Educational Intervention in Increasing Knowledge About Prostate Cancer in High-Risk Neighborhoods: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Educational Intervention in Increasing Knowledge About Prostate Cancer in High-Risk Neighborhoods (NCT03197896), a non-randomized na study. The primary outcome is Change in Prostate Cancer Knowledge as Measured by the Decisional Conflict Scale.

2. Clinical Question

The trial asks whether an educational session focused on prostate cancer information is associated with a change in decision-related scores, compared with a session on general health information, in high-risk neighborhoods. The primary outcome is titled as a change in prostate cancer knowledge measured by the Decisional Conflict Scale (DCS), with assessment at 4 months. The registry record does not report the primary outcome results, so it cannot establish what change occurred or whether the groups differed.

3. Trial Design

The registry describes a completed, parallel-group study with nonrandomized allocation and no masking. The recorded enrollment is 239. The two named groups received different educational content: prostate cancer information in Group I and general health information in Group II. The record identifies the study as an educational intervention and lists the sponsor as Sidney Kimmel Comprehensive Cancer Center at Thomas Jefferson University.

The study began on 2016-09-29, and primary completion is recorded as 2018-07-20. Its status is completed. The registry lists phase as NA. These administrative details establish the study's recorded timing and status, but they do not supply outcome findings.

Nonrandomized allocation matters when interpreting a comparison. Assignment may be related to participant characteristics, setting, or other factors that also influence decision-related scores. The registry record does not report how allocation occurred, whether groups were comparable at baseline, or whether analyses adjusted for differences. Consequently, a difference between groups, if reported elsewhere, could not automatically be attributed to the educational content from this record alone.

The parallel structure means the groups received their respective educational content rather than being described as successive phases of one intervention. However, the registry does not report details such as the number or length of sessions, educator training, intervention fidelity, or whether participants received additional information outside the study. Those details are not reported in the registry record. The record also does not give specific eligibility criteria or enough participant characteristics to assess how closely the enrolled group represents the broader population of high-risk neighborhoods.

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

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 Prostate Cancer Knowledge as Measured by the Decisional Conflict Scale, measured over 4 months.

The primary outcome is titled Change in Prostate Cancer Knowledge as Measured by the Decisional Conflict Scale, with a 4-month timeframe. The DCS is described as a measure of uncertainty in health decision-making. It contains 16 items rated on a 5-point Likert scale; item responses are averaged and multiplied by 25 to produce scores from 0 (no conflict) to 100 (high conflict). Lower scores indicate greater clarity, confidence, and satisfaction with a decision. Higher scores indicate uncertainty, lack of information or support, and low confidence. The self-efficacy subscale concerns confidence in decision-making.

This distinction between the endpoint title and the instrument's stated construct is important. The scale description focuses on decisional conflict, not a direct test of factual prostate cancer knowledge. It can therefore inform readers about uncertainty and confidence around a health decision, but the record does not establish that it directly measures how much factual knowledge participants retained. The registry lists 2 outcome measures, but details of the other measure are not reported in the registry record.

A change measure can be useful when the research question concerns movement from an earlier assessment to a later one. Interpretation requires knowing the starting and ending scores, the direction and size of change, and how missing assessments were handled. Those outcome estimates and details are not reported in the registry record. The endpoint definition alone describes what the scale is intended to measure; it does not show what participants experienced.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins by separating the design, the outcome measure, and the analysis result. The design describes how participants entered groups. The outcome definition describes what was measured and when. The analysis result would quantify the observed scores or changes and their uncertainty. The registry record describes the first two but does not report the primary outcome analysis, so conclusions about results cannot be drawn from the endpoint description alone.

What does nonrandomized allocation imply?

Random allocation is used in trials to make group assignment independent of participants' characteristics on average. This study is recorded as nonrandomized, so that protection against systematic group differences cannot be assumed. General health information and prostate cancer information may have been received by groups that differed in relevant ways before the educational sessions. Such differences could influence later DCS scores even if the educational content had no effect.

This is a general limitation of nonrandomized comparisons, not proof that the groups were different. To assess it, readers would need information about allocation procedures, characteristics measured before the intervention, and the analysis approach. The registry record does not report those details. It also does not state whether adjusted estimates were planned or performed. Without that information, a simple comparison of group outcomes, were one available, would require cautious interpretation.

What does the DCS score represent?

The DCS is described as measuring uncertainty in health decision-making. It has 16 items rated on a 5-point Likert scale, with item responses averaged and multiplied by 25. The resulting scale ranges from 0 (no conflict) to 100 (high conflict). The score direction is meaningful: lower scores indicate greater clarity, confidence, and satisfaction, while higher scores reflect uncertainty, lack of information or support, and low confidence. The description also identifies a self-efficacy subscale that assesses confidence in decision-making.

