Pilot Study of DFN-11 Injection in Medication Overuse Headache: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pilot Study of DFN-11 Injection in Medication Overuse Headache (NCT02583425), a na phase 2 study. The primary outcome is The Number of Headache Hours in the Baseline Period (28 Days of Subjects Using Their Usual Medication for Headaches) and in the Treatment Period (28 Days of Subjects Using DFN-11 for Headaches).

2. Clinical Question

Statistically, the central question is whether headache hours differed between the baseline and treatment observation periods among participants in this pilot. A within-participant comparison can describe how measurements changed over time in the people observed. It cannot, by itself, separate a treatment-associated change from changes that might have occurred over time for other reasons. The registry record does not report a concurrent control group, random allocation, or masking that could address those alternative explanations. The clinical question is therefore descriptive and exploratory in this design, while the absent outcome estimates prevent even a quantitative description of the observed change.

3. Trial Design

This was a Phase 2 pilot study of DFN-11 Injection for medication overuse headache. The registry record describes a single-group model, allocation as NA, and masking as none. Enrollment is recorded as 27. The study began in 2015-09, had a primary completion date of 2016-08, and is listed as terminated. The reason for termination is not reported in the registry record.

The arm description states that DFN-11 Injection was used upon occurrence of migraine. The primary outcome compares headache hours during a 28-day baseline period, when subjects used their usual headache medication, with headache hours during a 28-day treatment period, when subjects used DFN-11 for headaches. The listed total timeframe is 56 days. The secondary outcome concerns the number of acute headache medication doses across the same baseline and treatment periods.

Although baseline and treatment observations come from the same single-group study, baseline is not an independent control arm. The periods occur at different times, and the registry record does not describe random ordering or a washout procedure. It also does not report how the observation periods were scheduled relative to each participant's study entry, what happened if a participant did not complete either period, or whether participants could use other headache medications during treatment.

The record does not report eligibility criteria, demographic or clinical characteristics, the planned sample size, or a sample-size justification. It also does not explain why enrollment was 27 or why the study was terminated. These omissions limit assessment of recruitment, representativeness, and the extent to which the design was completed as intended. Enrollment alone does not establish how many participants contributed data to either period or to a particular endpoint; that analysis population is not reported in the registry record.

With no randomized comparator and no masking, the study design can describe observations made during the DFN-11 treatment period relative to baseline, if those results are reported elsewhere. It cannot provide the same protection against bias and time-related differences as a randomized, masked comparison. In this registry record, the outcome analysis itself is not listed, so no observed comparison can be assessed.

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.

Screening

Reasons for not completing this period:

Baseline

Reasons for not completing this period:

Treatment Period

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.

6. Primary Endpoint

The registry lists the primary outcome as The Number of Headache Hours in the Baseline Period (28 Days of Subjects Using Their Usual Medication for Headaches) and in the Treatment Period (28 Days of Subjects Using DFN-11 for Headaches), measured over 28 days Baseline period and 28 days of Treatment period (Total 56 days).

The primary endpoint is the number of headache hours over a 28-day baseline period and a 28-day treatment period. The registry record specifies hours as the unit and a mean as the measure of central tendency, with standard deviation as the dispersion measure. The stated timeframe covers 56 days in total. The record does not provide a more detailed operational definition of a headache hour, such as how headache duration was recorded or how overlapping episodes were handled.

Headache hours are a continuous measure of time spent with headache. In general, this kind of endpoint can capture both the frequency and duration burden of headache during a specified observation period. A mean describes the average recorded hours in the analyzed group, while the standard deviation describes the spread of individual measurements around that mean. These summaries answer different questions: the mean concerns the group average, and the standard deviation concerns variability among observations. Neither describes the precision of an estimated change; that would generally require an uncertainty measure such as a confidence interval.

A within-participant baseline and treatment comparison may be useful for describing changes over time in people who contributed observations to both periods. Interpretation depends on how measurements were collected and analyzed, and on whether the same participants contributed to each period. Those details are not reported in the registry record. No baseline mean, treatment-period mean, change estimate, standard error, confidence interval, or hypothesis test is listed. The endpoint is defined, but its observed result and statistical precision cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods help turn observations into estimates and describe how uncertain those estimates are. The registry record specifies that the primary endpoint is a mean of a continuous measure, reports standard deviation as the dispersion measure, and names the observation periods. It does not report the analysis method used for that endpoint. The explanations below are general and should not be read as descriptions of analyses performed in this study.

