Evaluating Strategies to Present Colon Cancer Screening Information: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluating Strategies to Present Colon Cancer Screening Information (NCT02485561), a randomized na study. The primary outcome is Intentions to Get Screened for Colon Cancer.

2. Clinical Question

3. Trial Design

The registry describes a randomized, parallel-group study with three experimental conditions. The listed allocation is randomized, and the masking designation is single; who was masked is not reported in the registry record. The study is listed as completed, with enrollment of 486. Its start date is 2015-06-01 and its primary completion date is 2017-01-31. The phase is listed as not applicable.

All three groups received colon cancer and screening information based on public educational materials. The information-only group received the information without a narrative. The screener-narrative group received a personal account from someone who had been screened. The survivor-narrative group received a personal account from someone who had been screened and diagnosed with colon cancer. Thus, the randomized contrast was between information alone and information paired with one of two kinds of personal narrative.

The study description says participants completed surveys before the intervention, immediately afterward, and one month after randomization; follow-up surveys at 6 and 12 months were added to assess behavior change. The primary outcome reported for this analysis is the immediate post-intervention measure, not a later screening behavior measure. The primary outcome population consists of participants who completed the baseline, intervention, and immediate post-intervention surveys. The registry record does not report the original sample-size justification, detailed eligibility criteria, or which individuals were masked.

The observed primary outcome counts are 159 in the information-only group, 155 in the screener-narrative group, and 159 in the survivor-narrative group. These are the outcome-specific counts, rather than a statement about the analysis population for every survey or secondary measure. The registry record does not report further detail about how participants were assigned, whether assignment was stratified, or how incomplete follow-up was handled.

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: Nearly all participants completed all study components online. They provided informed consent and proceeded to the baseline survey (n=486). Only those that completed the baseline survey were randomized (n=477) to one of three intervention conditions, so that number is smaller than the total who started the study.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Participants who completed the baseline, intervention, and immediately post-intervention survey

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.

Population: Participants who completed the baseline survey and were randomized to receive the assigned study intervention

6. Primary Endpoint

The registry lists the primary outcome as Intentions to Get Screened for Colon Cancer, measured over Immediately post-intervention.

The primary endpoint is mean intention to get screened for colon cancer immediately after the intervention. The registry describes a mean based on three survey items, each answered using slider bars coded from 1, not at all, to 100, extremely. The items asked about the likelihood of being screened in the next 6 months, the importance of screening, and commitment to screening. Higher scores indicate greater intention to get screened for colorectal cancer.

This measure captures participants’ stated intentions, rather than whether they later completed screening. The registry describes later follow-up surveys, but the primary endpoint is the immediate post-intervention measure. It therefore addresses a near-term response to the educational material, not a change in screening behavior over time.

Combining the three items into a mean offers a single continuous summary of these related aspects of intention. The registry reports the group means and standard deviations, which describe the average response and the spread of individual scores within each group. An average can help compare groups, but it does not show the full distribution of responses or establish why any difference occurred. The registry record does not report additional psychometric information about the three-item measure.

7. Results Posted in the Registry

• Screener Narrative: mean 65.51 versus 68.64 on control; difference -3.13 (95% CI -9.07 to 2.81), standardized effect d = -0.12; z-test p = 0.302.
• Survivor Narrative: mean 64.30 versus 68.64 on control; difference -4.34 (95% CI -10.55 to 1.87), standardized effect d = -0.15; z-test p = 0.171.

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 for Getting Screened for Colon Cancer

• 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 deviations.
• Result:
  • Screener Narrative: mean 5.81 versus 5.80 on control; difference 0.01 (95% CI -0.29 to 0.31), standardized effect d = 0.01; z-test p = 0.948.
  • Survivor Narrative: mean 5.66 versus 5.80 on control; difference -0.14 (95% CI -0.44 to 0.16), standardized effect d = -0.10; z-test p = 0.353.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Screener Narrative and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Survivor Narrative and the control. The interval gives the range of effects that remain compatible with the data.

Absolute Perceived Susceptibility to Colon Cancer

• 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 deviations.
• Result:
  • Screener Narrative: mean 3.03 versus 2.98 on control; difference 0.05 (95% CI -0.11 to 0.21), standardized effect d = 0.07; z-test p = 0.549.
  • Survivor Narrative: mean 3.08 versus 2.98 on control; difference 0.10 (95% CI -0.07 to 0.27), standardized effect d = 0.13; z-test p = 0.247.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Screener Narrative and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Survivor Narrative and the control. The interval gives the range of effects that remain compatible with the data.

