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 in Individuals At-risk for Type 1 Diabetes Mellitus (NCT03428945), a randomized phase 2 study. The primary outcome is Change From Treatment Assignment Glucose Tolerance to Abnormal Glucose Tolerance or Diabetes.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03428945 |
| Phase | Phase 2 |
| Condition | Type1 Diabetes Mellitus |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 273 |
| Arms in the primary outcome | 2 |
| Lead sponsor | National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) |
| Results posted | Yes |
2. Clinical Question
Population
The trial concerns individuals at risk for type 1 diabetes mellitus. The primary outcome population is described as participants included in the time-to-event analysis. The registry record does not give further eligibility details or describe how risk status was defined, so those details cannot be inferred from the posted primary result.
Intervention
Participants assigned to the active-treatment arm received hydroxychloroquine, described as a compound for oral use. The record characterizes the study as randomized and double-blind and describes close monitoring for progression of type 1 diabetes. The registry record does not report further dosing or adherence details in the available trial details.
Comparator
The comparison group received a placebo tablet matching the active drug. The trial is described as placebo controlled, with a 2:1 randomization plan favoring hydroxychloroquine. The posted primary outcome results list 168 participants for hydroxychloroquine and 83 for placebo in the time-to-event analysis; these are the outcome-analysis group counts, not the safety group counts.
Primary question
The primary question is whether the time from random treatment assignment to confirmed abnormal glucose tolerance or clinical diabetes differs between the hydroxychloroquine and placebo arms. Glucose tolerance was measured every 6 months for up to 4 years. The posted outcome is the median time in months for each arm, with interquartile-range limits. The registry record does not post a hazard ratio, confidence interval, or p value for a between-arm comparison, so the medians alone do not establish whether the arms differed statistically.
3. Trial Design
This was a phase 2, randomized, double-blind, parallel-group, placebo-controlled clinical trial. The registry describes it as a multicenter study and says randomization was planned in a 2:1 ratio between hydroxychloroquine and placebo. The treatment arms were hydroxychloroquine, an oral compound, and a matching placebo tablet. Participants were to receive close monitoring for progression of type 1 diabetes.
The record gives enrollment as 273. That figure is not the same as the group counts displayed for every outcome: the primary time-to-event analysis lists 168 participants in the hydroxychloroquine arm and 83 in the placebo arm. The safety record separately lists 183 participants at risk in the hydroxychloroquine group and 90 in the placebo group. These counts refer to different reported analysis contexts and should not be combined or treated as interchangeable.
The trial status is terminated. The record lists a start date of 2018-08-15 and a primary completion date of 2022-10-27. The reason for termination is not reported in the registry record, and the status alone does not establish why the trial ended or what effect termination had on the results.
The primary outcome was time in months from random treatment assignment to confirmed abnormal glucose tolerance or clinical diabetes. Glucose tolerance was measured every 6 months for up to 4 years. The posted summary reports a median time and interquartile-range limits for each arm. The registry record does not describe the randomization procedure in more detail, the allocation-concealment process, the specific masking procedures, or the analytic methods used to produce the median estimates.
The record lists one outcome measure and no posted secondary outcome measures. It does not report a statistical analysis plan, a sample-size justification, or interim-analysis details. The listed enrollment should therefore be read as a trial record entry, not as evidence about the assumptions or methods used to plan the study.
