An Accessible Digital Intervention to Promote HIV Testing/Counseling and Prevention Among Adolescents: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for An Accessible Digital Intervention to Promote HIV Testing/Counseling and Prevention Among Adolescents (NCT03713034), a randomized na study. The primary outcome is Attitudes Around HIV Testing and Counseling.

2. Clinical Question

3. Trial Design

The record describes a randomized, double-blind, parallel-group trial comparing PlayTest! with control games. The enrollment field reports 296. The record status is completed, with a start date of 2018-11-01 and a primary completion date of 2020-10-01. These record details describe the trial’s registration; they do not by themselves provide outcome results or explain how each design feature was implemented.

The brief summary calls this Phase II of a study previously registered as NCT02812329. It says the study focused on adapting and expanding the reach of an earlier-developed HIV-prevention video game, including web access and distribution, and evaluating it in a randomized controlled trial. The phase field itself is listed as NA. The two intervention descriptions identify the active game as PlayTest! and the comparison as control games.

The primary outcome is a continuous mean score for attitudes around HIV testing and counseling, assessed at baseline, 4 weeks, 3 months, and 6 months. The outcome description says only participants who completed the study were analyzed for this measure. The registry record does not report how many participants completed the study, how randomization was generated or concealed, how masking was maintained, or which statistical model was used. The record lists secondary outcomes concerning intentions to get tested, students tested over Month 1 through Month 6, and knowledge about HTC. It does not report numerical results for the primary outcome or those secondary outcomes.

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: Only participants that completed the study were analyzed in 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 Attitudes Around HIV Testing and Counseling, measured over Baseline, 4 weeks, 3 months and 6 months.

The primary endpoint measures attitudes around HIV testing and counseling (HTC). Participants responded to seven items, including whether they felt it was important for them to get tested for HIV. Each item used a 5-point response scale from -2 (strongly disagree) to +2 (strongly agree). Positive values indicate healthier attitudes toward HTC. A “not sure” response was assigned a neutral score of 0, and a few items were reverse coded because lower values indicated healthier attitudes. The seven item scores were averaged for each participant, with higher mean scores representing more positive attitudes.

A score built from several attitude items can provide a summary of a participant’s responses rather than treating each item as a separate primary measure. Repeating the assessment at baseline, 4 weeks, 3 months, and 6 months allows the endpoint to be considered across the listed follow-up times. The registry record does not report the observed means, variability, group comparisons, or a primary time-point contrast. It therefore defines what the measure was intended to capture, but not what the trial found about changes or differences in attitudes.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies a continuous primary outcome summarized as a mean and standard deviation. It describes an individual score formed by averaging seven responses about attitudes around HIV testing and counseling. The score ranges from -2 to +2 by item, and higher mean scores are defined as more positive attitudes. Although these definitions make the scale’s direction and construction clear, the record does not report the observed means or standard deviations at any assessment time.

What does a mean score represent?

As a general statistical concept, a mean represents the arithmetic average of measured values in a group. It can summarize the typical score, while the standard deviation describes how spread out individual scores are around that group mean. A mean alone does not show the full distribution: groups with the same mean can have different variability. For this endpoint, the mean is an average across the seven attitude items for each participant; group-level summaries would then describe those participant scores. The registry record specifies this construction but supplies no group-level summaries.

How should the scoring details be read?

The item response scale runs from -2 (strongly disagree) to +2 (strongly agree). Positive values are identified as healthier attitudes, and “not sure” is coded as 0. A few items are reverse coded because a lower response value indicates a healthier attitude on those items. Reverse coding is a general scoring approach that aligns item directions before combining them, so that the overall score has a consistent interpretation. The record does not identify which items were reverse coded or provide the item-level data, and those details should not be inferred.

What do the repeated assessments allow?

