Development of a Resiliency Training Program for Parents of Children With Specific Learning Disabilities: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Development of a Resiliency Training Program for Parents of Children With Specific Learning Disabilities (NCT02772432), a randomized na study. The primary outcome is Distress.

2. Clinical Question

The primary outcome is a self-reported distress score. A higher score indicates more distress, so the direction of a change score is meaningful: a negative change indicates lower distress at follow-up than at baseline, while a positive change indicates higher distress. The posted group summaries and comparison describe the observed change contrast. They do not by themselves establish how broadly the findings apply to other parents, settings, or forms of support.

3. Trial Design

The registry identifies this as a randomized, parallel-group study with no masking. It reports 53 participants enrolled and a completed status. The study was sponsored by Massachusetts General Hospital. The recorded start date is 2016-09-01, and the primary completion date is 2018-05-18. The phase is listed as not applicable.

The study summary describes a developmental program with distinct aims. Phase I used focus group interviews with expert clinicians, organizational leaders, and parents of children with special needs to identify psychosocial needs, difficult concerns, areas where support or resources were lacking, and needs for education or skills training. It also sought feedback on the Benson-Henry Institute's Relaxation Response Resiliency Program. Phase II used those findings to develop and assess feasibility and acceptability of a virtual 8-session program for parents of children with specific learning disabilities, and to test it in a pilot wait-list control trial.

The registry lists 3RP treatment and waitlist control as the arms. The treatment description specifies an adapted program incorporating relaxation-response elicitation, stress awareness, and adaptive strategies. The waitlist arm is identified as the control, but the record does not explain its activities in detail or the timing of any later access to the program.

For the primary outcome, the posted group sizes are 31 for 3RP treatment and 22 for waitlist control. The record identifies a mean change in distress from baseline (week 0) to 12 weeks post intervention as the primary endpoint. It also lists stress reactivity as a secondary outcome. The allocation sequence method, concealment procedures, masking of outcome assessment, and details of the randomized implementation are not reported in the registry record. A clinicaltrials.gov phase label of not applicable should not be read as evidence about the clinical maturity or effectiveness of the intervention.

4. Participant Flow and Accounting

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

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Distress, measured over change between baseline (week 0) to 12 weeks post intervention.

The primary endpoint is change in distress between baseline (week 0) and 12 weeks post intervention. Distress was measured with the Visual Analog Scale (VAS)-Distress, a 1-item scale on which respondents rate their distress from 0 to 10. The registry states that higher scores indicate more distress. The endpoint is reported as a mean change score, with standard deviations describing variation among participants in each arm.

A change score focuses on how a participant's recorded distress differs between the two assessment times, rather than on a single follow-up score alone. Comparing mean changes between randomized groups can describe whether the groups moved in different directions over the study period. In this record, a negative mean change corresponds to lower distress at follow-up relative to baseline, and a positive change corresponds to higher distress.

Self-reported distress is relevant to a program aimed at parents' psychosocial needs and stress. A brief single-item rating can capture participants' own assessment of distress, though it does not describe every dimension of psychosocial wellbeing. The registry does not report the scale's validation properties in this particular population, a threshold for a meaningful change, or further details about how the outcome was administered. The endpoint therefore supports interpretation of the posted distress ratings, not broader claims about all aspects of resilience or family wellbeing.

7. Results Posted in the Registry

• 3RP Treatment: mean -1.47 versus 0.48 on control; difference -1.95 (95% CI -3.25 to -0.65), standardized effect d = -0.81; z-test p = 0.003.

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.

Stress Reactivity

• 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:
  • 3RP Treatment: mean 7.74 versus -0.95 on control; difference 8.69 (95% CI 5.41 to 11.97), standardized effect d = 1.33; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for 3RP Treatment than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Stress reactivity is the one secondary endpoint with posted group summaries. Its comparison points in the opposite numerical direction from the primary distress contrast: the treatment-arm mean change is 7.74 and the waitlist-control mean change is -0.95, giving a posted mean difference of 8.69. The confidence interval for that contrast is 5.406 to 11.97, and the unadjusted p-value is <0.001. Those figures describe the numerical direction and uncertainty of the recorded score change, but the registry does not define the scale's direction or provide enough information to say whether an increase represents more or less stress reactivity.