What does a mean describe?

For a continuous outcome such as headache hours, a mean is the arithmetic average of the recorded values in the analysis population. It gives a measure of the group's central level, but it can be influenced by unusually high or low observations. The standard deviation describes how widely individual values vary around the mean. It is not a confidence interval and does not directly show how precisely a group mean or a treatment-period change has been estimated. The record does not report either period's mean or standard deviation, so the distributions and their variability cannot be assessed.

Why does the within-participant structure matter?

When the same participants are measured in baseline and treatment periods, the observations are paired: each participant's measurements are related to one another. In general, an analysis of within-participant change uses that pairing rather than treating the periods as independent groups. The appropriate analysis depends on the outcome distribution, the availability of paired observations, and the analysis plan. The registry record does not say whether the same participants contributed measurements in both periods, how incomplete pairs were treated, or what statistical method was used. A comparison of two group means alone would not communicate the within-participant variation that can be important for a paired analysis.

A confidence interval, in general, describes a range of values compatible with the data and the assumptions of the statistical method. Its width reflects uncertainty as well as the amount and variability of information available. It is useful to consider the estimated change and its confidence interval together: the estimate describes the observed direction and magnitude, while the interval indicates precision. No confidence interval or change estimate is reported in the registry record. A p-value, if reported, would address compatibility with a specified null model under stated assumptions; it would not give the probability that the treatment works, nor would it measure clinical importance. No p-value or test is listed.

What can a single-group comparison establish?

In general, a baseline-to-treatment comparison describes change over time among observed participants. Because there is no randomized control group in the recorded design, it cannot distinguish treatment-related change from all other explanations for a temporal difference. Examples include natural fluctuation, changes in medication use, study participation effects, and other time-varying influences. These are general design considerations, not claims about what occurred in this study. The record does not report whether such factors were measured or incorporated into an analysis.

Allocation is listed as NA, masking as none, and the model as single group. This means a randomized between-group treatment contrast is not described in the registry record. The baseline period may still provide a useful personal reference, but it does not reproduce the protection against confounding that random allocation to a concurrent control can offer. Lack of masking can also matter in general when outcomes or their recording may be influenced by expectations. The record does not explain how headache hours were recorded or whether outcome assessment was masked.

Why do analysis populations and missing measurements matter?

In general, an analysis population defines which participants and observations contribute to a result. A study may have an enrollment count that differs from the number with complete outcome data. Missingness can affect an estimate if the probability of missing data is related to the outcome or participant characteristics. Methods for handling missing data rely on assumptions, and different assumptions can lead to different estimates. The registry record does not report an analysis population, the completeness of headache-hour records, reasons for missingness, or a missing-data method. Therefore, the enrolled count cannot be treated as the number analyzed.

The endpoint covers repeated daily experience over 28-day periods, but the registry description does not state whether hours were recorded daily, collected retrospectively, or derived in another way. In general, measurement frequency and recall can affect data quality and the interpretation of an average across a period. The registry record also does not specify the rules for defining a headache hour, handling days without a diary entry, or aggregating participant-level measurements. These details would help assess reproducibility and possible measurement error.

How should planning illustrations be understood?

General sample-size illustrations can show how a hypothetical study's required size changes under assumed design choices and effect sizes. The registry record describes a planning illustration based on the observed effect, with 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. It also specifies that time-to-event illustrations count total events, while other illustrations count participants per arm. Such assumptions are planning inputs, not evidence that the trial used that design. In particular, this study is recorded as single group, so an equal-allocation, two-arm illustration should not be mistaken for its actual allocation or analysis. The record does not report a sample-size justification for the trial, and no planning output is reported in the registry record. Planning values are not observed power and cannot replace outcome estimates or confidence intervals.

