Prolonged Exposure (PE) for Post Traumatic Stress Disorder (PTSD): Telemedicine Versus In Person: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Prolonged Exposure (PE) for Post Traumatic Stress Disorder (PTSD): Telemedicine Versus In Person (NCT01102764), a randomized na study. The primary outcome is Treatment Completion.

2. Clinical Question

This is a question about the comparative delivery of a behavioral treatment, not a comparison of PE with no treatment or with a different therapy. The registry identifies randomized allocation, which is intended to support a fair comparison by assigning participants to arms rather than letting participants or clinicians choose the delivery format. Randomization does not itself establish that the groups were comparable in every respect, nor does it replace the need to report outcome summaries and an analysis. Those details are not reported in the registry record.

3. Trial Design

The registry describes a randomized, double-masked, parallel-group study comparing PE by telemedicine with PE in person. Its status is completed. The listed phase is NA, consistent with the behavioral interventions recorded. The sponsor is the VA Office of Research and Development. The registry gives a start date of 2010-10 and a primary-completion date of 2015-06. These dates describe the study record and do not supply details about the timing of individual assessments or analyses.

There were 150 participants enrolled. For the primary outcome, the record says that 132 participants completed at least one session and were analyzed. The treatment-completion description says participants could receive as many as 12 sessions under the protocol. It defines treatment completers as those finishing at least 6 90-minute PE sessions, and defines dropout as initiating treatment but completing fewer than 6 sessions. These definitions distinguish enrollment, starting treatment, and completing a prespecified amount of treatment; they are not interchangeable.

The record labels the study double-masked, but does not report who was masked or how masking was implemented for a comparison of telemedicine and in-person delivery. It does not report the randomization sequence method, concealment procedures, site structure, or the allocation ratio actually achieved. These details should not be inferred from the design labels.

The primary endpoint is titled Treatment Completion, with sessions as its unit, a mean as its parameter, full range as its dispersion, and 13 weeks as its timeframe. The description also identifies broader clinical, process, and economic objectives. The registry lists secondary measures concerning PTSD symptoms, deployment-related risk and resilience, health-related functioning, satisfaction, treatment credibility, service-delivery perceptions, diagnostic assessment, and prior technology experience. The posted primary outcome is not reduced to one comparison, and the registry reports no analyses. Consequently, the design can be described, but the comparative outcome estimate and its precision cannot be reconstructed from this 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: There were 150 participants enrolled in the study, and 132 completed at least one session and were thus analyzed. The numbers here reflect those participants who were analyzed because they completed at least 1 treatment session.

Overall Study

Analysis population for the primary outcome, as defined in the registry: There were 150 participants enrolled in the study, and 132 completed at least one session and were thus analyzed. The numbers here reflect those participants who completed at least one session.

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 Completion, measured over 13 weeks.

Treatment Completion is the registered primary endpoint. It is recorded in sessions and summarized by a mean, with full range specified as the dispersion measure, over a 13-week timeframe. The treatment description sets out the operational distinction between completing treatment and dropping out: a completer finished at least 6 90-minute PE sessions, while dropout meant starting treatment and completing fewer than 6 sessions. Participants could have as many as 12 sessions under the protocol.

Session completion is a process measure. It can describe how much of the planned treatment participants received and can reflect retention in care, but it is not itself a direct measure of PTSD symptom change. The registry’s broader objective includes clinical outcomes such as PTSD and depression, as well as satisfaction, attrition, and cost. The record lists secondary measures relevant to several of those domains, but does not provide a single primary comparison linking session completion to clinical benefit.

For a comparison of delivery formats, a group mean can describe average sessions completed, while a measure of spread can show how varied individual completion was. The full range gives the minimum and maximum observed values but does not show the distribution between them. Without group-specific endpoint summaries, an estimated difference, or an uncertainty interval, readers cannot judge the size or precision of any contrast in treatment completion. The registry record does not report those results in a single comparison.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes randomized allocation and a parallel-group design. In general, randomization assigns participants to study arms by chance, helping avoid deliberate or predictable allocation based on prognosis. It does not guarantee identical groups, particularly in a finite study, and it cannot correct for missing outcomes or incomplete reporting. A parallel design compares groups receiving their assigned formats during the study rather than having each participant receive both formats in sequence. The registry does not report the random sequence generation or allocation concealment methods, so their implementation cannot be assessed.