The endpoint is scheduled at baseline, 4 weeks, 3 months, and 6 months. In general, repeated measurements can describe how an outcome varies over time and whether patterns differ between groups. Statistical methods for repeated measurements may account for the fact that observations from the same participant are related. The registry record does not identify whether a repeated-measures model, separate time-specific comparisons, or another approach was used. It also does not report a primary contrast, a model specification, covariate adjustment, or assumptions used for analysis. The times listed in the outcome definition are not sufficient to determine the statistical method.

What does randomization contribute?

In general, random allocation is intended to make comparison groups similar on average with respect to both measured and unmeasured baseline factors. A randomized design can support a causal comparison when the allocation process is implemented as intended and the analysis appropriately addresses outcomes and missing data. The registry labels allocation as randomized, masking as double, and the model as parallel. It does not describe the allocation sequence, concealment procedures, who was masked, or how departures from assigned intervention were handled. These omissions prevent a fuller assessment of how the design was carried out.

How should confidence intervals and significance tests be understood?

In general, a confidence interval communicates uncertainty around an estimated effect under a specified statistical method. A wider interval indicates less precision than a narrower interval, though interpretation also depends on the estimate and the question being asked. A significance test addresses compatibility of the data with a null hypothesis under its assumptions; it does not measure the size or practical importance of an effect. No confidence interval, test statistic, or p-value for the primary endpoint is reported in the registry record, so none can be interpreted for this comparison.

What can be concluded about planning calculations?

The record describes sample-size planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect, and that non-time-to-event illustrations refer to participants per arm. These are planning illustrations, not the trial’s original design justification and not observed power. Numerical planning outputs are not reported in the registry record for this record, and the actual primary-effect estimate needed to judge such illustrations is also absent. The registry record does not report a sample-size justification for the trial, so the planning assumptions should not be mistaken for its prespecified statistical plan.

10. Multiplicity, Missing Data and Analysis Populations

The record lists 20 outcome measures, including the primary attitude measure and secondary outcomes concerning intentions to get tested, testing counts over Month 1 through Month 6, and knowledge about HTC. Considering multiple outcomes and repeated assessment times creates a general multiplicity issue: the more comparisons examined, the greater the chance of observing an apparently notable result by chance if no adjustment or prespecified strategy is used. The registry record does not report a multiplicity adjustment, a hierarchy of outcomes, or which contrasts were prespecified. It also records zero analysis entries, so no analysis strategy for these comparisons is available in the record.

Missing-data handling is also not reported in the registry record. The primary-outcome description says only participants who completed the study were analyzed. It does not state how completion was defined, how many participants contributed scores at each time, why any observations were missing, or whether any method was used to account for missing outcomes. A completer-only analysis can differ from an analysis that includes participants with incomplete follow-up, particularly if completion is related to outcomes or group assignment. That is a general concern, not evidence that such a bias occurred in this trial.

The analysis population is not otherwise described in detail. The record does not say whether the primary analysis followed randomized assignment regardless of gameplay or used another population definition. Without these details and the missing-data procedures, the population represented by any estimated effect cannot be fully assessed from the registry 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 0% reporting threshold.

The registry lists serious adverse events and other adverse events separately for the two groups. For the PlayTest! Game group, the number at risk is 145 for each category, with 0 serious adverse events, 0 other adverse events, and 0 deaths recorded. For Control Games, the number at risk is 142 for each category, with 0 serious adverse events, 0 other adverse events, and 0 deaths recorded. No top serious-event terms are listed.

These are the adverse-event figures reported in the registry; they do not establish that no events occurred outside the registry’s reporting scope or observation process. The record does not provide event definitions, the method of collection, follow-up completeness for safety, or a detailed account of the population included in these counts. Zero recorded events should therefore be read as a registry count, not as proof that an intervention has no safety risks. The figures also do not provide a statistical comparison or quantify uncertainty around the event rates.

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

The record establishes that a randomized, double-blind, parallel-group study compared PlayTest! with control games and defined attitudes around HIV testing and counseling as its primary outcome. It explains how the seven-item score was constructed, the direction of the score, and the assessment times. This information helps readers understand what the study intended to measure.

