Evaluation and Treatment of Substance Abuse in Veterans With PTSD Disability Claims: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation and Treatment of Substance Abuse in Veterans With PTSD Disability Claims (NCT01597856), a randomized na study. The primary outcome is Treatment Attendance by Treatment Group Over Time.

2. Clinical Question

The trial also concerned whether treatment assignment was associated with symptoms over time and treatment-session attendance. The registry describes repeated questionnaires for participants assigned to the two study groups, and monitoring of attendance over time. It also describes examining relationships among compensation and pension award, substance use, beliefs about benefits, and treatment attendance. Those aims are not the same as a reported treatment-effect estimate: the registry record does not give a single numerical comparison for the primary attendance outcome.

The question is therefore about a group-level pattern in recorded attendance across time, not simply whether a participant attended treatment at least once. The primary outcome is a mean number of weeks attended, with treatment attendance defined to include substance abuse and/or mental health treatment. No conclusion about the size or direction of a group difference can be drawn from the registry record alone.

3. Trial Design

The registry describes a randomized, single-masked, parallel-group study. It lists an enrollment of 346 and a completed status. The study start date is 2013-03-18, and the primary completion date is 2017-09-30. The phase is listed as NA. The sponsor is the VA Office of Research and Development.

Two study conditions are described: SBIRT and no additional treatment. The record lists 85 participants in the SBIRT group and 87 in the no-additional-treatment group for the adverse-event reporting categories. It separately lists 174 participants as not randomized. These are the group counts in the adverse-event record; the registry does not explain the relationship between those counts and the overall enrollment in further detail. The number randomized is not reported in the registry record as a separate enrollment figure beyond these group listings.

The brief description says that enrolled participants completed questionnaires around the time of their compensation and pension exam. Those questionnaires covered substance abuse, PTSD, service use, and attitudes. Attendance at treatment was monitored over time. Participants assigned to either study group were to complete the same questionnaires two additional times during the study. Those assigned to SBIRT received information about substance use and PTSD and a referral to relevant treatment; the comparator group received no study-related therapy.

The trial uses a parallel-group structure, meaning the intervention groups are distinct rather than participants crossing between conditions. Random allocation is stated, but the method used to generate the allocation sequence, conceal assignment, or implement masking is not reported in the registry record. The identity of the person or people masked is also not reported. These details matter for judging how assignment and outcome measurement were protected from bias, but they cannot be inferred from the design labels alone.

The record describes observation of treatment attendance over a period that includes 4 weeks before baseline and continues through week 12 after baseline, for a total of 16 Weeks. That span includes pre-baseline and post-baseline time. The specific schedule of attendance summaries and the exact analysis population for each reported outcome 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: All enrolled Veterans completed study assessments at baseline, week 4 and week 12. Only Veterans with self-reported risky alcohol use or use of an illicit drug within the last 28 days were randomized to receive SBIRT counseling or No additional counseling conditions.

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 Treatment Attendance by Treatment Group Over Time, measured over 4 weeks pre-baseline through week 12 post baseline, total of 16 Weeks.

The primary outcome is titled treatment attendance by treatment group over time. It measures the mean number of weeks in which a participant attended substance abuse and/or mental health treatment, using the electronic medical record as the source. The timeframe runs from 4 weeks before baseline through week 12 after baseline, a total of 16 Weeks.

This outcome captures treatment contact over a period rather than a single attendance event. In general, tracking attendance can describe engagement with services across time, while a mean summarizes the group’s average attendance on the chosen scale. The record identifies the measure as a mean and its dispersion as a standard deviation. A standard deviation describes how spread out individual observations are around the mean; it is not itself a measure of uncertainty in the group mean.

The outcome is relevant to the study’s stated aim of examining treatment attendance, including substance abuse and mental health treatment. Attendance is not the same as symptom change, treatment quality, or clinical benefit. The registry also lists secondary outcomes concerning substance use by treatment group over time and mean PTSD severity score, but it does not report numerical results for them in the information available in the registry record.

