A Community Wellness Program for Adults Living With Long-term Physical Disability: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Community Wellness Program for Adults Living With Long-term Physical Disability (NCT03653390), a randomized na study. The primary outcome is Change in Self-reported Ability to Participate in Community Activities From Baseline to 6 Months.

2. Clinical Question

The trial asks whether a community-delivered wellness program is associated with a different change in perceived ability to take part in community activities than wellness education or usual activity. It focuses on middle-aged adults living with long-term physical disability, a population the registry describes as vulnerable to losses in function and participation. The primary outcome was assessed from baseline to 6 months.

The registry describes the primary analysis population as participants with a PROMIS APSR value at both baseline and 6 months. The resulting comparisons therefore concern the recorded outcome among participants meeting that criterion; they do not, by themselves, describe every randomized participant or establish why any participants lacked measurements.

3. Trial Design

The registry identifies this as a randomized, single-masked, parallel-group trial. It lists an enrollment of 516 and three groups: EnhanceWellness for Disability (EW-D), Wellness Education, and Control. The intervention descriptions indicate telephone-based delivery over a six-month period for both active programs, while control participants continued their usual lives. The identity of those who were masked is not reported in the registry record.

The listed primary outcome is change in self-reported ability to participate in community activities from baseline to 6 months. The primary analysis included participants with a PROMIS Ability to Participate in Social Roles and Activities short-form value at both time points. The registry reports group summaries for 161 EW-D participants, 148 Wellness Education participants, and 154 control participants for this outcome. These analysis counts are not the same as the trial’s total enrollment, and the reasons for the difference are not reported in the registry record.

The registry gives the study start as 2019-01-31, primary completion as 2022-11-14, and status as completed. It identifies the University of Washington as sponsor. No phase applies in the registry entry. The planned sample-size justification, the original analysis plan, details about how randomization was implemented, the identity of the masked party, and whether interim analyses were planned are not reported in the registry record.

Three groups allow the registry to report an overall comparison as well as pairwise comparisons. The sponsor reports an ANOVA for the overall group comparison and Tukey’s HSD tests for specified pairs. The outcome comparisons are focused on group changes, but their statistical interpretation should account for the fact that several outcomes and comparisons were examined.

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: After enrollment and prior to group assignment, participants complete the baseline survey. Because participants have the option to withdraw at any time, some may choose to withdraw or are lost to follow up prior to randomization.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All participants with a PROMIS APSR value at both baseline and 6 months were included in the analysis.

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 Change in Self-reported Ability to Participate in Community Activities From Baseline to 6 Months, measured over Change from baseline to 6 months.

The primary endpoint is change in perceived ability to participate in community activities from baseline to 6 months. It was measured with the PROMIS Ability to Participate in Social Roles and Activities short form, abbreviated APSR. The registry describes the outcome as a score on a scale, with higher scores indicating better ability to participate in social activities; the total score range is 8-40.

This measure is used to capture the participant’s own assessment of involvement in social roles and activities. That makes it relevant to a trial whose stated purpose includes community participation and quality of life: the outcome addresses perceived ability in an area the programs aim to support, rather than an objective count of activities alone. A change score compares a participant’s measured value at follow-up with their baseline value. The group means therefore describe average changes, not the final score at 6 months.

The registry reports mean changes and standard deviations for participants with an APSR value at both baseline and 6 months. Mean change summarizes the direction and average size of change in each analyzed group; the standard deviation describes variation among participants. These summaries do not show the full distribution of individual responses, nor do they establish whether a change is important to participants. A threshold for clinical importance is not reported in the registry record.

7. Results Posted in the Registry

• EnhanceWellness for Disability (EW-D): mean 2.49 versus 0.09 on control; difference 2.40 (95% CI 1.21 to 3.59), standardized effect d = 0.44; z-test p = <0.001.
• Wellness Education: mean 1.25 versus 0.09 on control; difference 1.16 (95% CI -0.02 to 2.34), standardized effect d = 0.22; z-test p = 0.053.

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.

