secondary comparisons are reported in the registry record. Without group estimates and uncertainty measures, statistical significance and the range of effects compatible with the data cannot be assessed. The appropriate reading is that the record specifies a comparative study and its intended measurements, while leaving the comparative results unavailable.
The registry describes the study as completed and reports enrollment of 3043, but enrollment alone does not establish how many participants contributed data to each outcome. Analysis populations, missing outcome data, and reasons for exclusions are not reported in the registry record. Those omissions prevent a reader from determining how complete the endpoint data were or whether the analyzed groups corresponded to the enrolled groups.
9. Statistical Methods Explained
The registry gives some design and measurement details, but does not report a full statistical methods plan or comparative results. The following explains general statistical concepts relevant to reading this study without attributing unreported analyses to the investigators.
What does a median with an inter-quartile range describe?
The primary endpoint is specified as a median with an inter-quartile range. As a general statistical explanation, the median marks the middle of the observed distribution when values are ordered. The inter-quartile range describes the span between the lower and upper quartiles, giving a sense of the spread of the middle part of that distribution. It is useful when a distribution is skewed or contains values that make a mean and standard deviation less representative of a typical observation.
A median and inter-quartile range describe each group’s distribution; they do not, by themselves, provide a formal estimate of the difference between groups or its uncertainty. To assess a comparison, readers generally need a stated contrast and an uncertainty measure, such as a confidence interval, or a clearly described test. The registry record does not report those results for the primary endpoint.
What does a confidence interval communicate?
As a general explanation, a confidence interval expresses the uncertainty around an estimated quantity under the assumptions of the statistical method. A narrower interval indicates greater precision than a wider interval for the same type of estimate. It does not mean that every value inside the interval is equally plausible, nor does it correct for bias caused by non-random treatment assignment. No confidence interval for the primary comparison is reported in the registry record.
Why does non-random allocation matter?
With non-random allocation, treatment groups can differ systematically. For example, a factor related to clinical status could influence which regimen is selected and also be related to platelet measurements or later events. This is the general problem of confounding. Random assignment is one way studies seek to balance such factors on average; it is not the design listed for this study.
Statistical adjustment may account for measured characteristics if they are collected and modeled appropriately. It cannot guarantee balance on characteristics that were not measured, were measured poorly, or were handled inadequately. The registry record does not report baseline group characteristics, adjustment variables, model specifications, or adjusted treatment estimates. It is therefore not possible to determine from the record whether or how confounding was addressed.
Why might over-dispersion matter?
As a general statistical point, count data can vary more than a simple model assumes. This is called over-dispersion. If it is present and ignored, standard errors can be too small and uncertainty can be understated. Methods designed for over-dispersed counts can alter uncertainty estimates while leaving the broad outcome definition unchanged. The registry lists outcomes that include numbers of participants with events, but does not report the statistical models, dispersion checks, or methods used for those outcomes. There is no basis in the record to say whether over-dispersion was assessed or relevant to a particular analysis.
How should the planning illustrations be understood?
The registry’s planning assumptions describe an illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The stated effect to detect is a fraction of the observed effect. For non-time-to-event outcomes, the illustration is expressed as participants per arm for a specified power; for time-to-event outcomes, it is expressed as a total number of events. These are planning illustrations, not observed power and not proof that a comparison was adequately powered.
The planning assumptions do not establish the trial’s original sample-size rationale. The sample-size justification, the effect used for the illustration, and a trial-specific power calculation are not reported in the registry record. The record also does not report a primary comparison from which to assess the observed effect or precision.
What can be inferred from the listed analysis count?
The registry lists zero analyses. This is a statement about what the record contains, not evidence that no analysis was performed outside the registry. It does mean that analysis methods and comparative estimates cannot be evaluated from the registry record. In general, a transparent report would identify the analysis population, handling of missing data, treatment of multiple outcomes, model assumptions, and estimates with measures of uncertainty. Those elements are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies a primary endpoint and several secondary outcomes, but does not report how multiple outcomes or multiple regimen comparisons were handled. It lists outcomes for platelet-fibrin clot strength, high on-treatment platelet reactivity, cardiovascular events, and new-onset dyspnea. It does not state which comparisons were prespecified, whether each regimen was compared with clopidogrel, or whether other pairwise comparisons were planned.
