Web-Based Decision Aid in Improving Informed Decisions in Patients With Stage 0-IIIA Breast Cancer Considering Contralateral Prophylactic Mastectomy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Web-Based Decision Aid in Improving Informed Decisions in Patients With Stage 0-IIIA Breast Cancer Considering Contralateral Prophylactic Mastectomy (NCT03061175), a randomized na study. The primary outcome is Contralateral Prophylactic Mastectomy (CPM) Knowledge Assessed by Surveys for CPM-DA Participants vs. UC Participants.

2. Clinical Question

3. Trial Design

This completed pilot trial is recorded as randomized, with a parallel-group design and no masking. The registry identifies Rutgers, The State University of New Jersey, as the sponsor. It lists enrollment of 94 and records the study start as 2015-09-24 and primary completion as 2018-04-11. The phase is listed as not applicable.

Participants were assigned to one of two approaches. In the web-based CPM decision-aid arm, participants received access instructions and credentials for the online decision aid. In the usual-care arm, participants received the care available to patients considering CPM and information from a medical oncologist. The intervention descriptions do not provide further detail about how either approach was delivered or standardized.

The posted primary outcome was CPM knowledge, assessed by survey at 2-4 week follow-up. The arm summaries report results for 39 participants in the decision-aid arm and 44 in usual care. The record also lists secondary outcomes concerning self-efficacy, cancer worry, CPM motivations, and perceived risk of recurrence. No separate statistical analysis records are listed. The original protocol details, the method used to generate the random allocation sequence, allocation concealment, and the trial's original sample-size justification are not reported in the registry record.

The parallel randomized design makes the arm comparison the relevant descriptive contrast: it compares outcomes for participants assigned to the decision aid with outcomes for those assigned to usual care. No masking was used, so participants and relevant study personnel were not masked according to the registry. The registry does not describe whether outcome assessment or data analysis was masked. As a pilot, the study contributes preliminary comparative information; the record does not state a formal criterion for progression to a larger trial.

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.

Baseline

Reasons for not completing this period:

Followup 1 at 2-4 Weeks Post-surgery

Reasons for not completing this period:

Followup 2 at 6 Months

Reasons for not completing this period:

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 Contralateral Prophylactic Mastectomy (CPM) Knowledge Assessed by Surveys for CPM-DA Participants vs. UC Participants, measured over 2-4 week follow up.

The primary endpoint is CPM knowledge assessed by survey at 2-4 week follow-up. The registry describes a 10-item multiple-choice measure developed by Kirsten and Smith. Scores range from 0-100% correct, with higher scores indicating more correct knowledge items. The items concern the definition of CPM; surgical recovery time and risks or side effects; whether CPM improves survival; and whether CPM reduces the risk of disease progression.

Knowledge is relevant to the stated decision context because the trial concerns patients making an informed decision about CPM. A score on the measure is intended to characterize what participants know about the procedure and related claims, rather than to record whether participants chose surgery. It is a continuous measure, and the registry describes the arm results using means and standard errors. The result therefore summarizes average scores; it does not show how individual participants answered particular questions or whether their understanding changed in specific topics.

The endpoint description says follow-up scores are to be reported as the difference between knowledge at baseline and follow-up for both arms. The posted arm summaries identify a score on a scale at follow-up, but the registry does not provide details explaining how the baseline and follow-up information was combined in the displayed summary. That reporting detail limits how specifically the published mean contrast can be interpreted as a change from baseline. The record also does not report a threshold defining a meaningful difference in knowledge scores.

7. Results Posted in the Registry

• Arm I (Web-Based CPM-DA): mean 62.47 versus 51.33 on control; difference 11.14 (95% CI 1.93 to 20.35), standardized effect d = 0.52; z-test p = 0.018.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Self-Efficacy at 2-4 Week Follow up Survey

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Arm I (Web-Based CPM-DA): mean 4.00 versus 3.85 on control; difference 0.15 (95% CI -0.16 to 0.46), standardized effect d = 0.22; z-test p = 0.350.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Arm I (Web-Based CPM-DA) and the control. The interval gives the range of effects that remain compatible with the data.

Cancer Worry Assessed by 2-4 Week Follow-up Surveys

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Arm I (Web-Based CPM-DA): mean 2.91 versus 2.84 on control; difference 0.07 (95% CI -0.56 to 0.70), standardized effect d = 0.05; z-test p = 0.826.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Arm I (Web-Based CPM-DA) and the control. The interval gives the range of effects that remain compatible with the data.