What does the randomized design contribute?

In general, randomization supports an estimate of the effect of assignment to one delivery strategy versus the other, provided that follow-up and analysis are handled appropriately. A clear analysis should identify which participants are included, how outcomes are summarized, and how the comparison accounts for the outcome’s structure. The registry says that 132 participants who completed at least one session were analyzed for the primary outcome. It does not report whether an intention-to-treat analysis was conducted, how participants with missing endpoint data were handled, or whether the analysis followed randomized assignment regardless of treatment received.

The registry labels masking as double. Masking can reduce the influence of expectations on treatment delivery, assessment, or reporting, depending on who is masked. In general, masking is more challenging to interpret when treatment formats are visibly different. The record does not identify the masked parties or describe safeguards, so the label alone does not show how the procedure worked.

What does the endpoint summary mean?

The primary endpoint is a mean number of sessions, with full range as the stated dispersion and a 13-week timeframe. In general, a mean describes the arithmetic average of observed values, while the range describes the lowest and highest observed values. A range does not indicate how values are distributed between those endpoints and can be sensitive to extreme observations. The registry does not report the arm-specific means, ranges, or a formal contrast as one primary comparison. It therefore does not allow readers to assess the observed difference or its precision.

The endpoint also sits alongside a treatment-completion definition based on reaching at least 6 sessions. A continuous session count and a threshold-based completion status answer related but distinct questions. The count retains information about session totals; a threshold categorizes participants according to whether they reached the stated criterion. The record does not report one consolidated analysis showing how the registered mean endpoint and completion classification were jointly handled. It says the primary outcome has several categories or time points and was not reduced to one comparison.

Why does over-dispersion matter in general?

For count outcomes, a simple model may assume that variation follows a particular relationship to the mean. Over-dispersion occurs when observed variation is greater than that assumption allows. In general, ignoring over-dispersion can make standard errors too small and confidence intervals too narrow, giving an overly precise impression. This is a general consideration for count data, not a claim about this trial: the registry does not report a count model, a dispersion assessment, or a statistical analysis of the session outcome.

What can a confidence interval communicate?

In general, an estimate gives a best-supported value for a contrast under the chosen analysis, while its confidence interval communicates uncertainty around that estimate. A narrow interval indicates greater statistical precision than a wide interval, given the same method and assumptions. An interval can include values consistent with little difference as well as values that might be meaningful; interpretation depends on the endpoint, clinical context, and prespecified criteria. No primary estimate or confidence interval is reported as a single comparison in this record, so neither magnitude nor precision can be evaluated.

How should the planning illustrations be read?

The registry’s sample-size assumptions describe planning illustrations based on an observed effect, using a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The effect to detect is described as a stated fraction of the observed effect. Such illustrations are conditional calculations: they show the number of participants per arm under specified assumptions, rather than the number observed in a new study or evidence about the probability that the current study found an effect. They are not observed power. The record does not report a protocol sample-size justification or explain how any planning illustration relates to the original design. A sample-size calculation cannot replace a reported treatment estimate and its uncertainty.

The registry says that no analyses are reported. It does not describe a prespecified statistical analysis plan, an interim analysis, adjustment for baseline covariates, or handling of multiple outcomes. These omissions prevent a reader from determining which model or inferential procedure, if any, underlies a comparative result. General statistical principles can clarify what such methods would do, but they cannot fill in trial-specific methods absent from the record.