Change in Self-report of Confidence in Managing One's Chronic Illness (Disease Management Self-efficacy) From Baseline to 3 Months

• 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:
  • EnhanceWellness for Disability (EW-D): mean 2.19 versus -0.07 on control; difference 2.26 (95% CI 0.71 to 3.81), standardized effect d = 0.32; z-test p = 0.004.
  • Wellness Education: mean 0.01 versus -0.07 on control; difference 0.08 (95% CI -1.39 to 1.55), standardized effect d = 0.01; z-test p = 0.915.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for EnhanceWellness for Disability (EW-D) than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Wellness Education and the control. The interval gives the range of effects that remain compatible with the data.

Change in Self-reported Interference Due to Pain From Baseline to 3 Months

• 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:
  • EnhanceWellness for Disability (EW-D): mean -1.22 versus -0.23 on control; difference -0.99 (95% CI -2.42 to 0.44), standardized effect d = -0.15; z-test p = 0.175.
  • Wellness Education: mean -0.55 versus -0.23 on control; difference -0.32 (95% CI -1.80 to 1.16), standardized effect d = -0.05; z-test p = 0.672.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between EnhanceWellness for Disability (EW-D) 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 Wellness Education and the control. The interval gives the range of effects that remain compatible with the data.

Change in Self-reported Interference Due to Fatigue From Baseline to 3 Months

• 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:
  • EnhanceWellness for Disability (EW-D): mean -1.89 versus -0.76 on control; difference -1.13 (95% CI -2.56 to 0.30), standardized effect d = -0.17; z-test p = 0.121.
  • Wellness Education: mean -1.09 versus -0.76 on control; difference -0.33 (95% CI -1.79 to 1.13), standardized effect d = -0.05; z-test p = 0.658.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between EnhanceWellness for Disability (EW-D) 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 Wellness Education and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists secondary outcomes covering disease-management self-efficacy, pain and fatigue interference, psychological resilience, and activity outside the home, including social activity and travel measures. The secondary results that are described in detail include disease-management self-efficacy and pain and fatigue interference at 3 months. Across these measures, the available results do not form a uniform pattern of group differences that mirrors the primary participation result.

The clearest secondary signal is for disease-management self-efficacy. The reported overall ANOVA has p < 0.01, and the sponsor’s Tukey comparison between EW-D and Wellness Education reports a net mean difference of -2.18, a 95% confidence interval from -4.05 to -0.30, and p = 0.018. The unadjusted recalculation for EW-D versus Control gives a mean difference of 2.26, a 95% confidence interval from 0.715 to 3.805, and p = 0.004. The different contrast and analysis methods should not be treated as equivalent findings.

For pain and fatigue interference, the sponsor’s overall ANOVA p-values are 0.382 and 0.29, respectively. The recalculated comparisons with Control have confidence intervals that include zero. This indicates that the registry’s reported results do not establish clear group differences for those measures. Detailed results for the other listed secondary outcomes are not reported in the registry record.

Secondary outcomes can help describe whether observed patterns extend across related domains, but they are not substitutes for the primary endpoint. Each additional outcome or contrast creates further opportunity for chance findings when considered without a prespecified multiplicity strategy. The registry does not report a comprehensive adjustment plan for the secondary outcome family. Accordingly, individual nominal p-values from secondary analyses carry less weight than the primary result and should be viewed as supporting or exploratory evidence rather than standalone confirmation.

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

• Change in Self-report of Confidence in Managing One's Chronic Illness (Disease Management Self-efficacy) From Baseline to 3 Months
• Change in Self-reported Interference Due to Pain From Baseline to 3 Months
• Change in Self-reported Interference Due to Fatigue From Baseline to 3 Months
• Change in Psychological Resilience From Baseline to 3 Months
• Change in Number of Trips Outside the Home From Baseline to 12 Months
• Change in Radius of Gyration From Baseline to 12 Months
• Change in Number of Trips Outside the Home Containing "Social" Elements From Baseline to 12 Months
• Change in Time Spent in Activities Outside the Home Containing Social Elements From Baseline to 12 Months

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: it is a score, and the registry reports group means and standard deviations. The sponsor’s reported methods include an overall ANOVA and Tukey’s HSD pairwise tests. The additional comparisons are simple unadjusted recalculations from posted summary statistics, not replacements for the sponsor’s own analysis. The registry does not report enough detail to reconstruct the full analysis model or determine why the sponsor and recalculated estimates differ.

