Exposure With Acceptance-Based Versus Habituation-Based Rationale for Public Speaking Anxiety: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Exposure With Acceptance-Based Versus Habituation-Based Rationale for Public Speaking Anxiety (NCT00842946), a randomized na study. The primary outcome is Number of Participants in Remission (Per Structured Clinical Interview for DSM-IV Axis I Disorders (SCID)).

2. Clinical Question

The trial asks whether behavioral exposure framed around psychological acceptance differs from behavioral exposure framed around habituation in remission from public speaking anxiety. Its primary outcome is the number of participants in remission at 6-weeks post-treatment, assessed using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID).

The study summary hypothesizes that the acceptance-based group would experience a greater decrease in anxiety and greater improvement in quality of life. Those are stated expectations, not the primary posted outcome. The record lists one outcome measure, remission, and does not post secondary outcomes. The result therefore addresses the recorded diagnostic remission measure rather than every outcome raised in the study summary.

3. Trial Design

The registry describes a completed, randomized, single-masked, parallel-group behavioral study sponsored by Drexel University. The study compared two rationales for behavioral exposure: psychological acceptance and habituation. Both arms are described as behavioral exposure; the stated contrast is the context or rationale in which exposure occurred.

The record lists total enrollment as 45. The acceptance arm lists 21 participants and the habituation arm lists 24. The listed outcome is the number of participants in remission, assessed at 6-weeks post-treatment with the SCID. The registry does not describe the exact sequence or content of treatment sessions, how the rationales were delivered, or how masking was implemented. Those details are not reported in the registry record.

The study start is recorded as 2009-02 and primary completion as 2009-11; its status is completed. The phase is listed as NA. These administrative details establish the context of the record, but they do not explain the trial’s design choices. The registry record does not report the planned sample-size justification, the intended statistical analysis plan, or whether an interim analysis was planned.

Randomization supports a comparison between groups, but the record does not give details about sequence generation, concealment, stratification, or balance in baseline characteristics. Single masking is recorded, but who was masked is not specified. The parallel design indicates distinct groups assigned to the two rationales; the record does not indicate crossover between them. Interpretation should therefore remain focused on the posted group counts and the limits of the design information documented in the registry.

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

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 Number of Participants in Remission (Per Structured Clinical Interview for DSM-IV Axis I Disorders (SCID)), measured over 6-weeks post-treatment.

The primary endpoint is the number of participants in remission at 6-weeks post-treatment, as assessed by the SCID. The measure is recorded as a count of participants, with the arm totals and numbers in remission reported separately. In the posted results, the acceptance group has 21 participants, with 21 in remission; the habituation group has 24 participants, with 20 in remission.

The SCID is described in the registry as a structured diagnostic interview based on DSM-IV criteria. In general, a structured interview applies a consistent diagnostic framework across participants. Remission defined through such an assessment is a categorical outcome: each participant is classified as in remission or not in remission according to the assessment. This differs from a continuous score, such as a symptom scale, which can represent gradations in severity.

Diagnostic remission is used to describe whether participants meet the specified diagnostic outcome at the assessment time. It does not by itself describe the full course of anxiety, changes in quality of life, or performance during public speaking. The registry description notes that interrater reliability estimates for the SCID range from moderate to high for most Axis I disorders. The record does not report whether interviewers were masked to group assignment, or how remission was determined when an assessment was unavailable.

7. Results Posted in the Registry

• Habituation: 83.3% (20/24) versus 100.0% (21/21) on control; risk difference -16.7 percentage points (95% CI -31.6 to -1.8), risk ratio 0.83 (0.70–1.00); unadjusted two-proportion z-test p = 0.050.

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is binary at the participant level: a participant is either counted as in remission or is not. The posted arm results give the group size and the number in remission. In general, binary outcomes can be described using counts, risks, risk differences, and relative risks. Each measure answers a related but distinct question, and each depends on the event definition and follow-up point being compared.

What does the risk difference describe?

A risk is the proportion of a group experiencing the defined event. Here the event is remission by the SCID at 6-weeks post-treatment. The registry reports the acceptance group risk as 1.0 and the habituation group risk as 0.833. The reported risk difference is -0.167 for habituation relative to acceptance. In general, a risk difference subtracts one group’s risk from the other group’s risk; its sign depends on which group is placed first. With this contrast, a negative value corresponds to a lower estimated remission risk in habituation than in acceptance.

The risk difference is expressed on the absolute scale. It describes the separation between the group risks rather than a proportional change. The reported confidence interval, -0.316 to -0.018, gives a range of values compatible with the data under the interval method used. The registry does not state that method. Since the interval is entirely negative, its endpoints indicate that the estimated contrast favors a higher remission risk in acceptance in this unadjusted comparison. The upper endpoint is close to zero, so the result is compatible with a small absolute separation as well as a larger one in the same direction.

What does the relative risk describe?

