A Study to Examine the Safety and Efficacy of Drospirenone and Ethinyl Estradiol (YAZ) Versus Placebo In HS: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Examine the Safety and Efficacy of Drospirenone and Ethinyl Estradiol (YAZ) Versus Placebo In HS (NCT00722800), a randomized phase 2 study. The primary outcome is Mean Improvement in the Sartorius Severity Score at Month 6..

2. Clinical Question

The study also listed changes in pain and dermatology-related quality of life as secondary outcomes at Month 6. Their numerical results are not reported in the registry record. The clinical question is therefore only partly addressed by the posted results: the primary outcome has arm-level summaries, while the secondary outcomes and a formal between-group analysis are absent. The record reports enrollment of 4 and status as terminated, but does not report why the study ended or whether termination affected the planned outcome assessments.

3. Trial Design

The registry describes a Phase 2, randomized, triple-masked, parallel-group study at a single center. The comparison was drospirenone and ethinyl estradiol (YAZ) versus placebo for hidradenitis suppurativa. The record reports enrollment of 4. The arm-level outcome summaries each report n=2.0. Those summaries provide the basis for describing the posted results, but the small amount of information behind each mean limits how stable or broadly applicable those means can be.

The registry lists the study start as 2008-10 and primary completion as 2011-12. Its status is terminated. The reason for termination, the timing of the termination decision, and whether the primary completion date represents completion of the planned follow-up are not reported in the registry record. The record identifies the design as randomized and triple-masked, but does not identify which people or roles were masked, how randomization was generated, or how treatment allocation was concealed.

The primary outcome was mean improvement in the Sartorius Severity Score at Month 6. Two secondary outcomes were listed: change from baseline in the VAS Pain Scale and change from baseline in the Dermatology Life Quality Index (DLQI) Score, both at Month 6. Numerical findings for those secondary outcomes are not reported in the registry record. Details of eligibility criteria, baseline participant characteristics, treatment duration, medication use, and follow-up procedures are also not reported.

Because the record gives arm-level means and standard deviations without confidence intervals or a formal test of the treatment contrast, it supports a descriptive account rather than a complete inferential assessment. Randomization is a design feature intended to support fair comparisons, but the record does not report enough detail to assess how randomization was implemented or whether it achieved comparable groups. With so few reported participants, chance differences at baseline and sensitivity to individual observations are important interpretive concerns.

4. Participant Flow and Accounting

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

Before assignment: One subject was ineligible because she was taking ibuprofen regularly.

Overall Study

Reasons for not completing this period:

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.

Population: One subject was excluded because she was regularly taking ibuprofen. The other subject changed her mind about study participation.

6. Primary Endpoint

The registry lists the primary outcome as Mean Improvement in the Sartorius Severity Score at Month 6., measured over 6 months.

The primary endpoint is mean improvement in the Sartorius Severity Score at Month 6. The score reflects hidradenitis suppurativa symptoms through the number of lesions, including abscesses, nodules, and fistulas, and the longest distance between lesions. Assessment can cover up to 8 distinct anatomical regions. The score ranges from 5 to indefinite, and lower scores indicate less lesion involvement.

Change from baseline gives the direction of movement over follow-up. Under the registry's definition, a negative change indicates improvement in disease severity, while a positive change indicates worsening. The posted mean changes are -3.5 for the YAZ arm and 12.0 for the placebo arm. These are arm-specific averages; they do not show how each participant's score changed or how consistently individual changes followed the arm mean.

A severity score is used to represent clinical features in a structured way, making change over time describable and comparable between treatment groups. However, interpretation depends on how the score was measured, the completeness and consistency of assessments, and the distribution of participant-level changes. Those details are not reported in the registry record. The record also does not report a clinically meaningful threshold for interpreting a change, so the posted values cannot be classified against such a threshold from the available information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry reports a continuous primary outcome summarized by the mean and standard deviation in each treatment arm. A mean describes the average observed change, while a standard deviation describes how spread out individual observations are around that average. These statistics answer different questions: the mean characterizes the center of the observed values, and the standard deviation characterizes their dispersion. Neither alone states how precisely a between-group effect has been estimated.