The registry identifies six secondary outcomes, including identification with the character, measures of engagement, self-efficacy, affect, defensive information processing, and absolute perceived susceptibility to colon cancer. Numerical results are available in the record for self-efficacy and absolute perceived susceptibility. For both, the reported group averages are close, and the sponsor-reported overall ANOVA p-values do not indicate clear evidence of differences across the three groups.

These secondary outcomes provide context about possible responses to the educational materials beyond the primary intention measure. Their general pattern does not suggest a markedly different response across the groups in the numerical results available, and it is broadly consistent with the primary analysis not showing clear statistical evidence of group differences. This should not be extended to the other listed secondary outcomes: their numerical results are not reported in the registry record.

Secondary outcomes generally carry less confirmatory weight than a prespecified primary outcome, particularly when several outcomes or comparisons are examined. Testing many outcomes can increase the chance of at least one apparently noteworthy result even when there is no underlying effect. The registry record does not report whether a multiplicity procedure was used, nor does it provide a complete statistical plan for ranking or interpreting secondary analyses. Any unadjusted secondary findings should therefore be treated as exploratory evidence, not as independent confirmation of the primary result.

The secondary results also concern immediate post-intervention measures. They do not establish whether participants later completed screening. The registry record describes later follow-up surveys, but those behavioral outcomes are not numerically reported in the information available for these comparisons.

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

• Identification With the Character
• Three Measures of Engagement
• Self-efficacy for Getting Screened for Colon Cancer
• Affect
• Defensive Information Processing
• Absolute Perceived Susceptibility to Colon Cancer

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: each participant’s score is a mean of survey items, and the registry reports a group mean and standard deviation. A mean difference expresses the distance between two group averages on the outcome’s original scale. A negative mean difference in these recalculations means that the narrative group’s observed mean was lower than the information-only group’s observed mean. The score’s units are points on the stated 0-100 scale; the difference is not a percentage change.

What does the reported ANOVA test?

ANOVA, or analysis of variance, compares mean outcomes across multiple groups. The sponsor-reported primary analysis includes all three randomized groups and reports an F-value of 1.019 with p = .362. The F-value summarizes how the variation between group means compares with variation within groups under the ANOVA model. The p-value describes how compatible the observed test statistic is with the model’s no-difference hypothesis, assuming the model’s conditions hold. It is not the probability that the null hypothesis is true, and it does not measure the size or practical importance of a difference.

The overall ANOVA is not itself a set of pairwise tests. It addresses whether there is evidence that the means differ somewhere among the three groups. The recalculated comparisons instead focus on each narrative arm against information only. That distinction matters: an overall test and two individual comparisons need not have the same estimate, uncertainty, or p-value. The registry record does not report a sponsor-adjusted pairwise analysis for the primary outcome.

What do the recalculated comparisons represent?

The posted pairwise calculations are simple, unadjusted comparisons of group summary statistics. They use each group’s mean, standard deviation, and outcome count to estimate a mean difference and its confidence interval. They are not described as covariate-adjusted, and they should not be interpreted as replacing the sponsor’s reported overall analysis. Since the registry’s discrepancy indicator is false, no discrepancy between sponsor and recalculated results is flagged.

The standard deviation describes how widely individual scores vary around a group mean. It is not the uncertainty of the mean difference. The standard error describes the estimated sampling uncertainty of a statistic, and it contributes to the width of a confidence interval. In this study, the reported group standard deviations are much larger than the estimated mean differences, a feature reflected in the uncertainty intervals. This is a descriptive comparison of the posted statistics, not a new calculated effect.

How should a p-value be read?

A p-value is evaluated in relation to a statistical model and a null hypothesis. A relatively large p-value does not prove there is no difference; it means the observed data do not provide strong evidence against the null under that test. Conversely, a small p-value would not by itself establish that an effect is important or that an intervention caused a meaningful change. Interpretation also depends on study design, outcome quality, uncertainty, and the analysis choices.