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 | Placebo |
|---|---|---|
| STARTED | 183 | 90 |
| COMPLETED | 168 | 77 |
| NOT COMPLETED | 15 | 13 |
Reasons for not completing this period:
| Reason | Hydroxychloroquine | Placebo |
|---|---|---|
| Lost to Follow-up | 5 | 3 |
| Withdrawal by Subject | 10 | 10 |
Analysis population for the primary outcome, as defined in the registry: Participants included in the time-to-event analysis
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 | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 183 | 90 | 273 | |
| Age, Categorical: <=18 years | Participants | 165 | 77 | 242 |
| Age, Categorical: Between 18 and 65 years | Participants | 18 | 13 | 31 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Age, Continuous | years | 11.7 (8.3 to 15.6) | 10.9 (8.2 to 15.7) | 11.3 (8.3 to 15.6) |
| Sex: Female, Male: Female | Participants | 61 | 33 | 94 |
| Sex: Female, Male: Male | Participants | 122 | 57 | 179 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 15 | 4 | 19 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 162 | 82 | 244 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 6 | 4 | 10 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 1 | 1 | 2 |
| Race (NIH/OMB): White | Participants | 171 | 83 | 254 |
| Race (NIH/OMB): More than one race | Participants | 3 | 4 | 7 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 8 | 2 | 10 |
| Region of Enrollment: Canada | participants | 9 | 7 | 16 |
| Region of Enrollment: Sweden | participants | 1 | 0 | 1 |
| Region of Enrollment: United States | participants | 155 | 72 | 227 |
| Region of Enrollment: United Kingdom | participants | 2 | 2 | 4 |
| Region of Enrollment: Italy | participants | 0 | 2 | 2 |
| Region of Enrollment: Australia | participants | 13 | 7 | 20 |
| Region of Enrollment: Finland | participants | 3 | 0 | 3 |
| Relationship to person with Type 1 Diabetes: More than one first degree relative | Participants | 15 | 6 | 21 |
| Relationship to person with Type 1 Diabetes: Sibling(s) | Participants | 100 | 48 | 148 |
| Relationship to person with Type 1 Diabetes: Offspring | Participants | 6 | 5 | 11 |
| Relationship to person with Type 1 Diabetes: Parent(s) | Participants | 42 | 22 | 64 |
| Relationship to person with Type 1 Diabetes: Second Degree Relative | Participants | 9 | 6 | 15 |
| Relationship to person with Type 1 Diabetes: Third Degree Relative | Participants | 1 | 0 | 1 |
| Relationship to person with Type 1 Diabetes: No Relatives | Participants | 10 | 3 | 13 |
| Autoantibodies positive: 1 positive Autoantibody | Participants | 2 | 1 | 3 |
| Autoantibodies positive: 2 positive Autoantibodies | Participants | 35 | 23 | 58 |
| Autoantibodies positive: 3 positive Autoantibodies | Participants | 39 | 24 | 63 |
| Autoantibodies positive: 4 positive Autoantibodies | Participants | 46 | 18 | 64 |
| Autoantibodies positive: 5 positive Autoantibodies | Participants | 61 | 24 | 85 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Treatment Assignment Glucose Tolerance to Abnormal Glucose Tolerance or Diabetes, measured over Glucose tolerance is measured every 6 months for up to 4 years.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | Months |
| Endpoint classification | Time-to-Event Analysis |
The primary endpoint measures the time from random treatment assignment until a participant develops confirmed abnormal glucose tolerance or clinical diabetes. It is expressed in months. The registry says glucose tolerance was measured every 6 months for up to 4 years, and identifies the analysis population as participants included in the time-to-event analysis.
A time-to-event endpoint incorporates both whether an event was recorded and when it occurred. It can therefore describe the timing of progression rather than only the proportion of participants who experienced progression at a single assessment. In a trial with monitoring over time, some participants may not have a recorded event during the observation period; how such follow-up was handled is not reported in the registry record.
The posted summary uses the median time in each arm, alongside interquartile-range limits. The median is the point at which half of the observed time-to-event distribution lies on either side, subject to the methods used to estimate it. The interquartile range describes the middle portion of that distribution and conveys how spread out the times are. These summaries are not themselves a formal test of the difference between arms.
The median time was 19.7 months for hydroxychloroquine, with interquartile-range limits of 10.6 and 36.2 months. For placebo, the median was 18.8 months, with limits of 9.9 and 33.1 months. The registry record does not report a hazard ratio, confidence interval, or p value for the primary comparison. The endpoint is useful for describing when progression occurred in the analyzed groups, but the posted medians alone do not quantify the uncertainty around an arm-to-arm effect.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary results give a median time to confirmed abnormal glucose tolerance or clinical diabetes of 19.7 months in the hydroxychloroquine arm and 18.8 months in the placebo arm. The corresponding interquartile-range limits are 10.6 and 36.2 months for hydroxychloroquine, and 9.9 and 33.1 months for placebo. These are descriptive summaries of the time-to-event outcome in the analysis populations listed by the registry.
