Anti-platelet Effects of Colchicine in Healthy Volunteers: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Anti-platelet Effects of Colchicine in Healthy Volunteers (NCT02140372), a na phase 4 study. The primary outcome is Monocyte Platelet Aggregate: Baseline.

2. Clinical Question

The scientific question suggested by the study summary is whether platelet-activity and inflammation markers can be assessed around colchicine administration in healthy volunteers. This is a description of the study’s aim, not evidence of an effect. The record identifies light transmission aggregometry, platelet adhesion, and monocyte-platelet aggregates among the measures, and describes blood collection before dosing and at post-dose time points. It does not give results for these measures or an analysis comparing measurements across time or dose regimens. Consequently, the registered primary endpoint cannot establish whether colchicine changed platelet activity. Nor does the record establish how the different doses were handled or whether any formal dose comparison was planned.

3. Trial Design

The registry classifies this as a completed Phase 4 study with a single-group model. Enrollment is listed as 10. The start is recorded as 2014-05, and primary completion as 2015-01. NYU Langone Health is listed as sponsor. The condition is healthy, and colchicine is the listed drug intervention.

The allocation field is NA, and masking is recorded as none. The registry describes a volunteer group with a baseline blood draw followed by colchicine and additional blood draws at 2 hours and 24 hours. The study summary also describes blood collection before administration, at 2 hours, and at 24 hours, with blood evaluated for platelet-activity and inflammation markers. These details describe the intended measurement schedule; they do not supply outcome values.

The summary names 1.8 mg, delivered as 1.2 mg followed by 0.6 mg one hour later, 1.2 mg, and 0.6 mg. The record does not explain whether these were separate dose groups, alternative regimens, or how participants received them. It lists a volunteer group, not separate dose arms, and gives no comparator group. Accordingly, the design should not be read as a randomized comparison or as a controlled estimate of a treatment effect.

The registry lists 8 outcome measures and 0 analyses. The primary outcome is monocyte-platelet aggregate at baseline, with the measure specified as a median and inter-quartile range. Secondary outcome names include light transmission aggregometry at baseline and 2 hours and platelet adhesion at baseline and 2 hours; light transmission aggregometry entries are repeated in the record. Although the summary mentions a 24-hour blood draw, no 24-hour endpoint appears in the listed secondary outcomes. The registry record does not report why these entries differ or provide a statistical analysis plan.

This is a pilot study, as described in its summary. The registry does not report a sample-size justification for the enrollment or enough design detail to determine the intended analysis of repeated measurements or dose regimens. The study’s completed status indicates its recorded administrative status, not that results are available or that a particular statistical question was answered.

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

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Monocyte Platelet Aggregate: Baseline, measured over Baseline.

The registered primary outcome is “Monocyte Platelet Aggregate: Baseline.” Its unit is given as percentage of monocyte-platelet aggregate, and its summary statistic is specified as a median with inter-quartile range. The endpoint refers to aggregates involving monocytes and platelets, measured in a blood sample. Such a marker can be used to characterize platelet-related activity; the study summary places this measure among markers of platelet activity and inflammation.

General statistical context: A median describes the central position of observed values after ordering them. The inter-quartile range describes the spread of the middle portion of those values and is less influenced by extreme observations than a range or a mean and standard deviation. These summaries can be useful when measurements are skewed or include outlying values. They describe a distribution; on their own, they do not quantify a treatment effect or establish a difference between time points or groups.

The word “Baseline” is important to interpretation. The registry does not report an actual baseline median, an inter-quartile range, or a post-dose primary endpoint value. Nor does it define a primary comparison of baseline with a later measurement. The study summary describes post-dose blood collection, but a collection schedule is not itself an analyzed endpoint. Without reported values and an analysis, the primary outcome cannot show whether the marker changed after colchicine administration.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

General statistical context: Statistical interpretation starts by distinguishing the design, the measurements, and the analysis. The design describes how participants and interventions are organized; the measurement definition specifies what is recorded; the analysis explains how those observations are combined to address a question. A registry can describe the first two without reporting the third. In this record, the design is identified as single-group, the primary measure is named, and the analysis count is 0. Outcome values and an analysis are not reported in the registry record.

What does a median and inter-quartile range describe?

General statistical context: The median is a central summary: after values are ordered, it indicates the middle of the distribution. The inter-quartile range describes the spread of the central portion of values. These summaries can be useful when data are not well represented by a mean and standard deviation, for example when values are skewed or contain unusually high or low observations. They do not show the full shape of a distribution, and they do not by themselves compare measurements or indicate how uncertain a treatment effect is.

For this study, the registry specifies a median and inter-quartile range for the baseline monocyte-platelet aggregate measure. It supplies no numerical median or inter-quartile range. Without those values, it is not possible to describe the observed baseline distribution. Without corresponding post-dose values and a defined comparison, it is also not possible to interpret change over time.

Why does the single-group design matter?

