Streamlined Genetic Testing in Prostate Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Streamlined Genetic Testing in Prostate Cancer (NCT04359758), a randomized na study. The primary outcome is Number of Participants Completing Genetic Testing.

2. Clinical Question

In practical terms, the trial asks whether assignment to a streamlined education and testing pathway is associated with a different number of participants completing testing than assignment to a referral for usual genetic counseling. This is a question about completion of testing, not by itself about the genetic findings, participants’ understanding of those findings, or any health outcome. The registry lists Decision Satisfaction, Decisional Regret, and Distress as secondary outcomes.

The brief summary also says that participants would be contacted two months after randomization to complete a follow-up survey. The registry record does not clarify how that survey timing relates to the primary outcome timeframe of Three Months Post-Randomization. The numerical primary-outcome comparison and numerical results for the secondary outcomes are not reported in the registry record, so the direction and size of any difference cannot be described.

3. Trial Design

The registry identifies this as a randomized, parallel-group trial with no masking. Participants were assigned to Proactive Streamlined Genetic Education and Testing or Usual Care. In the streamlined arm, participants could review genetic education print materials and could proceed directly with genetic testing. In the usual-care arm, participants were sent a referral letter recommending a genetic counseling session and providing contact information.

The eligible population was described as prostate cancer survivors who met criteria for genetic counseling referral. The brief summary describes baseline survey completion before randomization. The registry lists enrollment as 112, while the brief summary describes participants as n=120. The record does not reconcile these figures or explain whether they refer to different stages or definitions of enrollment.

The study is marked COMPLETED. Its listed start date is 2020-03-01, and its primary completion date is 2021-10-01. The phase is listed as NA. Georgetown University is identified as the sponsor. These administrative details do not establish how many participants completed each assessment or how the outcomes were analyzed.

The primary outcome is the number of participants completing genetic testing, based on receipt of results as indicated in clinic records. Its stated timeframe is Three Months Post-Randomization, and its population is intent to treat, defined in the record as all participants assigned to the two arms. The brief summary describes a follow-up survey two months after randomization, but the registry does not explain its relationship to the primary outcome timeframe.

The registry lists four outcome measures and six analyses. It does not provide a detailed statistical analysis plan, the allocation sequence method, procedures for concealing assignments, or details about how outcome data were handled. These design and analysis details are not reported in the registry record and should not be inferred from the randomized, parallel, and unmasked labels alone.

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.

Before assignment: Of 216 potentially eligible participants, 112 completed the baseline survey and were randomized. Five participants were found to be ineligible after randomization (i.e., protocol violation). Thus, the final sample was comprised of 107 men who were randomized to ST (n=53) vs UC (n=54).

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent to Treat (all participants assigned to ST or UC).

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 Completing Genetic Testing, measured over Three Months Post-Randomization.

The primary endpoint counts participants who completed genetic testing. The registry defines completion through receipt of genetic testing results, as indicated in clinic records. This is a count of participants meeting the endpoint definition, rather than a measure of the number or type of genetic variants found.

Completion is relevant to the trial’s stated question because the two groups were offered different routes to education and testing. Counting participants who received results can describe whether testing reached completion under each assigned approach. The registry specifies an intent-to-treat population: all participants assigned to either group are included in that population definition, regardless of whether they followed the assigned pathway. How the registry’s analyses implemented that definition, including treatment of participants without an ascertainable outcome, is not reported.

The listed timeframe is Three Months Post-Randomization. The brief summary separately describes contacting participants for a follow-up survey two months after randomization. The registry does not clarify whether that survey posted information for the primary endpoint, whether the timing differed across outcomes, or how the two time descriptions relate.

The numerical count in each group, the between-group effect estimate, and its uncertainty are not reported in the registry record. Therefore, the endpoint definition explains what was intended to be counted, but it does not establish how many participants completed testing or how precisely any difference between assigned groups was estimated.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Randomization is a design method for assigning participants to study groups by chance. In general, it is used to reduce systematic differences between groups at the time of assignment, so that an outcome comparison can be interpreted in relation to the assigned strategies. The registry labels this trial RANDOMIZED and PARALLEL. It does not report the sequence-generation method, allocation concealment procedures, or whether any restrictions were used in assignment.

What does an intent-to-treat population mean?

In general, an intent-to-treat analysis compares participants according to the group to which they were assigned, rather than regrouping them according to what they ultimately did. This preserves the randomized assignment as the basis for comparison and can include participants who did not complete the assigned pathway. The registry defines the primary outcome population as all participants assigned to streamlined testing or usual care. It does not report how missing endpoint information, withdrawals, or protocol deviations were handled in practice.

What does the endpoint count?

The primary endpoint is a count of participants completing genetic testing, operationalized as receipt of genetic testing results in clinic records. A count describes how many participants met the endpoint definition. To compare randomized groups statistically, an analysis would ordinarily need the group-specific counts and the corresponding numbers included in the analysis, along with an effect measure and its uncertainty. Those numerical outcome details are not reported in the registry record. No particular test or model can be inferred from the endpoint type alone.

