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 Hydroxychloroquine for the Treatment of Hidradenitis Suppurativa (NCT03275870), a na phase 1, phase 2 study. The primary outcome is Change in Disease Severity.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03275870 |
| Phase | Phase 1, Phase 2 |
| Condition | Hidradenitis Suppurativa, Hidradenitis, Acne Inversa |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 17 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Elena Gonzalez Brant, MD |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns patients with hidradenitis suppurativa (HS). The registry describes HS as a disease involving recurring painful abscesses and scarring, and lists related condition terms including hidradenitis, acne inversa, boils, and follicular occlusion conditions. The registry record does not report further eligibility details in the information available for this analysis.
Intervention
Participants received hydroxychloroquine, described as 200mg BID for 6 months. The registry’s study summary says blood samples were planned at baseline and following 6 months of treatment to examine inflammatory molecules. The record does not report detailed adherence information or the actual blood-sample findings.
Comparator
There was no separate comparison group: the study is recorded as single-group, with allocation listed as NA and masking as none. The registry describes baseline and post-treatment measurements, not a randomized or concurrent control comparison. Changes during treatment therefore cannot, by themselves, distinguish treatment effects from other influences over time.
Primary question
The primary outcome was change in disease severity, measured with Sartorius severity scoring at baseline and after treatment, with a 6-month timeframe. Scores range from a minimum of 0, with no maximum, and higher scores indicate a worse outcome. The registry record does not report the numerical baseline or post-treatment scores or the estimated change, so the magnitude and direction of the observed change cannot be described from this record.
3. Trial Design
This was a completed pilot study of hydroxychloroquine for hidradenitis suppurativa, registered as Phase 1 and Phase 2. The registry records enrollment of 17 and a single-group model. Allocation is listed as NA, and masking as none. These design features mean that participants were not assigned between a hydroxychloroquine group and a control group within this study. The registry sponsor is Elena Gonzalez Brant, MD.
The intervention is listed as hydroxychloroquine 200mg BID for 6 months. The registry’s summary describes blood sampling at baseline and following 6 months of treatment, with the aim of examining inflammatory molecules. It also lists change in Quality of Life as a secondary outcome. These aims do not establish that all planned measurements were obtained or that results were reported; details of measurement completion are not reported in the registry record.
The recorded study start date is 2017-09-28, the primary completion date is 2019-06-30, and the status is completed. These dates describe the registry record and do not give the timing or duration of individual participants’ follow-up. The primary endpoint timeframe is 6 months.
Because there was no separate control group and masking was absent, the study can describe outcomes observed during treatment but cannot provide a randomized comparison. A before-and-after change within the same group may be affected by natural variation in symptoms, other care, expectations, or measurement conditions. The registry record does not report a protocol, detailed eligibility criteria, or a statistical analysis plan. In particular, the reason for the enrollment target and any plans for interim analyses 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
| Stage | Hydroxychloroquine Treatment |
|---|---|
| STARTED | 17 |
| COMPLETED | 3 |
| NOT COMPLETED | 14 |
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 | Hydroxychloroquine Treatment |
|---|---|---|
| Participants analysed | 17 | |
| Age, Continuous | years | 38.9 (19 to 64) |
| Sex: Female, Male: Female | Participants | 14 |
| Sex: Female, Male: Male | Participants | 3 |
| Race/Ethnicity, Customized: Caucasian | Participants | 14 |
| Race/Ethnicity, Customized: Black | Participants | 3 |
| Region of Enrollment: United States | participants | 17 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Disease Severity, measured over 6 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | score on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change in disease severity, measured by Sartorius scoring at baseline and after 6 months of treatment. The scale has a minimum score of 0, no stated maximum, and higher scores mean a worse outcome. A change score is intended to describe how the measured severity differs between the two assessments. Its meaning depends on both the numerical change and the direction used to define that change; the registry record does not state that direction explicitly.
Severity scoring provides a structured way to represent disease status, rather than relying only on an overall impression. The registry identifies the outcome as a mean with standard deviation, which would describe the group’s average score and the spread of individual scores. A group mean can help summarize the cohort, but it does not show whether every participant changed similarly. The standard deviation describes variability among measured values; it is not the precision of the estimated mean.