The primary p-value of .362 is the sponsor-reported omnibus result. The pairwise p-values of 0.302 and 0.171 are unadjusted recalculations. Because more than one comparison or outcome may be examined, multiple testing can make apparently notable findings more likely by chance. Whether and how the trial’s analyses addressed this issue is not reported in the registry record. Therefore, the individual unadjusted p-values should be read as descriptive inferential results rather than as a complete confirmatory testing strategy.

What assumptions matter for continuous outcomes?

Mean-based comparisons rely on assumptions about the data and the model, including an adequate representation of the outcome distribution and appropriate treatment of variation across groups. The registry record does not report diagnostic checks or details about model assumptions. Standard deviations summarize variability but do not show distribution shape, outliers, or whether scores cluster near the ends of the response scale. The outcome is bounded by its survey scale, but further distributional information is not reported in the registry record.

Randomization supports comparison of assigned groups, but it does not eliminate uncertainty or automatically resolve missing outcome data. The registry describes the primary analysis population as people who completed the baseline, intervention, and immediate post-intervention survey. How missing responses were handled, whether any imputation was used, and whether other analysis populations were evaluated are not reported in the registry record.

Why distinguish statistical and practical meaning?

Statistical evidence concerns how compatible the observed data are with a specified model. Practical meaning concerns whether the size of a difference matters for the research question or for subsequent behavior. The registry does not report a threshold for a meaningful difference on the intention scale. Therefore, the reported mean differences and their intervals can be described, but they cannot be classified against a prespecified clinical or behavioral importance threshold from this record.

11. Confidence Intervals and Precision

The confidence intervals around the recalculated mean differences describe uncertainty in the estimated contrasts. For the screener narrative versus information only, the estimated difference is -3.13, with a 95% confidence interval from -9.073 to 2.813. For the survivor narrative versus information only, the estimated difference is -4.34, with a 95% confidence interval from -10.55 to 1.872. Both intervals include zero, meaning that the estimates are compatible with no difference as well as with values on either side of zero.

A confidence interval is not a guarantee that the true effect lies within the particular interval. In general, a 95% confidence interval is produced by a procedure that would cover the true parameter in 95% of repeated studies under its assumptions. The interval’s width reflects statistical precision: broader intervals leave more uncertainty about the size and direction of the underlying difference.

These intervals also show why a non-significant result should not be read as proof of equivalence. The registry record does not report a prespecified equivalence margin or a threshold for a meaningful change in intention. Without such a threshold, the intervals cannot establish that any possible differences are too small to matter. Nor do they establish that a larger study would necessarily find a difference.

The sponsor-reported primary result is an overall ANOVA and does not include a confidence interval in the registry record. The intervals are recalculated pairwise estimates, not intervals reported by the sponsor. They describe immediate post-intervention intention among participants included in those comparisons and do not quantify uncertainty about later screening behavior.

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, not total participants or total events. The registry’s planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set as the stated fraction of the observed effect. These are planning illustrations based on the observed effect, not the trial’s original design assumptions; the original design justification is not reported in the registry record.

The 80% power column describes the per-arm sample size that the planning calculation estimates would give an 80% chance of detecting the specified effect under its assumptions, if that effect were the true effect and the analysis model held. The 90% power column gives the corresponding per-arm planning figure for a 90% chance. These are conventional design targets, not guarantees about what a study will find. The figures are not observed power.

Each set of planning rows considers detecting the full observed effect, 75% of the observed effect, or 50% of the observed effect. Smaller effects are harder to distinguish from random variation, so the planning calculations require more participants per arm as the effect to detect becomes smaller. The observed effect is itself uncertain, especially when estimated from a study with limited precision. Using it as the basis for planning therefore does not establish the effect that a future study should expect.

The displayed planning values apply to two-arm comparisons, while the sponsor’s primary analysis is an overall comparison among three groups. They should not be interpreted as a reconstruction of the trial’s design or as a recommendation about a future study’s size. The registry record does not report the original assumptions used to choose enrollment.