General statistical context: In a single-group study, measurements may be collected from participants under one study condition, sometimes at more than one time. A before-and-after comparison can describe whether recorded values differ over time, if both sets of measurements and a valid analysis are available. Such a comparison is not equivalent to a randomized comparison against a control group. Time-related changes, measurement variability, and other influences can contribute to an observed difference. A control group can help address some alternative explanations, but the registry does not list one for this study.

Here, the allocation field is NA, masking is none, and the model is single-group. The record does not describe a randomized control comparison. It also does not report a before-and-after estimate. Consequently, there is no basis in the registry record for attributing a change in a platelet marker to colchicine.

What can be learned from repeated blood collection?

General statistical context: Repeated measurements can be informative because values from the same participant may be related. An analysis should account for that relationship when estimating change or comparing time points. Simply treating repeated observations as independent can misrepresent uncertainty. The appropriate method depends on the outcome distribution, the measurement schedule, and the question being asked. The registry record does not report the planned or used method for repeated measurements, so no particular approach can be attributed to this study.

The summary describes blood collection before administration and at 2 hours and 24 hours. The primary endpoint, however, is specifically labeled baseline. The listed secondary outcomes include baseline and 2-hour measures, while the summary also describes a 24-hour collection. The record does not reconcile these descriptions or report which measurements were analyzed.

How should the sample-size illustration be read?

General statistical context: A sample-size calculation is a planning exercise that asks how many participants might be needed to detect a defined effect under stated assumptions. It does not establish what the study observed. A calculation based on an effect estimated from observed data is especially dependent on that estimate and should not be called observed power. A planning number also does not prove that the original study was designed using those assumptions.

The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect expressed as a stated fraction of the observed effect. It states that non-time-to-event planning values are participants per arm for 80% or 90% power, while time-to-event values represent total events. These are planning assumptions, not evidence that the trial had two arms or used that design. The registry itself describes a single-group study and does not report a design justification. The planning illustration is not an observed-power result.

What does over-dispersion mean in general?

General statistical context: Over-dispersion occurs when observed variability is greater than a statistical model expects. If it is ignored, standard errors can be too small and confidence intervals too narrow, making results appear more precise than they are. The relevance of over-dispersion depends on the outcome type and analysis model. The registry does not report a model or an analysis for which over-dispersion could be assessed, so it is not possible to say whether it arose in this study.

What would a confidence interval add?

General statistical context: A confidence interval expresses uncertainty around an estimate under the assumptions of the analysis. Its width conveys precision: a narrower interval indicates less statistical uncertainty than a wider one, while the interval’s location indicates which effect values are compatible with the data and model. A confidence interval does not correct a weak design, unmeasured confounding, or incomplete reporting. No confidence interval or effect estimate is reported in the registry record, so the precision of any treatment-related change cannot be assessed.

The registry lists 0 analyses. That does not establish whether analyses were conducted outside the registry; it means no analysis is recorded there. No statistical test, adjusted estimate, missing-data method, or analysis population is reported. Therefore, statistical significance, effect magnitude, and precision cannot be inferred from the design description or the safety counts.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 8 outcome measures and 0 analyses. It names a primary baseline monocyte-platelet aggregate outcome and several secondary measures, including light transmission aggregometry and platelet adhesion. Light transmission aggregometry entries are repeated in the registry list. The record does not explain the repeated entries, describe a hierarchy among secondary outcomes, or specify which comparisons were intended to be confirmatory.

General statistical context: When several outcomes or comparisons are tested, the chance of obtaining at least one apparently notable result can increase. A prespecified analysis hierarchy or a method for adjusting across tests can help interpret multiple results. The registry record does not report a multiplicity strategy, planned tests, or analysis results. It is therefore not possible to determine how multiple outcomes or time points would have been handled.

The study summary describes blood collection at baseline, 2 hours, and 24 hours. The primary outcome is labeled baseline, while the listed secondary outcomes name baseline and 2-hour measurements; the record does not list a 24-hour outcome among those entries. It does not explain this difference or identify the time point used for each outcome analysis.

Missing-data methods, the number of participants with measurements at each time point, exclusions, and analysis populations are not reported in the registry record. The enrollment figure alone does not show how many observations were available for any specific endpoint. No assumptions about missingness or methods for handling incomplete measurements can be inferred.

11. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry lists 10 at risk for serious adverse events and 0 affected. It also lists 10 at risk for other adverse events and 0 affected. These figures describe the adverse-event entries recorded for the volunteer group; they do not establish that every possible event was assessed or that the categories capture all safety information.

The death entry is null. A death count is therefore not reported in the registry record. A null entry should not be rewritten as a reported count of zero.

General statistical context: A count of 0 affected in a small study is a description of the observations recorded, not proof that an event cannot occur. Safety interpretation depends on how events were defined and collected, the period of observation, completeness of follow-up, and the amount of information available. The registry does not report those details or provide event-level descriptions, severity, timing, or exposure-specific safety results. The listed counts should consequently be read narrowly as registry entries, not as a comprehensive estimate of risk.