What does the change score mean?

Change from baseline is the follow-up score relative to the baseline score. For this endpoint, the registry explicitly states that negative changes indicate improvement because smaller Sartorius Severity Scores indicate less lesion involvement. The YAZ arm's reported mean change is -3.5; the placebo arm's reported mean change is 12.0. Reading the sign in the direction defined by the registry is essential. A negative value should not be mistaken for worsening, nor does a positive value represent improvement under this endpoint definition.

These are arm-specific averages, not a reported estimate of the difference between arms. A formal comparison would estimate the contrast and describe its uncertainty, taking account of the design and the analysis method. The registry record does not report a contrast estimate, confidence interval, or p-value for the primary comparison. No such quantities should be inferred from the arm summaries by treating them as a completed sponsor analysis.

Why does the standard deviation matter?

Standard deviation indicates how much participant outcomes vary around their arm mean. The reported standard deviations are 2.121 for YAZ and 33.94 for placebo. The larger reported spread in the placebo arm signals that its mean may not describe every participant's outcome well. General statistical principle: when observations are highly dispersed, the mean can be a less representative description of an individual outcome, and an estimate based on a small arm can be sensitive to any one observation.

In this trial, each arm-level summary reports n=2.0. That makes the summaries especially limited as descriptions of a broader population. General statistical principle: small samples tend to yield imprecise estimates, and their observed variability may not closely represent variability in a larger target population. The record does not provide participant-level data, so the shape of the outcome distribution, the presence of unusual observations, and the pattern of individual changes cannot be assessed.

What would a confidence interval add?

A confidence interval gives a range of values compatible with an estimate under the assumptions of the chosen method. It helps readers assess precision, rather than relying only on whether an estimate is positive or negative. The registry record does not report a confidence interval for the treatment contrast. Standard deviations within each arm do not provide the same information as a confidence interval for the contrast. The uncertainty around the comparative effect therefore remains unreported.

A p-value, if reported, would address how compatible the observed data are with a specified null model under a particular analysis. It would not measure the size or clinical importance of an effect. No p-value or formal test result for the primary comparison is reported in the registry record. The trial's planned statistical tests and analysis specifications are not reported, so the results cannot be checked against a stated analysis plan.

What can be learned from the planning illustrations?

The record describes sample-size planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The illustrations consider an effect defined as a stated fraction of the observed effect. They are planning illustrations, not observed power and not evidence about what the trial was designed to enroll. The registry does not report the trial's own sample-size justification, and planning values should not be interpreted as proof that the trial had a particular chance of detecting an effect.

General statistical principle: a sample-size calculation depends on assumptions about the effect to detect, variability, significance level, allocation, and analysis method. If those assumptions differ from the eventual data or intended analysis, the resulting planning figure may not describe the study's actual precision. In this record, no planning illustration can overcome the limited information in the observed arm summaries.

How should over-dispersion be considered?

General statistical principle: over-dispersion describes variability greater than a model assumes. When a model fails to represent the observed variability, standard errors and inferential conclusions can be unreliable. The posted record gives a notably larger standard deviation in the placebo arm, but it does not report a fitted model or an over-dispersion assessment. The summary alone is not sufficient to claim that a formal over-dispersion problem was identified. It does underscore why model assumptions and uncertainty estimates would matter in a fuller analysis.

The registry identifies a continuous endpoint with mean and standard deviation summaries. It does not report whether the primary analysis used a model, adjusted for baseline values, or followed another approach. It also does not report whether any transformation, robust method, or other response to the spread of outcomes was considered. These omissions prevent a detailed evaluation of the statistical method used for the comparison.

Randomization supports the intended comparison by assigning participants to treatment groups, while masking is intended to limit knowledge of treatment assignment. The registry labels the study randomized and triple-masked. General statistical principle: these features can reduce certain sources of bias, but they do not guarantee that groups are balanced in a small study or that outcomes are completely observed. The allocation procedure, masking roles, and assessment of masking are not reported in the registry record.