The primary distress result and the secondary stress-reactivity result therefore should not be combined into a single claim about improvement. They are distinct outcomes, and the record does not state how they were intended to relate conceptually or how a change in stress reactivity should be interpreted. The secondary result may provide additional context about the intervention's measured outcomes, but its scale description is insufficient to assign a favorable or unfavorable meaning to its direction.

Secondary outcomes commonly have a more exploratory role than a prespecified primary endpoint. When multiple outcomes are examined, the chance of obtaining at least one apparently notable result by chance can increase. Statistical adjustment or a hierarchy of testing can address some multiplicity concerns, but the registry does not report whether such a procedure was planned or used. The secondary comparison is unadjusted, and the registry has no reported secondary analysis entries. It therefore carries less confirmatory weight than a fully prespecified, transparently analyzed primary result, while still being a relevant finding to consider in planning future research.

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

• Stress Reactivity

9. Statistical Interpretation

10. Statistical Methods Explained

What does a mean change represent?

For a continuous measure such as a distress score, the mean is the arithmetic average across participants with recorded values. A change score expresses the difference between a participant's follow-up score and baseline score according to the study's scoring convention. The registry reports mean changes for each arm and standard deviations around those changes. The mean summarizes the center of the group results, while the standard deviation describes how dispersed the individual changes are around that center. Neither statistic alone shows the full distribution or whether some participants had very different experiences.

In general, a change-score comparison asks whether the average movement over time differs between groups. This differs from comparing only follow-up scores because baseline values contribute to each participant's change. The registry record does not provide the baseline and follow-up means separately, so those values cannot be reconstructed from the posted change summaries. Nor does the record describe a model that adjusts for baseline score or other characteristics.

How should the mean difference be read?

The mean difference is the treatment-arm mean change minus the waitlist-control mean change. In this record it is -1.95. The negative sign indicates that the average change was lower in the treatment arm than in the control arm. Because higher VAS-Distress scores mean greater distress, that direction corresponds to a more favorable change in the treatment group on this measure. The estimate is a contrast between group averages; it is not a statement that each individual participant's score changed by that amount.

The posted p-value is unadjusted. In general, a p-value describes how unusual data at least as incompatible with a no-difference model would be if that model and the test assumptions were correct. It does not give the probability that the no-difference model is true, the probability that the program is effective, or the size or practical importance of a difference. The value 0.003 is evidence against a zero mean difference under the unadjusted calculation, but it should be considered alongside the estimate, its interval, the design, and the incompleteness of the analysis record.

What does the confidence interval add?

A confidence interval represents uncertainty around an estimate under the method used to calculate it. It gives a range of values that are compatible with the observed data and statistical assumptions at the stated confidence level. The primary comparison's interval runs from -3.248 to -0.652, and it excludes zero. That feature is consistent with the unadjusted p-value. The interval does not account for every source of uncertainty, such as selective reporting, measurement limitations, or errors in the assumptions used for the calculation.

The comparison is a simple unadjusted recalculation from posted summary statistics. The record does not list a reported primary analysis or provide a model specification, standard-error method, or analysis population. General statistical interpretation should therefore distinguish the arithmetic contrast derived from the summaries from an analysis that might have been planned or performed by study investigators. No discrepancy is flagged for the posted primary result, but that does not substitute for a full statistical analysis plan.

Why can spread and sample size affect precision?

In general, estimates are less precise when observations vary widely or when there are fewer observations. The standard deviations for the primary change scores are 2.44 for treatment and 2.33 for control. These summarize observed variability, while the confidence interval communicates uncertainty in the difference between the means. A confidence interval is not a range containing every participant's result. Individual change scores can fall outside it, because it describes uncertainty about the group contrast rather than the spread of individual observations.