However, the registry record does not report the primary outcome values or a comparison between groups. It therefore cannot establish whether attitudes differed, how large any difference was, whether it persisted across the listed assessment times, or how precisely it was estimated. The same limitation applies to the listed secondary outcomes: their names are recorded, but numerical findings are not reported in the record details.

The record’s completed status does not answer the outcome question. Nor does the enrollment field by itself show how many participants contributed data to a particular analysis. The primary endpoint description specifies a completer-only analysis, but the number of completers and the handling of incomplete observations are not reported in the registry record.

In general, trial findings depend on more than the design label or a measure’s definition. They also require outcome estimates, uncertainty, and enough methodological detail to understand the analysis population and assumptions. Those elements are not available for the primary comparison in this record. Accordingly, the registry information supports describing the study’s design and measurement approach, but not a conclusion about the comparative effect of the games on the primary endpoint.

13. Why This Trial Matters Statistically

This trial is statistically notable for combining a randomized comparison with a continuous, multi-item attitude score assessed at several times. The record gives a reasonably explicit account of how the score was constructed: seven items were averaged, “not sure” was neutral, some items were reverse coded, and higher scores represented more positive attitudes toward HTC. These details matter because the meaning of an estimate depends on what the scale measures and which direction represents a more favorable score.

The time points also make the analysis question important. Baseline, 4 weeks, 3 months, and 6 months could support different summaries, such as a comparison at one time or a comparison of patterns over time. Those questions are not interchangeable. The registry record does not report which contrast was the primary statistical target or how repeated measurements were analyzed, so readers cannot determine the intended inferential focus.

The record also illustrates why a completed trial registration is not equivalent to a complete results account. It identifies the randomized design, intervention groups, outcome measures, and adverse-event counts, but provides no numerical primary-outcome comparison. For statistical interpretation, estimates and their uncertainty are essential; an endpoint definition alone cannot show the magnitude or precision of a finding. The gap between a clearly described measure and absent comparative results limits what can be learned from this record about the trial’s outcome.

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 trial-specific limitations of interpretation follow from what the registry record does and does not report. The primary endpoint is restricted to participants who completed the study, but the record does not state how many contributed data or how completion was defined. It also does not describe missing-data handling, reasons for incomplete follow-up, or the analysis population beyond the completer statement. These omissions limit assessment of how representative the analyzed scores may be.

The outcome is assessed at baseline, 4 weeks, 3 months, and 6 months, but the record does not state which time-point comparison was primary or how scores across time were modeled. It does not identify the statistical test or model, covariate adjustments, or a method for accounting for multiple outcome measures and assessment times. Thus, the analysis strategy cannot be reconstructed from the registry description.

The record labels the study double-blind but does not specify which individuals were masked or how masking was maintained, particularly in a comparison of different games. The randomization procedures and allocation concealment are also not reported. The active-game description ends before fully detailing the skills it aims to empower, so its complete intervention content is not described in the available record. Finally, no numerical outcome estimates or uncertainty measures are reported for the primary comparison. These gaps prevent an assessment of effect size, precision, or the robustness of the findings.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: An Accessible Digital Intervention to Promote HIV Testing/Counseling and Prevention Among Adolescents — NCT03713034.
• Registry record last updated 2024-02-15; status last verified 2024-02.
• Results first posted 2022-01-18.
• 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

NCT03713034 is a completed randomized, double-blind, parallel-group study of PlayTest! versus control games. The record reports enrollment of 296 and describes the study as Phase II in its brief summary, while its phase field is NA. The primary outcome is a seven-item mean score measuring attitudes around HIV testing and counseling, assessed at baseline, 4 weeks, 3 months, and 6 months. Higher values indicate more positive attitudes. The primary-outcome description says only participants who completed the study were analyzed.

The registry lists secondary outcomes related to testing intentions, numbers of students tested over Month 1 through Month 6, and knowledge about HTC. It reports zero recorded serious adverse events, other adverse events, and deaths in both groups. Primary and secondary comparative outcome values, analysis methods, missing-data procedures, and multiplicity handling are not reported in the registry record.