Self-Defense Training in Women With Trauma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Self-Defense Training in Women With Trauma (NCT01380379), a na na study. The primary outcome is Change in Self-efficacy From Baseline to Post-treatment.

2. Clinical Question

The study’s stated aim was to examine whether psychological gains associated with self-defense training might also be seen among women with histories of violence. Its primary outcome is change in general self-efficacy. Assertiveness change between baseline and post-intervention is listed as a secondary outcome. Because the study has a single group and no comparator, its central outcome question concerns change over time among participants, not a difference between training and an alternative intervention.

This distinction matters when interpreting the clinical question. A before-and-after change can describe what happened over the study period, but by itself it cannot separate changes related to training from other influences. The registry record does not report outcome estimates, participant-level results, or details of the analysis used to address that issue.

3. Trial Design

This is a completed pilot study, registered as NCT01380379, with the title “Self-Defense Training in Women With Trauma.” The official title is “A Pilot Study of Self-Defense Training in Women With Trauma.” Stanford University is listed as sponsor. The record gives a start date of 2011-04 and a primary completion date of 2013-08. The listed phase is NA.

The design is recorded as single-group, with masking listed as none and allocation listed as NA. One intervention is described: life skills and self-defense training. Its group format is characterized as therapeutic, with education, skills, and empowerment activities. Since there is no comparator arm, the design does not support a direct within-trial comparison between training and an untreated or alternative-treatment group.

Enrollment is listed as 9. That registry figure does not establish how many participants contributed data to the primary outcome analysis; the analysis population and outcome-specific denominators are not reported in the registry record. The adverse-event information separately lists 8 at risk for each of its two event categories, and the reason for that denominator is not reported.

The registry lists two outcome measures and two analyses. The primary outcome concerns change in self-efficacy from baseline to post-treatment, with the timeframe described as change from baseline to 8 weeks. The secondary outcome is change in assertiveness between baseline and post-intervention. The record does not report the statistical model, the analysis population, handling of missing observations, or whether any analysis was adjusted for other variables.

The study’s pilot status and single-group structure should shape the interpretation. The available registry information describes the question and intervention but does not establish a confirmatory testing framework. A planning illustration based on an observed effect is not the same as the study’s design, and its assumptions describe a hypothetical two-arm setting rather than this single-group 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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The data is the change in general self efficacy from baseline to post-class, with higher scores indicating a greater increase in self-efficacy

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 Change in Self-efficacy From Baseline to Post-treatment, measured over Change in GSE from baseline to 8 weeks.

The primary endpoint is change in general self-efficacy from baseline to post-treatment. The outcome description identifies the General Self-Efficacy measure as a measure of perceived self-competence. It is calculated by summing responses across 10 items and has a possible score range of 10-40. Higher scores represent a stronger sense of personal competence. The stated outcome population interprets a higher change score as a greater increase in self-efficacy.

Self-efficacy is relevant to the study’s stated aim because the investigators wanted to examine psychological gains associated with self-defense training among women with prior experiences of physical and/or sexual violence. A measure of perceived competence can describe a participant-reported psychological outcome; it is not itself a direct measure of physical safety or a clinical diagnosis. The registry record does not report the instrument’s administration details, scoring procedures beyond the description above, or evidence about its performance in this study population.

The endpoint is framed as a change from baseline to post-treatment, with the timeframe specified as change from baseline to 8 weeks. Interpreting a change score requires knowing the result and how precisely it was estimated. Neither the observed mean change nor a measure of its uncertainty is reported in the registry record. Consequently, the endpoint’s definition can be described, but the size and precision of the reported change cannot be evaluated from the registry information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The design and available outcome information determine which statistical questions can be answered. Here, the study is recorded as single-group, and the primary outcome is a continuous change score. The registry record does not report the numerical outcome estimate or the analysis method. The explanations below describe general statistical concepts that help interpret this kind of study; they are not claims about analyses conducted in this trial.

What does a change score represent?

A change score describes how a measured outcome differs between a participant’s baseline assessment and a later assessment. For a group, the mean change summarizes the average change among the observations included in the analysis. It is important to know how the score was calculated, which participants contributed data, and whether the estimate has been adjusted for any other factors. The registry record gives the intended timing and describes the outcome, but does not report those analysis details or the resulting mean change.

A change score is not the same as a comparison against a control group. In a controlled study, the contrast between groups can help distinguish changes associated with the intervention from changes that might also occur over time in a comparison group. In a single-group design, the within-group change has no such concurrent reference. It remains useful as a description of change among participants, but causal interpretation is more limited.

How should uncertainty be read?

An estimate gives the observed value for the analysis, while a confidence interval conveys its statistical uncertainty under the model’s assumptions. It is not a guarantee that the true value lies within the interval, and it does not address every source of bias. A p-value addresses compatibility between the data and a specified null model under assumptions; it does not measure the size or practical importance of an effect. These quantities work best alongside the estimate and study design, rather than as stand-alone evidence.