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 = -3.130; pooled standard deviation σ = 26.853.
2. n = 2 × (1.96 + 0.842)² × 26.853² / -3.130² = 1,155.4, rounded up to 1,156 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 <- -3.13                      # observed difference in means
sigma <- 26.8529460853281                     # 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(2485561)
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 = 1,156 (80% power), 1,547 (90% power)
 75% of observed effect: n per arm = 2,055 (80% power), 2,750 (90% power)
 50% of observed effect: n per arm = 4,622 (80% power), 6,188 (90% power)
power.t.test: 1156.4 
Simulated power at n = 1,156 per arm: 0.798 (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. Analyses Reported by the Sponsor

For the primary endpoint, the sponsor’s reported analysis is an ANOVA across the information-only, screener-narrative, and survivor-narrative groups. It reports an F-value of 1.019 and p = .362. This is the registry’s own overall analysis of the three groups.

The recalculated estimates address two separate contrasts: screener narrative versus information only, and survivor narrative versus information only. They use the posted group summaries to produce unadjusted mean differences, confidence intervals, and p-values. They are not a reproduction of the sponsor’s omnibus ANOVA and should not be substituted for it. The sponsor’s overall result and the recalculated pairwise results answer different questions.

The registry record does not report sponsor pairwise estimates or confidence intervals for the primary endpoint, so the recalculations offer a supplementary view of the contrasts rather than a comparison against sponsor-reported pairwise results. The discrepancy indicator is false; the record does not flag a conflict between the sponsor analysis and the recalculations. For interpretation, the sponsor-reported overall analysis remains the trial’s reported result, while the recalculations make the two comparisons with information only more explicit.

15. Multiplicity, Missing Data and Analysis Populations

The registry reports an overall primary-outcome ANOVA and identifies multiple secondary outcomes and analyses. It does not report whether the trial used a formal strategy to control the family-wise error rate or another multiplicity procedure across outcomes, time points, or pairwise comparisons. This is important because the chance of at least one false-positive finding can increase when many statistical tests are conducted. The pairwise recalculations are explicitly unadjusted and should be interpreted accordingly.

The record lists 21 analyses and 10 outcome measures, but does not describe how these analyses were selected, whether hypotheses were ranked in advance, or whether any analyses were exploratory. A detailed prespecified statistical analysis plan is not reported in the registry record. It is therefore not possible to determine from the record whether reported analyses correspond to all planned analyses or how selective reporting was prevented.

The primary outcome population is defined as participants who completed the baseline, intervention, and immediate post-intervention survey. Outcome counts are 159 for information only, 155 for the screener narrative, and 159 for the survivor narrative. The registry record does not report the number or reasons for missing responses at each measurement, a method for handling missing data, or whether an intention-to-treat analysis was conducted. The impact of incomplete follow-up on the estimates cannot therefore be assessed from this record.

The record also does not report whether interim analyses were planned or conducted, or whether any stopping rule was used. These details should not be inferred from the trial’s completed status. The populations used for analyses other than the primary endpoint are not fully specified in the numerical outcome details. These gaps limit assessment of analysis choices, missingness, and the degree to which the posted results represent a prespecified confirmatory analysis.

16. 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 adverse-event entries report zero serious adverse events in the information-only group, zero in the screener-narrative group, and zero in the survivor-narrative group. The entries also report zero deaths in each group. The record lists the at-risk counts as 159, 155, and 159, respectively. These are the posted figures for the listed groups and should be read as reported event counts, not as proof that no event could occur outside the recorded reporting period.

The registry also records zero other adverse events in each group. Definitions of serious and other adverse events, the collection period, and the procedures used to collect or verify these events are not reported in the registry record. The record does not describe event severity categories beyond the serious/other distinction or provide individual event narratives. The absence of recorded events in these entries is a safety-reporting observation; it does not establish the absence of all possible harms.

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

The primary result describes a comparison of immediate survey intentions after participants received screening information alone or screening information paired with one of two personal narratives. The sponsor-reported overall ANOVA does not provide strong statistical evidence of a difference in mean intention across the three groups. The unadjusted recalculated comparisons likewise have confidence intervals that include zero. These findings indicate uncertainty about the size and direction of any group differences; they do not prove that the groups are equivalent.

The endpoint is intention, not completed screening. A stated likelihood, the perceived importance of screening, and commitment to screening may be relevant to behavior, but this outcome by itself cannot establish that participants later obtained screening. Although the study description mentions later follow-up surveys, numerical results for later screening behavior are not reported in the registry record.