10. Multiplicity, Missing Data and Analysis Populations

The study description covers a broad set of outcomes: clinical measures, treatment process and satisfaction, and economic outcomes. The registry lists secondary measures concerning PTSD symptoms, deployment risk and resilience, health-related functioning, outpatient satisfaction, treatment credibility, perceptions of service delivery, diagnostic assessment, and prior experience with computer and audiovisual technology. It also reports 11 outcome measures, while reporting zero analyses. The primary outcome is not reduced to one comparison because it has several categories or time points.

When a study evaluates many outcomes, time points, or comparisons, the chance of at least one apparently unusual finding can increase if each is tested separately. In general, multiplicity procedures can control or describe this issue, but the appropriate approach depends on the prespecified questions and analysis plan. The registry does not report a multiplicity strategy, a hierarchy of outcomes, or which contrasts were planned. It is therefore not possible to determine how any potential secondary findings would have been interpreted or whether statistical testing was adjusted.

The record identifies an analysis population of participants who completed at least one session. It does not report how missing endpoint data were handled, whether participants were analyzed according to their randomized assignment, or whether any sensitivity analyses were performed. These details matter because excluding participants or handling incomplete outcomes in different ways can affect both the estimated contrast and its uncertainty. The reasons for not contributing to the stated analysis are not reported in the registry record.

For these reasons, the registered material does not support a full assessment of multiplicity, missing-data assumptions, or the analysis population. The absence of those details is an interpretive limitation, not proof that a particular method was or was not used outside the registry record.

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

Serious events with the highest arm-level rate: death (1.3%).

The adverse-event record lists 74 participants at risk for serious adverse events in the telemedicine arm, with 0 affected, and 76 at risk in the in-person arm, with 1 affected. For other adverse events, it lists 74 at risk and 0 affected in the telemedicine arm, and 76 at risk and 0 affected in the in-person arm. These are descriptive counts; they do not by themselves establish a difference in safety between delivery formats.

The registry lists Death as the serious-event term, with 1.3% shown. However, the separate deaths fields for both arms are null. The record does not clarify the relationship between the serious-event term and those death fields. The reported figures should therefore be read as the registry records them, without assuming that the event was a death counted in the separate fields or that it was caused by the intervention.

Rare events are difficult to compare reliably using small counts alone. In general, a formal comparison would need to account for uncertainty, the event definition, follow-up, and whether events were adjudicated or considered related to treatment. Those details are not reported in the registry record. The adverse-event entries should not be interpreted as a complete measure of all possible harms or as evidence of causation.

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

The registry record identifies a randomized comparison of PE delivered via telemedicine and PE delivered in person, with treatment completion as the primary endpoint. It defines completion and dropout in terms of sessions and gives a 13-week timeframe. It also describes broader clinical, process, and economic objectives. These registry entries clarify what the study set out to investigate, but they do not answer the comparative question on their own.

The primary result is not reported as one comparison. No single group contrast, uncertainty interval, or analysis is reported for treatment completion. Consequently, the available record does not establish that the delivery formats produced the same level of completion, nor that one produced more or less completion. It also cannot show how precise a comparative estimate would be. A lack of a reported result must not be interpreted as evidence of equivalence or as proof that no difference exists.

Even if a comparative completion result were available, treatment completion would address session participation and retention rather than symptom change by itself. The registry’s stated objectives include PTSD and depression outcomes, satisfaction, attrition, and cost. The listed secondary measures span several domains, but the record does not present a complete comparative account of those outcomes. Conclusions about those domains cannot be substituted for, or inferred from, session completion.

The enrollment and analysis descriptions also refer to different stages of participation. The registry reports 150 enrolled and 132 who completed at least one session and were analyzed for the primary outcome. Without further details about participant flow and missing outcomes, the consequences of this analysis population for the comparison are uncertain. Similarly, the adverse-event counts are descriptive and do not identify causation.

The study may be relevant to questions about treatment delivery because it directly compares telemedicine and in-person formats for PE. Statistical interpretation, however, requires the outcome estimates, analysis methods, and uncertainty to be available. The registry record supports understanding the intended question and some design features, but the registered results do not permit a conclusion about comparative effectiveness, equivalence, or safety.

