Subclinical Cardiovascular Disease in Psoriatic Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Subclinical Cardiovascular Disease in Psoriatic Disease (NCT03228017), a non-randomized phase 4 study. The primary outcome is Mean Fold Change in Brachial Vein Endothelial Inflammatory Transcript.

2. Clinical Question

The clinical question concerns biological measures that may help characterize vascular inflammation and thrombotic risk in psoriatic disease. The study description names three aims: evaluating associations between psoriatic disease and vascular function, evaluating associations with thrombotic risk, and examining the effects of aspirin and statins on those measures. These aims are broader than the registered primary endpoint, which focuses on an endothelial inflammatory transcript.

The registry record does not report results for that endpoint or estimates of associations between disease status, medication use, and the measured outcomes. It therefore does not establish the size, direction, or precision of any relationship. The study’s non-randomized structure also means that differences between participants may reflect factors other than disease status or medication use. The record does not provide enough information to determine which factors were measured or how they were handled in an analysis.

3. Trial Design

This is a completed Phase 4 study with non-randomized allocation, no masking, and a parallel model. The registry reports enrollment of 63. Its recorded start date is 2017-08-01, and its primary completion date is 2019-04-01. The sponsor is NYU Langone Health.

The two listed groups are “Psoriatic Disease Patients,” described as having moderate to severe psoriatic disease, and “Healthy Control.” The record does not provide a description for the healthy control group. It identifies aspirin and/or atorvastatin as a drug intervention, but does not describe participant assignment, medication schedules, dose, duration, adherence assessment, or treatment-specific comparison groups in the posted results. Those details are not reported in the registry record.

The non-randomized allocation matters when interpreting group differences. In a randomized study, assignment is intended to reduce systematic differences between comparison groups. Here, the disease and healthy-control groups are not a like-for-like randomized control comparison. Characteristics associated with disease status, health, or medication use could therefore contribute to observed differences. The registry does not report whether or how such characteristics were adjusted for.

The primary endpoint is a continuous measure: mean fold change in a brachial vein endothelial inflammatory transcript. The registered timeframe is baseline and 5 Months. Endothelial sampling coupled to real-time PCR is described as the method for monitoring brachial vein endothelial inflammation. The record lists four outcome measures and three secondary-outcome labels, but reports no analysis entries. It does not provide the full measurement schedule for secondary outcomes or explain how outcome data were summarized.

The registry marks the study completed, but completion status alone does not show that every planned assessment was obtained or analyzed. The participant flow, number with endpoint measurements, protocol deviations, and analysis populations are not reported in the registry record.

4. Participant Flow and Accounting

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

Overall Study

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 Mean Fold Change in Brachial Vein Endothelial Inflammatory Transcript, measured over Baseline, 5 Months.

The primary endpoint is mean fold change in a brachial vein endothelial inflammatory transcript. It is a continuous measure, reported in fold-change units, with the registered timeframe of baseline and 5 Months. The endpoint description says endothelial sampling and real-time PCR analysis are used to monitor brachial vein endothelial inflammation.

In general, a continuous endpoint retains information about the amount of a measured biological response rather than reducing it to categories such as present or absent. A mean describes the average value in a group; the standard deviation describes how spread out individual measurements are around that average. The registry identifies the endpoint parameter as a mean and its dispersion as a standard deviation, but does not provide the observed means or standard deviations.

In general, endothelial inflammatory measures can be used to study a biological process relevant to vascular function. A measured change in a transcript is a biomarker result, not by itself a clinical event or a direct measure of a participant’s overall health. The registry’s study description connects the endpoint to vascular inflammation, but does not report the endpoint’s clinical interpretation, assay performance, or a threshold for a meaningful change.

The record does not report primary endpoint results, the number of participants with paired measurements, or the method used to calculate fold change. It also does not report how missing measurements were handled. Without those details and the actual estimates, the magnitude, direction, and precision of the endpoint cannot be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registered endpoint is a mean of a continuous measurement, with standard deviation identified as its dispersion. The record does not report endpoint estimates or analysis entries, so no specific inferential method or numerical result can be interpreted. The concepts below are general explanations of methods relevant to this type of outcome; they should not be read as a claim that the study used a particular method.

What does a mean describe?

In general, a mean condenses a set of measurements into an average. It can be useful for describing the typical measured level in a group, but it does not show the full distribution. Participants may have values both above and below the mean, and the same mean can arise from different patterns of individual measurements. The standard deviation describes the spread of values around the mean; it is not the uncertainty of the mean itself.

For a measurement taken at baseline and again later, an analysis might describe values at each time point, changes within participants, or differences in change between groups. These answer different questions. A within-group change asks whether measurements shifted over time among participants in that group. A between-group contrast asks whether the shifts differ across groups. The registry identifies the baseline and 5 Months timeframe but does not report which contrast was used, how repeated measurements were linked, or whether the endpoint was analyzed as change from baseline.

What does a confidence interval convey?