The equal-allocation assumption appearing in the planning illustration is a planning convention, not a description of the observed allocation. The posted group sizes are 31 and 22. No original sample-size justification, target enrollment rationale, or trial-specific power calculation is reported in the registry record. Planning estimates calculated from the observed result should not be mistaken for the design assumptions used when the study began.

What does an unmasked randomized design contribute?

Randomization is intended to make assignment independent of participant characteristics, on average, and can support a causal comparison when allocation and follow-up are implemented appropriately. The record confirms randomized allocation but does not report how the sequence was generated, whether allocation was concealed, or whether analyses followed assignment. No masking was used. For a self-reported outcome, awareness of assignment may influence expectations or responses. These considerations do not erase the observed contrast, but they qualify what can be attributed to the assigned program.

In general, a waitlist control can help compare change over the same period against a group not yet receiving the intervention. It does not necessarily control for attention, group contact, or expectations to the same degree as an active comparison. The registry does not give enough detail about the waitlist experience to assess those possibilities. The recorded contrast is consequently between the assigned program and the waitlist condition as implemented, rather than between specific isolated treatment components.

11. Confidence Intervals and Precision

The primary mean difference is -1.95, and its confidence interval extends from -3.248 to -0.652. The full interval lies below zero, so the data are compatible with a negative mean change difference under the unadjusted calculation. The interval's width also shows that the point estimate should not be treated as exact: a range of negative contrasts remains compatible with the calculation. The interval does not establish that the true contrast equals the central estimate.

In general, a confidence interval conveys both direction and precision. An interval that excludes zero is often associated with a small p-value under a corresponding test, as is the case in the posted primary comparison. But excluding zero does not by itself show that the effect is large, meaningful to participants, or likely to recur in another sample. The registry does not report a threshold for a clinically or personally important change in VAS-Distress, so the practical interpretation of values within the interval cannot be settled from this record.

The group standard deviations, 2.44 and 2.33, reflect variability in observed change scores. The interval for the mean difference concerns uncertainty about the contrast between group averages, not the range of individual outcomes. It should not be read as a prediction interval for a new participant or as evidence that every participant experienced reduced distress.

The estimates also have limitations beyond sampling uncertainty. The study was a pilot, the primary outcome was self-reported, and the trial was unmasked. The registry does not report missing-data methods, the number of participants contributing outcome data at each time, or a detailed analysis plan. A conventional confidence interval does not incorporate uncertainty from those unreported design and analysis details. Thus, the interval is useful for describing precision in the posted calculation, but it cannot resolve broader questions about bias, generalizability, or reproducibility.

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 events. They are illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The illustrations consider detecting the full observed effect, 75% of the observed effect, or 50% 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 gives the planned number of participants per arm for a design with an 80% chance of detecting the specified effect under the stated assumptions, if that effect is the true one and the model assumptions hold. The 90% power column uses a higher target chance of detection under those same assumptions. In plain terms, higher planned power generally calls for more participants when the other assumptions are held constant. These columns are planning illustrations, not a description of the study's observed power.

The rows based on smaller fractions of the observed effect require larger participant counts than planning for the full observed effect. This is expected in general: smaller differences are harder to distinguish from random variation, so more information is needed to detect them with the same power target. The figures rely on the effect estimated in this pilot, which may be uncertain and may not represent the effect in a future study. They should be interpreted as conditional planning scenarios, not as evidence that a future trial will produce the observed result.

The posted group sizes were 31 for 3RP treatment and 22 for waitlist control. The planning illustrations assume equal allocation, unlike the observed arm counts. The registry does not report an original target based on a prespecified effect or variance. The displayed curve should be read as a visual version of the same planning relationship: as the target effect gets smaller, the required participants per arm increase under the stated assumptions.

