Feasibility of Expressive Writing for Body Image Distress and Anxiety Among Adolescent and Young Adult Cancer Survivors: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Feasibility of Expressive Writing for Body Image Distress and Anxiety Among Adolescent and Young Adult Cancer Survivors (NCT06046014), a randomized na study. The primary outcome is Feasibility of In-home Body Image (BI) -Focused Expressive Writing (EW) Intervention for Post-treatment Adolescent and Young Adult (AYA) Cancer Survivors With BI Distress (Recruitment).

2. Clinical Question

The study’s stated broader objective is to assess feasibility of the writing intervention and its potential relevance to body image distress and anxiety. Its stated hypothesis is that the intervention will reduce both concerns. However, the posted primary outcome is recruitment, not a measure of change in distress or anxiety. The recruitment result therefore addresses whether participants were recruited within the specified timeframe; it does not directly answer whether either psychological outcome changed or differed between arms.

The trial compares expressive writing with an attention-control writing program in a randomized, parallel design. That comparison can inform feasibility in the context of this particular pilot, while the posted result should be interpreted according to the endpoint actually reported. The registry record does not report a separate primary outcome result for body image distress or anxiety.

3. Trial Design

This is a randomized, parallel-arm pilot trial listed as completed. The registry record gives an enrollment of 30 and describes two groups: Expressive Writing (EW), a four-week, in-home, body-image-focused writing intervention, and Attention Control, a four-week control writing program. Masking is listed as none, so the trial is recorded as open-label. The phase is listed as NA.

The sponsor is the University of Michigan Rogel Cancer Center. The record lists a start date of 2024-09-14 and a primary completion date of 2025-06-01. Its central feasibility outcome concerns recruitment within 6 months. The record gives 14 participants in the expressive-writing arm and 13 in the attention-control arm for the posted primary result. For that outcome, it reports 10 participants in each arm.

The registry describes the intended population as post-treatment adolescent and young adult cancer survivors with body image distress. The background summary discusses anxiety and body image distress as concerns of interest, but the primary endpoint reported is recruitment. The record identifies five outcome measures, but no secondary results are posted. It also contains no separate analysis entries.

Random assignment is intended to create groups that are comparable on average, although chance differences can remain, especially in a small pilot. With no masking listed, participants and study personnel were not recorded as masked. Further details about allocation procedures, eligibility criteria, baseline characteristics, intervention adherence, and the original design assumptions are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

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 Feasibility of In-home Body Image (BI) -Focused Expressive Writing (EW) Intervention for Post-treatment Adolescent and Young Adult (AYA) Cancer Survivors With BI Distress (Recruitment), measured over 6 months.

The primary endpoint is recruitment feasibility: the record describes it as the percent of patients recruited within 6 months. Its unit is participants, and the posted arm-level result is a count of 10 in the expressive-writing arm and 10 in the attention-control arm. The arm denominators listed for this comparison are 14 and 13, respectively. The registry record does not explain the precise denominator used to define the percentage in the endpoint description, such as the number of eligible or approached people.

A recruitment endpoint is used in a feasibility study to assess whether a proposed study population can be enrolled within a specified period. This can help characterize whether a larger or more definitive study is operationally plausible. It is distinct from an endpoint measuring symptom severity, anxiety, intervention engagement, or change from baseline.

The record’s study summary says the intervention was intended to address body image distress and anxiety, but the posted primary result does not quantify either outcome. The endpoint therefore supports interpretation about recruitment as recorded, not conclusions about psychological benefit or harm. The registry record does not report a recruitment target or a prespecified threshold for judging recruitment feasibility.

7. Results Posted in the Registry

• Expressive Writing (EW): 71.4% (10/14) versus 76.9% (10/13) on control; risk difference -5.5 percentage points (95% CI -38.4 to 27.4), risk ratio 0.93 (0.59–1.45); unadjusted two-proportion z-test p = 0.745.

8. Statistical Interpretation

9. Statistical Methods Explained

What does a risk difference describe?

For a binary outcome, such as whether a participant is counted for a recruitment measure, a risk is the proportion with that outcome in a group. A risk difference subtracts one group’s risk from the other’s. In this comparison, the estimated risk difference is -0.055 for expressive writing relative to attention control. A value below zero indicates that the estimated proportion is lower in the expressive-writing arm on this coding of the comparison. The interval from -0.384 to 0.274 expresses uncertainty around that estimate and includes zero, the value corresponding to no difference.