The record reports no analysis records. Consequently, the posted summaries should be interpreted as descriptive outcome information rather than a full statistical report. Without a stated analysis population, handling of missing outcomes, prespecified model, and inferential results, the assumptions behind a comparative claim cannot be evaluated. The statistical reading should remain anchored to the reported means, standard deviations, and arm sizes, without converting them into an unreported treatment-effect estimate.

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("Drospirenone and Ethinyl Estradiol (YAZ)", "Placebo Tablets")
n   <- c(2, 2)
m   <- c(-3.5, 12)
sp  <- c(2.1213, 33.9411)
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  Drospirenone and Ethinyl Estradiol (YAZ)  2  -3.500  2.121  -22.559  15.559
CARM  Placebo Tablets  2  12.000  33.941  -292.949  316.949

11. Multiplicity, Missing Data and Analysis Populations

The registry lists the primary Sartorius Severity Score outcome and two secondary outcomes: change from baseline in VAS Pain Scale and change from baseline in DLQI Score, each at Month 6. It reports three outcome measures in total. The secondary outcome results are not reported in the registry record. This means the posted evidence does not give a complete account of the registered outcome set.

When a study assesses multiple outcomes, multiple time points, or multiple comparisons, the chance of finding an apparently notable result by chance can increase. General statistical principle: a prespecified approach to multiplicity can help define how evidence across tests should be interpreted. The registry does not report whether any multiplicity adjustment was planned or used, or how the primary and secondary outcomes were prioritized in the analysis. It is therefore not possible to assess the effect of multiple testing on the reported findings.

Missing-data handling is not reported in the registry record. The record does not say whether all randomized participants contributed Month 6 outcomes, whether any outcome observations were missing, or how missing values were handled. It also does not report an analysis population, such as which participants were included in the primary analysis. These details matter because exclusions or incomplete follow-up can affect the meaning of the observed summaries.

The trial status is terminated, but the reason for termination and its relation to outcome availability are not reported. No statistical analysis records are listed. Without further information, it is not possible to determine whether the posted results represent the planned analysis, a partial analysis, or another reporting set. These gaps are distinct from the observed arm means: they concern how complete and comparable the analyzed data may be.

12. 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.

Most frequent non-serious adverse event terms

The registry reports serious adverse event counts separately by treatment arm. For YAZ, 0 serious adverse events are reported among 2 participants at risk. For placebo, 0 serious adverse events are reported among 2 participants at risk. These are the recorded counts in the registry; they should not be read as proof that serious harms are impossible or that the treatments have equivalent safety.

For other adverse events, the record reports 1 affected participant among 2 at risk in each arm. The event terms and details are not reported in the registry record, and the record does not provide timing, duration, severity, or whether an event led to treatment discontinuation. The deaths fields are not populated, so death counts are not reported in the registry record. No serious adverse event terms are listed.

General statistical principle: safety counts from very small groups are highly limited for detecting uncommon events or comparing risk. Counts also do not describe the clinical nature of an event. The figures are best read as a brief account of what the registry records, rather than as a comprehensive assessment of comparative safety.

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

The posted primary outcome summaries describe average Month 6 change in the Sartorius Severity Score. The mean is -3.5 for YAZ and 12.0 for placebo, with standard deviations of 2.121 and 33.94, respectively. Under the registry's definition, negative change indicates improvement and positive change indicates worsening. The arm means therefore have different directions, but the record does not report a formal estimate of the between-arm contrast or its uncertainty.

These results do not establish that YAZ caused a particular change, nor do they establish that the two treatments are equivalent. The randomized design is relevant, but the very small arm summaries and the absence of a reported inferential analysis limit causal and precision claims. The comparatively large placebo-arm standard deviation also indicates that the placebo observations were more dispersed, while the small amount of data makes it difficult to characterize that variability reliably.

The results do not address the secondary outcomes in the registry because numerical findings for pain and DLQI are not reported. The safety summaries likewise contain only counts, with no event descriptions or detailed follow-up. The status is terminated, but the reason and consequences for outcome collection are not reported.