What does the overall ANOVA test?

General: An analysis of variance tests whether the observed group means are compatible with a common underlying mean, considering variation within groups as well as differences between group averages. An overall result indicates evidence of some difference among the groups; it does not, by itself, identify which pair differs. The registry reports an overall p < 0.01 for the primary outcome. Pairwise comparisons are needed to examine particular group contrasts.

Why are pairwise tests reported?

General: Pairwise tests address specified comparisons between groups. Tukey’s HSD is a method for conducting multiple pairwise comparisons while accounting for the family of pairwise tests in the set. The sponsor reports Tukey’s HSD results for EW-D versus Wellness Education, EW-D versus Control, and Wellness Education versus Control. Those results are the sponsor’s own reported comparisons and take precedence over the separate unadjusted recalculations when the two differ.

General: A p-value measures how compatible the observed data are with a specified null model, under the assumptions of the analysis. It is not the probability that the null hypothesis is true, nor is it a measure of the size or importance of an effect. A small p-value can occur alongside uncertainty about the practical meaning of a change; a larger p-value does not prove that groups are identical. Estimates and confidence intervals are useful because they describe possible effect sizes and the precision of the evidence, not merely whether a threshold was crossed.

What do the recalculations represent?

The recalculated pairwise estimates compare posted group means using simple unadjusted calculations. They do not reproduce the sponsor’s Tukey procedure. For EW-D versus Control, the recalculated mean difference is 2.4, while the sponsor’s net difference is -2.40; the opposite signs are consistent with a different ordering of the groups in the comparison. However, the confidence intervals and p-values also differ, and the registry does not report the reason. It would be inappropriate to attribute the mismatch to a particular model, adjustment, or analysis choice without that information.

General: An unadjusted pairwise analysis treats a comparison separately rather than controlling the chance of false-positive findings across a collection of tests. When many outcomes or contrasts are examined, some nominally small p-values can occur by chance. Multiplicity procedures address this issue by adjusting the interpretation or thresholds across a defined family of tests. The sponsor uses Tukey’s HSD for the primary pairwise comparisons, but the registry record does not report a broader multiplicity plan covering all outcome measures and time points.

What does a standard deviation describe?

General: A standard deviation describes how spread out individual observations are around their group mean. It is not the uncertainty of the mean itself, and it does not indicate how many participants improved or worsened. The posted primary standard deviations are 5.95 for EW-D, 5.58 for Wellness Education, and 4.8 for Control. Because individual-level outcome distributions are not reported, the means and standard deviations alone cannot show whether responses were concentrated near the average or included widely differing patterns.

The primary analysis population was restricted to participants with APSR measurements at both baseline and 6 months. The method used to handle missing values, the number of randomized participants without the required measurements, and any sensitivity analyses are not reported in the registry record. The record also does not report whether the primary comparison followed an intention-to-treat principle, how covariates were selected, or whether model assumptions were checked.

General: Statistical tests for means often rely on assumptions about independent observations, the distribution of errors, and the way variability is modeled. The registry entry does not provide sufficient analysis details to evaluate those assumptions for the sponsor’s model. The reported estimates should therefore be read as the registry’s posted analysis results, with the limitations created by the missing methodological detail kept in view.

11. Confidence Intervals and Precision

A confidence interval describes a range of values compatible with the data and the method used to calculate the interval. It is not a guarantee that the true effect lies inside the interval, and its width gives information about precision: narrower intervals indicate a more precise estimate than wider intervals. The intervals reported by the sponsor are 95% confidence intervals for the pairwise comparisons. Intervals that include zero are compatible with no mean difference under the analysis, as well as with differences in either direction.

For EW-D versus Control, the sponsor’s reported net mean difference is -2.40, with a 95% confidence interval from -3.85 to -0.95. The interval excludes zero, consistent with the sponsor’s p < 0.01 result. For Wellness Education versus Control, the reported interval runs from -2.64 to 0.32 around a net difference of -1.16; it includes zero. For EW-D versus Wellness Education, the interval runs from -2.71 to 0.22 around -1.24; it also includes zero. The group ordering explains the negative sign in the sponsor’s net contrasts; the posted group means show the corresponding ordering in average change.