The values do not constitute a complete statistical comparison. The registry record does not report a hazard ratio, confidence interval, or p value for the primary endpoint. Without an effect estimate and its uncertainty, the medians do not establish whether the observed difference is compatible with no between-arm difference or with a range of other effects. It would be inappropriate to infer statistical significance from the medians or from whether the interquartile ranges overlap.
The outcome analysis lists 168 participants for hydroxychloroquine and 83 for placebo. The safety record gives different at-risk group counts: 183 and 90, respectively. The distinction matters because participant counts depend on the particular analysis and outcome. The registry record does not explain the reasons for the differences between the outcome-analysis and safety counts, so they should not be reconciled by assumption.
The trial is marked terminated, but the registry record does not report the reason. Termination does not by itself show that the trial stopped for benefit, harm, futility, recruitment difficulty, or any other particular reason. Nor does the status reveal whether the planned observation period was completed for all participants. The endpoint timeframe states that glucose tolerance was measured every 6 months for up to 4 years, but details of actual follow-up and completeness are not reported in the registry record.
The record posts one outcome measure and no secondary outcome measures. It also reports zero posted analyses. This means the available registry results do not include a formal treatment-effect analysis for the primary endpoint. It does not establish that no analyses were conducted outside the registry record. The sponsor's own inferential analysis, if reported elsewhere, is not available in these posted results and therefore cannot be assessed from this record.
The safety summaries should be read separately from the primary efficacy endpoint. Serious adverse events are listed for each safety group, along with other adverse events and deaths. These counts are descriptive; the registry record does not supply an adjusted safety comparison or a statistical uncertainty estimate. They cannot determine, by themselves, whether an event pattern was caused by treatment.
9. Statistical Methods Explained
What does a median time summarize?
For a time-to-event endpoint, the outcome is the elapsed time from a defined starting point until an event is recorded. In this trial, the starting point was random treatment assignment, and the event was confirmed abnormal glucose tolerance or clinical diabetes. A median time summarizes the center of the event-time distribution: it is the estimated time by which half of the relevant distribution has experienced the event. The registry reports median times of 19.7 months for hydroxychloroquine and 18.8 months for placebo.
Time-to-event methods are useful when participants can have different lengths of follow-up. They can also account for participants whose event is not observed during their available follow-up, using censoring methods. Censoring means that the event time is not known beyond a participant's last observed time, rather than treating that participant as event-free indefinitely. This is a general explanation of the method family; the registry record does not specify whether the posted medians were estimated using Kaplan-Meier methods or another approach, how censoring was defined, or how loss to follow-up was handled.
What do the interquartile-range limits add?
The interquartile range describes the spread of the middle half of a distribution, with limits around the median. The posted limits are 10.6 and 36.2 months for hydroxychloroquine and 9.9 and 33.1 months for placebo. They convey that event times varied among participants. An interquartile range is not a confidence interval for the median or for a treatment effect. It describes variation in the observed distribution, whereas a confidence interval describes statistical uncertainty about an estimated quantity.
Because these limits describe each arm separately, they do not directly test whether the arms differ. Overlap or non-overlap between interquartile ranges is not a substitute for a formal comparison. A treatment-effect estimate, together with an uncertainty interval and an appropriate analysis, would be needed to assess the comparative result. The registry record does not report those inferential statistics.
What would a hazard ratio contribute?
A hazard ratio is a relative comparison of event rates over time under a specified model. In general, it can use more of the observed event-time information than a comparison of medians alone. Interpretation depends on the model and its assumptions, including whether the relative event rate is reasonably stable over follow-up when a proportional-hazards model is used. A hazard ratio is not the same as a ratio of median times and does not by itself describe absolute event probabilities.
No hazard ratio or confidence interval is posted for this endpoint in the registry record. No proportional-hazards assessment or other model diagnostics are reported either. The registry record therefore does not support a model-based interpretation of the treatment contrast. The medians remain descriptive summaries, not substitutes for an absent hazard-ratio analysis.
How should uncertainty be considered?