The primary outcome has several categories or time points and is not reduced in the record to one comparison. Consequently, a single effect estimate, its uncertainty, and a test of an overall treatment-group difference are not reported in the registry record. Without those results, the endpoint description identifies what was intended to be measured, but does not establish the direction, size, or precision of any difference between groups.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the study as randomized, single-masked, and parallel-group. These labels describe broad features of design, not a complete statistical analysis plan. The specific randomization procedure, masking procedures, model used for the primary outcome, covariate adjustments, and inferential testing approach are not reported in the registry record.

What does a mean measure?

The primary outcome is a mean number of weeks of substance abuse and/or mental health treatment attended. In general, a mean is an average across observed values. It can be a useful summary when the research question concerns typical attendance at the group level, but its interpretation depends on how the underlying observations are distributed and how the time points are defined. The record gives the outcome unit as weeks and identifies standard deviation as the dispersion measure.

In general, a standard deviation describes variation among observations around the mean. It should not be read as the precision of the mean estimate. Precision is commonly represented by a confidence interval or another uncertainty measure. The registry record does not report an uncertainty interval or an inferential result for the primary attendance comparison.

Why does the time structure matter?

The attendance timeframe covers 4 weeks before baseline through week 12 after baseline, for a total of 16 Weeks. The outcome is described as treatment attendance by group over time, and the registry indicates that it has several categories or time points. A repeated-measures analysis, in general, can account for the fact that observations from the same participant over time are related. But the record does not identify whether such a model was used, how time was represented, or whether the reported result was intended to summarize change, average differences, or differences at particular times.

General statistical practice distinguishes within-group change from a between-group contrast. A change in one group alone does not establish that the groups differed, because both groups may change over time. A randomized comparison usually focuses on differences between assigned groups, interpreted according to the stated outcome and analysis population. The posted registry information does not report those contrasts for attendance.

What does randomization contribute?

In general, random allocation is intended to make treatment groups comparable on average at assignment, including on measured and unmeasured characteristics. It does not guarantee exact balance in a particular trial, nor does the design label show whether allocation was concealed or implemented without departures. The method used to generate and conceal allocation is not reported in the registry record. The record also does not specify whether analyses followed assigned groups regardless of treatment received.

The registry lists 85 participants in the SBIRT adverse-event category, 87 in the no-additional-treatment category, and 174 in the not-randomized category. Those are safety-record group counts, not a description of the analytic denominators at every time point. The enrollment is 346. The record does not provide a participant-flow account that links enrollment, randomization, follow-up, and inclusion in each outcome analysis.

What can a confidence interval tell a reader?

In general, a confidence interval presents a range of values compatible with an estimate under the assumptions of the statistical method. A narrower interval indicates greater precision than a wider interval, while an interval that includes a no-difference value can indicate that the data do not distinguish the estimate from no difference at the chosen level of uncertainty. This general explanation does not imply that such an interval was reported for this study: no primary attendance estimate or interval is reported in the registry record.

Similarly, a p-value is not a measure of effect size or clinical importance. It describes how unusual data at least as incompatible with a null hypothesis would be under specified assumptions. The registry record reports no analysis entries and does not give a primary-outcome p-value. There is therefore no basis to characterize statistical significance for the main attendance question.

How should sample-size illustrations be read?

The sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is specified as a fraction of the observed effect. Such calculations are planning illustrations, not observed power and not evidence that a study was adequately powered for its outcomes. No numerical sample-size illustration is reported in the record, and the registry does not report the trial’s own sample-size justification. The observed effect needed to interpret such an illustration is also not reported for the primary attendance outcome.

In general, power depends on the effect size, variability, sample size, analysis, and significance threshold. If a calculation uses an observed effect, it is conditional on that estimate and can be unstable, particularly when the estimate is imprecise. A planning calculation cannot substitute for reporting the observed effect with its uncertainty. The registry record does not give the assumptions or analysis details needed to evaluate the original design rationale beyond the stated illustration assumptions.

Why can over-dispersion matter?

In general, over-dispersion means that the observed variability is greater than a model assumes. When that happens, standard errors from an overly restrictive model can be too small, making uncertainty appear lower than it is. The primary endpoint is described as a mean with standard deviation, but no fitted model or distributional assessment is reported. It would therefore be inappropriate to claim that over-dispersion was present or that a particular correction was used.