Finally, methods should be interpreted as a coherent plan rather than selected after seeing results. The registry record does not report a statistical analysis plan, test selection, covariate adjustment, or sensitivity analyses. It is therefore not possible to judge whether the analysis was prespecified, whether assumptions were checked, or whether alternative methods gave similar conclusions. These absences describe reporting limitations; they do not establish that a particular analysis was or was not performed outside the record.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists two outcome measures: the primary measure of headache hours and the secondary measure of acute headache medication doses. It reports zero analysis entries. Neither outcome has a numerical estimate or statistical test in the record, so there is no reported result on which to assess statistical significance or consistency across outcomes.

Multiplicity is a general statistical issue that arises when several hypotheses or outcomes are examined. If each is tested separately, the chance of at least one apparently unusual result can increase. A prespecified hierarchy, adjustment procedure, or clear distinction between confirmatory and exploratory outcomes can help readers interpret multiple analyses. The registry record does not report a multiplicity strategy, whether the secondary outcome was intended to be confirmatory, or whether any additional analyses were conducted. No adjustment should be assumed.

Missing data also affect interpretation. The record gives enrollment as 27 but does not state how many participants had outcome data in baseline, treatment, or both periods. It does not report missingness, reasons for incomplete measurement, exclusions, or an imputation or sensitivity-analysis method. General statistical practice distinguishes the number enrolled from the analysis population and assesses whether missing observations could influence the estimated effect. Here, that assessment cannot be made from the registry record.

The registry record also does not report a statistical analysis plan or define an analysis population. It is not possible to establish which participants were included, how protocol deviations were handled, or whether the analysis followed a prespecified approach. These are reporting gaps, not proof that no analyses were conducted. They mean that the endpoint definitions are available, but the process connecting collected observations to an estimate is not documented in this record.

11. 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 5% reporting threshold.

Most frequent non-serious adverse event terms

The safety listing for DFN-11 records 0 participants affected by serious adverse events among 10 at risk. It separately records 5 participants affected by other adverse events among 10 at risk, and 0 deaths. The registry record lists no serious adverse-event terms. These are the recorded counts; they should not be converted into percentages or treated as a complete account of every possible safety outcome.

In general, serious adverse events and other adverse events are distinct reporting categories. A count of participants affected is not necessarily the same as a count of event episodes, because a participant may experience more than one event. The registry record does not define the event collection period, provide event-level descriptions for the other adverse events, or explain how events were classified. It also does not report severity, relationship to DFN-11, timing, or discontinuations due to adverse events.

The at-risk counts are listed as 10 for each category, while enrollment is recorded as 27. The record does not explain the difference, so the safety denominator should not be assumed to represent every enrolled participant. The absence of listed serious events in this record does not establish that serious risks are absent, and the counts cannot be compared with another treatment because no control arm is described. They are a limited registry safety summary, not a comparative estimate.

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

The record establishes that a Phase 2 pilot study of DFN-11 Injection for medication overuse headache was conducted as a single-group study and is listed as terminated. It defines a primary endpoint based on headache hours over baseline and treatment periods, and a secondary endpoint based on acute headache medication doses. It also records a small set of safety counts. These registry entries describe the study and the information entered in the registry.

The record does not report the primary endpoint's baseline or treatment mean, an estimated change, or an uncertainty interval. It therefore does not show whether headache hours increased, decreased, or stayed similar in the participants with observations. The same limitation applies to acute headache medication doses: the outcome is named, but no result is provided in the registry record. No conclusion about effect size or precision can be drawn from endpoint titles, enrollment, or study status.

Even if a within-participant difference were available, the design would make causal interpretation limited. A baseline period is not a randomized control group. Changes over time can have multiple explanations, and the record does not report a design feature that separates those explanations from the effect of DFN-11. The lack of masking is also relevant in general when participants know which treatment period they are in, although the record does not document how this influenced measurement or reporting.

The safety counts show what is entered for the listed categories and at-risk groups. They do not supply detailed event descriptions or a comparison with another intervention. Zero recorded deaths and zero participants affected by serious adverse events in the listed group should not be interpreted as proof of no risk, particularly when the record does not explain the at-risk population or the duration and completeness of safety collection.