CPM Motivations Assessed by Surveys

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Arm I (Web-Based CPM-DA): mean 2.77 versus 2.73 on control; difference 0.04 (95% CI -0.28 to 0.36), standardized effect d = 0.05; z-test p = 0.806.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Arm I (Web-Based CPM-DA) and the control. The interval gives the range of effects that remain compatible with the data.

The registry identifies secondary questions about self-efficacy, cancer worry, CPM motivations, and perceived risk of recurrence. Numerical arm summaries and comparisons are posted for self-efficacy, cancer worry, and CPM motivations. A numerical result for perceived risk of recurrence is not reported in the registry record. These outcomes address related but distinct aspects of participants' experience and thinking; they are not interchangeable with the primary knowledge measure.

Across the secondary comparisons with numerical results, the reported mean contrasts are small in relation to their uncertainty, and their confidence intervals include zero. The posted unadjusted p-values do not indicate clear evidence of arm differences on those outcomes. This pattern differs from the primary knowledge result, whose reported confidence interval lies above zero. The measures therefore do not all show the same degree of separation between groups, and the secondary findings do not independently replicate the primary contrast.

Secondary outcomes generally carry less confirmatory weight when many measures are examined without a reported multiplicity strategy. Testing several outcomes increases the opportunity for at least one result to appear unusual by chance. The registry does not report whether outcomes were ordered in a hierarchy, whether a family-wise or other error-rate adjustment was planned, or whether these outcomes were exploratory. Their unadjusted results are best treated as descriptive rather than as definitive evidence of separate effects.

The secondary results can help identify questions for future research, but the registry does not report interpretive thresholds for the scales, detailed scale descriptions, or a prespecified framework for comparing them. The short follow-up period also limits conclusions to the period measured. The secondary outcomes should therefore be considered alongside the primary endpoint and the study's reporting gaps, not as a comprehensive account of longer-term decision quality or outcomes.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Self-Efficacy at 2-4 Week Follow up Survey
• Cancer Worry Assessed by 2-4 Week Follow-up Surveys
• CPM Motivations Assessed by Surveys
• Perceived Risk of Recurrence Assessed by 2 Items on Surveys

9. Statistical Interpretation

10. Statistical Methods Explained

The reported outcome is continuous: each participant's knowledge is represented by a score, and the arm summaries are means. A mean gives the arithmetic average of the scores in a group. It is useful for describing the overall level of a continuous measure, although it does not show the distribution of scores, the range of individual responses, or whether a small number of scores strongly influence the average.

What does the mean difference represent?

The comparison is reported as the decision-aid arm mean minus the usual-care arm mean. The posted means are 62.47 and 51.33, and the reported mean difference is 11.14. A positive value indicates that the mean score in the first arm is higher in this contrast. The difference is expressed in the score's units; it is not a percentage increase, a ratio, or a measure of how many individual participants had higher scores. No new calculation is needed to interpret the reported estimate.

The registry also lists standard errors for each arm mean: 3.4 for the decision-aid arm and 3.24 for usual care. A standard error describes the estimated sampling uncertainty in a mean, rather than the spread of individual participant scores. It tends to be smaller when a mean is estimated more precisely. It should not be read as though most individual scores fall within one standard error of the mean. The registry does not provide the standard deviations of the outcome scores as the arm-level dispersion measure.

How should the confidence interval be read?

A confidence interval gives a range of values compatible with the data and the method used to estimate uncertainty. The interval for the primary mean difference is 1.935 to 20.35. It describes uncertainty about the mean contrast, not a range containing a stated proportion of individual participants' scores. The registry does not report the exact method used to construct this interval, so the analysis cannot be identified more specifically from the record.

The interval does not by itself resolve whether the observed contrast is important for decisions or patients. That judgment would require a meaningful-difference threshold or other interpretive information, which is not reported in the registry record. The interval's position relative to zero is useful for considering compatibility with no difference in means, but the endpoints also show that the estimated magnitude is not exact.

What does the p-value add?