As a general statistical point, testing multiple outcomes or contrasts can increase the chance of obtaining at least one apparently unusual result by chance. Researchers may use a prespecified hierarchy, adjustment procedure, or another strategy to address multiplicity. The appropriate choice depends on the scientific aims and analysis plan. No multiplicity strategy is reported in the registry record, so the status of any nominal p-value or selective emphasis cannot be assessed from the record.
Missing-data methods are also not reported. The registry does not provide outcome-specific denominators, the number of missing measurements, reasons for missingness, or methods used to handle missing values. As a general principle, missingness can affect an estimate when the probability of having an observed measurement is related to participant characteristics or outcomes. Without the relevant counts and methods, the direction or size of any resulting bias cannot be determined.
The record does not identify analysis populations, such as whether analyses included all enrolled participants, only participants who received treatment, or only those with an available endpoint measurement. It also does not explain exclusions, protocol deviations, or how participants were assigned to an analysis group. These details are not reported in the registry record.
Because the record lists zero analyses and supplies no comparative outcome estimates, multiplicity, missing-data handling, and population definitions remain unresolved. These gaps limit both reproducibility and interpretation; they do not establish that a particular analysis was or was not performed outside the registry.
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 |
|---|---|---|---|
| Clopidogrel 75mg Qdpo. | 0 | 1511 | 0.0% |
| Ticagrelor 90mg Bidpo. | 0 | 501 | 0.0% |
| Ticagrelor 45mg Bidpo. | 0 | 525 | 0.0% |
| Ticagrelor 90mg Qdpo. | 0 | 506 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Clopidogrel 75mg Qdpo. | 0 of 1511 |
| Ticagrelor 90mg Bidpo. | 0 of 501 |
| Ticagrelor 45mg Bidpo. | 0 of 525 |
| Ticagrelor 90mg Qdpo. | 0 of 506 |
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 |
|---|---|
| Clopidogrel 75mg Qdpo. | 0 of 1511 |
| Ticagrelor 90mg Bidpo. | 0 of 501 |
| Ticagrelor 45mg Bidpo. | 0 of 525 |
| Ticagrelor 90mg Qdpo. | 0 of 506 |
The adverse-event record lists four treatment groups and reports zero serious events, zero other adverse events, and zero deaths in each group. The recorded at-risk counts are 1511 for clopidogrel 75mg Qdpo., 501 for ticagrelor 90mg Bidpo., 525 for ticagrelor 45mg Bidpo., and 506 for ticagrelor 90mg Qdpo. These are registry entries, not a comparative safety analysis.
Zero events in the registry fields should be read as zero reported in those fields. The record does not provide event definitions, ascertainment procedures, follow-up duration for safety, or explanations of how adverse events were collected. It also does not report confidence intervals or statistical comparisons for safety outcomes. The figures therefore do not establish that no adverse events occurred outside the recorded categories or period.
The registry lists no top serious adverse-event terms. This means no such terms appear in that part of the record; it does not supply information about how serious events were sought, adjudicated, or classified. Further safety details are not reported in the registry record.
As a general statistical point, observing no events in a group does not prove that the underlying event risk is zero. Precision depends in part on the amount of follow-up and completeness of event ascertainment, neither of which is described sufficiently in the record to quantify. The listed figures should not be used alone to rank the regimens or infer comparative safety.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed, retrospective, multicenter study compared three ticagrelor regimen labels with a clopidogrel regimen in patients with coronary artery disease. It identifies ADP-induced inhibition of platelet aggregation as the primary endpoint, describes how blood samples were collected and tested, and names several secondary outcomes. It also records enrollment of 3043 and identifies the design as non-randomized.
The record does not report primary-endpoint values or comparative estimates. It therefore does not show the observed platelet inhibition in each group, the size or direction of any difference, or how precise an estimate might be. No reported analysis permits a statistical comparison of the regimens on the primary endpoint. The same is true for the named secondary outcomes: their results are not reported in the registry record.
Accordingly, the registry information does not establish that one regimen produces greater or lesser platelet inhibition than another. It also does not establish equivalence or absence of a meaningful difference. Those conclusions require estimates and uncertainty information, not merely the endpoint definition and treatment labels.
The non-randomized allocation is important to interpretation. As a general principle, group differences may arise from treatment or from differences in the people who received each treatment. Without reported baseline characteristics and analysis methods, the extent to which such differences were addressed cannot be judged. The registry itself cautions that the arms are not a like-for-like control comparison.
