Improving Mind/Body Health and Functioning With Integrative Exercise: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Improving Mind/Body Health and Functioning With Integrative Exercise (NCT02856412), a randomized na study. The primary outcome is Clinician Administered PTSD Scale (CAPS) Score Comparison Between Subjects Randomized to Integrative Exercise Treatment vs. Illness Management and Recovery.

2. Clinical Question

3. Trial Design

This was a randomized, parallel-group trial with single masking. The registry lists the study as completed, with enrollment of 84 and no applicable phase designation. The study was sponsored by the VA Office of Research and Development. Its listed start date is 2017-09-04, and its primary completion date is 2023-02-01.

One group was assigned to Veterans Group Exercise, the integrative exercise intervention. The other was assigned to Illness Management and Recovery, a health education program. Both programs were scheduled three times weekly for 12 weeks, and each session was described as lasting approximately 60 minutes. The exercise program included strength, flexibility, cardiovascular, and controlled-breathing elements. The registry description of the education classes is incomplete, so additional details about their content are not reported in the registry record.

The primary endpoint was the CAPS-5 score at 12 weeks. The posted group summaries include 41 participants in Veterans Group Exercise and 43 in Illness Management and Recovery. Random allocation supports a comparison between assigned groups, but the registry does not report how the randomization sequence was generated or concealed. It identifies masking as single without specifying who was masked. Those procedural details are not reported in the registry record.

The registry lists secondary measures covering mindfulness, leisure-time exercise, PTSD symptoms, general symptoms, sleep quality, and insomnia severity. Numeric results are posted for some of these measures. The record does not describe the original sample-size justification, a detailed analysis plan, or how participants were handled in the analysis if they did not complete the assigned program.

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 Clinician Administered PTSD Scale (CAPS) Score Comparison Between Subjects Randomized to Integrative Exercise Treatment vs. Illness Management and Recovery, measured over 12 weeks.

The primary endpoint is the Clinician Administered PTSD Scale score at 12 weeks. The record describes the CAPS-5 as a 20-item measure with dimensional and categorical assessment of PTSD. The dimensional score ranges from 0–80, with higher scores indicating worse symptom severity. Items combine symptom frequency and intensity, and the assessment also addresses matters such as symptom duration, distress, functioning, overall severity, response validity, and the dissociative subtype.

A clinician-rated symptom measure provides a structured way to characterize PTSD severity at the specified follow-up. Comparing the group means gives a concise estimate of how average endpoint scores differed between the randomized groups. The reported means are 24.4 for Veterans Group Exercise and 22.0 for Illness Management and Recovery. The listed mean difference is -2.4, with the comparison expressed as the Illness Management and Recovery mean relative to Veterans Group Exercise.

The score’s direction is important: a lower CAPS-5 score indicates less measured severity, not a benefit established by the score alone. The posted result is an endpoint comparison, not a report of change from baseline. Baseline CAPS-5 results, a baseline-adjusted estimate, and details on who completed the assessment are not reported in the registry record. The result therefore describes the recorded group means at 12 weeks and their estimated contrast, rather than the course of symptoms within individuals.

7. Results Posted in the Registry

• Illness Management and Recovery: mean 22.00 versus 24.40 on control; difference -2.40 (95% CI -7.19 to 2.39), standardized effect d = -0.21; z-test p = 0.326.

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.

Five Facet Mindfulness Questionnaire (FFMQ)- Observing

• 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:
  • Illness Management and Recovery: mean 26.40 versus 22.20 on control; difference 4.20 (95% CI 0.12 to 8.28), standardized effect d = 0.44; z-test p = 0.044.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for Illness Management and Recovery than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Godin Leisure-Time Exercise Questionnaire

• 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:
  • Illness Management and Recovery: mean 43.80 versus 44.20 on control; difference -0.40 (95% CI -16.75 to 15.95), standardized effect d = -0.01; z-test p = 0.962.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Illness Management and Recovery and the control. The interval gives the range of effects that remain compatible with the data.

