Coaching Veterans to Healthy Weights and Wellness: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Coaching Veterans to Healthy Weights and Wellness (NCT00967668), a randomized na study. The primary outcome is Change in Weight.

2. Clinical Question

3. Trial Design

Coaching Veterans to Healthy Weights and Wellness, also titled ASPIRE: Coaching Veterans to Healthy Weights and Wellness, was a completed randomized, parallel-group trial sponsored by the US Department of Veterans Affairs. The registry lists an enrollment of 481 and identifies obesity as the condition. The study started in 2010-01, with primary completion in 2012-10.

Participants were assigned to ASPIRE-Phone Lifestyle Coaching, ASPIRE-Group Lifestyle Coaching, or MOVE! Usual Care. The outcome record gives arm sizes of 162.0, 160.0, and 159.0, respectively. The phone approach used coaching around small changes to physical activity and diet. The group approach used on-site weekly visits with the same general focus. Both ASPIRE descriptions specify an initial treatment of 3 months and 21 months of follow-up phone support. MOVE! usual care consisted of weekly on-site group visits following MOVE! protocols, with unstructured follow-up phone support.

The design is listed as parallel and masking as none. Further information about the randomization sequence, concealment, implementation, or handling of departures from assigned treatment is not reported in the registry record. The registry describes the primary outcome as expected weight change at 12 months, estimated with a linear mixed-effects model using all available data. It does not report the visit schedule, the detailed statistical model, or the analysis population definition. Phase is listed as NA.

4. Participant Flow and Accounting

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

Overall Study

Reasons for not completing this period:

5. Baseline Characteristics

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

Population: Number of participants randomized to each arm

6. Primary Endpoint

The registry lists the primary outcome as Change in Weight, measured over 12 months after enrollment.

The primary endpoint is change in weight from baseline to 12 months after enrollment, expressed in kilograms. A negative mean change represents a decrease in weight over that interval; a positive mean change would represent an increase. The registry describes the quantity as expected weight change and says it was estimated with a linear mixed-effects model using all available data.

Weight change is a continuous outcome: it retains the magnitude of change rather than reducing each participant’s result to a category such as gained or lost weight. The arm-level estimates are means with 95% confidence intervals. Those intervals convey uncertainty around each arm’s estimated mean change. They are not themselves estimates of the difference between arms, and their overlap or separation should not replace a direct between-group comparison.

The registry also lists Change in Weight as a secondary outcome. Details distinguishing that listing from the primary endpoint are not reported in the registry record. In particular, the registry does not describe a separate secondary-outcome definition, assessment schedule, or analysis. The posted figures therefore support a description of mean weight change at the primary time point, but do not give a complete account of every planned or measured weight outcome.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean change describe?

For a continuous outcome such as weight change, a mean summarizes the average change in an arm. The negative values reported for all three arms indicate average decreases from baseline to the 12-month assessment. A mean does not show how individual participants’ changes were distributed. Some participants may have changed more or less than the arm mean, but individual-level distributions are not reported in the registry record.

The endpoint is described as expected weight change estimated with a linear mixed-effects model. In general, mixed-effects models can use repeated measurements from participants and account for the fact that observations from the same person are related. They can also estimate outcome patterns across assessment times. The specific model structure, included time points, covariates, covariance assumptions, and estimation details are not reported in the registry record, so those features cannot be attributed to this analysis.

What do the confidence intervals convey?

Each arm mean is accompanied by a 95% confidence interval. In general, a confidence interval gives a range of values compatible with the estimate under the statistical model and its assumptions, while reflecting sampling uncertainty. It is not a range containing every participant’s outcome, and it does not directly quantify the uncertainty in a contrast between two arms. The registry’s intervals are reported for individual arm means; intervals for the between-group comparisons are not reported in the registry record.

Comparing arm-specific intervals informally is not equivalent to testing a treatment contrast. A formal contrast uses the relevant estimates and their joint uncertainty. It is possible for the pattern of separate intervals to appear suggestive without revealing the result of a prespecified pairwise test. Here, the posted regression result does not include the contrast estimates needed to describe such pairwise comparisons.

How should the regression result be read?

The registry names Regression, Linear as the method and reports p <0.05 for an analysis involving all three arms. In general, a p-value measures how unusual data at least as inconsistent with a specified null hypothesis would be if that hypothesis and the statistical model were correct. It does not measure the probability that the null hypothesis is true, the probability that the result occurred by chance, or the size of a difference.

The registry does not identify the exact null hypothesis, test statistic, regression coefficients, degrees of freedom, or whether the reported result is an overall test or another form of comparison. Although the analysis is recorded across the three groups, its reported p-value cannot be used to recover the missing coefficients or pairwise results. The value is a thresholded report, not a precise p-value.