The endpoint description calls the measure a percent of patients recruited within 6 months, while the reported unit and arm-level values are participants and counts. The record does not specify the eligible or approached population denominator used for that percentage. Interpreting the arm comparison as a difference in recruitment proportions is consistent with the posted risk-difference calculation, but the operational definition should be clarified for a full assessment.

How do relative measures differ?

A relative risk compares the risks in two groups by division. An odds ratio compares the odds, rather than the risks, in each group. These relative measures can communicate contrasts on a proportional scale, while the risk difference gives an absolute contrast on the risk scale. They may look different numerically because they use different scales; they are not separate outcome results. The registry comparison reports a relative risk of 0.929 and an odds ratio of 0.75.

For the relative risk, a value of 1 corresponds to equal risks; for the odds ratio, a value of 1 corresponds to equal odds. Their respective confidence intervals, 0.595 to 1.45 and 0.132 to 4.25, include 1. Neither interval establishes a clear between-arm separation. Odds ratios are not interchangeable with risk differences, and their interpretation depends on the underlying risks. In a small study, all of these estimates can be sensitive to the observed counts.

What does the p-value add?

The posted unadjusted p-value is 0.745. A p-value is a measure of how unusual data at least as discrepant as those observed would be under a specified null model and its assumptions. It is not the probability that the null hypothesis is true, nor is it a measure of the size or practical importance of a difference. It also does not indicate whether a study was adequately powered. The p-value should not replace the estimate and confidence interval, particularly when the interval spans effects in either direction.

The registry record identifies the p-value as unadjusted. It does not report an adjusted comparison or covariates used in a model. Because the trial is randomized, an unadjusted arm comparison may be a direct summary of the randomized groups, but randomization does not guarantee that every characteristic is balanced in a small sample. Baseline characteristics and any prespecified analysis model are not reported in the registry record.

Why do confidence intervals matter?

A confidence interval gives a range of values compatible with the observed data under the statistical procedure used, while reflecting sampling uncertainty. A narrow interval indicates greater precision for the parameter on that scale; a wide interval indicates less precision. For the risk difference, the interval extends from -0.384 to 0.274, spanning the no-difference value and meaningfully different directions. The relative-risk and odds-ratio intervals are also wide. These features make the estimates uncertain, rather than proving that the arms are the same.

Confidence intervals do not account automatically for every possible source of uncertainty. They rely on the statistical model and endpoint definition, and they do not resolve uncertainties about missing data, selection, measurement, or generalizability. Those details are not reported in the registry record.

What is and is not documented about the analysis?

The posted comparison contains a binary-outcome estimate, confidence limits, and an unadjusted p-value. The record lists no separate analysis entries. It does not report the original sample-size assumptions, a prespecified statistical analysis plan, an interim-analysis plan, the handling of missing outcomes, or the analysis population. These omissions limit assessment of whether the reported comparison follows a prespecified plan or how participants with incomplete data were handled.

There are five outcome measures identified in the record, but no secondary results are posted. Without a complete outcome-level analysis plan and results, it is not possible to determine whether or how multiple comparisons were controlled. General statistical practice recognizes that testing multiple outcomes can increase the chance of at least one apparently notable finding by chance; that general concern does not establish that such a finding occurred in this trial.

10. Confidence Intervals and Precision

The primary risk-difference estimate is -0.055, and its confidence interval runs from -0.384 to 0.274. Because the interval contains zero, the data are compatible with no between-arm difference as well as with differences favoring either direction on the recruitment-proportion scale. The interval is wide relative to the estimate, so the result does not pin down the magnitude of the contrast precisely.

The relative risk is 0.929, with a confidence interval from 0.595 to 1.45. The odds ratio is 0.75, with a confidence interval from 0.132 to 4.25. Each interval includes 1, the no-difference value for its relative scale, and each allows a substantial range of possible contrasts. These intervals reinforce that the comparison is uncertain; they do not demonstrate equivalence between the arms.

Precision is limited in part by the small posted arm denominators, 14 and 13. In general, fewer observations tend to yield less precise estimates, especially for binary outcomes when the number of events is limited. The displayed intervals quantify sampling uncertainty under the calculations used, but they do not address uncertainty from an unclear recruitment denominator, missing data, or unreported analytic choices. Those issues are not described in the registry record.

The unadjusted p-value of 0.745 is consistent with an estimate that does not clearly separate the arms, but the confidence interval is more informative about the range of effects compatible with the data. The interval should be read as uncertainty around the estimated recruitment contrast, not as a range containing a known true value with certainty and not as evidence that the intervention had no effect on other outcomes.