The relative risk compares the event risk in one group with the event risk in the other. The posted value is 0.833 for habituation relative to acceptance, with a confidence interval from 0.697 to 0.997. A value representing equal risks is 1; values below that reference indicate a lower event risk in the group in the numerator, given the stated comparison direction. The interval reaches close to 1, so the estimated relative contrast is also near the equal-risk reference at its upper end. Relative and absolute measures can help readers understand the same data from different perspectives; neither removes uncertainty or establishes a causal explanation on its own.

How should the p-value be read?

The reported unadjusted p-value is 0.05. In general, a p-value measures how unusual data at least as incompatible with a specified null model would be if that model were true and the statistical assumptions held. It is not the probability that the null model is true, and it does not measure the probability that the observed result will recur. The record does not report the test used, its assumptions, or whether the p-value was prespecified.

The adjective unadjusted indicates that the posted value is not described as adjusted for other factors or comparisons. Because the registry does not report the analysis plan, it is not possible to determine whether the comparison was the only planned test or whether any adjustment had been intended. The record lists one outcome measure and no secondary outcomes, but that alone does not establish the full set of analyses considered by investigators.

What can the counts establish?

The counts show the observed remission classifications in the two arms at the specified follow-up. They do not show individual changes from baseline, because baseline remission status and participant-level transitions are not reported. They also do not show the distribution of anxiety scores or quality-of-life measures. The trial summary states a hypothesis about those outcomes, but the registry does not post secondary outcome results for them.

In general, binary outcomes discard distinctions among participants who share the same classification. A remission count does not indicate how close a participant was to the diagnostic threshold, how symptoms changed over time, or whether benefits persisted after the assessment. These are limits of the endpoint as a summary, not evidence that such effects occurred or did not occur.

The registry records no posted analysis count. It does provide an unadjusted comparison, but the statistical procedure and analysis population are not described. The reported estimates therefore should be interpreted as the registry’s posted summary statistics, without attributing an undocumented model or adjustment to the investigators.

10. Confidence Intervals and Precision

Confidence intervals communicate uncertainty around an estimated comparison. In general, an interval is constructed using a statistical method and its assumptions; it is not a guarantee that the true effect lies within its endpoints. The registry reports a risk-difference estimate of -0.167 with an interval from -0.316 to -0.018, and a relative-risk estimate of 0.833 with an interval from 0.697 to 0.997. The methods used to calculate these intervals are not reported in the registry record.

For the risk difference, the reported interval is wholly below zero, with its upper endpoint close to zero. This shows that the posted interval includes estimates near no absolute difference as well as estimates farther in the same direction. For the relative risk, the interval is below the equal-risk reference of 1, with its upper endpoint also close to that reference. The two measures use different scales, so their numerical values should not be compared directly.

Precision concerns the range of values consistent with the observed data and the method, not whether the result is important or clinically meaningful. The counts are limited to the enrolled groups, and the record does not report a prespecified threshold for a meaningful remission difference. The intervals do not account for any unreported analysis choices, outcome selection, or missing assessments. The registry also does not report the number of participants assessed at follow-up separately from the listed arm totals, or describe missing-data handling. These omissions limit what can be concluded about the uncertainty surrounding the complete trial population.

The p-value of 0.05 is consistent with a result close to the conventional boundary often used for statistical significance, but it does not replace the intervals. The intervals show the range of estimated contrasts under their calculation method; the p-value condenses a test against a specified null model. Neither statistic alone determines the strength, durability, or practical relevance of the finding.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure and no posted secondary outcomes. It also records no posted statistical analyses, although an unadjusted comparison is reported for the primary remission outcome. The statistical analysis plan, including the intended treatment of multiple comparisons, is not reported in the registry record. It is therefore not possible to establish whether the posted contrast was the only analysis planned or whether other outcomes or models were considered.

In general, multiplicity arises when several hypotheses are tested or several outcomes are examined. Repeated testing can increase the chance of observing a result that appears notable by chance, so a prespecified analysis plan and appropriate adjustment can matter. This general concern should not be taken as evidence that unreported analyses occurred in this study. The record does not provide enough information to assess that question.

The registry does not report the number of participants with missing follow-up assessments, the reasons for missingness, or a missing-data method. It also does not identify whether the analysis included all randomized participants, only participants who completed treatment, or another population. The posted arm totals and remission counts describe the reported results, but do not by themselves establish how missing observations were handled.

In general, an intention-to-treat analysis retains participants in their randomized groups, while a per-protocol analysis may restrict the analysis to participants meeting specified treatment or follow-up criteria. Neither approach is identified in the registry record. The record also does not report whether an interim analysis was planned or conducted, or whether the primary endpoint or analysis changed during the study. These details are needed to evaluate analysis choices and the potential influence of missing data or multiple testing; they should not be inferred from the posted p-value.

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 1% reporting threshold.

The registry’s adverse-event figures list zero serious adverse events among 21 participants at risk in the acceptance group and zero among 24 participants at risk in the habituation group. The listed figures for other adverse events are also zero in both groups. No serious adverse-event terms are listed.

These figures describe what is recorded for the groups and at-risk counts. They do not establish that no adverse experiences occurred outside the registry’s reporting definitions or observation period. The record does not give detailed definitions, collection procedures, severity criteria, or the time period used for adverse-event monitoring. It also does not provide information about events that may not have met the listed categories.