The unadjusted p-value for the primary comparison is 0.018. In general, a p-value describes how unusual data at least as incompatible with a specified null hypothesis would be if that null hypothesis and the assumptions of the statistical test were true. It is not the probability that the null hypothesis is true, nor does it measure the size or practical importance of an effect. The registry does not identify the exact test used to obtain this p-value. Since the value is explicitly unadjusted, it should not be interpreted as accounting for the set of outcomes examined.

The trial description says that the investigators would characterize the knowledge data using estimated marginal means, standard errors, and Cohen's d separately by study arm. The posted data also give an arm mean contrast and its confidence interval. However, the analysis model, any covariates, the method of estimating marginal means, and the handling of baseline scores are not reported in the registry record. The endpoint description mentions baseline and follow-up knowledge scores, but the posted summary does not explain whether the displayed means represent raw follow-up scores, change scores, or another analysis quantity. This prevents a more specific account of the estimand or model.

What is an effect size?

Cohen's d is a standardized mean difference: in general, it expresses a mean contrast relative to a measure of score variability. Standardization can help compare effects measured on different scales, but the result depends on how the variability is defined and does not replace interpretation in the original score units. The registry describes Cohen's d as part of its planned characterization, and the posted comparison data include a standardized estimate. The numerical value is not needed to understand the primary result and is not repeated. The registry does not report a threshold that would classify a standardized effect as important in this setting.

The registry lists outcome counts for each arm, but it does not describe the population used for analysis, whether all randomized participants were included, or how unavailable follow-up surveys were treated. It also does not report a protocol-defined analysis plan, diagnostic checks, or sensitivity analyses. These omissions matter because choices about analysis populations, missing data, and model specification can affect the estimate and its uncertainty. They should be treated as unreported details rather than inferred from the summarized results.

In general, over-dispersion means that observed variability is greater than a model assumes. If a model does not allow for enough variability, standard errors may be too small and intervals too narrow. This is a general statistical consideration, not a reported feature of this trial: the registry does not provide enough distributional or model information to determine whether over-dispersion was assessed or relevant to the knowledge score.

11. Confidence Intervals and Precision

The primary mean difference is reported as 11.14, with a 95% confidence interval from 1.935 to 20.35. The interval is the main posted description of precision: it shows that the estimate is uncertain across a range of possible values for the mean contrast. Both endpoints are above zero, but the interval includes a broad range of positive differences. It therefore supports a directional reading of the posted comparison while leaving uncertainty about the size of the contrast.

A confidence interval is not a prediction interval for individual scores and does not mean that a stated percentage of participants had a score inside its endpoints. In general, it is constructed by a statistical procedure that, under repeated use and its assumptions, would cover the target parameter at the stated rate. The exact interval construction and model are not reported in the registry record. Accordingly, the interval can be described as posted without attributing it to a particular model.

The arm summaries include 39 participants for the decision aid and 44 for usual care. The reported standard errors are 3.4 and 3.24. These quantify uncertainty in the arm means, not the diversity of knowledge scores among participants. The registry does not give score distributions or the standard deviations for these arm summaries, so the precision information is limited to the reported standard errors and the contrast interval.

Precision and statistical evidence are not the same as practical importance. The interval's placement above zero and the unadjusted p-value of 0.018 address compatibility with a no-difference hypothesis under the relevant analysis assumptions. Neither provides a threshold for meaningful knowledge change. A prespecified meaningful-difference threshold and more complete methods would be needed to assess that question. The registry does not report such a threshold or the confidence-interval method.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm for 80% power and participants per arm for 90% power; they are not total event counts. The assumptions listed for these illustrations are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is defined as the stated fraction of the observed effect. The original trial's own sample-size assumptions and justification are not reported in the registry record.

The 80% power column describes the number of participants per arm that the planning calculation estimates would be needed for an 80% chance of detecting the specified effect, if that effect and the planning assumptions applied. The 90% column uses the same general interpretation with a higher target chance of detection. These are planning illustrations, not guarantees about what a trial of that size would find; actual results depend on the true effect, variability, and analysis conditions.

