Project SERVE: Post Deployment Functioning: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Project SERVE: Post Deployment Functioning (NCT01123642), a registered phase not stated study. The primary outcome is World Health Organization Disability Assessment Schedule II (WHODAS II).

2. Clinical Question

The study’s focus is functional recovery and readjustment after return from a warzone, rather than a treatment contrast. WHODAS II covers understanding and communicating, mobility, self-care, relationships, life activities, work or school, and participation in society. Higher scores represent more impairment. The record also lists psychosocial functioning, quality of life, and clinician-assessed PTSD as secondary outcomes. The clinical question is therefore descriptive and longitudinal: how disability and related aspects of functioning develop among the followed Veterans. Since no outcome estimates or analyses are reported, the registry record does not establish the direction, size, or precision of any observed change.

3. Trial Design

Project SERVE: Post Deployment Functioning (NCT01123642) is described as a follow-up study of Operation Enduring Freedom and Operation Iraqi Freedom Veterans. The study began in 2010-10, had primary completion in 2014-06, and is marked COMPLETED in the registry record. Enrollment is listed as 345. The primary outcome description states that 309 participants were deemed eligible and that analyses use a total sample N = 309 followed over time. These figures describe enrollment and the stated analysis population; they do not provide outcome-specific denominators at each assessment.

The primary measure, WHODAS II, was scheduled at baseline and at 4 months, 8 months, and 12 months. The record notes that sample sizes vary over time because of attrition and missing data. It does not give the number assessed at each visit or explain how individual missing observations were handled. Secondary measures listed are the Inventory of Psychosocial Functioning (IPF), Quality of Life Scale (QLS), and Clinician Administered PTSD Scale (CAPS-5). Four outcome measures are recorded overall, but the registry record does not provide analysis results for them.

The record describes one group, OEF/OIF Veterans. It does not describe a randomized allocation, a separate comparator group, or an assigned intervention. Allocation is not stated, and the record specifically does not support treating the listed group as a like-for-like control comparison. Thus, the design information supports interpreting the study as repeated follow-up of a cohort, not as a randomized trial estimating a treatment effect. Detailed recruitment procedures, eligibility criteria, follow-up procedures beyond the stated assessment schedule, and the statistical analysis plan are not reported in the registry record.

4. Participant Flow and Accounting

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

Before assignment: A total of 345 participants were consented into the study, after which final eligibility was determined during the baseline assessment (see inclusion/exclusion criteria). Of the 345 enrolled, 309 met inclusion criteria and were deemed eligible for follow-up in the longitudinal study.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: A total of 345 participants were enrolled, of which 309 were deemed eligible. Analyses are conducted with the total sample N = 309, followed over time. Sample sizes vary over time due to attrition and missing data.

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: A total of 345 participants were enrolled (signed informed consent), of which 309 met final eligibility criteria. Results are analyzed using the 309 eligible enrolled participants.

6. Primary Endpoint

The registry lists the primary outcome as World Health Organization Disability Assessment Schedule II (WHODAS II), measured over one year.

The primary endpoint is the World Health Organization Disability Assessment Schedule II (WHODAS II), reported as a mean with standard deviation in units on a scale. The instrument is described as measuring general disability across several areas: understanding and communicating, getting around, self-care, getting along with people, life activities, work or school, and participation in society. The record states that total scores range from 1 (no disability) to 5 (extreme/cannot do), with higher scores indicating more impairment.

Assessments were scheduled at baseline, 4 months, 8 months, and 12 months. Repeated measurement can describe whether the average disability score changes during follow-up and how much individual scores vary around the group mean. Functional status is relevant to the study’s stated focus on Veterans’ readjustment and functional impairment. That rationale does not itself establish that a score changed or that any change was caused by a particular exposure or service.

The registry record gives the endpoint definition and schedule but no observed means, standard deviations, changes, confidence intervals, or tests. Therefore, the endpoint’s numerical trajectory and its precision are not reported in the registry record. The score description also does not give a threshold for a clinically important change.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous and is specified as a mean with standard deviation. In general, a mean describes the central value of a set of scores, while a standard deviation describes how spread out individual scores are around that mean. Neither statistic, by itself, describes the full distribution or the uncertainty in the mean. A confidence interval is generally used to express uncertainty around an estimate; no confidence interval for WHODAS II is reported in the registry record.

What does repeated measurement contribute?

WHODAS II assessments were scheduled at baseline, 4 months, 8 months, and 12 months. Repeated observations allow a study to describe a course over time rather than a single measurement. Because observations from the same participant are related, an analysis of repeated measurements generally needs to account for within-person correlation. Treating all measurements as if they came from unrelated people can misstate uncertainty. The registry record does not identify a model or method used to account for repeated measurements, and it reports no fitted trajectory or test.

What does the mean and standard deviation tell a reader?