The appropriate reading is consequently bounded: the registry provides design and outcome definitions, but not an analyzed estimate of the primary or secondary outcome. Absence of a result in the record is not evidence of no change. Likewise, a study marked terminated does not, on its own, identify why it stopped or what effect that had on data collection. Further interpretation would require outcome analyses and additional study conduct details that are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of the distinction between an outcome definition and an outcome result. The registry record specifies headache hours, the mean, standard deviation, and baseline and treatment observation periods. Those details identify what the study intended to measure. Without estimates and measures of uncertainty, however, readers cannot assess the observed change, its variability, or its precision. Clear endpoint definitions are useful, but they are not a substitute for reporting analyzed results.

The single-group design also illustrates why a before-and-after comparison has a different interpretation from a randomized comparison. Repeated observations from the same participants can provide a meaningful description of change within those participants. They do not automatically establish that an intervention caused the change. Time, expectations, changes in usual medication, and natural variation are general considerations when interpreting differences across periods; the record does not report how they were addressed.

Another statistical issue is the distinction between enrollment and analysis. The record reports enrollment of 27, while the safety categories list 10 at risk. It does not explain which participants contributed outcome data or how the groups of observations were formed. This makes denominator transparency important: readers need to know who was assessed, who contributed data, and how incomplete records were handled before drawing conclusions from an estimate.

Finally, a terminated study with outcome definitions but no analysis entries highlights the limits of registry summaries for evaluating statistical evidence. The record does not report why the study was terminated, whether data collection was complete, or whether a planned analysis was carried out. The statistical lesson is not that the intervention had a particular effect, but that interpretation depends on transparent reporting of estimates, uncertainty, analysis populations, and methods alongside the design.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

Several limitations specific to this record constrain interpretation. The registry describes the study as single group, with allocation recorded as NA and masking as none. There is no randomized comparator arm in the listed design. The baseline period offers a reference for the treatment period but cannot control for all changes over time. The record does not describe procedures to reduce or assess the influence of time trends, participant expectations, or changes in other care.

The primary endpoint is named as headache hours, but its operational definition and collection method are not reported. The record does not explain how headache hours were recorded, how missing days were handled, or how participant-level data were aggregated. It identifies the mean and standard deviation but gives no outcome values or analysis. The secondary endpoint likewise has no reported result. The registry's zero analysis entries leave the study's outcome findings unavailable in this record.

Enrollment is recorded as 27, but the registry does not report an analysis population or outcome-specific denominators. The safety listing gives 10 at risk in each adverse-event category, and the reason for that count relative to enrollment is not reported. The record also does not describe completeness of follow-up or missing-data handling. As a result, the extent to which the reported safety counts or any unreported endpoint data represent enrolled participants cannot be assessed.

The record lists the study as terminated, but does not report the reason. It also does not report a sample-size justification, detailed analysis plan, multiplicity approach, or methods for handling missing data. These gaps limit assessment of whether the study met its intended objectives and how analyses were selected or interpreted. The registry record alone does not establish that these details were absent from all study materials; it establishes only that they are not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Pilot Study of DFN-11 Injection in Medication Overuse Headache — NCT02583425.
• Registry record last updated 2018-04-03; status last verified 2018-02.
• Results first posted 2018-04-03.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT02583425 is a Phase 2 pilot study of DFN-11 Injection for medication overuse headache. The registry describes a single-group design, allocation as NA, no masking, enrollment of 27, and status as terminated. The recorded start is 2015-09, and primary completion is 2016-08. The reason for termination is not reported in the registry record.

The primary endpoint is mean headache hours, with standard deviation, during a 28-day baseline period and a 28-day treatment period; the listed total timeframe is 56 days. The secondary outcome concerns acute headache medication doses in those periods. The registry record lists two outcome measures and zero analysis entries, with no numerical outcome estimates reported.

For DFN-11, the safety listing records 0 affected by serious adverse events among 10 at risk, 5 affected by other adverse events among 10 at risk, and 0 deaths. No serious-event terms are listed. The design and definitions are documented, but outcome effects, uncertainty, analysis populations, missing-data procedures, and the reason for termination are not reported in the registry record.