Why does over-dispersion matter in general?

Over-dispersion concerns count outcomes whose variability is greater than a model assumes. It can affect standard errors and the reliability of tests if the model does not account for the extra variation. The primary outcome in this trial is continuous weight change, and the registry does not report a count-model analysis for that endpoint. Over-dispersion therefore is not a reported feature of the primary analysis. More generally, choosing a model that reflects the outcome’s distribution and dependence structure is important, but the necessary model details are not reported in the registry record.

What is not documented?

The registry does not report the sample-size justification, target effect used in planning, detailed model specification, or prespecified contrast structure. It also does not describe interim analyses or provide a multiplicity adjustment plan. These omissions limit assessment of how the reported analysis was selected and how its uncertainty should be interpreted. They do not establish that such procedures were absent; they mean the details are not reported in the registry record.

10. Analyses Reported by the Sponsor

The registry records a sponsor analysis using linear regression across the three groups and reports p <0.05. It does not report the regression coefficient or coefficients, the comparison’s exact definition, a confidence interval for a contrast, or enough detail to identify the tested hypothesis. The sponsor result therefore supports only the limited statement that a regression analysis was reported the stated significance threshold.

The posted arm-level results give estimated mean changes and 95% confidence intervals for each group, but these are not recalculated between-group effects. No recalculated contrast is reported in the registry record, so there is no independent numerical comparison to set against the sponsor’s result. The record does not flag a discrepancy between the sponsor result and a recalculation.

The sponsor’s p-value should not be expanded into claims about which particular arms differ or how large a difference may be. Those conclusions require estimates and uncertainty for the relevant contrasts. The arm means offer descriptive context, while the sponsor’s regression result is the only reported inferential comparison. Its interpretation remains limited by the missing model and test details.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome of Change in Weight and also includes Change in Weight among secondary outcomes. It records two outcome measures and one analysis, but does not provide enough detail to determine how the listed measures relate, whether other outcomes were assessed but not posted, or which comparisons were planned. The relationship between the primary and secondary listings is not reported in the registry record.

When a study tests multiple outcomes, time points, or pairwise contrasts, the chance of at least one false-positive result can increase if no adjustment or prespecified hierarchy is used. In general, multiplicity methods address that issue by controlling an error criterion across a family of tests or by defining a testing sequence. The registry does not report a multiplicity plan, a hierarchy of outcomes, or adjustments to the reported p-value. It is therefore not possible to determine whether the recorded p <0.05 reflects an adjustment or how it fits within the full set of analyses.

The primary endpoint description says the model used all available data. In general, this can allow participants with incomplete measurement records to contribute information, depending on the model and assumptions. It does not by itself explain why measurements are missing, how many were missing at each time point, whether reasons differed by arm, or how sensitive estimates are to assumptions about missingness. Those details are not reported in the registry record.

The registry does not define whether the analysis followed intention-to-treat principles, included only participants with observed outcomes, or used another analysis population. It also does not describe adherence, withdrawals, protocol deviations, imputation, or sensitivity analyses. Randomized assignment is recorded, but the relationship between assignment and inclusion in the primary analysis cannot be fully assessed from the posted information.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports zero participants affected by serious adverse events in each arm: 0 of 162 in ASPIRE-Phone Lifestyle Coaching, 0 of 160 in ASPIRE-Group Lifestyle Coaching, and 0 of 159 in MOVE! Usual Care. The corresponding numbers at risk are reported for each group. No serious adverse event terms are listed. Death counts are not reported in the registry record.

These figures describe what was posted; they do not establish that no serious events occurred outside the registry’s reporting or observation process. With zero affected participants recorded in each arm, the data do not provide a comparative estimate of serious-event risk or its uncertainty. The registry does not report the safety follow-up period, event definitions, methods for collecting events, or whether event ascertainment was comparable across groups.

The record separately lists other adverse events affecting 45 participants in the phone-coaching arm, 33 in the group-coaching arm, and 15 in MOVE! usual care. These are counts, not adjusted comparisons, and the registry does not provide event descriptions in the reported safety details. Neither these counts nor the serious-event figures alone establish that an intervention caused or prevented an event.

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

The posted results describe mean weight change at 12 months for three randomized groups. All three arm means were negative. The mean was -2.8 kilograms for group coaching and -1.4 kilograms for both phone coaching and MOVE! usual care. Confidence intervals are reported for each mean, providing information about their precision as arm-level estimates. These results describe group averages, not the experience of every participant.