The rows consider planning for the full observed effect and for smaller fractions of it. As the effect targeted for detection becomes smaller, more participants are needed under the stated assumptions. The figures are calculated from the observed effect in this trial and are not evidence that the trial was designed around that effect. They are not observed power: observed power is not an appropriate substitute for interpreting the estimate and its confidence interval. The registry record does not report the assumptions used when the trial was originally planned.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 11.140; pooled standard deviation σ = 21.371.
2. n = 2 × (1.96 + 0.842)² × 21.371² / 11.140² = 57.8, rounded up to 58 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 11.14                      # observed difference in means
sigma <- 21.3707366551831                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(3061175)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 58 (80% power), 78 (90% power)
 75% of observed effect: n per arm = 103 (80% power), 138 (90% power)
 50% of observed effect: n per arm = 232 (80% power), 310 (90% power)
power.t.test: 58.7 
Simulated power at n = 58 per arm: 0.794 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry record lists one primary outcome and several secondary outcomes, but it does not report a statistical plan for managing multiplicity. In a trial that examines multiple outcomes, the chance of at least one apparently notable result can increase if each result is interpreted separately. A plan may specify a hierarchy, identify a single primary test, or adjust inference across a family of tests. None of those approaches is described in the registry record, so the posted p-values should be read as unadjusted comparisons rather than as multiplicity-controlled findings.

The primary result has an unadjusted p-value of 0.018. That value is attached to the posted primary comparison and does not account for testing secondary outcomes. The secondary outcomes with numerical results also have unadjusted comparisons. The record does not state whether the primary result was intended to be confirmatory, whether secondary outcomes were exploratory, or whether any results were selected for reporting according to a prespecified rule. This uncertainty affects how strongly nominal p-values can be interpreted.

Missing-data procedures are not reported. The record does not explain how many participants completed each survey, why some outcomes may be unavailable, or whether incomplete responses were excluded, imputed, or handled through a model. The outcome summaries give arm-specific participant counts, but they do not establish which participants were randomized, which contributed data at each time point, or how missing values were treated. No assumption about the missingness mechanism can be made from the posted summaries.

The analysis population is also not reported in the registry record. It is therefore not possible to determine whether the comparison follows an intention-to-treat principle, includes only participants with observed surveys, or uses another population definition. The record does not describe deviations from assigned care or how such deviations were handled. Details of the original statistical analysis plan, baseline adjustment, covariate selection, and sensitivity analyses are likewise not reported. These omissions do not negate the posted estimates, but they limit assessment of their robustness and the extent to which analysis choices were prespecified.

15. 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.

Most frequent non-serious adverse event terms

For serious adverse events, the registry reports 0 affected among 46 at risk in the web-based decision-aid arm and 0 affected among 47 at risk in usual care. Deaths are reported as 0 in each arm. For other adverse events, the registry reports 0 affected among 46 at risk in the decision-aid arm and 1 affected among 47 at risk in usual care.

These counts describe the safety information recorded for the trial; they do not establish that no unrecorded events occurred. The record does not provide event terms for serious adverse events, because none are listed, and does not give further detail about the single other adverse event, its severity, timing, or relationship to study participation. The at-risk counts are the denominators reported for these safety summaries and should not be assumed to match the outcome analysis populations.

The study is a pilot and the safety counts are limited in size. The registry does not describe a detailed safety monitoring plan or give context for interpreting uncommon events. The posted figures should be read as recorded counts, not as a complete assessment of all possible harms.

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

The posted primary result shows a higher mean CPM knowledge score at 2-4 week follow-up in the web-based decision-aid arm than in usual care. The estimated mean difference is 11.14, and its 95% confidence interval ranges from 1.935 to 20.35. The unadjusted p-value is 0.018. These statistics describe the observed comparison and its uncertainty; they do not by themselves establish how important the difference is for participants or their decisions.

The endpoint measures answers to a knowledge survey. It does not directly measure whether participants made a choice consistent with their values, felt confident about that choice, underwent CPM, or had a subsequent health outcome. Although the registry lists self-efficacy, cancer worry, motivations, and perceived recurrence risk as secondary outcomes, those concepts are separate from knowledge. A knowledge-score contrast should not be treated as proof that decision quality or clinical outcomes changed.

The study compared assignment to a web-based aid with usual care that included information from a medical oncologist. It therefore addresses this particular decision-support comparison in the registry's population, rather than every way of supporting patients considering CPM. The follow-up is described as 2-4 weeks. Longer-term effects and whether knowledge persists are not reported in the registry record.