These features explain how the scale is intended to be read, but they do not show how participants scored. In addition, the primary outcome title links the DCS to prostate cancer knowledge, while the scale description defines decisional conflict. These are related but not interchangeable concepts. Factual knowledge concerns what a participant knows; decisional conflict concerns uncertainty and confidence around a decision. The registry record does not explain how this construct distinction was addressed in the study.

Why do estimates and uncertainty matter?

A group estimate describes the observed score or change for that group. A contrast between groups describes how far apart their outcomes were under a chosen analysis. A confidence interval is a general statistical tool for expressing uncertainty around an estimate: it gives a range of values reasonably compatible with the data and model. A narrow interval indicates greater precision than a wide interval, although interpretation also depends on the study design and the measure. No primary estimates or confidence intervals are reported in the registry record.

A p-value is also a general statistical summary, but it does not describe the size of an effect or its practical importance. It cannot remedy nonrandomized allocation, account for unreported missing outcomes, or establish that a measure captures the intended construct. The registry record lists no analyses, and no p-value for the primary comparison is reported. No result should be inferred from the completed status of the study.

How should the planning illustrations be understood?

The record describes planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The assumed effect to detect is a stated fraction of the observed effect. These are planning calculations, not evidence that the trial had a particular probability of detecting an effect and not observed power. Such illustrations can indicate how a future study's required enrollment might change under different effect assumptions, but they are only as useful as the underlying effect estimate and assumptions.

The registry record does not report the primary outcome estimate on which an observed-effect-based illustration would depend. It also does not report the study's own sample-size justification or statistical plan. The planning assumptions should therefore not be mistaken for a documented protocol decision or an analysis of this study's actual outcomes. Any calculated enrollment requirements in this context are hypothetical planning quantities, not trial findings.

What does the registry's analysis status tell readers?

The registry lists no analyses. This means that the record does not furnish a statistical comparison to interpret. It does not establish whether analyses were performed outside the registry, and no conclusion about unpublished analyses can be drawn. For a registered-result interpretation, the practical consequence is straightforward: the intervention groups' primary outcome results, uncertainty, and analytic details are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 2 outcome measures but does not report the details of the other measure in the information available for interpretation. It also lists no analyses. A multiplicity plan would explain how the study handled the possibility of examining several outcomes or comparisons, which can increase the chance of finding an apparently notable result by chance. Whether an adjustment was planned or used is not reported in the registry record. There is no basis for inferring a particular hierarchy, correction, or selective-reporting strategy.

Missing-data handling is also not described. The record does not report how many participants had a DCS assessment at the relevant time, whether all enrolled participants were included in the analysis, how incomplete questionnaires were scored, or how missing follow-up assessments were handled. These details matter because observed scores may not represent everyone enrolled if availability of an assessment is related to participant characteristics or outcomes. This is a general concern; the record does not establish that such a pattern occurred.

The analysis population is not reported in the registry record. Enrollment of 239 identifies the recorded study enrollment, but it does not state how many participants contributed to the primary outcome analysis or which inclusion rules were used. Baseline adjustment, treatment of protocol deviations, and any sensitivity analyses are likewise not reported in the registry record. Without these details and a posted result, readers cannot assess how robust a primary estimate would be to missing information or analytic choices.

The absence of a registered analysis should be distinguished from evidence that no analysis was ever conducted. It means only that the registry record does not supply the analysis needed to assess the outcome. No assumptions should be made about multiplicity or missing-data procedures.

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 safety record lists serious adverse events as 0 affected in Group I and 0 affected in Group II. It also lists other adverse events as 0 affected in each group, and deaths as 0 in each group. The at-risk figures are 121 for Group I and 118 for Group II in both the serious and other adverse-event entries. These are the figures recorded for the safety categories; they should not be treated as outcome denominators for the primary DCS measure.

Zero reported events in these entries means that the registry lists no affected participants for those categories. It does not, by itself, establish that no event of any kind occurred, because the record does not describe event definitions, collection procedures, observation time for safety reporting, or completeness of reporting. The registry also gives no terms for serious adverse events. The safety entries therefore should be read as the posted counts, not as a complete characterization of all possible risks.

These safety counts do not answer the primary question about decisional conflict or knowledge. They also do not establish a comparative safety effect. In a nonrandomized study, differences between groups would require cautious interpretation, and the record does not report such a comparison.

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

The registry record is useful for understanding the educational comparison the study was designed to examine. One group received general prostate information, while the other received information about health promotion actions. The primary endpoint was scheduled at 4 months and used the DCS, a scale described as measuring uncertainty and confidence in health decision-making. The record identifies a completed study and reports its enrollment and safety entries.

It does not report the primary endpoint results. Readers therefore cannot tell from this record whether scores changed, which direction any change took, how large it was, or how precisely it was estimated. No statistical comparison is reported. Completion of a study is an administrative status, not evidence that the intervention changed an outcome. Likewise, the absence of a posted result is not evidence of no effect.