How should uncertainty be understood?

In general, a confidence interval expresses the range of effect values compatible with the observed data under a specified statistical method. Its width conveys precision: a wider interval reflects greater uncertainty than a narrower interval. A p-value, when reported, describes how unusual data at least as incompatible with a specified null hypothesis would be under that hypothesis and the analysis assumptions. Neither quantity alone establishes the importance of an effect. The registry record does not report a confidence interval or p-value for the primary comparison, so the precision and statistical evidence for a difference cannot be assessed from this record.

What does no masking imply?

The registry lists masking as NONE. In general, lack of masking means participants, study personnel, or outcome assessors may know the assigned group, depending on the procedures used. Knowledge of assignment can matter for outcomes influenced by behavior, expectations, or judgment. The primary outcome is defined through clinic records, but the registry does not describe record ascertainment or whether assessors were aware of assignment. The label alone does not establish that measurement bias occurred.

What can be inferred from the analysis counts?

The registry lists four outcome measures and six analyses. These counts do not identify the statistical tests, models, covariates, analysis populations for each outcome, or the relationship between measures and analyses. They also do not show whether analyses were prespecified or exploratory. The specific statistical analysis plan, including any interim analyses, is not reported in the registry record. No such procedures should be inferred from the number of analyses.

How should multiplicity be considered?

When multiple outcomes or comparisons are examined, the chance of obtaining at least one apparently notable finding can increase if each is assessed separately without accounting for the family of tests. In general, multiplicity methods can alter the interpretation of p-values or confidence intervals, depending on the plan and the scientific question. The registry names secondary outcomes of Decision Satisfaction, Decisional Regret, and Distress, and lists multiple outcome measures and analyses. It does not report whether a multiplicity adjustment was used, which outcome comparisons were grouped together, or how results were prioritized.

What do the planning assumptions describe?

The record describes sample-size assumptions as a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The effect to detect is described as a stated fraction of the observed effect. The general purpose of such an illustration is to show how a hypothetical target effect and design assumptions relate to a planning sample size. It is not an observed power calculation and does not report the trial’s own design justification. The sample-size justification used to plan the trial is not reported in the registry record.

For count outcomes, the assumptions used for planning do not by themselves identify the model used for the trial’s final analysis. If count variability exceeds what a selected model assumes, general statistical methods may need to account for over-dispersion; this is a general consideration, not a reported feature of this trial. The registry does not report a dispersion estimate, a model choice, or whether over-dispersion was assessed. Since the observed primary outcome results and the analysis method are not reported, readers cannot evaluate model fit, reproduce the primary comparison, or judge whether the analysis assumptions were suitable.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists Decision Satisfaction, Decisional Regret, and Distress as secondary outcomes. It also records four outcome measures and six analyses. Those figures do not specify the complete set of hypotheses tested, how outcome measures correspond to analyses, or which comparisons were considered confirmatory. The record does not report whether statistical tests were adjusted for multiplicity or how the interpretation of secondary analyses was planned. Without that information and the numerical results, no secondary finding can be evaluated for its statistical strength.

The primary endpoint population is described as intent to treat, including all participants assigned to either group. The registry does not report the number with an observed primary endpoint in each arm, the amount or pattern of missing outcome information, or any imputation or other missing-data method. It also does not say whether participants with unavailable clinic records were counted as not completing testing, excluded, or handled another way. These details are necessary to understand how the stated population definition was applied.

The statistical analysis plan, including any interim analyses, is not reported in the registry record. The sample-size rationale used to plan the trial is also not reported. The posted planning assumptions are described as an illustration, not as a record of the trial’s original design justification. In general, a clear account of prespecified outcomes, missing-data procedures, and multiplicity methods helps readers distinguish planned analyses from analyses selected after results are known. The available registry entries do not provide that account.

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 53 participants at risk for serious adverse events in Proactive Streamlined Genetic Education and Testing, with 0 affected, and 55 at risk in Usual Care, also with 0 affected. Deaths are listed as 0 in each group. No serious adverse event terms are listed.

These entries describe the safety figures recorded in the registry. They should not be read as a complete account of all possible adverse events: the record does not provide event definitions beyond the serious-event category, explain the collection and reporting procedures, or list non-serious event results. A zero in the affected count means that the registry reports no affected participants for that listed category; it does not establish that every event was assessed or that unreported events did not occur.

The groups have different listed at-risk counts, but the registry does not explain the relationship between these counts and the enrollment figure or the brief-summary participant count. The record also does not provide comparative safety estimates or uncertainty intervals. The figures therefore support a limited description of what was entered for serious events and deaths, not a broad conclusion about safety.

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

The registry record describes a randomized comparison between an offer of streamlined genetic education with an option to proceed directly to testing and a referral for usual genetic counseling. It defines the primary endpoint as participants receiving genetic testing results according to clinic records, in an intent-to-treat population. These details clarify the question the trial was designed to address.