A mean can summarize average disability at an assessment, while the standard deviation indicates variability among scores at that assessment. A change in a group mean would describe a change in the group average, not necessarily the path of every participant. The scale’s direction matters for interpretation: the record states that higher WHODAS II scores indicate more impairment. However, no assessment-specific means or standard deviations are reported, so there is no numerical change to interpret.

General statistical caution also applies when distributions are skewed or contain outlying values: the mean and standard deviation may not fully represent the pattern of scores. Over-dispersion is a concept usually discussed when observed variability exceeds that expected under a model; accounting for it can affect standard errors and uncertainty. The registry record does not report a distributional assessment or a method for handling over-dispersion. Since the outcome is continuous, it would not be appropriate to assume a particular count model or variance structure without a reported analysis plan.

What can the planning calculations establish?

The sample-size assumptions describe planning illustrations, not the study’s actual design or results. They use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is defined as a stated fraction of the observed effect. The record says that time-to-event illustrations, where applicable, use a total number of events, while other illustrations use participants per arm. These are planning conventions; they do not show that the study assigned participants to two arms.

Planning estimates can help explore how a hypothetical future study might be sized under stated assumptions. They are not observed power, and they cannot substitute for an effect estimate with uncertainty. In this record, no numerical WHODAS II effect estimate or outcome analysis is reported. The planning illustrations should therefore be read as conditional calculations, not as evidence about the cohort’s functional outcomes. The registry record does not report the original protocol’s sample-size justification or establish that the illustrations reflect its design assumptions.

Which inferential methods were actually used?

The registry record does not report a statistical analysis plan, a repeated-measures model, covariate adjustment, interim analyses, hypothesis tests, or outcome estimates. It records 0 analyses. Consequently, it is not possible to attribute a particular method to the investigators or to evaluate whether assumptions for a specific model were checked. General explanations of means, variability, repeated measures, and confidence intervals describe statistical concepts only; they are not claims about analyses conducted in this study.

There are no recalculated estimates reported. Where a recalculation is based on posted summary statistics, it is a simple unadjusted calculation and may not match an adjusted sponsor analysis. No sponsor analysis or corresponding discrepancy is described in the registry record, so no comparison between sponsor and recalculated estimates can be made. The central statistical limitation is that the record gives endpoint definitions and design context without the numerical results needed to evaluate an effect, its uncertainty, or the assumptions behind an analysis.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary WHODAS II outcome and secondary outcomes including the Inventory of Psychosocial Functioning, Quality of Life Scale, and Clinician Administered PTSD Scale. It records four outcome measures and 0 analyses. It does not report how many hypotheses were tested, whether outcomes or time points were prioritized for formal testing, or whether any adjustment for multiple comparisons was planned or used. A multiplicity procedure is therefore not reported in the registry record.

In general, when many outcomes or time points are tested, the chance of at least one apparently notable result can increase. Procedures to address multiplicity can control or describe that issue, but no such procedure can be attributed to this study from the registry information. More importantly, with no reported outcome tests, there are no findings on which to assess multiplicity in practice.

The outcome description states that the analytic population is N = 309, drawn from 345 enrolled participants, with 309 deemed eligible. It also says that sample sizes vary over time because of attrition and missing data. Assessment-specific denominators, reasons for missingness, and the handling of missing measurements are not reported in the registry record. It is consequently unclear whether an analysis used all available observations, a restricted set of participants, or another approach.

In general, missing data can affect both the representativeness of the analyzed observations and the uncertainty of an estimate. The impact depends on why observations are missing and on the analysis method; neither is described. The record also does not report an analysis population definition beyond the stated total sample, or sensitivity analyses addressing missing data. These omissions prevent an assessment of whether missingness could influence a reported trajectory.

11. 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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: hospitalized for physical condition (3.6%), er for physical condition (2.3%), hospitalized for suicidal ideation/attempt (1.9%), hospitalized for mental health (1.0%), hospitalized for homicidal ideation (0.3%).

The adverse-event record lists one group, OEF/OIF/OND Veterans, with 309 at risk for serious events and 28 affected. It separately lists 309 at risk for other events and 2 affected. These are the record’s separate serious and other event fields; they should not be combined into a new total. The record does not identify these as comparative treatment-arm rates, since no control arm is described.

The listed serious-event terms include “Hospitalized for physical condition” (3.6%), “ER for physical condition” (2.3%), “hospitalized for suicidal ideation/attempt” (1.9%), “Hospitalized for mental health” (1.0%), and “hospitalized for homicidal ideation” (0.3%). The registry record lists these terms and percentages but does not give further event-level detail, timing, or a basis for attributing events to a study intervention. Deaths are not reported in the registry record.

These safety entries describe what the registry recorded, not a comparison of risks between treatments. The study description does not establish that a treatment was assigned, and the adverse-event figures alone cannot determine causation. The record does not explain whether event categories overlap or provide additional definitions, so the listed terms should be read as registry categories rather than mutually exclusive participant groups.