No estimate, confidence interval, or p-value for the primary endpoint is reported in the registry record. The uncertainty of the primary outcome therefore cannot be described numerically. Nor can the record establish whether the study’s analysis met assumptions needed for a particular test, because the test and its diagnostics are not reported.

Why does the single-group structure matter?

Without a concurrent comparator, a before-and-after analysis cannot directly estimate how participants would have changed over the same period without the training. General influences such as the passage of time, other services or experiences, and repeated measurement can contribute to change. These are general considerations for single-group studies, not documented explanations for this trial’s outcomes. The registry record does not report a design or analysis that isolates the intervention’s contribution.

Masking is recorded as none. The record does not say whether outcome assessment was independent or whether participants knew how their responses would be used. In general, awareness of an intervention or study aims can affect self-reported outcomes. This is a possible measurement consideration, not evidence that responses in this study were affected.

What does over-dispersion mean in general?

Over-dispersion occurs when the variability in data is greater than a statistical model expects. If a model assumes less variability than is present, its uncertainty estimates may be too small and its inferential results too optimistic. The relevance of over-dispersion depends on the data type and model. The primary outcome is described as a mean of a continuous measure, and the registry record does not report an analysis that would allow assessment of over-dispersion. It should not be assumed either to be present or absent.

How should the planning illustration be understood?

The registry record describes a planning illustration based on the observed effect. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is described as a stated fraction of the observed effect. For non-time-to-event outcomes, the illustration is expressed as participants per arm for 80% or 90% power. No numerical planning results or fractions are reported in the registry record.

These assumptions describe a hypothetical two-arm planning exercise, not the recorded single-group design. A planning sample size is a prospective illustration of the sample that might be needed under specified assumptions. It is not an observed outcome, does not demonstrate that a trial had adequate power, and is never observed power. Because the numerical illustration and the effect value are not reported in the registry record, their size or sensitivity to assumptions cannot be assessed.

In general, planning calculations depend on the target effect, variability, significance level, allocation, and analysis method. Smaller target effects generally require more information to distinguish from random variation, all else equal. Such general relationships do not reveal what effect this pilot observed or what sample size would be justified for a future study. In particular, an effect estimated imprecisely in a pilot can make a planning illustration unstable. The registry record does not describe the rationale for its planning assumptions.

What can be inferred from the analysis listing?

The registry lists two outcome measures and two analyses, but does not describe the statistical procedures, missing-data methods, or analysis populations. A count of listed analyses does not indicate whether those analyses were adjusted, whether assumptions were checked, or whether all results were reported. The results needed to evaluate those issues are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary self-efficacy outcome and a secondary assertiveness outcome. It also lists two outcome measures and two analyses. Testing or estimating more than one outcome can raise multiplicity questions: when several hypotheses are assessed, the chance of at least one apparently notable result can increase if each is judged independently. General approaches include prespecifying a primary outcome, adjusting inferential thresholds, or treating secondary analyses as exploratory. The registry record does not report whether any multiplicity strategy was used.

The existence of a designated primary outcome helps identify the main question, but it does not establish how the analyses were conducted or interpreted. The record does not give a statistical analysis plan, a family of hypotheses, adjustment procedures, or the results for either outcome. It is therefore not possible to determine whether multiplicity was addressed or how it should affect interpretation of the findings.

Missing-data handling is also not reported in the registry record. Enrollment is listed as 9, while the adverse-event information lists 8 at risk; those figures refer to different record items and do not establish the number analyzed for the primary outcome. The outcome-specific denominator, follow-up completeness, reasons for missing assessments, and any imputation or sensitivity analysis are not reported. Missing outcomes can affect both the estimate and its uncertainty, especially if missingness is related to participants’ outcomes or experiences.

The analysis population is not reported in the registry record. It is not stated whether the primary analysis included all enrolled participants, only those with both assessments, or another defined set. That distinction matters for interpreting a before-and-after estimate and for understanding who the result represents. No claim about the handling of incomplete observations or the analysis population can be made from the available registry entries.

11. 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 record lists the intervention group as “Life Skills and Self-defense Training.” It records 0 serious adverse events among 8 at risk and 1 other adverse event among 8 at risk. These are separate event categories and should be read using their listed denominators. The record does not describe the other adverse event or report its severity, timing, or relationship to the intervention.

The deaths field is null. A null entry means deaths are not reported in that field; it should not be converted into a count of zero. The list of serious adverse-event terms is empty, but that does not provide additional detail about event monitoring or ascertainment. The reason the adverse-event denominators differ from the enrollment figure is not reported in the registry record.

These counts describe the registry’s recorded safety information; they are not comparative rates because the study has no comparator group. They also do not establish that all possible adverse events were captured or that no other events occurred. The record’s stated concern about potential triggering of trauma symptoms gives context for why participant safety and comfort were important to the study, but the available counts alone cannot characterize that experience.