The registry record does not report the actual baseline and post-treatment means, the mean change, or its standard deviation. It also does not report a confidence interval or a p-value for this endpoint. Consequently, the size, direction, and precision of the observed change cannot be assessed from the outcome information. The score’s unbounded upper end also means that the record does not define a maximum possible severity value.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a single-group study of hydroxychloroquine treatment, with a primary assessment of Sartorius severity score at baseline and after 6 months. It records enrollment of 17 and lists a mean and standard deviation as the outcome summary. However, numerical primary-outcome results are not reported in the registry record. Baseline and post-treatment means, the mean change, its variability, and inferential estimates are therefore not available to characterize the observed result.
This absence matters for both direction and magnitude. The endpoint description says that higher Sartorius scores indicate worse disease, but without the scores or a stated change estimate there is no basis for saying whether severity increased or decreased on average. Nor can the size of any change be judged against the scale or against a clinically meaningful threshold; a threshold is not reported in the registry record.
Precision also cannot be evaluated from a point estimate alone, and the registry record does not report a confidence interval for the primary endpoint. In general, a confidence interval expresses uncertainty around an estimate under the assumptions of the analysis. Its width helps readers distinguish a relatively precise estimate from one that is compatible with a broad range of values. No such interval is reported for the primary outcome, so the uncertainty around the estimated change cannot be described.
The single-group design further limits causal interpretation. A baseline-to-follow-up difference, if known, would be a within-group observation rather than a contrast against a concurrent untreated or active-control group. Changes over time could have multiple explanations, including variation in symptoms, other care, or measurement. The design does not isolate the contribution of hydroxychloroquine from these possibilities.
The record lists 6 participants affected by other adverse events and no participants affected by serious adverse events among those at risk. These are safety counts, not measures of the primary efficacy outcome. The record does not provide event descriptions in the information available for this analysis, and the counts alone cannot establish causation or characterize event severity beyond the serious-versus-other categories recorded.
Overall, the registry documents the study design, intended endpoint, treatment period, and some safety counts. It does not report the numerical primary outcome needed to judge the observed severity change, or the analysis details needed to evaluate its statistical uncertainty. No conclusion about treatment efficacy follows from the design and available outcome information alone.
9. Statistical Methods Explained
The primary measure is continuous: Sartorius severity scoring is recorded as a score, and the outcome summary is specified as a mean with standard deviation. A mean gives the arithmetic center of a set of measurements. A standard deviation describes how dispersed individual measurements are around that mean. These quantities answer different questions: the mean describes the group’s average, while the standard deviation describes variation among observations. Neither quantity is reported numerically for the primary outcome in the registry record.
What does a baseline-to-follow-up change represent?
The endpoint compares baseline and post-treatment scores in the same study group. In general, repeated measurements on the same participants are related: a participant’s follow-up score may be associated with that participant’s baseline score. An analysis that accounts for this pairing can differ in precision from an analysis that treats the measurements as unrelated. The registry describes a comparison of baseline and post-treatment Sartorius scoring, but the specific statistical method used for that comparison is not reported in the registry record. It is therefore not possible to say whether the reported analysis used a paired method, an unpaired method, or another approach.
The score’s direction is stated: higher scores mean a worse outcome. Interpreting a change estimate requires knowing which subtraction or sign convention was used. The registry record does not report a numerical change estimate or specify its sign convention. It also does not report a clinically important change threshold. A statistical difference, if one were estimated, would not automatically establish that the difference is meaningful to patients; clinical importance depends on context and an appropriate threshold.
How should uncertainty be assessed?
In general, a confidence interval gives a range of estimates compatible with the data and the statistical model at a stated confidence level. It reflects sampling uncertainty under the model’s assumptions. A narrow interval indicates more precision than a wide interval, though precision alone does not determine clinical importance or eliminate bias. The registry record does not report a confidence interval for the primary outcome. It also does not report a p-value, a test statistic, or the specific hypothesis test used. The statistical significance of the primary result therefore cannot be assessed from the registry record.
Standard deviation and standard error should not be treated as interchangeable. Standard deviation describes spread among individual measurements; standard error describes uncertainty in an estimated quantity, such as a mean. The endpoint description names standard deviation, but does not give a numerical value. No standard error is reported. Without the outcome estimates and their uncertainty, a reader cannot determine how stable the group average may be or how much individual scores varied.
What do the planning illustrations mean?
Any sample-size figures associated with planning are illustrations based on the observed effect, not the study’s own design justification. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. The record characterizes these calculations as planning illustrations, not as a description of the trial’s single-group design. In general, such calculations ask how many participants per arm would be needed under specified assumptions to target a chosen power for a particular effect. They depend on the effect size, variability, statistical test, allocation, and other design choices. They should not be interpreted as observed power, and they do not show that this study was planned or conducted as a two-arm trial.