The recalculated intervals are not interchangeable with the sponsor’s Tukey intervals. For EW-D versus Control, the unadjusted recalculated estimate is 2.4, with a 95% confidence interval from 1.209 to 3.591. For Wellness Education versus Control, it is 1.16, with a 95% confidence interval from -0.016 to 2.336. The disagreement in interval limits is part of the discrepancy, not merely a sign convention. The cause is not reported in the registry record, and the sponsor’s analysis takes precedence.

General: Confidence intervals quantify statistical uncertainty under the calculation method; they do not account automatically for every source of uncertainty, such as missing outcomes, measurement limitations, or selective reporting. Nor do they establish whether an effect is clinically important. The registry does not report a meaningful-change threshold for the APSR outcome, so precision and practical importance remain separate questions.

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 expressed as participants per arm, not total events. They are planning illustrations based on the observed effect in the posted data, not the trial’s original sample-size calculation. The listed assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The planning scenarios consider detecting 100%, 75%, or 50% of the observed effect. The original design assumptions and sample-size justification are not reported in the registry record.

The 80% power column gives the estimated participants per arm for a future two-arm study to have an 80% chance of detecting the stated effect under the listed assumptions, if that effect and assumptions are correct. The 90% power column gives the corresponding per-arm planning figure for a 90% chance. These are design targets, not evidence about the probability that the completed trial found a real effect. They are not observed power.

Smaller effects are harder to distinguish from random variation when other assumptions remain fixed, so the planning illustrations require more participants per arm when the target is a smaller fraction of the observed effect. For example, the primary EW-D versus Control planning figures are 81 participants per arm for 80% power when planning for 100% of the observed effect, and 321 participants per arm when planning for 50% of the observed effect. These figures are not guarantees: actual requirements depend on whether future participants, outcome variability, allocation, and analysis assumptions resemble those used for the illustration.

The illustrations are based on a pairwise comparison and should not be read as a full design for a multi-group trial with multiple outcomes. They do not account for any features absent from the listed assumptions, and the registry does not report the trial’s original planning rationale. Their purpose is to show how the required sample size changes under specified effect-size scenarios.

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 = 5.418.
2. n = 2 × (1.96 + 0.842)² × 5.418² / 2.400² = 80.0, rounded up to 81 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 <- 5.4184397032625                     # 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(3653390)
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 = 81 (80% power), 108 (90% power)
 75% of observed effect: n per arm = 143 (80% power), 191 (90% power)
 50% of observed effect: n per arm = 321 (80% power), 429 (90% power)
power.t.test: 81 
Simulated power at n = 81 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

The registry reports the sponsor’s own primary analysis as an overall ANOVA with p < 0.01, followed by Tukey’s HSD pairwise comparisons. The reported EW-D versus Control contrast is -2.40, with a 95% confidence interval from -3.85 to -0.95 and p < 0.01. The other reported pairwise comparisons have intervals that include zero: EW-D versus Wellness Education has a net difference of -1.24, 95% confidence interval from -2.71 to 0.22, p = 0.11; Wellness Education versus Control has a net difference of -1.16, 95% confidence interval from -2.64 to 0.32, p = 0.16.

Simple unadjusted recalculations from the posted means and standard deviations yield different confidence intervals and p-values for comparisons with Control. The recalculated EW-D versus Control estimate is 2.4, with a 95% confidence interval from 1.209 to 3.591 and p < 0.001. The Wellness Education versus Control estimate is 1.16, with a 95% confidence interval from -0.016 to 2.336 and p = 0.053. The signs are reversed because the comparisons are expressed in the opposite group order, but the differences in interval limits and p-values remain.

The registry record flags a discrepancy, but its cause is not reported. The sponsor’s own analysis takes precedence over the simple recalculations. The recalculations are useful as an independent check of the posted summaries, not as a correction to the sponsor’s analysis or a reconstruction of its method.

15. Multiplicity, Missing Data and Analysis Populations

The record reports an overall primary-outcome ANOVA and Tukey’s HSD tests for the pairwise group comparisons. Tukey’s procedure addresses multiplicity among its set of pairwise comparisons. The registry record does not report whether a broader strategy was planned for the collection of primary and secondary outcomes, or how inference across different follow-up times was intended to be controlled.