In general, a confidence interval expresses the uncertainty associated with an estimated effect under the analysis assumptions. A narrower interval indicates greater precision than a wider interval, while the interval's location conveys the range of effect sizes compatible with the data and model. A p value addresses a particular null hypothesis under the model; it does not measure the probability that the null hypothesis is true or the clinical importance of an effect. No confidence interval or p value for the primary arm comparison is reported in the registry record.
For time-to-event data, the number of participants alone is not enough to determine precision. The amount and timing of observed events, follow-up duration, censoring, and the analysis method also matter. The record lists outcome-analysis counts but does not give event counts, numbers censored, or a detailed follow-up distribution. Precision of the primary comparison therefore cannot be reconstructed from the posted medians and group counts.
What is and is not a recalculation?
The registry record gives arm-level median times and interquartile-range limits, but it does not give the summary statistics needed for an unadjusted recalculation of a hazard ratio or its uncertainty. The available results do not permit a valid inferential comparison to be recreated from the arm medians. No recalculated treatment effect is therefore presented. The registry record does not post a sponsor analysis for this endpoint, so there is no sponsor estimate or analysis to compare with a recalculation.
In general, a simple recalculation from posted summary statistics would not replace a sponsor's prespecified analysis. The analysis population, event definition, censoring rules, and adjustment methods can affect an estimate. Here, those details are not reported in the registry record, and the posted summary does not include the information needed to reproduce an adjusted time-to-event analysis.
How should planning illustrations be read?
Sample-size calculations are planning tools, not trial outcomes. The planning assumptions described for the illustrations use a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. For time-to-event tables, the stated planning quantity is the total number of events. These illustrations are based on the observed effect and are not the trial's own design justification.
Such illustrations do not describe observed power. Observed power is not a useful substitute for an uncertainty interval around the trial's actual estimate. A planning calculation depends on its assumptions and should not be read as proof that the trial was adequately powered or that its results are conclusive. The registry record does not report the sponsor's sample-size justification or the assumptions used in the original design.
For this primary endpoint, the registry record does not provide an inferential effect estimate from which to judge the degree of evidence precisely. The listed medians and interquartile-range limits support descriptive interpretation, while the missing comparison statistics and analysis details limit conclusions about the treatment contrast.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists one outcome measure and no posted secondary outcome measures. It also reports zero posted analyses. These entries describe what is available in the registry record; they do not establish that the trial had no other planned outcomes or that no analyses were performed outside the record.
Multiplicity arises when multiple outcomes, time points, subgroups, or statistical comparisons are tested. Testing multiple questions can increase the chance of at least one apparently notable result by chance if no adjustment or prespecified hierarchy is used. The registry record does not report whether multiplicity was considered, whether a hierarchy of outcomes was planned, or whether adjustments were used. With no posted secondary outcome results, the extent of any multiplicity across analyses cannot be assessed.
Details about missing data are also not reported in the registry record. In a time-to-event analysis, incomplete observation may be handled through censoring, but the validity of that approach depends on follow-up and assumptions about why observation ends. The record does not give numbers censored, reasons for missing observations, follow-up completeness, or sensitivity analyses. It therefore does not allow an assessment of how missing outcome information may have affected the results.
The primary analysis population is described as participants included in the time-to-event analysis. The registry record does not say whether this population corresponds to an intention-to-treat population, a per-protocol population, or another prespecified group. Nor does it explain inclusion and exclusion rules for the analysis. The listed analysis counts should be interpreted as the counts attached to the posted endpoint, without assuming a particular analysis-population definition.
The absence of these details limits reproducibility and interpretation. It does not demonstrate that appropriate methods were or were not used; it means that the relevant methods are not reported in the registry record.