The registry’s planning assumptions do not replace a protocol-based sample-size justification. The reason for the enrollment target, the effect considered important when planning the study, and the method used to select that target are not reported in the registry record. Because the numerical primary outcome is also not reported in the information available for this analysis, readers cannot independently assess the effect estimate underlying planning illustrations from these details alone.
Why does over-dispersion matter in general?
For count outcomes, over-dispersion means that observed variation is greater than a simple model assumes. It can make standard errors too small if the model fails to account for that extra variation. The primary endpoint in this study is a continuous score, not a count outcome, and the registry record does not report use of a count model. This general concept should not be mistaken for a method reported for this trial.
More broadly, the specific analysis population, handling of repeated measurements, missing-data method, covariate adjustment, model diagnostics, and multiplicity procedure are not reported in the registry record. Without those details and the numerical outcome results, the analysis cannot be reproduced or fully evaluated from the registry information alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists Change in Disease Severity as the primary outcome and Change in Quality of Life as a secondary outcome. It also records two outcome measures and two analyses. The exact mapping between analyses and outcome measures, the number of statistical comparisons performed, and any prespecified hierarchy among outcomes are not reported in the registry record.
When multiple outcomes or comparisons are tested, the chance of at least one apparently unusual result can increase. In general, a multiplicity procedure may adjust interpretation or testing to account for that family of comparisons. Whether any adjustment was planned or used in this study is not reported in the registry record. No p-values for these outcomes are reported in the information available for this analysis, so the impact of multiplicity on the reported findings cannot be assessed.
The registry record does not report the number of participants with complete primary outcome measurements, the amount or pattern of missing data, or how missing observations were handled. It does not say whether the analysis included all enrolled participants, only participants with follow-up measurements, or another analysis population. The record also does not report imputation, sensitivity analyses, or a prespecified approach for participants who discontinued treatment or missed an assessment.
These omissions matter because missingness can affect both the estimate and its uncertainty, particularly if the likelihood of missing a measurement is related to disease status or treatment experience. This is a general statistical concern, not evidence that missing data occurred in this study. Without information on completeness and analysis populations, readers cannot determine whether the reported cohort reflects all enrolled participants or how robust an estimate would be to alternative assumptions about unavailable measurements.
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 |
|---|---|---|---|
| Hydroxychloroquine Treatment | 0 | 17 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Hydroxychloroquine Treatment | 0 of 17 |
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 |
|---|---|
| Hydroxychloroquine Treatment | 6 of 17 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Hydroxychloroquine Treatment |
|---|---|---|
| Nausea | Gastrointestinal disorders | 2 of 17 |
| headache | Nervous system disorders | 1 of 17 |
| urticaria | Skin and subcutaneous tissue disorders | 1 of 17 |
| Depression | Psychiatric disorders | 1 of 17 |
| blurred vision | Eye disorders | 1 of 17 |
The registry safety information lists no participants affected by serious adverse events among 17 at risk. It lists 6 participants affected by other adverse events among 17 at risk, and 0 deaths. These are the counts recorded for the hydroxychloroquine treatment group. They are descriptive safety figures; they do not establish that an event was caused by hydroxychloroquine.
The registry record does not list serious adverse event terms in the information available for this analysis. Specific descriptions of the other adverse events, their timing, duration, severity, and relationship to treatment are not reported in the registry record. The counts therefore cannot show which types of events occurred or whether they shared a pattern.
A count of zero serious adverse events means none were recorded as affected in this group in the registry safety information. It does not establish that the risk is absent. In general, safety estimates from a study depend on the amount and duration of observation, event definitions, and how events were collected and reported. Those details are not reported. The group size and safety counts should be read as descriptive registry data, not as a definitive estimate of risk.
12. What the Result Does, and Does Not, Mean
The study records a 6-month course of hydroxychloroquine and a planned baseline-to-follow-up assessment of Sartorius disease severity. It is a completed, single-group pilot study with enrollment of 17 and no masking. The registry also lists Change in Quality of Life as a secondary outcome and reports safety counts for the treatment group.
The registry record does not report numerical primary outcome results. It is therefore not possible to state what average change in disease severity was observed, whether scores moved in a better or worse direction, or how precise an estimate would be. No conclusion about efficacy can be drawn from the endpoint description alone. The record also does not provide numerical quality-of-life results in the information available for this analysis.
