Preventing Sexual Violence Through a Comprehensive, Peer-led Initiative: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Preventing Sexual Violence Through a Comprehensive, Peer-led Initiative (NCT03207386), a na na study. The primary outcome is Number of Participants Reporting Any Form of Sexual Violence Perpetration.

2. Clinical Question

3. Trial Design

The registry describes a completed behavioral study of Youth VIP, a youth-led prevention initiative implemented with middle and high school students in Rapid City, South Dakota. The study is characterized as a multiple baseline study. Its allocation is listed as NA, masking as NONE, and model as SEQUENTIAL. These registry labels do not provide enough detail to reconstruct the sequence of implementation or the analysis design.

The planned program began with a youth summit at which consenting students would be trained as popular opinion leaders. Youth and adult mentors were then to participate in working groups addressing prevention strategies, including bystander intervention, social marketing messaging, parent education, norms change, and social emotional learning. The registry also describes collaboration with a Research Programming Advisory Board made up of community members and professionals from Rapid City.

The study summary describes six surveys across three years, including several before programming and others after prevention programming took place. Survey data from a demographically similar community were intended to help assess changes over time among youth in Rapid City. The record does not state the timing of each survey, the community’s sample size, or how the comparison data were analyzed.

Enrollment is listed as 2647. Participants could be in both the large camp condition and the small camp condition, so counts across results reports may not align with that enrollment. The registry lists the study as completed, with a start date of 2017-02-27 and a primary completion date of 2020-07-01. Randomization, a formal control-arm structure, and detailed implementation and analysis procedures 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

Analysis population for the primary outcome, as defined in the registry: Participants could be in both the large camp condition and/or the small camp condition, thus numbers do not consistently add up to 2647 across the results reports for the study.

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 Number of Participants Reporting Any Form of Sexual Violence Perpetration, measured over 6 months.

The primary outcome is titled “Number of Participants Reporting Any Form of Sexual Violence Perpetration.” It is a count of participants who reported at least one of the assessed perpetration experiences during the past 6 months. The response options for the underlying measures were yes or no, and the outcome counts participants who answered yes to any form of sexual violence perpetration. The registry gives the unit as participants and the timeframe as 6 months.

The outcome draws on several measures intended to cover a range of interpersonal violence experiences. The description includes items concerning sexual coercion, physically forced sex, incapacitated sex, sexual and dating violence, bullying, homophobic teasing, sexual harassment, sexual rumors, and racial bullying. Mirror items were used to assess victimization and perpetration experiences. The registry does not state how responses to different items were combined beyond counting participants reporting any form of perpetration.

A participant count is used to express how many participants reported at least one qualifying experience, rather than the total number of experiences. This distinction matters because a participant with multiple affirmative responses still contributes to the participant count as someone reporting any form. The record does not report the primary outcome’s observed counts, estimates of change, or uncertainty intervals. A secondary outcome is the number of participants reporting any form of sexual violence victimization.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods explain how data are converted into estimates and how much uncertainty surrounds those estimates. In this record, the stated endpoint is a participant count: the number reporting any qualifying form of sexual violence perpetration during the past 6 months. The registry lists zero analyses, so the analysis method used for that endpoint and the resulting estimate are not reported in the registry record.

What does the endpoint count?

The survey items are described as yes-or-no measures. The outcome counts participants reporting yes to any form of perpetration, rather than counting each affirmative item or each event separately. This kind of outcome reduces a collection of experiences to a participant-level indicator: whether a person reported at least one qualifying experience during the stated recall period. It can be straightforward to describe, but it does not convey the number, frequency, or severity of experiences. Those details are not reported in the registry record.

The measure description names multiple content areas and says that mirror items assessed victimization and perpetration. It also identifies sources for some item groups. The record does not report item-level scoring rules, treatment of contradictory responses, or whether and how a response to one item was combined with another when responses were missing. These details affect how the participant count should be interpreted and cannot be filled in from the endpoint title alone.

How should change over time be understood?

The study summary describes several surveys before programming and further surveys after programming, across three years. Repeated measurements can describe how outcomes change over time. A multiple baseline design may use differences in the timing of implementation to help distinguish program-associated patterns from broader time trends. That is a general description of the design concept, not confirmation of the precise analytic procedure used in this study. The registry record does not report implementation sequences, model specifications, adjustment variables, or estimates from a time-based analysis.

Survey data from a demographically similar community were intended to provide a comparison for changes among Rapid City youth. In general, an external community comparison can help contextualize whether a trend is also seen outside the program community. Its usefulness depends on how comparable the communities and measurements are, and on how the comparison is incorporated statistically. The registry does not report the comparison community’s sample size, its specific selection process, or the analysis results.