In general, a confidence interval expresses the statistical uncertainty around an estimated quantity under the assumptions of the analysis. A narrower interval indicates greater precision than a wider interval, while the interval’s location indicates which values are compatible with the estimate and method. It does not remove concerns about bias, confounding, measurement quality, or an unsuitable analysis. No confidence interval for the primary endpoint is reported in the registry record.

A p-value, in general, describes how incompatible the observed data are with a specified null model, assuming that model and the analysis assumptions hold. It does not measure the probability that a hypothesis is true, the size or importance of an effect, or the probability that results will replicate. The registry record does not report p-values or identify a hypothesis test for the primary endpoint.

Why does non-randomized allocation matter?

In general, random assignment can balance measured and unmeasured participant characteristics across groups on average. In a non-randomized study, group membership may be related to characteristics that also influence an outcome. Statistical adjustment can address some measured differences when suitable data and a justified model are available, but it cannot guarantee removal of confounding, especially from unmeasured factors. The registry identifies allocation as non-randomized and does not report a covariate-adjustment plan or adjusted estimates.

The listed disease and healthy-control groups also differ by the condition defining group membership. A comparison between them can describe an association in the studied participants, but it should not automatically be interpreted as an effect caused by disease. Medication use could introduce further differences if it is related to participant characteristics or disease severity. The record does not specify medication assignment or report analyses separating medication associations from disease-group comparisons.

What does over-dispersion mean in general?

Over-dispersion means that observed variation is greater than a model expects. It is especially relevant to count outcomes when a simple model assumes a particular relationship between the mean and variance. A model that understates variability can produce confidence intervals that are too narrow and tests that appear more decisive than warranted. The primary endpoint is described as a continuous measure, not a count, and the registry does not report an over-dispersion assessment or a model. This general concept should not be taken as evidence that over-dispersion was present or that a particular model was used.

How should sample-size planning be read?

In general, a sample-size calculation depends on assumptions about the effect to detect, outcome variability, significance level, power target, allocation, and analysis method. A planning illustration is conditional on those assumptions; it does not show that a study had a particular probability of finding an effect after the data have been collected. The registry describes an illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. It says that the effect to detect is a stated fraction of the observed effect. The observed effect and the illustration values are not reported in the registry record, so the numerical implications cannot be assessed. These planning calculations are not observed power.

The registry reports no analysis entries. It does not report a statistical analysis plan, model specification, handling of repeated measurements, adjustment strategy, or inferential results. Consequently, general explanations of means, uncertainty, confounding, and planning cannot establish which methods were actually used for this study.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Psoriatic Disease Patients", "Healthy Control")
n   <- c(45, 18)
m   <- c(8.6, 2.8)
sp  <- c(8.6, 2.2)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Psoriatic Disease Patients  45  8.600  8.600  6.016  11.184
CARM  Healthy Control  18  2.800  2.200  1.706  3.894

11. Multiplicity, Missing Data and Analysis Populations

The record lists four outcome measures and names secondary outcomes involving composite endothelial inflammation and circulating thromboxane B2. It does not report a multiplicity strategy, a hierarchy of outcome tests, or which outcomes were designated for confirmatory interpretation. The listed secondary-outcome labels include two closely worded references to fold change in composite endothelial inflammation; the registry record does not explain their relationship.

In general, testing several outcomes or several contrasts can increase the chance of obtaining at least one apparently unusual result by chance. Researchers may address this through prespecified outcome hierarchies, adjusted significance thresholds, or other procedures. The record does not say whether any such approach was planned or used. Because it reports no analysis entries or results, there are no reported outcome-specific estimates or p-values to assess in light of multiplicity.

Missing-data handling is not reported in the registry record. The record does not state how many participants had endpoint measurements at baseline and 5 Months, whether any measurements were missing, why data may have been unavailable, or whether an imputation or other missing-data method was used. It also does not report a sensitivity analysis examining the effect of missing observations.

Analysis populations are not reported in the registry record. The enrollment and adverse-event counts do not identify how many participants contributed data to the primary endpoint or any secondary outcome. The record also does not describe exclusions, participant flow, protocol deviations, or whether analyses followed an intention-to-treat, per-protocol, or other population definition. Without these details, the relationship between enrollment and the analyzed data cannot be evaluated.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

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

The adverse-event record lists the numbers at risk and event counts separately for the two groups. Among 45 psoriatic disease patients, the record lists 0 serious adverse events, 0 other adverse events, and 0 deaths. Among 18 healthy controls, it also lists 0 serious adverse events, 0 other adverse events, and 0 deaths.

These are counts in the registry record. They do not provide event rates, and no rates should be inferred from them. The record does not explain the event-collection period, definitions, method of collection, or whether all participants were followed for the same duration. It also does not provide a narrative safety assessment or list serious-event terms.

In general, a recorded count of zero does not establish that an event is impossible or that a study can rule out uncommon events. Interpretation depends on the amount and duration of observation, how events were sought and classified, and the completeness of reporting. Those details are not reported in the registry record. The counts therefore describe what was entered for these groups but do not establish comparative safety or support a broad conclusion about risk.