PTSD Checklist for DSM-5 (PCL-5)

• 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:
  • Illness Management and Recovery: mean 39.90 versus 36.30 on control; difference 3.60 (95% CI -3.52 to 10.72), standardized effect d = 0.22; z-test p = 0.322.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Illness Management and Recovery and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists secondary measures spanning mindfulness, leisure-time exercise, PTSD symptoms, general symptoms, sleep quality, and insomnia severity. Numeric results are posted for the mindfulness observation score, the Godin leisure-time exercise questionnaire, and the PTSD checklist. The posted patterns are not uniform: the mindfulness contrast is the one with an interval not spanning zero, while the other posted contrasts remain compatible with no difference.

These measures address related but distinct aspects of health and functioning. A mindfulness score or leisure-time exercise score is not interchangeable with clinician-rated PTSD severity. The primary CAPS-5 comparison remains the central result for the study’s stated primary question. The secondary findings can add context, but they cannot be used to resolve uncertainty in the primary estimate or to claim that an effect on one measured domain establishes an effect on another.

Unadjusted secondary results carry less weight because multiple outcomes create more opportunities for chance findings. The registry record does not report a multiplicity plan, a hierarchy among secondary outcomes, or a confirmatory testing strategy. A result that appears more distinct from zero in one secondary measure should therefore be treated as exploratory rather than as standalone confirmation.

The registry also lists sleep quality, insomnia severity, and a general symptom measure among the secondary outcomes, but numeric group comparisons for those measures are not included in the posted outcome records. Their results are not reported in the registry record in the available numeric summaries. The overall secondary picture is consequently incomplete, and it should not be generalized to every listed domain.

The combination of a primary interval spanning zero and mixed secondary patterns supports a cautious reading: the posted data do not show a consistent separation across outcomes. That observation is descriptive, not a formal test that all outcomes are equal or that the programs have no effects in any domain.

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

• Five Facet Mindfulness Questionnaire (FFMQ)- Observing
• Godin Leisure-Time Exercise Questionnaire
• PTSD Checklist for DSM-5 (PCL-5)
• Symptom Check-List-90-Revised (SCL-90-R)
• Pittsburgh Sleep Quality Index (PSQI)
• Insomnia Severity Index (ISI)

9. Statistical Interpretation

10. Statistical Methods Explained

The outcome is continuous, and the registry reports a mean and standard deviation for each group. A mean describes the group’s average score. A standard deviation describes how spread out individual scores are around that average. These summaries help distinguish the estimated location of each group from the variability among participants. They do not show the shape of the score distribution or identify individual participants’ outcomes.

What does the mean difference represent?

The reported primary contrast is -2.4, comparing Illness Management and Recovery with Veterans Group Exercise. The group means are 22.0 and 24.4, respectively. The contrast communicates the estimated difference between those averages, not a difference in the proportions of participants who improved. Since higher CAPS-5 scores indicate worse severity, the negative direction corresponds to a lower average score in Illness Management and Recovery. It does not by itself establish a causal effect or a clinically important difference.

The registry record does not report whether the primary estimate came from a particular regression model, whether it was adjusted for baseline scores, or which analysis population was used. Randomization describes how participants were assigned; it does not supply missing analysis details. The posted comparison should therefore be interpreted using the information actually reported, without assuming an unreported model or adjustment.

How should a confidence interval be read?

In general, a confidence interval expresses uncertainty around an estimated contrast. Its endpoints describe a range of values that are compatible with the data and the method used to calculate the interval. It is not a guarantee that the true difference lies within those endpoints, nor does it assign a probability to each possible value after the data have been observed. The primary interval runs from -7.191 to 2.391 and includes zero. That means the result is compatible with no group difference as well as with differences in either direction.

What does the p-value add?

In general, a p-value describes how unusual results at least as discrepant as the observed result would be under a specified null model. It is not the probability that the null hypothesis is true, nor a measure of the size or importance of a difference. The primary unadjusted p-value is 0.326. The registry does not report enough detail to reconstruct the full analysis procedure, and the record does not state a primary outcome testing threshold for the trial’s own analysis.