The primary outcome is a laboratory measure. Even if its results were available, that measure would not by itself establish a difference in cardiovascular events, death, or other clinical outcomes. Those outcomes are listed, but their results are unavailable in the record. The zero adverse-event entries are also limited to what was recorded in the registry and do not support a complete comparative safety conclusion.
The study record is therefore informative about the design labels, planned measurement, and the absence of posted comparative analyses, but not about the magnitude or certainty of treatment differences. Interpretation should remain at that level rather than extending beyond the results documented in the registry.
13. Why This Trial Matters Statistically
This study is statistically notable because it compares several antiplatelet regimens using a laboratory endpoint while the registry identifies allocation as non-randomized. That combination makes the distinction between measurement and causal interpretation especially important. A clearly defined assay can describe platelet inhibition, but a group contrast in a non-randomized study may also reflect who received each regimen.
The registry describes the primary measure in detail, including the ADP pathway, the timing of sample collection relative to the last dose, and the use of a median with an inter-quartile range. Such measurement information helps readers understand what the endpoint represents and how its timing differed between once-daily and twice-daily regimens. At the same time, no group values are reported, so the record cannot answer the comparative question quantitatively.
The study also illustrates why outcomes should be separated by type. Platelet-function measures, measures of platelet-fibrin clot strength, high on-treatment platelet reactivity, clinical cardiovascular events, and dyspnea are not interchangeable outcomes. Their definitions, analysis methods, and results matter individually. The registry lists these outcomes but does not provide their comparative findings.
Finally, the record makes visible the difference between study completion and reporting completeness. The study is marked completed, yet the registry lists zero analyses and lacks the endpoint estimates needed for interpretation. This does not show that no work was done; it means the recorded information is insufficient for readers to assess the comparative effects, uncertainty, or robustness of the analyses.
For biostatistical reading, the central lesson is to distinguish a protocol-like description of what was measured from evidence about what the groups experienced. Design limitations, outcome summaries, uncertainty, missingness, and analysis choices all contribute to a defensible interpretation. Several of those elements are not reported in the registry record.
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 most direct limitation is that the registry record does not report the primary endpoint results. Although it specifies a median and inter-quartile range, neither the group summaries nor a between-group estimate is included. The record likewise provides no confidence intervals or p-values for the primary comparison. The primary endpoint’s population field is blank, and outcome-specific analysis denominators are not reported.
The study is retrospective and non-randomized. The registry warns that the treatment arms are not a like-for-like control comparison. Baseline characteristics, treatment assignment procedures, and any adjustment for confounding are not reported in the registry record. As a result, the extent to which the groups were comparable cannot be assessed.
Although masking is listed as single, the identity of the masked party and the procedures used to maintain masking are not described. Eligibility criteria, recruitment details, treatment duration, adherence, and follow-up procedures are also not reported. These gaps matter when judging selection, measurement, and follow-up differences.
The record names secondary outcomes but does not provide their results, full definitions, or analysis methods. It lists six outcome measures, while the detailed outcome information available in the record does not fully describe all of them. Multiplicity procedures, missing-data methods, and analysis-population definitions are not reported. The adverse-event fields contain zero entries, but the event-collection and follow-up procedures are not described.
Finally, the registry’s sample-size assumptions describe a planning illustration, not the trial’s original design rationale or observed power. The effect used for that illustration and the original sample-size justification are not reported in the registry record. Together, these limitations leave the comparative findings and their reliability undetermined from the record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Efficacy and Safety of Low-dose Ticagrelor — NCT03381742.
- Registry record last updated 2019-09-30; status last verified 2019-06.
- Results first posted 2019-09-30.
- 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
The registry record describes SUPERIOR, a completed retrospective multicenter study of ticagrelor regimens and clopidogrel in patients with coronary artery disease. It lists enrollment of 3043, non-randomized allocation, single masking, a parallel model, and PHASE2 and PHASE3. The recorded study start was 2017-12-13, and primary completion was 2018-12-13.
The primary endpoint was ADP-induced inhibition of platelet aggregation, expressed as a percentage and summarized as a median with an inter-quartile range, with a timeframe of up to 5 days. The listed groups were ticagrelor 45mg bidpo., ticagrelor 90mg qdpo., ticagrelor 90mg bidpo., and clopidogrel 75mg qdpo.
The registry names secondary platelet-function and clinical outcomes, but lists zero analyses and does not report comparative outcome results. Its adverse-event fields record zero serious events, other adverse events, and deaths in each group. The registry cautions that the non-randomized arms are not a like-for-like control comparison. Comparative effects and their precision are not reported in the registry record.