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

The registry record establishes that a completed, single-group Phase 4 pilot study of colchicine in healthy volunteers was registered. It describes a blood-collection schedule and identifies platelet-activity and inflammation markers of interest. The primary outcome is baseline monocyte-platelet aggregate, summarized as a median and inter-quartile range. The record does not report the primary outcome values or an analysis.

That distinction limits what can be concluded. A study objective is not a result, and a measurement schedule does not demonstrate that values changed. The registry’s primary outcome is defined at baseline, not as a change from baseline. Although the summary describes post-dose blood collection, no post-dose primary result, effect estimate, confidence interval, or statistical test is reported. The record therefore does not establish the magnitude, direction, or precision of any change in platelet activity or inflammation.

The design also does not support a randomized comparison: it is single-group, allocation is NA, masking is none, and no separate comparator is listed. The dose summary names several regimens but does not explain how they were used or assigned. Accordingly, the record does not support a causal comparison among doses or between colchicine and a control condition.

The adverse-event entries report 0 affected for serious events and 0 affected for other events, with 10 at risk in each category. These counts are limited to what the registry records; the death entry is null, and fuller safety methods and follow-up details are not reported.

The appropriate interpretation is therefore descriptive and cautious. This record documents the study’s registered design and intended measurements, but it does not provide results that establish whether colchicine changed the measured markers. Missing reported results should not be mistaken for evidence of no effect, and the planning illustration should not be mistaken for an observed analysis or for the study’s original design justification.

13. Why This Trial Matters Statistically

This study is statistically instructive because its stated scientific interest and its registered primary endpoint are not the same thing. The summary describes evaluating blood markers before and after colchicine, while the primary outcome is specifically named as a baseline measure. A baseline description can characterize participants, but, by itself, it does not estimate a post-dose change. Clear alignment between the scientific question, endpoint definition, measurement schedule, and analysis is essential for interpretable results.

The record also illustrates why a measurement schedule is not a statistical analysis. Blood collection is described at baseline, 2 hours, and 24 hours, yet the listed secondary outcomes name baseline and 2-hour measures, and the registry reports 0 analyses. Without outcome values and a defined comparison, there is no estimate to interpret and no way to assess precision or uncertainty.

Its single-group design makes the distinction between observed change and causal effect especially important. A before-and-after difference, if reported, would describe change over time in the studied group. Without a separate control group, it would not by itself isolate the effect of colchicine from other influences. The dose description creates a further interpretive issue because the record does not explain how the listed regimens were used.

Finally, the sample-size illustration is explicitly a planning exercise based on an observed effect and stated assumptions. Such calculations can help frame future study planning, but they do not supply missing results, establish the original rationale for enrollment, or amount to observed power. These distinctions help keep design information, statistical evidence, and planning scenarios separate.

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.

Several limitations are specific to the registry record. The primary endpoint is specified at baseline, while the study summary describes post-dose measurements. No post-dose primary outcome, change-from-baseline definition, or analysis is reported. The listed secondary outcomes do not fully match the measurement schedule described in the summary: 24-hour collection is mentioned there, but a 24-hour secondary endpoint is not listed.

The dose description is incomplete for interpreting comparisons. It names 1.8 mg, 1.2 mg, and 0.6 mg regimens, but the record does not say how volunteers received them or whether dose groups were formed. The arm description refers to a volunteer group rather than distinct dose groups. No separate comparator is listed, and the study is recorded as single-group with allocation NA and masking none.

The registry reports 8 outcome measures and 0 analyses, but supplies no outcome values, estimates, confidence intervals, statistical tests, or analysis population. It does not report participant characteristics, measurement completeness by time point, missing-data handling, or reasons for any unavailable observations. Repeated light transmission aggregometry entries are not explained. The record also does not provide enough detail to assess how platelet measurements were collected, processed, or analyzed.

Safety reporting is similarly limited: event definitions, ascertainment procedures, observation duration, and event-level details are not reported. The death entry is null. These limitations concern what can be learned from the registry record and should not be treated as evidence that unreported procedures or analyses did not occur elsewhere.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Anti-platelet Effects of Colchicine in Healthy Volunteers — NCT02140372.
• Registry record last updated 2016-02-23; status last verified 2016-01.
• Results first posted 2016-02-23.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT02140372 is a completed Phase 4, single-group study titled “Anti-platelet Effects of Colchicine in Healthy Volunteers,” sponsored by NYU Langone Health. Enrollment is listed as 10. The study summary describes colchicine dosing and blood collection at baseline, 2 hours, and 24 hours to evaluate platelet-activity and inflammation markers.

The primary outcome is baseline monocyte-platelet aggregate, specified as a median with inter-quartile range. The registry lists 8 outcome measures and 0 analyses. It does not report endpoint values, a treatment-effect estimate, confidence intervals, or a statistical test. Allocation is NA, masking is none, and no separate comparator is listed. The safety entries show 0 affected for serious adverse events and 0 affected for other adverse events; the death entry is null.

The record describes study intent and design, but does not provide results from which to assess a colchicine-associated change.