13. Why This Trial Matters Statistically

This trial is statistically relevant because it frames a delivery-format question within a randomized comparison: the treatment named in both arms is PE, while the recorded difference is telemedicine versus in-person delivery. That design can, in principle, help isolate the consequences of delivery format more clearly than a comparison between unrelated treatments, provided that randomization, follow-up, and outcome analysis are appropriately reported.

The endpoint also illustrates why a study’s objective and its primary measure need careful interpretation. Treatment completion counts sessions and applies a completion threshold, while the broader objective includes clinical, process, and economic outcomes. A measure of attendance or completion can inform understanding of treatment participation, but it does not directly answer whether PTSD symptoms changed or whether participants experienced better functioning. Keeping those concepts separate is essential when reading trial results.

The registry record demonstrates another statistical principle: a design description is not a result. Randomization, masking, and a defined endpoint provide context for evaluating evidence, but readers also need a reported contrast and an account of its uncertainty. Here the primary outcome is not reduced to one comparison, and no analyses are reported. That makes the missing result itself important: the central comparative question cannot be settled from the posted record.

Finally, the participant and safety information show why denominators and outcome definitions matter. The record distinguishes enrolled participants from those who completed at least one session and were analyzed. It also reports serious-event counts separately from other events and contains a Death event term alongside null death fields. Such details call for careful description rather than causal interpretation. The trial is useful as an example of how to separate study design, process outcomes, clinical outcomes, and the limits of registry reporting.

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 most direct limitation is that the registry does not present the primary treatment-completion outcome as a single comparison. It says the outcome has several categories or time points and was not reduced to one comparison, and it reports zero analyses. There is therefore no registered estimate or uncertainty interval with which to judge the size, direction, or precision of a contrast between delivery formats.

The description gives an analysis population of participants who completed at least one session, but does not report a full participant-flow account, the reasons some enrolled participants were not included in that population, or their distribution by arm in the primary-outcome summary. It does not state how missing outcome data were handled. The effect of these features on a comparative analysis cannot be determined from the record.

Although the trial is labelled double-masked, the masked parties and practical procedures are not described. The record also does not report the randomization sequence method or allocation concealment. These omissions limit assessment of how the design protections were implemented; the design labels alone cannot establish their success.

The primary endpoint is a mean session count with full range as its dispersion measure, and the protocol description also defines completion using a threshold. The record does not provide the underlying group summaries or explain how the several outcome categories or time points were incorporated into a primary comparison. It also does not report an analysis plan, model choice, multiplicity strategy, interim analyses, or sample-size justification.

Finally, the adverse-event information contains a Death term and a percentage, while the separate deaths fields are null. The record does not explain that discrepancy. Event attribution, event ascertainment methods, and comparative safety analyses are not reported. These limitations concern what can be established from the registry record and should not be replaced with assumptions about procedures or findings.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Prolonged Exposure (PE) for Post Traumatic Stress Disorder (PTSD): Telemedicine Versus In Person — NCT01102764.
• Registry record last updated 2019-03-04; status last verified 2018-11.
• Results first posted 2016-09-01.
• 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 record for NCT01102764 concerns a completed randomized, double-masked, parallel-group study of PE delivered by telemedicine or in person for Veterans with PTSD. The sponsor is the VA Office of Research and Development. The record lists 150 participants enrolled and says that 132 completed at least one session and were analyzed for the primary outcome.

The primary endpoint is Treatment Completion, measured in sessions, summarized by a mean with full range specified, over 13 weeks. The treatment description allows as many as 12 sessions and defines completion as at least 6 90-minute sessions. The registry also lists secondary measures across clinical, functional, satisfaction, and technology-related domains.

The primary outcome is not reduced to one comparison, and the registry reports no analyses. Thus, the record describes the question and design but does not provide a single comparative result for treatment completion. Adverse-event counts are reported, but the serious-event entry for Death is not reconciled with the null death fields. The registry record does not support conclusions about comparative effectiveness, equivalence, or causation.