Deaths are recorded as not reported for both groups. That is different from a reported count of zero. The registry’s safety figures should therefore be read as a narrow summary of the posted categories, not as a complete account of all possible harms or experiences during the study. They are also separate from the remission endpoint and do not explain the efficacy comparison.

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

The posted result describes remission at 6-weeks post-treatment in two randomized groups receiving behavioral exposure with different rationales. The acceptance group had 21 participants in remission among 21 listed participants; the habituation group had 20 in remission among 24 listed participants. The reported unadjusted risk difference and relative risk both indicate a lower estimated remission outcome in habituation relative to acceptance, with confidence intervals close to the reference values at their upper endpoints.

This finding does not establish that the acceptance-based rationale caused the observed difference. Randomization is an important design feature, but the record does not report baseline characteristics, masking details, treatment adherence, or the analysis population. The statistical comparison is unadjusted, and the analysis method is not described. The result also concerns a single recorded assessment time and does not show whether remission persisted beyond 6-weeks post-treatment.

The primary outcome is not the same as the study summary’s hypothesized decrease in anxiety or improvement in quality of life. Those outcomes are not posted as secondary results. Nor does remission alone show how much anxiety changed for individual participants, how exposure was experienced, or whether the two rationales differed in other respects.

The reported p-value should not be interpreted as proof, and the confidence intervals should not be interpreted as guarantees. The estimates quantify the observed contrast with uncertainty under the reported analysis, while important design and analysis details remain unreported. The data support describing the registry’s remission comparison; they do not support broader claims about all outcomes, all participants with public speaking anxiety, or the long-term effects of either approach.

14. Why This Trial Matters Statistically

This trial illustrates how a behavioral intervention can be compared by changing its rationale while retaining exposure as the shared treatment element. Statistically, that design directs attention to the contrast between acceptance-based and habituation-based contexts, rather than to exposure versus no exposure. The registry describes the two behavioral approaches but does not provide enough detail to determine how distinct their delivery was in practice.

The outcome also demonstrates the interpretive limits of a binary endpoint. Remission can be clinically legible as a diagnostic classification, but a count of participants in remission cannot describe the full range of symptom change or quality-of-life experience. The study summary raises those broader outcomes, while the posted result focuses on remission at a specified follow-up.

The reported absolute and relative comparisons offer complementary descriptions of the same event data. Their intervals show why an estimate should be read alongside its uncertainty rather than treated as a definitive ranking. The registry’s unadjusted p-value, near a conventional threshold, does not resolve questions about precision, the analysis plan, missing data, or the completeness of outcome reporting.

For biostatisticians and clinical researchers, the record is a useful reminder that randomization and a reported comparison do not provide every detail needed for appraisal. The contrast can be described accurately, while causal attribution and generalization remain constrained by unreported design and analysis information. Clear distinction between observed counts, estimated contrasts, and unanswered methodological questions is essential to interpreting a small behavioral trial without overstating its findings.

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.

Several trial-specific details needed to assess the remission comparison are not reported in the registry record. These include eligibility criteria, participant characteristics, baseline diagnostic status, sequence generation, allocation concealment, and the identity of the person or group masked. Without these details, the record does not allow assessment of baseline comparability or the practical implementation of masking.

The intervention descriptions identify exposure in acceptance and habituation contexts but do not specify treatment dose, session structure, therapist training, treatment fidelity, or adherence. The registry also does not report whether participants received other care during the study. These omissions make it difficult to know how the behavioral approaches were operationalized or whether the comparison isolated the rationale.

The primary outcome is reported at 6-weeks post-treatment, with no longer-term assessment posted. No secondary outcome results are reported, despite the study summary’s stated expectations about anxiety and quality of life. The record does not describe missing assessments, analysis populations, the statistical method, or the handling of missing data. The planned sample-size justification and any interim analyses are also not reported in the registry record.

Finally, the record does not provide details needed to judge the completeness of safety monitoring. Serious and other adverse-event counts are listed, but definitions and collection procedures are not. These limitations concern what can be learned from the registry record; they do not establish that the trial lacked procedures that were simply not documented there.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Exposure With Acceptance-Based Versus Habituation-Based Rationale for Public Speaking Anxiety — NCT00842946.
• Registry record last updated 2014-06-02; status last verified 2014-05.
• Results first posted 2014-06-02.
• 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

The registry describes a completed randomized, single-masked, parallel behavioral study sponsored by Drexel University. Total enrollment is 45, with 21 participants listed in the acceptance arm and 24 in the habituation arm. The primary outcome is the number in remission according to the SCID at 6-weeks post-treatment.

The posted counts are 21 in remission in acceptance and 20 in remission in habituation. For habituation relative to acceptance, the reported risk difference is -0.167, with a confidence interval from -0.316 to -0.018; the relative risk is 0.833, with a confidence interval from 0.697 to 0.997. The unadjusted p-value is 0.05.

The record lists no secondary outcomes or posted statistical analyses. Details about the statistical plan, analysis population, missing data, participant characteristics, and follow-up beyond the primary assessment are not reported in the registry record.