11. 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 event counts. They are illustrative calculations based on the observed effect, rather than the trial’s own design assumptions. The registry record does not report the original sample-size justification or the assumptions used to plan this pilot.

The listed planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. For each row, the effect to detect is defined as the stated fraction of the observed effect. The 80% power column describes the participants per arm estimated to give an 80% chance of detecting that specified effect under those assumptions, if the assumptions and model apply. The 90% column gives the corresponding per-arm planning figure for a 90% chance. These are planning targets, not observed participant counts.

The figures increase as the assumed effect becomes smaller: the rows consider 100%, 75%, and 50% of the observed effect. This is the expected general pattern because smaller between-arm differences are harder to distinguish from random variation, so more participants are needed to detect them with the same planned power and significance level. For example, the 100% row lists 995 participants per arm for 80% power and 1,332 for 90% power; the 75% row lists 1,739 and 2,327; and the 50% row lists 3,841 and 5,142.

These figures are not observed power. They are planning illustrations derived from the observed effect and should not be treated as a retrospective score of whether the trial succeeded. Because the observed effect comes from a small feasibility comparison, it is uncertain; using it as the basis for planning can produce unstable estimates. The illustrations also do not substitute for a prospectively specified sample-size justification.

12. 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, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.769; treatment proportion p₁ = 0.714; average p̄ = 0.742.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6190 = 1.2131.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.6177 = 0.5199.
4. n = (1.2131 + 0.5199)² / (-0.0549)² = 994.8, rounded up to 995 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
p0 <- 0.769230769230769                          # control proportion
p1 <- 0.714285714285714                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^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 (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(6046014)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 995 (80% power), 1,332 (90% power)
 75% of observed effect: n per arm = 1,739 (80% power), 2,327 (90% power)
 50% of observed effect: n per arm = 3,841 (80% power), 5,142 (90% power)
power.prop.test: 994.8 
Simulated power at n = 995 per arm: 0.801 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-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.

13. Multiplicity, Missing Data and Analysis Populations

The registry record identifies five outcome measures, but no secondary results are posted. Only the recruitment result is described in the posted comparison. The record does not state whether a hierarchy of outcomes was prespecified, whether any multiplicity adjustment was planned, or how multiple outcomes were to be interpreted. Without those details and the secondary results, the extent to which multiple testing is relevant to the reported findings cannot be assessed.

Missing-data procedures are not reported in the registry record. It is not stated how missing recruitment information or missing outcome measurements, if any, were handled. The record also does not identify whether the comparison used an intention-to-treat, per-protocol, or another analysis population. The posted arm denominators are 14 and 13, while the overall enrollment entry is 30; the record does not explain the relationship between those entries or whether all enrolled participants contributed to each outcome.

The analysis plan is not reported, and the record contains no separate analysis entries. It does not describe an interim-analysis plan, covariate adjustment, or any sensitivity analyses. These absences do not show that such procedures were or were not used outside what is registered; they mean that the registry record does not document them.

These limitations matter because analysis choices can affect how an estimate is interpreted. For example, exclusion of participants with incomplete outcomes can change the population represented by a comparison, while multiple outcome testing can complicate interpretation of isolated findings. No such effect can be determined from the posted recruitment result alone. The primary endpoint’s denominator is also not fully explained, limiting assessment of what recruitment rate the reported counts represent.

14. 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 record reports zero serious adverse events and zero other adverse events for the expressive-writing arm, with 14 participants at risk in each category. It reports zero serious adverse events and zero other adverse events for the attention-control arm, with 13 participants at risk in each category. Deaths are reported as 0 in both groups.

These entries describe the posted event counts, not a complete assessment of safety. The registry record does not report the event definitions, the method or frequency of ascertainment, or the timeframe covered by adverse-event monitoring. Zero recorded events in these groups does not establish that no events occurred outside the reported collection or that a risk is absent. The counts should be understood within the size and reporting scope of this trial, rather than as a general estimate of safety in all AYA cancer survivors.

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

The central result is a small feasibility comparison with 10 participants recorded for the recruitment measure in each arm. The estimated risk difference is -0.055, and its confidence interval, -0.384 to 0.274, allows effects in either direction. The relative measures likewise have confidence intervals that include their respective no-difference values. Taken together, the posted statistics do not provide a precise estimate of the difference in recruitment between the writing programs.

This result does not show that expressive writing reduced body image distress or anxiety. Those concerns motivate the study and appear in its stated hypothesis, but no secondary results are posted and the primary endpoint is recruitment. Nor does the result establish that the writing programs have equivalent recruitment, because the uncertainty is broad. It is a report of what the small randomized comparison estimated, not a definitive judgment about the programs.