What do uncertainty measures tell readers?

In general, a confidence interval gives a range of values compatible with the data and the statistical method, expressing the precision of an estimate. A narrow interval indicates greater precision than a wide interval, while neither interval width nor a test result establishes that a finding is clinically or socially important. No confidence interval or other uncertainty measure for the primary outcome is reported in the registry record. No p-value or estimated effect is reported either, so there is no statistical result to evaluate for precision or compatibility with no change.

For counts or binary outcomes, analysts may use methods suited to the form of the data and to repeated observations or clustering. The appropriate method depends on features such as how observations are linked across surveys, whether participants are grouped within schools or communities, and whether the outcome is modeled as a count or as a participant-level yes-or-no response. These are general considerations. The registry record does not identify the model, variance assumptions, or adjustments used for the primary outcome analysis.

What does the planning illustration represent?

Any sample-size values associated with the record are planning illustrations based on an observed effect, not observed power and not evidence that the study was designed with those values as its target. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. For non-time-to-event outcomes, such illustrations refer to participants per arm. The registry record does not report the trial’s own sample-size justification, so the illustration should not be interpreted as the original design rationale or as proof that the study could detect a particular effect.

Because the record reports no analyses, the observed effect used for a planning illustration and the underlying analysis cannot be evaluated from the registry entry. In general, planning calculations depend on assumptions about the target effect, variability, allocation, and analysis. Their outputs are prospective planning aids, not summaries of what happened in the study.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Attended Large Camp", "Did Not Attend Large Camp", "Attended Small Camp", "Did Not Attend Small Camp")
n      <- c(104, 2434, 81, 2457)
events <- c(5, 54, 2, 57)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Attended Large Camp  104  5  4.8  1.6  10.9  2.1  10.8  2.1  10.8
ARM  Did Not Attend Large Camp  2434  54  2.2  1.7  2.9  1.7  2.9  1.7  2.9
ARM  Attended Small Camp  81  2  2.5  0.3  8.6  0.7  8.6  0.8  8.5
ARM  Did Not Attend Small Camp  2457  57  2.3  1.8  3.0  1.8  3.0  1.8  3.0

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures: the primary measure of participants reporting any form of sexual violence perpetration and a secondary measure of participants reporting any form of sexual violence victimization. It does not report a multiplicity plan describing how inference across outcomes or repeated survey occasions was handled. In general, testing multiple outcomes or time points can increase the chance of at least one apparently notable result by chance. Prespecifying outcomes and a testing strategy can help readers understand which findings are confirmatory and how results should be interpreted. The registry record does not report such a strategy.

Missing-data procedures are also not reported in the registry record. The study summary describes repeated surveys, but does not state how many participants completed each survey, whether participants missed particular assessments, or how incomplete item responses were treated. In general, missing responses can affect estimates when people with missing data differ from those with observed data. Analysts may use different approaches depending on why data are missing and on the analysis design; no specific approach can be attributed to this study from the record.

The record does not describe analysis populations, such as whether analyses included all enrolled participants, only participants completing particular surveys, or another defined group. It also does not explain how overlap between large camp and small camp participation was handled in analyses. Because participants could be in both conditions, participant counts across results reports may not consistently sum to the enrollment of 2647. Without a reported population definition and analysis, the consequences of overlap for estimates cannot be assessed.

12. 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 0% reporting threshold.

The registry lists the Youth VIP group with 2647 participants at risk for serious adverse events and 0 participants affected. It also lists 2647 at risk for other adverse events and 0 affected, with 0 deaths. No serious adverse event terms are listed. These figures describe the safety information entered in the registry for this group.

Zero reported events should be read as the registry’s recorded count, not as proof that no unwanted experiences occurred or that every possible harm was assessed. The record does not report the definitions used for serious or other adverse events, the method and period of safety monitoring, or whether all participants contributed the same amount of follow-up. It also does not describe how events were solicited or collected.

The safety figures do not provide evidence about the primary outcome, which concerns reports of sexual violence perpetration over the past 6 months. Nor do they provide a comparison with another group, since the record lists one Youth VIP group and does not describe a randomized control comparison. The figures should therefore be interpreted narrowly as registry-reported adverse-event counts.

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

The record establishes that a completed evaluation of Youth VIP was registered, describes the program and its intended population, and identifies a primary participant-count outcome concerning reports of sexual violence perpetration during the past 6 months. It also describes repeated surveys and an intended comparison with survey data from a demographically similar community. These details explain what the evaluation set out to examine.