Several details needed for a fuller interpretation are also absent. The record does not report the original sample-size justification, the analysis model, the analysis population, missing-data methods, multiplicity strategy, or a threshold for an important score difference. The endpoint description refers to baseline-to-follow-up differences, while the posted summary does not clarify precisely how the displayed values were calculated. These limitations call for a measured interpretation of the estimate and its precision.

Nothing in the result determines what an individual should choose. It is a group-level statistical comparison of a survey measure, not medical advice. The data do not show that the decision aid works or does not work in every setting, nor do they establish the effect on health outcomes. They show that the posted mean knowledge score was higher in the decision-aid arm, with uncertainty captured by the reported confidence interval and limitations in the registry's analysis details.

17. Why This Trial Matters Statistically

This trial is statistically informative because it connects a randomized comparison to a decision-relevant measure rather than treating a decision aid as an intervention whose value can be inferred from access alone. The primary endpoint focuses on knowledge about CPM, including the procedure, recovery, risks, and claims about survival and disease progression. That makes the measured outcome closely tied to the information context described by the trial.

The result also illustrates why effect estimates and precision should be read together. The mean contrast is reported alongside a confidence interval and an unadjusted p-value. The estimate gives the scale of the group difference, while the interval conveys uncertainty about its magnitude. A p-value alone would not show that range or answer whether the contrast is meaningful on the knowledge scale.

The trial's pilot character matters for interpretation. Its posted outcome summaries describe a limited study population, and the record does not give the original design rationale or the analysis plan. Planning illustrations based on the observed effect can show how sample size changes with the target effect under stated assumptions, but cannot reconstruct the original design or determine the study's observed power. A future study would need its own prespecified assumptions and a clearly stated target effect.

Finally, the record highlights the importance of transparent reporting. The outcomes and arm summaries offer useful descriptive information, yet missing details about analysis populations, incomplete data, baseline handling, and multiplicity restrict how fully the comparisons can be evaluated. These are not merely technical footnotes: they shape what can be concluded from an estimate and how confidently it can be applied beyond the study. The most defensible reading keeps the primary knowledge comparison distinct from broader claims about decisions or health.

18. 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 are specific to the way this trial is represented in the registry. First, the study is identified as a pilot, and the registry lists enrollment of 94. The primary outcome summaries include 39 participants in the decision-aid arm and 44 in usual care. The record does not explain the difference between overall enrollment and the outcome-specific counts, so the extent and reasons for any unavailable outcome data cannot be determined.

Second, the endpoint description says follow-up scores are reported as differences between baseline and follow-up knowledge scores, but the posted group summaries do not clarify whether their means are raw follow-up scores, change scores, or another quantity. The analysis model, baseline adjustment, and method used for the reported confidence interval are not reported in the registry record. This makes it difficult to reconstruct the precise estimand or verify the analysis from the posted summaries alone.

Third, the registry does not describe how randomization was generated or concealed, whether any participants deviated from assigned care, or the analysis population. It also does not report how missing survey data were handled. The trial is recorded as having no masking, but the record does not specify whether any outcome assessment or analysis was masked.

Fourth, the follow-up period for the primary outcome is 2-4 weeks. Results from this period do not describe whether differences persisted beyond follow-up. Numerical results for perceived risk of recurrence are not reported in the registry record, despite the outcome being listed among the secondary outcomes. No scale interpretation thresholds are reported for the posted measures. Together, these gaps limit assessment of longer-term effects, completeness, and practical importance.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Web-Based Decision Aid in Improving Informed Decisions in Patients With Stage 0-IIIA Breast Cancer Considering Contralateral Prophylactic Mastectomy — NCT03061175.
• Registry record last updated 2021-04-20; status last verified 2021-04.
• Results first posted 2020-07-20.
• 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.

22. Record Summary

NCT03061175 is a completed randomized, parallel-group pilot trial sponsored by Rutgers, The State University of New Jersey. It compared a web-based CPM decision aid with usual care for patients with stage 0-IIIA breast cancer considering contralateral prophylactic mastectomy. Enrollment was 94, and the registry records no masking.

The primary endpoint was CPM knowledge assessed by survey at 2-4 week follow-up. The posted mean difference favored the decision-aid arm, with an estimate of 11.14, a 95% confidence interval from 1.935 to 20.35, and an unadjusted p-value of 0.018. The registry also lists secondary outcomes, but some analysis and interpretation details are not reported, including the missing-data approach, analysis population, multiplicity strategy, and original sample-size justification.