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 | 5 | 183 | 2.7% |
| Placebo | 1 | 90 | 1.1% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Hydroxychloroquine | 0 of 183 |
| Placebo | 0 of 90 |
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 | 125 of 183 |
| Placebo | 61 of 90 |
Most frequent serious adverse event terms
| Event term | Organ system | Hydroxychloroquine | Placebo |
|---|---|---|---|
| General disorders and administration site conditions - Other, specify | General disorders | 1 of 183 | 1 of 90 |
| Vomiting | Gastrointestinal disorders | 2 of 183 | 0 of 90 |
| Anaphylaxis | Immune system disorders | 1 of 183 | 0 of 90 |
| Appendicitis | Infections and infestations | 1 of 183 | 0 of 90 |
| Depression | Psychiatric disorders | 0 of 183 | 1 of 90 |
| Suicide attempt | Psychiatric disorders | 0 of 183 | 1 of 90 |
| Psychosis | Psychiatric disorders | 0 of 183 | 1 of 90 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Hydroxychloroquine | Placebo |
|---|---|---|---|
| Neutrophil count decreased | Investigations | 32 of 183 | 26 of 90 |
| Infections and infestations - Other, specify | Infections and infestations | 29 of 183 | 13 of 90 |
| Upper respiratory infection | Infections and infestations | 16 of 183 | 7 of 90 |
| Skin and subcutaneous tissue disorders - Other, specify | Skin and subcutaneous tissue disorders | 16 of 183 | 5 of 90 |
| Sinusitis | Infections and infestations | 11 of 183 | 5 of 90 |
| Injury, poisoning and procedural complications - Other, specify | Injury, poisoning and procedural complications | 8 of 183 | 5 of 90 |
| Surgical and medical procedures - Other, specify | Surgical and medical procedures | 10 of 183 | 3 of 90 |
| Fracture | Injury, poisoning and procedural complications | 8 of 183 | 3 of 90 |
| Otitis media | Infections and infestations | 4 of 183 | 5 of 90 |
| Investigations - Other, specify | Investigations | 6 of 183 | 3 of 90 |
Serious events with the highest arm-level rate: general disorders and administration site conditions - other, specify (1.1%), depression (1.1%), suicide attempt (1.1%), psychosis (1.1%), vomiting (1.1%).
The safety record lists serious adverse events for 183 participants at risk in the hydroxychloroquine group, with 5 affected, and for 90 participants at risk in the placebo group, with 1 affected. It lists other adverse events for 183 at risk in the hydroxychloroquine group, with 125 affected, and for 90 at risk in the placebo group, with 61 affected. Deaths are listed as 0 in each group.
These are descriptive counts within the safety record. They are not adjusted comparisons, and no confidence intervals or p values for differences between groups are reported. The registry record does not define the event-collection period or provide further details about severity, timing, recurrence, or relatedness to treatment. The at-risk counts differ from the group counts in the primary time-to-event analysis, so the denominators should not be substituted for one another.
The registry also lists serious-event terms with percentages: General disorders and administration site conditions - Other, specify, 1.1%; Depression, 1.1%; Suicide attempt, 1.1%; Psychosis, 1.1%; Vomiting, 1.1%; and Anaphylaxis, 0.5%. The record does not make the arm attribution for these listed terms clear in the registry entries. These figures should therefore not be assigned to a treatment arm or treated as comparative estimates.
Counts and listed terms can describe what was recorded, but they do not establish that treatment caused an event or that the groups differ in safety. The termination status does not explain the safety findings or indicate that safety was the reason for termination.
12. What the Result Does, and Does Not, Mean
The posted results describe median time to confirmed abnormal glucose tolerance or clinical diabetes in the two analyzed groups. The median was 19.7 months for hydroxychloroquine and 18.8 months for placebo, with interquartile-range limits of 10.6 to 36.2 months and 9.9 to 33.1 months, respectively. These summaries indicate the central timing and spread of the recorded time-to-event outcome in the analysis populations.
They do not establish whether hydroxychloroquine changed the timing of progression relative to placebo. The registry record does not report a hazard ratio, confidence interval, or p value for the primary comparison. It is not possible to infer statistical significance, the precision of an arm difference, or the range of comparative effects compatible with the data from the medians alone.
The results also do not show what would happen outside the participants and follow-up represented in the record. The population is described broadly as individuals at risk for type 1 diabetes, but further eligibility details are not reported. The primary outcome was monitored every 6 months for up to 4 years; actual follow-up completeness and censoring details are not reported in the registry record.
The safety counts describe recorded serious and other adverse events in the registry's safety groups, and deaths are listed as 0 in each group. They do not provide a causal comparison or a complete account of event timing, severity, or relatedness. The listed serious-event terms are not clearly attributed to arms in the available record.