This matters because the registry lists multiple outcome measures and includes outcomes assessed at different time points. When many hypotheses are tested, some results may appear statistically notable by chance even if there is no underlying effect. A prespecified hierarchy, adjustment method, or distinction between confirmatory and exploratory analyses can clarify how such results should be interpreted. Those details are not reported in the registry record. This does not establish that no such plan existed; it means the record does not describe one.

The primary analysis population is defined as participants with APSR values at baseline and 6 months. The handling of participants without both measurements is not reported in the registry record. In particular, the record does not state whether missing outcomes were imputed, whether only complete cases were analyzed, or whether sensitivity analyses assessed the impact of missingness. The reasons for missing outcomes and whether they differed among groups are also not reported.

The record does not state whether the primary analysis followed an intention-to-treat approach, whether participants were analyzed according to randomized assignment, or how protocol deviations were treated. It also does not report model covariates, diagnostic checks, interim analyses, or a detailed statistical analysis plan. These omissions limit assessment of the analysis choices and of how robust the estimates are to alternative assumptions. The reported results remain interpretable as the registry’s posted analyses, but they do not answer every question about design and analysis conduct.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: cellulitis (1.3%), multiple sclerosis relapse (1.3%), post surgical complications (1.3%), covid-19 (1.1%), fall/fall related injury (1.1%).

The registry reports serious adverse events among 183 participants at risk in EW-D, 159 in Wellness Education, and 163 in Control. The numbers affected were 12, 13, and 3, respectively. The reported death counts were 1, 0, and 0. These figures describe the posted safety counts; they do not establish that an event was caused by an intervention. The registry record does not provide enough detail to assess event timing, severity beyond the serious classification, or causal attribution.

For other adverse events, the numbers affected were 45 in EW-D, 9 in Wellness Education, and 0 in Control, with 183, 159, and 163 participants at risk, respectively. The serious-event terms listed among the leading terms include Cellulitis, Multiple Sclerosis Relapse, Post Surgical Complications, COVID-19, Fall/Fall Related Injury, and Wound Infection. The listed percentages are 1.3% for Cellulitis, 1.3% for Multiple Sclerosis Relapse, 1.3% for Post Surgical Complications, 1.1% for COVID-19, 1.1% for Fall/Fall Related Injury, and 1.1% for Wound Infection.

Safety counts should be read separately from the primary outcome analysis, whose population was defined by availability of baseline and 6-month APSR values. The registry does not report whether the safety at-risk groups correspond to the same analysis population. These counts alone do not support causal comparisons or conclusions about overall safety.

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

The primary outcome describes participants’ self-reported change in perceived ability to participate in community activities. The posted group averages are 2.49 for EW-D, 1.25 for Wellness Education, and 0.09 for Control. The sponsor’s analysis reports an overall group difference and a pairwise difference between EW-D and Control, while its pairwise results for EW-D versus Wellness Education and Wellness Education versus Control have confidence intervals that include zero.

These findings do not establish that every participant in a group experienced improvement, or that the average change was important to each participant. The standard deviations show variation around the group means, but the registry does not provide individual response distributions. A threshold for a clinically meaningful change in the APSR score is not reported in the registry record. Statistical evidence and practical importance are related but distinct questions.

The results also do not establish the mechanism by which any group differences arose. The study description says that it aims to contribute to understanding of intervention effectiveness and mechanisms of action, but the registry outcome summaries do not by themselves demonstrate a particular mechanism. Nor do the findings establish effects beyond the population, delivery setting, interventions, and follow-up periods described in the registry.

The discrepancy between the sponsor’s reported analyses and simple recalculations from posted summaries is important to interpretation. The sponsor’s own analysis takes precedence, while the reason for the discrepancy is not reported. Missing outcome handling, the broader multiplicity strategy, and the original sample-size justification are also not reported. These limits do not erase the reported results; they define how narrowly the conclusions should be drawn.