Even if a within-group change were reported, a single-group before-and-after comparison would not by itself show what would have happened over the same period without treatment. Participants were not compared with a concurrent control group, and masking was absent. General sources of change over time, measurement variation, and other care could influence a before-and-after result. A controlled design would be needed to make a stronger comparative assessment, but the registry record does not report such a comparison for this study.
The safety counts offer a limited description of reported events in the treatment group. No serious adverse events and no deaths are recorded among those at risk, while 6 participants are recorded as affected by other adverse events. The record does not provide the event details needed to characterize those events or assess causality. These counts should not be interpreted as proof of safety or of a treatment-related harm.
The appropriate reading is narrow: the registry documents a pilot study’s design, intended outcome, treatment period, and selected safety counts, but does not provide numerical efficacy estimates or the analysis details needed to evaluate uncertainty. This record alone cannot establish whether hydroxychloroquine changes HS severity or how the observed safety profile compares with another treatment or no treatment.
13. Why This Trial Matters Statistically
This study is statistically informative as an example of the difference between documenting a clinical question and reporting an analyzable result. The registry specifies a continuous severity outcome, its direction, the assessment timeframe, and a summary measure. Those details help clarify what was intended to be measured. Yet without baseline and follow-up values, a change estimate, or an uncertainty measure, readers cannot quantify the primary result.
The single-group design is also central to interpretation. Repeated measurement can describe within-group change, but it does not create a concurrent counterfactual comparison. A change over time may reflect treatment, natural fluctuation, other care, or measurement conditions. Recognizing this distinction prevents a before-and-after result from being read as if it were a randomized treatment contrast.
The record’s planning assumptions illustrate another important distinction. A planning calculation based on an observed effect and a hypothetical two-arm allocation is not the same as the design of this single-group study. Such illustrations can show how assumed effects and statistical choices influence planning, but they do not establish the trial’s original rationale or provide evidence of observed power.
Finally, the gap between the stated outcome and the reported numerical results has practical consequences for statistical review. Without outcome estimates, confidence intervals, missing-data information, and analysis details, readers cannot assess magnitude, precision, robustness, or the potential effect of multiple comparisons. The record remains useful for understanding the study’s structure and the limits of its available evidence, while leaving the primary efficacy question unresolved in the registry information.
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 main limitation for interpretation is the absence of numerical primary outcome results in the registry record. Although the primary endpoint is defined as change in Sartorius severity score from baseline to post-treatment, the actual scores, average change, and variability are not reported. This prevents assessment of the direction, size, and precision of the outcome.
The study has a single-group design, no masking, and no separate control comparison. Any change between baseline and follow-up would therefore be vulnerable to alternative explanations, including symptom fluctuation, other care, expectations, and measurement variation. The registry does not report enough information to assess how these influences were addressed.
The endpoint has a minimum of 0 and no maximum, and higher scores indicate a worse outcome. The record does not report a clinically meaningful change threshold or a numerical estimate that could be compared with one. The specific statistical method, analysis population, handling of missing data, and multiplicity approach are also not reported in the registry record.
The registry lists enrollment of 17, but the number with complete primary outcome measurements and the extent of follow-up are not reported in the information available for this analysis. Detailed eligibility criteria and participant characteristics are also not reported, limiting assessment of how broadly the findings might apply. The safety record gives counts but not event descriptions, timing, severity details, or causal assessments. These limitations leave substantial uncertainty about both efficacy and the interpretation of adverse events.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Hydroxychloroquine for the Treatment of Hidradenitis Suppurativa — NCT03275870.
- Registry record last updated 2020-04-02; status last verified 2020-03.
- Results first posted 2020-03-24.
- 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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Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry identifies NCT03275870 as a completed pilot study of hydroxychloroquine for hidradenitis suppurativa, recorded as Phase 1 and Phase 2. It lists a single-group design, no masking, and enrollment of 17. The recorded study start date is 2017-09-28, and the primary completion date is 2019-06-30.
The intervention is hydroxychloroquine 200mg BID for 6 months. The primary outcome is change in Sartorius disease severity score at 6 months; higher scores indicate a worse outcome. Change in Quality of Life is listed as a secondary outcome. Numerical primary efficacy results and detailed analysis information are not reported in the registry record.
The safety information records no serious adverse events, 6 participants affected by other adverse events, and 0 deaths in the treatment group. Event descriptions are not reported in the information available for this analysis. The design and missing numerical outcome results limit conclusions about treatment effects and their precision.