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

The registry record identifies a completed, non-randomized study of vascular and thrombotic measures in psoriatic disease, with a primary endpoint based on a mean fold change in a brachial vein endothelial inflammatory transcript. It also records aspirin and/or atorvastatin as an intervention and describes interest in how traditional cardiovascular prevention medications relate to vascular function and thrombotic risk.

What the record does not report is the primary endpoint estimate or the results for the secondary outcomes. There is no reported mean, standard deviation, confidence interval, p-value, or analysis entry from which to characterize the direction, magnitude, or precision of the findings. The record therefore does not establish whether the measured transcript changed, whether groups differed, or whether medication use was associated with an outcome.

Even if an observed difference were reported, the non-randomized design would require careful interpretation. General statistical principle: differences between non-randomized groups may reflect characteristics other than the exposure or group label being studied. The registry does not provide an adjusted analysis or enough detail to assess those possible influences. A group association would not alone demonstrate a causal effect.

The endpoint is a biological measure, not a reported clinical event. The registry record does not provide a threshold for clinical importance or a link between the transcript measurement and individual clinical outcomes. It also does not report whether missing measurements or participant exclusions affected the results.

Accordingly, the record can be read as documenting the study question, design, endpoint definition, enrollment, and adverse-event counts. It cannot be read as evidence for a particular outcome or medication effect because the relevant statistical results are not reported in the registry record. This distinction separates what was planned or measured from what the posted results can support.

14. Why This Trial Matters Statistically

This study is statistically notable because its questions combine disease-group comparisons, biological measurements, and interest in medication use within a non-randomized design. Those elements make it important to distinguish descriptive associations from causal effects. The group labels alone do not establish a randomized treatment contrast, and the registry does not report medication-specific comparison groups or analyses.

The primary endpoint is a continuous biomarker measured at baseline and 5 Months. Such an endpoint can retain information about the scale of a biological response, but its interpretation depends on the measurement process, the summary used, and the comparison being estimated. The registry describes endothelial sampling and real-time PCR but does not report endpoint values, assay details, or the analysis method. The endpoint’s statistical and clinical meaning therefore cannot be judged from the record alone.

The record also illustrates why reporting estimates and uncertainty matters. Enrollment and completion status do not substitute for the observed endpoint summary, an effect estimate, and a measure of precision. Without those results, readers cannot evaluate the size or consistency of any pattern, compare outcome estimates, or assess whether uncertainty is substantial.

Finally, the listing of multiple outcome measures makes clear why prespecified analysis choices matter. The registry does not report a multiplicity plan, missing-data strategy, or analysis population. These omissions limit assessment of how the outcomes were selected and interpreted. The statistical importance of the study lies in the questions and design it records, as well as in the limits on inference created by absent analysis details and results.

15. 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 consequential limitation for interpretation is that the registry record does not report outcome estimates or analysis entries. The primary endpoint is defined, but its observed mean, standard deviation, and any between-group or within-participant estimate are absent. Results for the listed secondary outcomes are also not reported. Statistical significance, precision, and direction of findings therefore cannot be evaluated.

The study is non-randomized, and its two groups are not a like-for-like randomized control comparison. The registry does not report how participants entered each group, baseline characteristics, potential confounders, or adjusted estimates. It is also unclear from the posted results how aspirin and/or atorvastatin use related to the listed groups. Medication allocation, dosing, duration, and adherence are not reported in the registry record.

Measurement and follow-up details are limited. The primary endpoint description refers to baseline and 5 Months, but the record does not report the number of paired observations, assay performance, participant flow, or missing-data handling. Analysis populations, protocol deviations, and sensitivity analyses are not reported. The record also does not explain the relationship among the four outcome measures and the secondary-outcome labels.

Safety counts are recorded, but event definitions, collection procedures, and observation periods are not described. The zero counts should not be interpreted beyond the listed groups and reported counts. The registry record also does not report a statistical analysis plan, multiplicity approach, or sponsor analysis. These gaps prevent a fuller assessment of design execution and the reliability or generalizability of any result.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Subclinical Cardiovascular Disease in Psoriatic Disease — NCT03228017.
• Registry record last updated 2021-09-28; status last verified 2021-08.
• Results first posted 2021-09-28.
• 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.

19. Record Summary

NCT03228017, “Subclinical Cardiovascular Disease in Psoriatic Disease,” is a completed Phase 4 study sponsored by NYU Langone Health. The registry lists non-randomized allocation, no masking, a parallel model, and enrollment of 63. The recorded start date is 2017-08-01, and the primary completion date is 2019-04-01.

The listed groups are people with moderate to severe psoriatic disease and healthy controls. Aspirin and/or atorvastatin are listed as a drug intervention. The primary endpoint is mean fold change in a brachial vein endothelial inflammatory transcript at baseline and 5 Months, measured using endothelial sampling and real-time PCR.

The record lists four outcome measures and reports no analysis entries. It does not report primary or secondary outcome estimates, missing-data methods, analysis populations, or a multiplicity plan. The adverse-event counts are zero for serious events, other events, and deaths in both groups. The registry record supports description of the study’s intended question and design, but not conclusions about its measured outcomes or medication effects.