General statistical principle: an observed difference in sample means can arise from a true treatment effect, chance variation, or features of data collection and analysis. A confidence interval, analysis details, and transparent accounting of participants and missing outcomes would help readers evaluate these possibilities. Those elements are not reported in the registry record. The findings are therefore best treated as limited descriptive evidence, not a definitive estimate of benefit or harm and not a basis for individual treatment decisions.

14. Why This Trial Matters Statistically

This trial is statistically notable because its registry record pairs a randomized design with very limited reported outcome data. Randomization and masking are valuable design features, but their presence does not eliminate uncertainty when arm-level summaries are based on n=2.0 in each group. A small study can describe what happened among the observed participants, yet provide little precision about outcomes in a wider population.

The contrast in reported standard deviations also matters. The YAZ arm has a standard deviation of 2.121, while the placebo arm has a standard deviation of 33.94. General statistical principle: variability affects the precision of comparisons, and uneven or substantial spread can make a simple summary an incomplete account of the data. Without participant-level outcomes, readers cannot determine whether the arm means reflect a consistent pattern or are strongly influenced by individual observations.

The registry lists a primary endpoint and two secondary outcomes, but only the primary arm summaries are numerically reported. It gives no formal comparison, confidence interval, or p-value. This limits the ability to distinguish a descriptive difference from a statistically uncertain estimate, and it prevents a full appraisal of whether the registered outcome set was analyzed as intended.

The terminated status further makes reporting context important. The record does not explain why the study ended or how termination affected follow-up and analysis. Those gaps do not erase the reported observations, but they constrain interpretation of completeness and robustness. The study is a useful example of why design labels alone are not enough: sample size, outcome availability, analysis methods, and uncertainty reporting are all needed to understand a clinical trial result.

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 main limitation is the small amount of outcome information: the registry reports n=2.0 in each arm, despite enrollment of 4. This leaves the arm means and standard deviations vulnerable to the influence of individual observations and provides little basis for characterizing outcome distributions. Participant-level results are not reported, so consistency of change within either group cannot be evaluated.

The registry does not report a formal between-group estimate, confidence interval, p-value, or detailed statistical analysis plan. It does not identify the analysis population, describe missing-data handling, or state whether baseline adjustment was used. Without these details, readers cannot assess the precision of the comparison or whether the posted summaries correspond to a prespecified analysis.

The study is listed as terminated, but the reason for termination and its effect on follow-up are not reported in the registry record. Baseline characteristics, eligibility criteria, treatment adherence, and details of outcome assessment are also not reported. These omissions make it difficult to judge group comparability, applicability, and completeness of endpoint measurement.

Only primary outcome summaries are posted; numerical results for the listed secondary outcomes are absent. Safety reporting is limited to counts without event terms or timing, and death counts are not reported in the registry record. The record also does not specify which roles were masked or how randomization was conducted. These trial-specific limitations mean that the descriptive pattern can be stated, but its reliability, clinical relevance, and generalizability remain uncertain.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study to Examine the Safety and Efficacy of Drospirenone and Ethinyl Estradiol (YAZ) Versus Placebo In HS — NCT00722800.
• Registry record last updated 2014-02-10; status last verified 2014-01.
• Results first posted 2014-01-16.
• 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

The registry describes a Phase 2, randomized, triple-masked, parallel-group, single-center study comparing drospirenone and ethinyl estradiol (YAZ) with placebo for hidradenitis suppurativa. Enrollment is reported as 4, and the study status is terminated. The start is listed as 2008-10 and primary completion as 2011-12.

The primary outcome is mean improvement in the Sartorius Severity Score at Month 6. The reported mean changes are -3.5 for YAZ and 12.0 for placebo, with standard deviations of 2.121 and 33.94. The arm summaries each report n=2.0. A formal comparison and its uncertainty are not reported in the registry record.

Two secondary outcomes are listed, but their numerical results are not reported. Serious adverse event counts are 0 in each arm among 2 at risk; other adverse event counts are 1 in each arm among 2 at risk. Reasons for termination, analysis details, missing-data handling, and participant characteristics are not reported in the registry record.