The registry also reports p <0.05 for a linear regression analysis involving the groups. Because the coefficients, exact comparison, and confidence interval for a between-group effect are not reported, the statistical significance statement does not show which groups differed or how large any difference was. It cannot be treated as proof that each coaching approach differed from usual care, nor as a measure of the practical importance of any contrast.

The results do not by themselves explain why weight changed, how participation or adherence varied, or whether the pattern would apply to people outside the study population. The registry’s brief summary describes the study’s coaching, diet, and activity features, but does not provide enough information to assess implementation or participant-level variation. The outcome is limited to the stated weight-change measure and timeframe.

Interpretation is also constrained by missing statistical and reporting detail. The registry does not report the full analysis plan, contrast estimates, handling of missing data beyond the all-available-data description, or multiplicity procedures. Those gaps do not invalidate the posted observations, but they limit how precisely the comparative question can be answered from the record. The data support a careful description of arm-level changes and a report of the sponsor’s regression result; they do not support a definitive account of the magnitude and precision of specific pairwise differences.

14. Why This Trial Matters Statistically

This trial illustrates why a statistically significant overall result and arm-specific means are not interchangeable with clearly reported between-group effects. Readers can see the estimated mean change within each group, but the inferential result is given only as p <0.05. Without the contrast estimates, their confidence intervals, and a clear statement of the tested hypothesis, the comparative finding cannot be described in terms of magnitude or precision.

It also highlights the distinction between estimating an outcome and explaining the analysis. The primary measure is continuous change in weight, and the registry names a linear mixed-effects model using all available data. Those descriptions are useful, but they do not specify the model structure, missing-data assumptions, or analysis population. Such details matter because they clarify what the estimate represents and how robust it may be to analytic choices.

The three-arm design makes careful comparison especially important. An overall regression result can address a different question from a contrast between any two particular groups. The reported arm means provide descriptive context, but they cannot establish the result of each pairwise comparison. Reporting the estimates and uncertainty for prespecified contrasts would make the inferential result easier to interpret.

Finally, the record distinguishes serious from other adverse events and gives counts by arm, while leaving other safety details unreported. This is a reminder that outcome reporting is multidimensional: efficacy endpoints, uncertainty, missingness, multiplicity, and safety each need clear definitions and analysis context. The statistical value of a registry record depends not only on numerical results but also on transparent descriptions of what was compared and how.

15. 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 gives arm-level means and confidence intervals but no numerical estimates for between-group contrasts. Although a linear regression analysis is reported with p <0.05, its coefficients, exact hypothesis, and test details are absent. This limits interpretation of the primary comparative question and prevents assessment of the size and precision of specific differences.

The analysis description is brief. The primary outcome is said to use a linear mixed-effects model with all available data, while the reported analysis method is listed as linear regression. The relationship between those descriptions is not explained. Model specification, covariate adjustment, within-participant correlation structure, assessment of assumptions, and the analysis population are not reported in the registry record.

Missing-data information is also limited. Counts with observed measurements at each assessment, reasons for missingness, and sensitivity analyses are not reported. The registry does not describe randomization procedures, allocation concealment, adherence, withdrawals, or protocol deviations. Masking is listed as none, but further information about outcome assessment is not reported.

The registry does not report a sample-size justification, interim-analysis details, or a multiplicity plan. It lists Change in Weight as both a primary and secondary outcome, without clarifying the distinction. Safety reporting includes serious-event counts and counts for other adverse events, but event definitions, follow-up duration, and death counts are not reported in the registry record. These gaps constrain interpretation of both comparative effectiveness estimates and safety patterns.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Coaching Veterans to Healthy Weights and Wellness — NCT00967668.
• Registry record last updated 2015-04-24; status last verified 2014-02.
• Results first posted 2014-08-29.
• 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.

19. Record Summary

Coaching Veterans to Healthy Weights and Wellness (ASPIRE) was a completed randomized, parallel-group trial sponsored by the US Department of Veterans Affairs, with enrollment of 481. It compared phone-based ASPIRE coaching, group-based ASPIRE coaching, and MOVE! usual care. The primary endpoint was expected weight change from baseline to 12 months, estimated using a linear mixed-effects model with all available data.

Reported mean changes were -1.4 kilograms for phone coaching, -2.8 kilograms for group coaching, and -1.4 kilograms for usual care, each with a 95% confidence interval. A linear regression result across the groups was reported as p <0.05, but the specific between-group estimates and test details are not reported in the registry record. Serious adverse events affected 0 participants in each arm. Missing-data methods, multiplicity procedures, and several design and analysis details are not reported.