The most defensible reading is that the registry reports evidence of a difference among groups on the primary outcome, with the sponsor’s pairwise analysis identifying EW-D versus Control as the comparison with an interval excluding zero. The reported data are less conclusive for the other primary pairwise comparisons, and secondary outcomes offer a mixed rather than uniformly consistent pattern.

18. Why This Trial Matters Statistically

This trial is statistically informative because it compares two active community wellness approaches with a control group on an outcome tied to participation, while also reporting an overall test and pairwise contrasts. The group means, standard deviations, confidence intervals, and p-values make it possible to distinguish the average direction of change from the uncertainty around group comparisons. The registry’s distinction between an overall result and pairwise results is important: an overall group difference does not mean every pair differs.

The record also illustrates why estimates and uncertainty should be read alongside significance tests. The sponsor’s EW-D versus Control result has a confidence interval that excludes zero, whereas the other primary pairwise intervals include zero. The magnitude and precision of each contrast matter, as do the choice of analysis population and the fact that the outcome is self-reported. Without a reported threshold for meaningful change, statistical significance does not settle practical significance.

A further statistical issue is transparency across analyses. Multiple outcomes and time points are listed, but the record does not describe a comprehensive multiplicity plan or the original sample-size justification. The sponsor’s primary pairwise analysis uses Tukey’s HSD, while simple recalculations from the summary statistics differ. Acknowledging that difference and giving precedence to the sponsor’s analysis avoids treating an unadjusted recalculation as if it were the planned inferential result.

Finally, the registry separates the primary outcome population from the safety counts, and the methods for missing outcomes are not reported. That distinction matters when readers assess who contributed data to each result. Clear reporting of analysis populations, missing-data handling, prespecified outcomes, and multiplicity methods helps readers judge how much confidence to place in findings. The record offers useful outcome summaries but leaves these methodological questions unresolved.

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.

Several limitations specific to this trial affect interpretation. The primary analysis includes participants with an APSR measurement at both baseline and 6 months, but the registry does not report how many randomized participants lacked one or both measurements, why measurements were missing, or how missingness was handled. If availability of follow-up data differed in ways related to outcomes or group assignment, the analyzed group summaries could be less representative of all randomized participants.

The outcome is self-reported perceived ability, which is relevant to participation but is not an objective measure of participation itself. The registry does not report a threshold for meaningful change, so it is not possible to determine from these results alone whether the observed average differences are important to participants. The group standard deviations also indicate that individual changes varied, while the registry summaries do not describe the distribution of responses.

The single-masked designation is reported, but the identity of the masked party is not. The record does not report the original sample-size justification, the complete statistical analysis plan, the handling of protocol deviations, covariate adjustment, model diagnostics, or interim analyses. It also does not describe a comprehensive multiplicity strategy for the several outcomes and time points. These gaps restrict assessment of prespecification and robustness.

The registry flags a discrepancy between the sponsor’s analysis and unadjusted recalculations from posted summaries. The sponsor’s analysis takes precedence, but the reason for the difference is not reported. The detailed secondary results available in the record do not cover every listed secondary outcome, limiting assessment of consistency across all planned domains. Finally, safety counts are descriptive and do not establish causality; the registry does not provide event-level context sufficient to explain the differences in counts among groups.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: A Community Wellness Program for Adults Living With Long-term Physical Disability — NCT03653390.
• Registry record last updated 2023-11-21; status last verified 2023-10.
• Results first posted 2023-11-21.
• 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

NCT03653390 is a completed randomized, single-masked, parallel-group community trial sponsored by the University of Washington, with enrollment of 516. It compared EnhanceWellness for Disability (EW-D), Wellness Education, and Control among adults living with long-term physical disability. The primary outcome was change in self-reported ability to participate in community activities from baseline to 6 months, measured with the PROMIS APSR short form.

The sponsor reports an overall primary-outcome ANOVA with p < 0.01 and a Tukey comparison showing a difference between EW-D and Control. Its other primary pairwise comparisons have confidence intervals that include zero. Simple unadjusted recalculations differ from the sponsor’s results, and the sponsor’s analysis takes precedence; the reason for the discrepancy is not reported. Secondary results are mixed, and the registry does not report a comprehensive multiplicity plan, missing-data method, or original sample-size justification.