“Unadjusted” is relevant because the reported p-value does not account for the possibility of testing multiple outcomes. If many outcomes are examined, some may appear more striking by chance even when there are no underlying differences. The registry does not report a planned correction or other approach for multiplicity. Consequently, secondary p-values should be interpreted with particular caution and should not be treated as confirmatory results.

Why does variability matter?

In general, greater spread in scores makes a group mean less precise when the amount of information is otherwise comparable. The posted standard deviations show substantial variation in scores in both primary groups. The confidence interval reflects uncertainty in the contrast, but the registry does not report a distributional assessment, outlier handling, or diagnostics for the analysis. These omissions make it impossible to assess whether particular modeling assumptions were checked.

The randomization and parallel-group structure support a comparison of assigned groups, but the registry record does not say whether the analysis followed assignment regardless of participation, used only people with observed endpoint values, or followed another rule. It also does not report how missing endpoint measurements were handled. These details can affect the interpretation of a mean comparison, especially if the available observations do not represent all randomized participants in the same way.

In general, over-dispersion matters when an analysis assumes less variability than the observations contain: standard errors may then be too small and uncertainty understated. That is a general statistical consideration, not a conclusion about this trial. The registry does not report a model that addresses over-dispersion or an assessment indicating that it was present. The posted continuous-outcome summaries alone do not establish whether such a model was needed.

11. Confidence Intervals and Precision

The primary mean difference is -2.4, and its confidence interval extends from -7.191 to 2.391. The interval includes zero, so the posted result does not isolate a single direction of difference. It permits values in which the average CAPS-5 score is lower in Illness Management and Recovery, values close to no difference, and values in the opposite direction. The width of the interval indicates that the estimate is not highly precise.

Precision is not the same as truth or clinical importance. A narrower interval would indicate less uncertainty under the method used, but it would not automatically make an estimate clinically meaningful. Conversely, an interval that includes zero does not show that there is no effect. It shows that the available data and analysis do not pin down the contrast tightly enough to rule out the range represented by the interval.

The group standard deviations were 11.1 for Veterans Group Exercise and 11.3 for Illness Management and Recovery. Those values describe variability in individual endpoint scores, not uncertainty in the means themselves. The confidence interval for the contrast is the relevant summary of precision for the between-group estimate. The registry does not report a clinically important difference threshold for the CAPS-5, so the interval cannot be interpreted against such a threshold.

Interpretation is also limited by missing design and analysis details. Baseline scores, a baseline-adjusted contrast, missing-data procedures, and the analysis population are not reported in the registry record. The interval should therefore be read as the uncertainty attached to the posted comparison, without assuming it accounts for those unreported elements.

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 primary effect, rather than the trial’s original enrollment plan. The listed assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and a target effect equal to a stated fraction of the observed effect. The trial’s own original design assumptions and sample-size justification are not reported in the registry record.

The 80% power column gives an illustrative number of participants per arm for a design with an 80% chance of detecting the specified effect under the stated assumptions, if that effect were the true one. The 90% power column describes the corresponding planning target with a greater chance of detecting that effect. These are design calculations, not estimates of the chance that the completed trial found a true effect.

For the primary comparison, planning for 100% of the observed effect gives 343 participants per arm for 80% power and 458 participants per arm for 90% power. Planning for 75% of the observed effect gives 609 participants per arm for 80% power and 815 participants per arm for 90% power. Planning for 50% of the observed effect gives 1,369 participants per arm for 80% power and 1,832 participants per arm for 90% power. The figures increase as the effect to detect becomes smaller, because smaller differences are harder to distinguish from random variation.

These are planning illustrations, not observed power. The trial’s enrollment and posted group sizes should not be compared with them as if they were proof that the trial did or did not have a particular probability of success.