The registry names the electronic medical record as the attendance data source. In general, administrative records can document recorded service use, but the completeness and coding of those records need to be considered when interpreting attendance. The record does not describe data validation, missing-data procedures, or whether non-VA treatment attendance could be captured. These are open reporting questions, not grounds for assuming a specific data problem.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome is described over time and is not reduced to one comparison because it has several categories or time points. This creates an important interpretive issue: results at multiple times or across multiple outcome components can represent multiple statistical tests. In general, considering many tests without a prespecified strategy can increase the chance of at least one apparently notable result occurring by chance. The registry record does not report whether a primary time point or summary measure was prespecified, or whether a multiplicity adjustment or hierarchy was used.

The record lists two secondary outcomes: substance use by treatment group over time and mean PTSD severity score. It does not report numerical results for these outcomes or describe a plan for controlling multiplicity across primary and secondary outcomes. The number of outcome measures is listed as 3, but the registry information does not explain the full analysis hierarchy or identify which findings, if any, were confirmatory.

Missing-data methods are not reported in the registry record. The study description says participants assigned to the two groups were to complete questionnaires two additional times and that attendance would be monitored over time. It does not say how incomplete questionnaires, gaps in attendance records, withdrawal, or loss to follow-up were handled. Nor does it state whether missingness was assessed by group or time point.

The record does not provide the analysis populations, such as whether participants were analyzed according to randomized assignment, or the number contributing data to each outcome analysis. The adverse-event category counts do not establish the attendance analysis denominators. Without those details, the reader cannot evaluate the effects of missing data, departures from assignment, or differing follow-up across groups.

In general, these omissions limit how confidently longitudinal estimates could be interpreted, especially if completeness differed between groups or over time. They do not show that missing data or multiplicity problems occurred; they mean the registry record does not report how these issues were addressed.

11. 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 adverse-event record lists three categories: SBIRT, No Additional Treatment, and Not Randomized. For SBIRT, 85 participants were at risk for serious adverse events and 85 were at risk for other adverse events; zero serious adverse events, zero other adverse events, and zero deaths are recorded. For No Additional Treatment, the corresponding at-risk counts are 87 and 87, with zero serious adverse events, zero other adverse events, and zero deaths. For Not Randomized, the corresponding at-risk counts are 174 and 174, also with zero serious adverse events, zero other adverse events, and zero deaths.

These figures describe the events recorded in the registry. The not-randomized category is not a treatment arm and should not be interpreted as a comparator in a randomized safety analysis. The record does not report additional details about event definitions, collection methods, observation time, or completeness of safety follow-up. The serious-event terms list is empty.

Zero reported events means no events are listed in these categories in the registry record; it does not prove that the underlying risk was zero. Event counts also do not, by themselves, establish that the groups had equivalent safety experience. Interpreting differences would require suitable denominators, comparable follow-up, and fuller information about how events were collected and classified. No medical conclusion should be drawn from the absence of recorded events alone.

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

The registry record describes a randomized comparison of SBIRT with no additional treatment among veterans in a study concerned with PTSD disability claims and substance use. Its primary outcome is mean weeks of substance abuse and/or mental health treatment attended over time, using electronic medical records. The record identifies the study question and its outcome definition, but it does not report a single primary attendance comparison or numerical result.

That absence limits what can be concluded. The direction of any group difference, its magnitude, and its precision are not reported in the registry record. The study’s stated intention to assess whether treatment groups differed is not itself evidence that they did. The same limitation applies to the listed secondary outcomes concerning substance use and PTSD severity: their numerical results are not reported in the information available in the registry record.

The design labels and enrollment count are useful context, but they cannot replace results. Randomization can support a fair comparison when implemented and analyzed appropriately; the details of allocation, analysis populations, and missing-data handling are not reported. The record also does not explain how attendance categories or time points were combined into an overall treatment contrast.

The posted safety counts record zero serious adverse events, other adverse events, and deaths for each listed category. These are descriptive counts, including a not-randomized category, and do not establish that risk was absent or that the randomized groups were equivalent. The safety information is separate from the attendance outcome and cannot answer the primary statistical question.

In general, a result is best interpreted through an effect estimate and its uncertainty, together with the analysis population and outcome definition. Those elements are not reported for the primary comparison. The registry record therefore supports a careful account of the trial’s design and intended measurement, but not a statement that SBIRT increased or decreased treatment attendance, changed symptoms, or produced a particular clinical effect.