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 = -1.950; pooled standard deviation σ = 2.395.
2. n = 2 × (1.96 + 0.842)² × 2.395² / -1.950² = 23.7, rounded up to 24 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 <- -1.95                      # observed difference in means
sigma <- 2.39531773650669                     # 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(2772432)
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 = 24 (80% power), 32 (90% power)
 75% of observed effect: n per arm = 43 (80% power), 57 (90% power)
 50% of observed effect: n per arm = 95 (80% power), 127 (90% power)
power.t.test: 24.7 
Simulated power at n = 24 per arm: 0.789 (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

Multiplicity concerns arise when a study assesses several outcomes, time points, subgroups, or analyses. In general, each additional statistical test creates another opportunity for a result to appear notable by chance. This study record lists a primary distress outcome and stress reactivity as a secondary outcome, and it reports three outcome measures overall. The registry does not report a multiplicity adjustment, a testing hierarchy, or a strategy for identifying which outcomes would be confirmatory. The unadjusted p-values should therefore be interpreted as individual comparisons rather than as results adjusted for the full set of outcomes or analyses.

The registry does not report missing-data methods, an imputation approach, or how participants without outcome measurements were handled. It also does not report outcome-specific numbers assessed at follow-up or the extent of missingness. Without those details, it is not possible to assess whether the posted means represent all randomized participants, only participants with complete observations, or another analysis population. The posted arm counts do not by themselves establish the number contributing data to each endpoint.

The analysis population is not described in the record. It does not state whether the primary comparison followed an intention-to-treat principle, included participants according to treatment received, or used a per-protocol subset. The registry lists randomized allocation, but the analysis plan, treatment adherence definitions, and handling of protocol deviations are not reported. The number of reported analyses is zero for the primary record, and no secondary analyses are listed. This limits the ability to distinguish prespecified investigator analyses from the simple unadjusted comparisons calculated from the posted summaries.

These omissions matter because choices about missing values, analysis populations, and multiplicity can affect estimates and uncertainty. Their absence from the registry record does not establish that investigators did not address them; it means the record does not document how they were handled. Interpretation should remain tied to the posted summaries and avoid treating the p-values as a complete account of the analysis.

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.

The registry reports zero serious adverse events among 31 participants at risk in the 3RP treatment group and zero among 22 participants at risk in the waitlist control group. It also reports zero other adverse events in both groups and zero deaths in both groups. These are the recorded figures for the study arms.

A recorded count of zero means no events of the listed type were reported in the registry for the specified group. It does not establish that no participant experienced any symptom or difficulty, and it does not show that uncommon harms are impossible. Interpretation also depends on how events were defined, collected, monitored, and attributed. The registry does not provide additional detail about event definitions, surveillance procedures, or reporting thresholds. These figures should therefore be read as the posted adverse-event counts, not as a complete characterization of safety.

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

The principal statistical result is a negative unadjusted mean difference in change in distress for 3RP treatment relative to waitlist control: -1.95. The posted confidence interval lies below zero, and the unadjusted p-value is 0.003. Together, these statistics describe a difference in average change between the randomized groups over the stated follow-up, with the treatment group's average moving toward lower distress on a scale where higher scores indicate more distress.

The result does not mean that every participant experienced reduced distress, or that the difference is necessarily important to participants. The record gives no threshold for meaningful change on the VAS-Distress measure. It also does not show individual response patterns, longer-term outcomes, or whether any difference persisted beyond 12 weeks post intervention. The primary endpoint is a single-item self-report and cannot stand in for every aspect of parental resilience, wellbeing, or family experience.

The study was randomized but unmasked, and the endpoint was self-reported. The registry does not document allocation concealment, a detailed analysis plan, missing-data handling, or the analysis population. These gaps limit how confidently the summary contrast can be attributed to the program alone. The waitlist design does not necessarily distinguish the program's specific components from attention, expectations, or other differences in experience.