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 = -2.400; pooled standard deviation σ = 11.203.
2. n = 2 × (1.96 + 0.842)² × 11.203² / -2.400² = 342.0, rounded up to 343 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 <- -2.4                      # observed difference in means
sigma <- 11.2028850813682                     # 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(2856412)
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 = 343 (80% power), 458 (90% power)
 75% of observed effect: n per arm = 609 (80% power), 815 (90% power)
 50% of observed effect: n per arm = 1,369 (80% power), 1,832 (90% power)
power.t.test: 343 
Simulated power at n = 343 per arm: 0.793 (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 arises when a study examines more than one outcome or carries out several statistical comparisons. Even when each comparison is analyzed correctly on its own, repeated testing increases the chance that at least one result will look unusual by chance. The registry lists several secondary measures in addition to the primary CAPS-5 endpoint, but a strategy for controlling or interpreting multiplicity is not reported in the registry record.

The posted secondary p-values are unadjusted. They should not be read as if each were the sole prespecified test in the study. The record does not report whether outcomes were prioritized in advance, whether any secondary results were designated exploratory, or whether a correction for multiple comparisons was planned. Without that information, the secondary findings are best treated as descriptive evidence that may guide further research, not as a set of independent confirmations.

Missing-data handling is another important uncertainty. The posted primary group summaries include 41 and 43 participants, but the registry does not explain whether these numbers represent all randomized participants, all participants with an observed 12-week score, or a particular analysis population. It does not report the amount or pattern of missing outcome data, reasons for missingness, imputation, or sensitivity analyses. If missingness relates to participants’ outcomes or their experience in the assigned group, a comparison based only on observed scores may be affected.

The record does not report whether participants were analyzed according to randomized assignment, whether adherence was required for inclusion, or whether any per-protocol analysis was performed. These analysis-population details are not interchangeable: different inclusion rules can change the question answered by an estimate. The randomized design is clear, but the statistical use of the randomized groups is not described in enough detail to determine the exact estimand.

These absences do not prove that the trial used an inappropriate method. They limit what can be concluded from the registry record. A prespecified analysis plan, a transparent account of missing observations, and a stated approach to multiplicity would make the scope and strength of the reported comparisons easier to evaluate.

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 serious adverse events for both groups. For Veterans Group Exercise, 41 participants were listed as at risk and 0 as affected by a serious adverse event. For Illness Management and Recovery, 43 were listed as at risk and 0 as affected. The reported death count was 0 in each group.

The record also reports other adverse events: 41 participants were listed as at risk and 0 as affected in Veterans Group Exercise, while 43 were listed as at risk and 0 as affected in Illness Management and Recovery. No serious adverse event terms are listed. These are the counts recorded in the registry, not proof that no unrecorded event occurred.

The registry does not provide additional details about event definitions, surveillance periods, severity categories beyond the serious and other groupings, or the process used to collect reports. The figures should therefore be read as posted safety counts with the scope of the registry record, rather than as a complete characterization of every possible safety outcome.

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

The primary result describes average CAPS-5 scores at 12 weeks in two randomized groups. Veterans Group Exercise had a mean of 24.4, and Illness Management and Recovery had a mean of 22.0. The estimated mean difference was -2.4, with a confidence interval from -7.191 to 2.391. The interval includes zero, so the estimate does not establish a clear difference between the group means.

This finding does not establish that the programs are equivalent. A nonspecific or uncertain result can reflect a truly small difference, substantial variation, or limited precision; the posted data do not distinguish among these possibilities. Equivalence or noninferiority would require a suitable prespecified margin and analysis, neither of which is reported in the registry record.

Nor does the endpoint comparison establish how much participants improved or worsened over time. Baseline outcome values and change-from-baseline results are not reported in the primary record. The means reflect scores at the stated endpoint, not a documented within-person change. The registry also does not report enough information about missingness and analysis populations to determine how representative the posted summaries are of everyone randomized.

The secondary results do not provide a consistent pattern that changes the primary interpretation. Their multiplicity and analysis status are unclear, and the registry does not report a plan that would support treating them as confirmatory. The safety record lists no affected participants for the reported serious or other adverse event categories, but its collection and observation details are not reported.