13. Why This Trial Matters Statistically

This trial is statistically notable because its primary question concerns attendance over time rather than a single endpoint measured once. Repeated observations can describe how service use evolves across a period that includes 4 weeks before baseline and continues through week 12 after baseline. Such a design raises questions about how time is modeled, how observations within a participant are handled, and whether an overall summary or time-specific contrasts are the focus.

The registry record makes the distinction between an outcome definition and an outcome result especially important. It identifies the mean number of weeks attended and names the electronic medical record as the measurement source, but it does not report a single primary comparison. The record also lists secondary measures related to substance use and PTSD severity without numerical results. A reader can understand the intended statistical question, while still recognizing that the available record does not answer it with an effect estimate.

Participant flow is another key statistical issue. Enrollment is listed as 346, while the adverse-event record contains categories for 85 in SBIRT, 87 in no additional treatment, and 174 not randomized. The record does not provide a fuller account linking these figures to the outcome analysis populations. That distinction matters because the number enrolled, randomized, followed, and analyzed can differ, and each denominator informs interpretation.

The study also illustrates why reporting multiplicity and missing-data methods matters for longitudinal outcomes. Multiple time points and several outcome measures can create more than one potential comparison, while incomplete records can affect estimated patterns over time. The registry does not state how either issue was handled. These gaps should be treated as limits on interpretation, not as evidence that the investigators used an inappropriate method.

Statistically, the record is useful for defining the study’s question, design labels, measurement period, and recorded adverse events. Its limitations also show why a transparent report needs the group estimates, uncertainty, analysis populations, and methods used to address time, multiplicity, and missingness before readers can assess the strength of a treatment comparison.

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 attendance outcome is longitudinal and has several categories or time points, yet the registry record does not reduce it to one comparison. No numerical estimate, uncertainty interval, or p-value for that outcome is reported. This prevents assessment of the direction, size, or precision of a group difference.

The registry does not report the statistical model, the handling of repeated observations, the definition of a primary time point, or any covariate adjustment. It also does not state whether the analysis followed randomized assignment or how deviations from assigned treatment were handled. The method used to generate and conceal allocation, and the identity of those masked, are not reported.

Although the record gives an enrollment of 346 and lists 85 for SBIRT, 87 for no additional treatment, and 174 not randomized in the adverse-event categories, it does not provide a detailed participant-flow account or outcome-specific denominators. The number with available attendance records at each time point is not reported in the registry record. Missing-data procedures, follow-up completeness, and reasons for missing observations are also not reported.

The primary outcome relies on electronic medical records, but the registry does not describe record validation, completeness, or whether attendance outside the recorded system was captured. These details could affect how fully the endpoint represents treatment attendance, but the record does not establish that a particular measurement problem occurred.

The listed secondary outcomes do not have numerical results in the registry information. The approach to multiplicity across time points and outcomes is not reported. The sample-size description gives planning assumptions for an illustration, but the trial’s own sample-size justification is not reported. Finally, adverse-event counts are listed without further information about event definitions, collection, or follow-up duration. Together, these reporting gaps constrain interpretation without proving that the underlying study analyses or data were flawed.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Evaluation and Treatment of Substance Abuse in Veterans With PTSD Disability Claims — NCT01597856.
• Registry record last updated 2020-01-27; status last verified 2020-01.
• Results first posted 2020-01-10.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry describes a completed, randomized, single-masked, parallel-group study sponsored by the VA Office of Research and Development. Enrollment is 346. The study compares SBIRT with no additional treatment in a context involving veterans applying for compensation and pension benefits and concerns about PTSD and substance use. The listed phase is NA.

The primary outcome is mean weeks of substance abuse and/or mental health treatment attendance, measured through electronic medical records from 4 weeks before baseline through week 12 after baseline, a total of 16 Weeks. The registry states that this outcome has several categories or time points and is not reduced to one comparison. No numerical primary result or analysis entry is reported in the registry record.

The adverse-event categories list zero serious adverse events, zero other adverse events, and zero deaths for SBIRT, no additional treatment, and participants not randomized. The record does not report detailed analysis populations, missing-data methods, or a complete statistical analysis plan.