The posted estimates are useful as pilot evidence about the observed outcome in this study, not as a definitive effect estimate for all parents of children with specific learning disabilities. The study summary describes aims concerning program development, feasibility, acceptability, and pilot effectiveness, but the registry record does not report detailed feasibility or acceptability results. The statistical findings alone cannot establish whether the program works or does not work, whether it should be used, or whether similar results would occur in a larger study.

17. Why This Trial Matters Statistically

This trial is statistically informative because it connects a program-development effort with a randomized comparison and a defined primary outcome. Its focus is a specific population: parents of children with specific learning disabilities. The registry describes an adaptation of a resiliency program, informed by focus groups about psychosocial needs, and a pilot wait-list control evaluation. That developmental context matters when deciding what conclusions a small randomized study can support.

The primary result illustrates the difference between reporting a point estimate and reporting uncertainty. The observed mean difference is -1.95, while the confidence interval communicates a range of values compatible with the unadjusted calculation. The group standard deviations also indicate that participant-level changes varied. Readers can therefore distinguish a group-average contrast from a guaranteed or uniform individual response.

The record also demonstrates why a statistically notable result is not the same as a complete evidentiary account. The randomized design is a strength for comparison, but the absence of masking, the self-reported endpoint, and missing documentation about analysis populations and missing data constrain interpretation. The secondary outcome's numerical result cannot be given a directional meaning without information about its scale. These are questions of measurement and reporting as well as statistical significance.

Finally, planning illustrations based on an observed pilot effect can help describe how assumptions about the target effect relate to future sample size. They are not a replacement for a prespecified design calculation. The registry does not report the original sample-size justification, so the illustrations should be separated from the trial's actual design history. This distinction is important when using pilot results to plan confirmatory research.

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 information recorded for this study. The primary endpoint is a single self-reported distress item, and the registry does not report validation details for this population or a threshold for a meaningful change. The study was unmasked, leaving self-reported scores potentially susceptible to expectations or awareness of assignment. The intervention is a multicomponent program, so the comparison cannot identify which component, if any, corresponds to the observed difference.

The trial is described as a pilot, with 31 participants in the treatment arm and 22 in the waitlist control arm. A pilot estimate can be imprecise and may not predict the result in another sample. The record does not report the original sample-size rationale, randomization sequence method, allocation concealment, analysis population, missing-data approach, or participant flow by outcome. It is therefore difficult to evaluate attrition, adherence, or the potential impact of incomplete outcome data.

The waitlist condition is not described in detail, and the record does not establish whether participants could access other services or when they might receive the program. The registry also does not report the direction or interpretation of the stress-reactivity scale, which limits understanding of the secondary result. No multiplicity approach is documented, and the posted analyses do not include investigator-reported analysis entries.

The recorded follow-up is 12 weeks post intervention. The registry does not report longer-term distress outcomes in this record, nor detailed feasibility or acceptability findings despite those being among the study's aims. As a result, these posted outcome summaries provide a limited view of the pilot and cannot answer questions about durability, implementation, or broader applicability.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Development of a Resiliency Training Program for Parents of Children With Specific Learning Disabilities — NCT02772432.
• Registry record last updated 2019-09-10; status last verified 2019-09.
• Results first posted 2019-09-10.
• 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

NCT02772432 is a completed, randomized, parallel-group study sponsored by Massachusetts General Hospital. It enrolled 53 participants and compared an adapted Relaxation Response Resiliency Program for parents of children with specific learning disabilities with a waitlist control. The study summary describes program development, feasibility and acceptability aims, and a pilot test.

The primary outcome was change in VAS-Distress from baseline (week 0) to 12 weeks post intervention. The posted mean changes were -1.47 for treatment and 0.48 for control, with an unadjusted mean difference of -1.95 and an unadjusted p-value of 0.003. The record also lists stress reactivity as a secondary outcome, but does not report its scale direction. Analysis-plan details, missing-data methods, and original sample-size assumptions are not reported in the registry record.