The trial's terminated status is factual, but the reason for termination is not reported in the registry record. It should not be taken as evidence of efficacy, lack of efficacy, harm, or any particular operational explanation. Overall, the posted data support a descriptive account of the primary endpoint and safety counts, while leaving the comparative effect and its uncertainty unresolved.
13. Why This Trial Matters Statistically
This trial illustrates why an endpoint summary and an inferential comparison answer different statistical questions. Median time describes the center of the time-to-event distribution in each group. It does not, by itself, quantify how strongly the distributions differ or how precisely the difference is estimated. The posted medians are therefore useful descriptive results, but they are not a replacement for a treatment-effect estimate and its uncertainty.
Time-to-event outcomes are particularly relevant when the timing of progression matters and participants can have different follow-up lengths. Their analysis depends on information beyond the median, including event occurrence, time under observation, censoring, and the handling of incomplete follow-up. The registry record does not report several of these details, making it difficult for readers to reproduce or critically assess the primary analysis.
The trial also provides a clear example of why analysis counts must be read in context. The primary endpoint lists one set of group counts, while the safety record lists different at-risk counts. Those figures are tied to distinct reported analyses and should not be treated as a single universal denominator. Understanding the population behind each result is essential to interpreting clinical trial summaries.
Finally, registry completeness matters. The record gives a primary outcome and descriptive arm-level values but no posted hazard ratio, confidence interval, p value, or secondary outcome results. This does not prove that no such analyses exist elsewhere, but it limits what can be concluded from the registry record itself. Careful statistical reading separates the reported descriptions from questions that the available inferential results cannot answer.
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 primary result is reported as arm-level medians and interquartile-range limits, without a formal comparative estimate. The registry record does not report a hazard ratio, confidence interval, or p value for the primary endpoint. As a result, the magnitude and precision of the between-arm effect cannot be assessed from the posted summary.
The analysis methods are not described in enough detail to reproduce the result. The registry record does not state the estimator used for the median time, the censoring rules, the handling of incomplete follow-up, the number of events, or the number of participants censored. It also does not report diagnostics or assumptions for a time-to-event model. The endpoint timeframe says measurements occurred every 6 months for up to 4 years, but actual follow-up completeness is not stated.
The outcome-analysis population is described only as participants included in the time-to-event analysis. The record does not define whether it was intention-to-treat, per protocol, or another population, and it does not explain why its group counts differ from the safety at-risk counts. Further eligibility criteria and the definition of at-risk status are not reported.
The trial is marked terminated, but the reason is not reported in the registry record. The record does not provide the sponsor's sample-size justification, statistical analysis plan, interim-analysis details, or information about multiplicity. It lists no posted secondary outcome measures and zero posted analyses, limiting the scope of interpretation and preventing assessment of how other planned analyses may relate to the primary result.
Safety reporting is also limited to event counts and a list of serious-event terms with percentages. The record does not provide a comparative analysis, event timing, relatedness, or clear arm attribution for the listed terms. These limits do not establish that the methods or reporting were inadequate; they identify information not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Hydroxychloroquine in Individuals At-risk for Type 1 Diabetes Mellitus — NCT03428945.
- Registry record last updated 2024-04-09; status last verified 2023-07.
- Results first posted 2024-04-09.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT03428945 is a phase 2, randomized, double-blind, parallel-group, multicenter, placebo-controlled trial of hydroxychloroquine in individuals at risk for type 1 diabetes mellitus. The registry describes a 2:1 randomization plan and close monitoring for progression. The trial status is terminated; the reason is not reported in the registry record.
The primary endpoint is time from random treatment assignment to confirmed abnormal glucose tolerance or clinical diabetes, measured in months. The posted medians are 19.7 months for hydroxychloroquine and 18.8 months for placebo, with reported interquartile-range limits for each arm. The registry record does not post a hazard ratio, confidence interval, or p value for the comparison.
The safety record lists serious and other adverse-event counts and 0 deaths in each group. It reports one outcome measure, no posted secondary outcome measures, and zero posted analyses. Missing-data methods, analysis-population definitions, and other key statistical details are not reported in the registry record.