The endpoint title refers to prostate cancer knowledge, but the stated instrument measures decisional conflict. A change in that score would concern uncertainty, clarity, confidence, and satisfaction around decision-making as described by the scale. It would not automatically show increased factual knowledge, a change in screening behavior, or an effect on health outcomes. Those claims would require appropriate measures and results, which are not reported in the registry record.

The nonrandomized allocation further limits what a group comparison could establish. If outcome estimates were available, observed differences could reflect pre-existing group differences as well as educational content. The registry does not report allocation procedures, baseline comparability, or adjusted analyses. It therefore does not support a causal conclusion about the effect of the educational content.

The study's findings cannot be judged for precision, robustness, or clinical importance without the estimates, uncertainty measures, analysis population, and missing-data information. The statistical meaning of the record is consequently about design and measurement, not evidence for or against an intervention effect. The appropriate conclusion is that this registry entry describes an intended comparison but does not report the outcome findings needed to answer it.

13. Why This Trial Matters Statistically

This trial raises several questions that are important when evaluating educational interventions statistically. The first is whether the measured outcome matches the intended concept. The study title and primary outcome title emphasize prostate cancer knowledge, but the DCS is described as measuring uncertainty in health decision-making. That distinction matters because a result on decisional conflict should not automatically be interpreted as a result on factual knowledge.

The second issue is the comparison structure. The registry records nonrandomized allocation and different educational content across groups. Statistical adjustment can sometimes address measured differences, but it cannot guarantee removal of bias from unmeasured differences. The record does not report allocation procedures, baseline comparisons, or adjusted analyses, so the extent to which group differences could be separated from intervention content cannot be assessed.

The third issue is completeness of results. A completed study with a defined primary endpoint does not by itself provide evidence about the endpoint. Without group estimates and uncertainty, readers cannot evaluate the size, direction, or precision of any change. The registry lists no analyses, making clear that the posted information is insufficient for an outcome-based conclusion.

Finally, the entry illustrates why planning calculations must be kept separate from results. Planning illustrations based on an observed effect are hypothetical design aids, not measures of what the trial found or of its observed power. When the underlying outcome estimate and the study's own statistical plan are not reported, those calculations cannot fill the evidentiary gap. These distinctions help readers avoid confusing study completion, outcome measurement, and demonstrated findings.

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 primary outcome is described as a change in prostate cancer knowledge measured by the DCS, yet the instrument description defines decisional conflict and decision-making confidence. That leaves uncertainty about how directly the chosen primary measure represents the knowledge concept emphasized in the outcome title. The record does not explain this relationship or identify a scoring interpretation that resolves it.

Although the study is described as taking place in high-risk neighborhoods, specific eligibility criteria and participant characteristics are not reported in the registry record. The reader therefore cannot assess which people were represented or how broadly findings might apply. The registry also does not describe how participants entered the nonrandomized groups, making potential selection differences difficult to evaluate.

Intervention delivery is described at a broad level: an educator reviewed general prostate information or health promotion actions. Session length, educational materials, educator preparation, adherence, and fidelity are not reported in the registry record. Without such information, the content and consistency of what participants received cannot be evaluated in detail.

Most importantly, the primary outcome results and analyses are not reported. Group scores, change estimates, uncertainty, analysis populations, and missing-data procedures are unavailable. The record also does not report a multiplicity plan or the study's own sample-size justification. These gaps prevent assessment of the results' magnitude, precision, and robustness, and they preclude an outcome-based conclusion from the registry entry alone.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Educational Intervention in Increasing Knowledge About Prostate Cancer in High-Risk Neighborhoods — NCT03197896.
• Registry record last updated 2026-03-25; status last verified 2026-03.
• Results first posted 2026-03-25.
• 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

This completed, parallel-group study is recorded as nonrandomized and unmasked. It enrolled 239 participants and compared an educational group receiving prostate cancer information with a group receiving general health information. The primary outcome was a change in prostate cancer knowledge measured by the Decisional Conflict Scale at 4 months. The scale description concerns uncertainty in health decision-making and gives a score range from 0 to 100.

The registry record does not report the primary outcome results or analyses. It lists no analyses, and details of the analysis population, missing-data handling, and multiplicity plan are not reported in the registry record. Safety entries list 0 serious adverse events, 0 other adverse events, and 0 deaths in each group. These entries do not replace outcome findings or establish the absence of all possible events.

The study began on 2016-09-29, with primary completion recorded as 2018-07-20. Its sponsor is Sidney Kimmel Comprehensive Cancer Center at Thomas Jefferson University. The entry describes the intended comparison and measurement approach, but it does not provide evidence from which to estimate the intervention's outcome effect.