The results also do not establish why participants gave the responses they did, whether a particular narrative changed an individual’s views, or whether effects differ across participant characteristics. The record does not report a meaningful-difference threshold for the scale, so statistical results cannot be translated into a judgment about whether the observed estimates matter in practice. Further, the primary analysis is based on participants who completed the specified surveys; the consequences of missing responses cannot be evaluated from the registry information.

Overall, the posted primary outcome results do not show clear evidence that adding either narrative changed immediate mean intention relative to information alone. This is a description of the observed results and their statistical precision, not a conclusion about the effectiveness of screening or a recommendation about educational materials. A lack of clear statistical evidence is not the same as proof of no effect, and any conclusion about subsequent behavior would require relevant follow-up results.

18. Why This Trial Matters Statistically

This trial poses a useful statistical question about how the framing of health information might relate to an immediate response. Its three-arm randomized design distinguishes information alone from information paired with a screener narrative or a survivor narrative. That structure permits an overall comparison among the conditions and focused comparisons of each narrative approach against the information-only condition.

The results illustrate why an average difference and its uncertainty should be considered together. The observed group means are not identical, but the recalculated confidence intervals are broad enough to include zero. The overall ANOVA also does not indicate strong evidence of differences. Reporting only the direction of the means could overstate what the data establish; reporting only that a result was not statistically significant could understate the uncertainty about possible differences.

The example also highlights the distinction between a proximal survey outcome and a later behavior. Immediate intention is a measurable response to the materials, but it is not the same endpoint as completing screening. The registry description includes follow-up surveys, while the numerical results address the immediate measure. Keeping the outcome and time point explicit prevents conclusions from extending beyond the reported analysis.

Finally, planning calculations based on an observed effect are illustrations rather than evidence of the trial’s original design rationale. They show how assumptions about the effect to detect and desired power influence a planning estimate, while the registry record does not report the original sample-size justification. Taken together, the study is a practical example of reading design, endpoint, sponsor analysis, recalculated contrasts, and uncertainty as connected but distinct parts of a clinical research result.

19. Limitations

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

The registry record does not report the original sample-size justification, detailed eligibility criteria, or a full statistical analysis plan. It also does not identify who was masked despite listing the study as single-masked. These omissions limit assessment of design choices and of the extent to which the reported analyses followed a prespecified plan.

The primary endpoint is an immediate self-reported intention measure, formed from three survey items. The record does not report additional measurement validation information or a threshold for a meaningful difference. The result therefore cannot be directly interpreted as a change in actual screening behavior or as a difference that is important to participants.

The primary outcome analysis includes participants who completed the baseline, intervention, and immediate post-intervention survey. The registry record does not report reasons for non-completion, a missing-data method, or a separate intention-to-treat analysis. If completion differed in relation to participants’ responses, the reported estimates could be affected; the record does not permit that possibility to be assessed.

The sponsor reports an overall ANOVA, while the pairwise estimates are unadjusted recalculations from summary statistics. The registry record does not report a multiplicity strategy or sponsor-reported pairwise estimates for the primary endpoint. It also does not report numerical findings for all listed secondary measures or for the later behavioral follow-up mentioned in the study description. Consequently, interpretation is limited to the outcomes and time point with numerical results in the record.

Generalizability is also difficult to assess because further participant characteristics and eligibility details are not reported in the registry record. These limitations do not negate the reported results, but they define the boundaries of what can be concluded from the available record.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Evaluating Strategies to Present Colon Cancer Screening Information — NCT02485561.
• Registry record last updated 2018-11-15; status last verified 2018-10.
• Results first posted 2018-11-15.
• 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.

23. Record Summary

NCT02485561 is a completed randomized, parallel-group study comparing information-only colorectal cancer screening materials with the same information paired with either a screener narrative or a survivor narrative. The primary outcome was mean intention to get screened immediately after the intervention, among participants completing the baseline, intervention, and immediate post-intervention survey.

The sponsor-reported overall ANOVA gave an F-value of 1.019 and p = .362. Unadjusted recalculated comparisons against information only had confidence intervals that included zero. The record also reports numerical results for two secondary outcomes, with no clear overall evidence of group differences in the sponsor-reported analyses. These outcomes measure immediate responses, not later screening behavior.

The registry record does not report the original sample-size justification, a detailed multiplicity or missing-data strategy, or numerical results for all listed secondary outcomes and later follow-up behavior. Serious adverse events and deaths are recorded as zero in each group.