The record does not provide outcome analyses. It therefore does not establish whether reports of perpetration changed after programming, how large any change was, or how precisely an effect was estimated. No conclusion about the direction or magnitude of an effect can be drawn from the endpoint definition, study completion status, or enrollment figure alone. The registry lists a secondary victimization outcome, but does not report results for that measure either.

The design description also limits what can be inferred about cause and effect from this record. The allocation is listed as NA, and the study is not described as a randomized comparison. In general, observed differences over time may be related to a program, but could also reflect other influences. The planned comparison community may help interpret trends, but the record does not give the analytic details or results needed to assess that contribution.

The adverse-event figures record zero serious adverse events, zero other adverse events, and zero deaths in the Youth VIP group. They do not resolve the missing efficacy analysis or establish that all harms were captured. Taken together, the registry record supports a description of the evaluation’s intent and structure, not a claim that Youth VIP did or did not change the measured outcomes.

14. Why This Trial Matters Statistically

This study is statistically notable for its evaluation setting and measurement structure. It concerns a youth-led prevention initiative delivered through youth-adult partnerships and working groups, while its outcome assessment was planned around repeated surveys rather than a single measurement. The study summary describes several surveys before programming and later surveys across three years, with data from a demographically similar community intended to inform assessment of change over time.

Repeated measurement raises important analytic questions. Outcomes observed at multiple times are related to the timing of data collection and may also be related within participants or communities. A multiple baseline design can make timing central to interpretation. As a general matter, readers need to know how implementation timing, repeated observations, community differences, and missing survey responses were handled to evaluate estimates. Those statistical details are not reported in the registry record.

The endpoint also illustrates the difference between counting people and counting events. The primary measure counts participants who reported any form of perpetration, based on yes-or-no items covering several experiences. That can provide a person-level summary, but does not describe the number of experiences or their distribution. Understanding that distinction is important when interpreting what an estimated change would mean.

Finally, the registry record lists two outcome measures but no analyses. This makes the entry useful for understanding the planned question and design labels, while leaving the empirical findings unavailable in the record. Statistical interpretation depends not only on an endpoint and enrollment, but also on reported estimates, uncertainty, and analysis procedures.

15. Limitations

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

The registry record does not report the primary or secondary outcome results, despite listing the study as completed. It also lists zero analyses. Consequently, readers cannot assess the observed change, its precision, or the extent to which the findings support the study’s intended question. The statistical analysis plan, model specifications, adjustment factors, and missing-data approach are not reported in the registry record.

The record describes a multiple baseline study and survey data from a demographically similar community, but does not explain the implementation sequence or the construction and analysis of the comparison. Allocation is listed as NA, and the record does not describe randomized assignment or a like-for-like control comparison. These gaps prevent assessment of how well alternative explanations for changes over time were addressed.

The endpoint description covers a range of experiences, but the record does not report item-level results or detailed scoring and aggregation procedures. It does not state how missing or inconsistent responses were handled. It also does not give survey completion counts over time, making it impossible to assess attrition or the composition of participants contributing to each assessment.

Enrollment is listed as 2647, while participants could be in both the large camp and small camp conditions. The record therefore cautions that counts across results reports may not consistently sum to enrollment. It does not explain how this overlap was treated analytically. The record also does not report details of safety-event definitions or monitoring procedures. These limitations are specific to the information available in the registry record and do not establish that the unreported procedures were absent from the study itself.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Preventing Sexual Violence Through a Comprehensive, Peer-led Initiative — NCT03207386.
• Registry record last updated 2021-11-12; status last verified 2021-11.
• Results first posted 2021-11-03.
• 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.

19. Record Summary

NCT03207386 is a completed behavioral evaluation of Youth Voices in Prevention, a youth-led sexual violence prevention initiative in Rapid City, South Dakota. The registry lists enrollment of 2647, a start date of 2017-02-27, and a primary completion date of 2020-07-01. The design is described as multiple baseline, with allocation listed as NA, masking as NONE, and model as SEQUENTIAL.

The primary outcome is the number of participants reporting any form of sexual violence perpetration during the past 6 months. The secondary outcome concerns participants reporting any form of sexual violence victimization. The study summary describes six surveys across three years and survey data from a demographically similar community to assess changes over time.

The record lists two outcome measures and zero analyses. It does not report outcome estimates or statistical analysis results. It records zero serious adverse events, zero other adverse events, and zero deaths for the Youth VIP group.