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

The study addresses a question about psychological change following a group intervention among women with histories of physical and/or sexual violence. The registry record specifies self-efficacy as the primary outcome and describes the score’s interpretation. It also identifies assertiveness change as a secondary outcome. These details make the intended questions clear, but they are not outcome findings.

The primary result is not reported in the registry record. There is no numerical change estimate or measure of precision from which to judge the size or uncertainty of the self-efficacy finding. The same limitation applies to the secondary outcome. Accordingly, the record does not establish whether either outcome increased, decreased, or remained similar over the study period.

Even if a numerical before-and-after change were reported, the single-group design would not by itself show that the intervention caused that change. Without a concurrent comparison group, other influences over time cannot be separated from the intervention’s contribution. This limitation concerns causal interpretation; it does not make a within-group description meaningless, but it changes the question that the data can answer.

The study is identified as a pilot, and its registered enrollment is 9. That figure alone does not show the number contributing to outcome analyses or how precisely an effect was estimated. No outcome-specific analysis denominator or uncertainty estimate is reported. The planning illustration described in the record is a hypothetical calculation under two-arm assumptions, not a result from this single-group study and not evidence of observed power.

The appropriate reading is therefore restrained: the registry record documents the study’s aim, design, intervention, outcome definitions, and limited adverse-event counts, but it does not provide results adequate to judge the size or precision of the primary outcome change. It also does not support a causal claim about the training or a broad conclusion about safety.

13. Why This Trial Matters Statistically

This study raises a useful statistical question about how to interpret psychological outcomes in a population for whom the intervention may require particular attention to comfort and trauma symptoms. The stated rationale distinguishes this population from healthy women without previous experiences of physical or sexual violence. The primary endpoint, change in self-efficacy, is a continuous measure intended to describe perceived competence, while assertiveness is listed as a secondary outcome.

Statistically, the study illustrates the difference between a within-group outcome description and a controlled treatment contrast. A single-group design can document change among participants, but it cannot show what would have happened during the same period under a comparator condition. That distinction is important whenever outcomes are measured before and after an intervention, particularly when participants’ experiences outside the study may also change over time.

The record also highlights the importance of complete reporting. An endpoint definition explains what investigators intended to measure, but interpretation requires the estimate, uncertainty, analysis population, and methods for handling missing observations. Without these, readers cannot evaluate precision, assess whether the analyses align with the questions, or judge how much the results might depend on incomplete data.

Finally, the planning illustration described in the record uses two-arm assumptions even though the study itself is single-group. Keeping planning calculations separate from observed trial results prevents a hypothetical future design from being mistaken for evidence generated by this pilot. The record’s missing outcome estimates make that distinction especially important: a planning framework cannot stand in for the observed result.

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 most consequential limitation in the registry record is the absence of reported outcome results. Although the primary endpoint and its timeframe are defined, no mean change, dispersion estimate, confidence interval, or p-value is reported. The record therefore does not permit assessment of the direction, size, or precision of the primary finding. Results for the secondary assertiveness outcome are also not reported.

The single-group design has no concurrent comparator, so a change over time would not isolate the effect of the training. The record also lists no masking. It does not report whether outcome collection was independent or how participants’ awareness of the intervention was handled. These are design and measurement considerations; the registry record does not establish that they caused bias in this study.

Enrollment is listed as 9, but the outcome analysis population and outcome-specific denominators are not reported. Missing-data methods, reasons for incomplete assessments, and sensitivity analyses are likewise not reported in the registry record. These omissions prevent readers from assessing how much the results may depend on who contributed data.

The intervention is described as a therapeutic group covering education, skills, and empowerment activities, but the registry record does not provide further implementation detail. It does not report adherence, variation in participation, or how the intervention was delivered across participants. The adverse-event record is also limited: it lists the event counts and denominators but does not describe the other adverse event, explain the denominator, or report deaths as a numerical count.

Finally, the planning assumptions are described, but numerical planning results and the observed effect used are not reported in the registry record. Those calculations cannot resolve the missing outcome evidence or strengthen causal interpretation of this single-group pilot.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Self-Defense Training in Women With Trauma — NCT01380379.
• Registry record last updated 2017-02-01; status last verified 2016-12.
• Results first posted 2017-02-01.
• 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

NCT01380379 is a completed pilot study sponsored by Stanford University, titled “Self-Defense Training in Women With Trauma.” The official title is “A Pilot Study of Self-Defense Training in Women With Trauma.” The record lists a start date of 2011-04, a primary completion date of 2013-08, enrollment of 9, phase NA, allocation NA, no masking, and a single-group model.

The intervention is life skills and self-defense training in a therapeutic group. The primary outcome is change in general self-efficacy from baseline to post-treatment, with change from baseline to 8 weeks specified as the timeframe. Assertiveness change between baseline and post-intervention is listed as a secondary outcome.

The registry record does not report the numerical primary or secondary outcome results, the analysis population, or missing-data methods. It lists 0 serious adverse events among 8 at risk and 1 other adverse event among 8 at risk; deaths are not reported as a numerical count.