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

The record documents a completed, one-group follow-up focused on functional outcomes among OEF/OIF Veterans. It defines WHODAS II as the primary measure, describes its scale direction and domains, and specifies assessments at baseline, 4 months, 8 months, and 12 months. It also lists related secondary outcomes and notes that the analyzed population was described as N = 309, with sample sizes varying over time because of attrition and missing data.

What the record does not provide is the primary outcome’s numerical result. There are no reported assessment means, standard deviations, changes, confidence intervals, or outcome tests; the record lists 0 analyses. It is therefore not possible to say from this registry record whether average disability increased, decreased, or remained stable, or how precisely any change was estimated. Lack of a reported result should not be interpreted as a finding of no effect or no change.

Even a reported change in a cohort followed over time would not by itself show that a particular treatment caused it. The record describes one group and no randomized control comparison. It also does not report the statistical model, covariate adjustment, handling of missing observations, or a threshold for clinically important change. Those omissions limit interpretation of any hypothetical score difference, and no such difference is reported.

The sample-size material should be interpreted as planning illustration rather than outcome evidence or observed power. Its stated assumptions include equal allocation between two arms, although the study description lists a single group. Those assumptions do not turn the follow-up into a randomized comparison. The defensible conclusion is limited to what the registry documents: the study was completed and had a stated longitudinal functional-outcome plan, but its statistical outcome findings are not reported in the registry record.

13. Why This Trial Matters Statistically

Functional status is the central outcome in this study’s stated focus on readjustment after deployment. A measure that spans communication, mobility, self-care, relationships, daily activities, work or school, and social participation provides a broad view of disability rather than limiting assessment to a single symptom category. Repeated assessment can also describe a trajectory, which is conceptually different from a one-time description.

Statistically, however, a well-defined measure and schedule are only part of the evidence. Interpretation requires the observed values, their variability, and an analysis that accounts appropriately for repeated observations and incomplete follow-up. The registry record states that attrition and missing data cause sample sizes to vary over time, but it does not report assessment-specific counts or the missing-data approach. It also records 0 analyses. Thus the scientific question is identifiable, while the outcome evidence needed to answer it is not reported in the registry record.

The design context matters as much as the endpoint. The record describes one group and no like-for-like control arm. Follow-up can characterize change in the cohort if results are available, but a trajectory alone cannot distinguish study-related effects from other influences. Planning calculations, even when they use standard assumptions, do not fill that gap and are not observed power.

This study is statistically notable as an example of the difference between a registered outcome framework and reported inferential results. The measure, assessment schedule, population description, and safety categories are recorded. But without outcome estimates and uncertainty, readers cannot judge the size, direction, or precision of functional change. Clear reporting of those elements would be necessary for a statistical interpretation beyond the study’s stated aim and design.

14. 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 primary limitation for interpreting this specific study is the absence of numerical outcome analyses in the registry record. Although WHODAS II is defined as the primary outcome and the assessment schedule is described, the record provides no means, standard deviations, change estimates, confidence intervals, or test results. It lists 0 analyses. Consequently, the functional trajectory and its precision cannot be evaluated.

The record describes a single group and does not provide a randomized or like-for-like comparator. The stated design therefore cannot support a treatment comparison from the information recorded. It also does not describe an assigned intervention. The study title and focus identify PTSD and alcohol misuse, while the listed conditions include depressive disorder; detailed eligibility rules and the characteristics of participants are not reported in the registry record.

Attrition and missing data are explicitly noted, and sample sizes vary over time. The registry record does not provide assessment-specific denominators, reasons for missingness, methods for handling missing observations, or sensitivity analyses. It is not possible to assess how incomplete follow-up might affect estimates, particularly because no estimates are reported.

The statistical analysis plan, model for repeated observations, covariate adjustment, multiplicity approach, and interim analyses are not reported in the registry record. The listed sample-size assumptions are planning illustrations rather than evidence about the analysis conducted or observed power. The adverse-event listing gives group-level fields and selected terms but does not report event timing, detailed definitions, or attribution. These record-level limitations constrain interpretation without establishing that any particular analysis or result was absent from other sources.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Project SERVE: Post Deployment Functioning — NCT01123642.
• Registry record last updated 2018-08-20; status last verified 2018-08.
• Results first posted 2015-08-14.
• 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.

18. Record Summary

Project SERVE: Post Deployment Functioning (NCT01123642) is listed as COMPLETED, with enrollment of 345, a start date of 2010-10, and primary completion in 2014-06. The registry record describes follow-up of OEF/OIF Veterans and identifies WHODAS II as the primary outcome, assessed at baseline, 4 months, 8 months, and 12 months. It states that 309 participants were deemed eligible and that the analysis population is N = 309, with assessment sample sizes varying because of attrition and missing data.

Secondary measures include the Inventory of Psychosocial Functioning, Quality of Life Scale, and Clinician Administered PTSD Scale. The record lists 0 analyses and does not report numerical outcome estimates or an analysis plan. It describes one group rather than a randomized comparison, and allocation is not stated. The recorded information supports describing the study’s intended functional-outcome follow-up, but not evaluating the results of that follow-up.