Accordingly, the posted record supports a restrained statistical conclusion: it gives an estimated 12-week group contrast with meaningful uncertainty, rather than a definitive statement about whether either program improves PTSD or other health outcomes. It also cannot determine which program is preferable for an individual. The statistics describe the recorded trial outcomes; they are not medical advice.

17. Why This Trial Matters Statistically

This trial is statistically informative because it compares two active programs rather than comparing an intervention with no scheduled contact. The exercise and education groups both had sessions three times weekly for 12 weeks, lasting approximately 60 minutes. That makes the primary contrast a comparison between two program assignments, not a simple test of exercise versus no activity or attention.

The primary measure is clinician-rated and has a defined direction: higher CAPS-5 scores indicate worse severity. That allows the sign of the estimated difference to be interpreted, while the confidence interval makes clear that direction alone is not enough to establish a reliable group difference. Reporting both group means and an interval around the contrast is useful because it separates the observed averages from the uncertainty in their comparison.

The record also illustrates why outcome multiplicity matters. A trial may collect measures across several domains, and an isolated secondary result can appear more compelling than the overall evidence warrants if no testing plan is available. Reading the primary outcome alongside the secondary pattern avoids allowing a single measure to substitute for the central question.

Finally, the planning illustrations show how the observed effect and desired power influence future sample-size planning. They are not a retrospective measure of success. Their assumptions are explicit, while the trial’s original design justification is not. That distinction is important when using registry results to plan later studies or to judge what the completed trial could resolve.

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.

The registry record leaves several trial-specific questions unanswered. It does not provide detailed eligibility criteria, baseline characteristics, or baseline CAPS-5 scores. Without baseline outcome information, the posted 12-week means cannot show the amount of change within each group or how the groups compared before treatment.

The record identifies the design as randomized, parallel, and single masked, but does not specify who was masked, how the sequence was generated, or how allocation was concealed. It also does not provide a complete description of the Illness Management and Recovery class content. These omissions limit assessment of how the programs were delivered and how the comparison was implemented.

The primary summaries include 41 and 43 participants, but the registry does not identify the analysis population or explain whether any randomized participants lacked endpoint data. Missing-data procedures, adherence information, protocol deviations, and sensitivity analyses are not reported. These details matter for understanding whether the estimated contrast represents assignment to the programs or a selected subset with observed scores.

There is no reported protocol-based sample-size justification, detailed statistical analysis plan, multiplicity strategy, or clinically important CAPS-5 difference threshold. The planning illustrations use the observed effect and stated assumptions, so they cannot fill in the missing original design rationale. Follow-up beyond the 12-week endpoint is not reported in the registry record.

These limitations do not invalidate the posted summaries, but they restrict how much can be inferred from them. In particular, they prevent a full assessment of baseline balance, missingness, analysis choices, longer-term outcomes, and the clinical importance of the estimated difference.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Improving Mind/Body Health and Functioning With Integrative Exercise — NCT02856412.
• Registry record last updated 2024-09-19; status last verified 2024-08.
• Results first posted 2024-09-19.
• 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

The registry describes a completed randomized, single-masked, parallel-group study of integrative exercise compared with Illness Management and Recovery for Veterans with PTSD. Enrollment was 84. Both programs were scheduled three times weekly for 12 weeks, and the primary endpoint was the CAPS-5 score at 12 weeks.

The primary means were 24.4 for Veterans Group Exercise and 22.0 for Illness Management and Recovery. The estimated mean difference was -2.4, with a confidence interval from -7.191 to 2.391 and an unadjusted p-value of 0.326. The interval includes zero, leaving uncertainty about the direction and size of the group difference.

Secondary results are mixed, with no reported multiplicity plan. The registry lists 0 serious and 0 other adverse events affected in each group, as well as 0 deaths in each group. Baseline results, missing-data methods, analysis populations, and the original sample-size justification are not reported in the registry record.