The record does not report the group-specific primary endpoint counts or a statistical comparison. It therefore does not show whether completion differed between the assigned approaches, how large any difference was, or how precisely it was estimated. Numerical findings for Decision Satisfaction, Decisional Regret, and Distress are also not reported. No conclusion about those outcomes can be drawn from their names alone.

In general, a randomized design can support a comparison of assigned strategies when the analysis and outcome ascertainment are adequately reported. Here, important details needed to assess the comparison—including the primary result, uncertainty, missing-data handling, and analysis methods—are not reported in the registry record. The enrollment figure of 112 and the brief-summary participant figure of n=120 are both recorded, but their relationship is not explained.

The serious-event entries report 0 affected participants in each group and 0 deaths in each group, with 53 and 55 participants at risk, respectively. These entries are limited to the registry’s reported serious-event and death fields; they do not establish the completeness of broader safety reporting.

Accordingly, the record supports an account of the trial’s design, endpoint, and selected safety entries, but it does not provide the outcome evidence needed to characterize the comparative result. The completed status is an administrative status, not a substitute for numerical outcome reporting.

13. Why This Trial Matters Statistically

This trial addresses a statistical question about whether two assigned approaches to genetic education and access are associated with different levels of testing completion. The distinction between the intervention and comparator is concrete: one offers education materials and the option to proceed directly with testing, while the other sends a referral recommending an individual counseling session. The primary endpoint uses receipt of results in clinic records as its completion definition.

The randomized, parallel-group design is relevant because it makes the assigned strategy the basis for comparison. The registry’s intent-to-treat definition similarly identifies assignment, rather than pathway completion, as the intended basis for the primary population. These design features help define the estimand in broad terms, but full interpretation also requires the observed counts, effect estimate, uncertainty, and explanation of missing outcome data.

The registry record is statistically informative about the intended comparison while remaining incomplete about its results. It names secondary outcomes and records multiple outcome measures and analyses, but does not explain multiplicity procedures or provide numerical estimates. That gap matters because a reader needs both the outcome values and the analysis context to distinguish a precise estimate from an uncertain one and to interpret multiple comparisons responsibly.

The record also illustrates why administrative completion, outcome reporting, and statistical interpretation are separate. A completed study status does not reveal whether the primary endpoint differed across groups. The serious-event entries can be described as recorded, but their scope and collection procedures are not detailed. The unexplained difference between the listed enrollment and the participant count in the brief summary is another point that limits reconstruction of the analyzed population.

For biostatisticians and clinical researchers, the key issue is not only what endpoint was planned, but whether the results and methods are reported well enough to evaluate the comparison. In this record, the design and endpoint are identifiable, while the primary estimate and several analysis details are not reported.

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 principal limitation for statistical interpretation is that the numerical primary endpoint results are not reported in the registry record. The group-specific counts, effect estimate, confidence interval, and p-value are absent. The registry also provides no numerical results for the listed secondary outcomes, so neither the size nor precision of any comparative finding can be assessed.

There is an unexplained difference between the enrollment figure of 112 and the brief summary’s participant count of n=120. The record does not say whether these figures refer to different recruitment or analysis stages. It also does not report the number of participants with available outcome data or how missing primary endpoint information was handled.

The primary timeframe is listed as Three Months Post-Randomization, while the brief summary describes follow-up survey contact two months after randomization. The registry does not explain how these timings relate. Further details about the statistical analysis plan, outcome ascertainment, randomization procedures, allocation concealment, and masking of assessors are not reported in the registry record.

The record lists four outcome measures and six analyses but does not map the entries to particular comparisons, explain which were prespecified, or state whether multiplicity was addressed. It does not report the original sample-size justification or any interim-analysis plan. The serious-event entries are limited to the reported serious adverse event and death fields; broader safety methods and non-serious event results are not described. These limitations restrict interpretation of both the trial’s efficacy-related outcomes and its safety reporting.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Streamlined Genetic Testing in Prostate Cancer — NCT04359758.
• Registry record last updated 2024-01-17; status last verified 2024-01.
• Results first posted 2022-12-22.
• 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

NCT04359758, titled Streamlined Genetic Testing in Prostate Cancer, is listed as a completed randomized, parallel-group trial with no masking. Georgetown University is the sponsor. The registry lists enrollment of 112, a start date of 2020-03-01, and a primary completion date of 2021-10-01; phase is listed as NA.

The comparison is between Proactive Streamlined Genetic Education and Testing and Usual Care. The primary endpoint is the number of participants completing genetic testing, defined by receipt of results in clinic records, with a Three Months Post-Randomization timeframe and an intent-to-treat population. Decision Satisfaction, Decisional Regret, and Distress are listed as secondary outcomes.

The primary numerical results, secondary outcome results, and key statistical analysis details are not reported in the registry record. The serious-event entries list 0 affected participants in each group and 0 deaths in each group.