The record’s enrollment entry is 30, whereas the arm denominators for the comparison are 14 and 13. The registry does not explain this relationship. The endpoint description refers to a percent recruited within 6 months, but the precise denominator for that percentage is not specified. Those reporting details matter for interpreting the absolute recruitment level and comparing it with future studies.

The trial can be considered in the context of its feasibility purpose: it reports a recruitment measure within a specified timeframe and compares that measure across two randomized groups. The result may help identify questions for future study design, including how to define recruitment denominators and what sample size is needed for more precise outcome estimates. It does not, by itself, answer whether the intervention changes psychological outcomes, and it should not be generalized beyond the population and setting described in the registry record without additional evidence.

16. Why This Trial Matters Statistically

Feasibility studies ask whether key study processes can be carried out and measured, not only whether an intervention changes a clinical or psychological outcome. In this trial, recruitment within 6 months is the posted primary endpoint. Treating recruitment as the endpoint keeps interpretation aligned with the study’s stated pilot purpose and avoids reading the result as a symptom-effect estimate.

The trial is randomized and compares an in-home body-image-focused expressive-writing program with an attention-control writing program. This design makes a between-arm recruitment comparison possible, but the posted arm denominators are small. The confidence interval for the risk difference is consequently important: it makes clear that the estimate is uncertain and compatible with several directions and magnitudes of difference. A point estimate alone would not convey that uncertainty.

Statistically, the record also illustrates why endpoint definitions and denominators matter. The primary description refers to a percentage recruited within 6 months, while the reported outcome is expressed as participant counts and the precise recruitment denominator is not explained. Transparent definitions are needed to judge what a feasibility result represents and to plan comparable future work.

Finally, the study’s motivation concerns body image distress and anxiety, while the posted primary result is about recruitment and no secondary results are posted. Separating feasibility evidence from outcome evidence is essential: a recruitment result can inform the practical planning of further research, but it cannot substitute for estimates of changes in distress or anxiety. The distinction helps keep the statistical conclusion proportional to what the registry record reports.

17. 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 posted arm denominators are 14 and 13, and the confidence interval for the risk difference is broad. The resulting comparison is imprecise and should not be treated as a stable estimate of a recruitment contrast. The record lists overall enrollment as 30 but does not explain why the comparison denominators differ from that entry or whether all enrolled participants are represented in the primary outcome analysis.

The endpoint description refers to the percent recruited within 6 months, but the registry record does not identify the eligible or approached population denominator used to calculate a recruitment percentage. Although the comparison reports counts of 10 in each arm, the relationship between those counts and the endpoint’s percentage wording is not detailed. A recruitment target or threshold for deeming the study feasible is also not reported.

The record does not report participant demographics, cancer types, recruitment sources, baseline characteristics, adherence, or intervention completion. It therefore provides limited information about how closely the enrolled participants reflect the intended population or how fully the writing programs were delivered. The record lists no masking, and it does not report an original analysis plan or sample-size justification.

Only the primary recruitment result is posted; no secondary results are available for the body image distress and anxiety concerns named in the study rationale. Missing-data methods, analysis populations, and multiplicity procedures are not reported. Adverse-event counts are posted, but the collection timeframe and ascertainment methods are not described. These trial-specific reporting gaps limit interpretation of recruitment, outcome effects, and safety beyond the recorded counts.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: Feasibility of Expressive Writing for Body Image Distress and Anxiety Among Adolescent and Young Adult Cancer Survivors — NCT06046014.
• Registry record last updated 2026-05-11; status last verified 2026-05.
• Results first posted 2026-05-11.
• 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.

21. Record Summary

NCT06046014 is a completed randomized, parallel, non-masked feasibility trial sponsored by the University of Michigan Rogel Cancer Center. It compares a four-week, in-home, body-image-focused expressive-writing program with a four-week attention-control writing program among post-treatment adolescent and young adult cancer survivors with body image distress. The listed enrollment is 30.

The primary endpoint concerns recruitment within 6 months. The posted comparison records 10 participants in each arm, with arm denominators of 14 and 13. The risk-difference estimate is -0.055, with a confidence interval from -0.384 to 0.274 and an unadjusted p-value of 0.745. No secondary results are posted. The record reports zero serious adverse events, zero other adverse events, and zero deaths in each arm. It does not report the original sample-size assumptions, missing-data methods, or analysis populations.