This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Variations of Cognitive Behavior Therapy for Social Anxiety Disorder (NCT00948974), a randomized na study. The primary outcome is Social Phobia and Anxiety Inventory (SPAI) - Social Phobia Subscale.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00948974 |
| Phase | NA |
| Condition | Social Anxiety Disorder |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 88 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Drexel University |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns people with generalized social anxiety disorder. The registry lists Social Anxiety Disorder as the condition and describes the purpose as comparing treatments for generalized social anxiety disorder. The population field for the primary outcome is blank, so further details about eligibility, participant characteristics, or the analysis population are not reported in the registry record.
Intervention
One randomized arm received cognitive therapy with exposure. Cognitive therapy is listed as a behavioral intervention. The registry does not describe the treatment schedule, session content, therapist training, or treatment adherence.
Comparator
The comparison arm received acceptance and commitment therapy with exposure. This is also listed as a behavioral intervention. Because exposure is included in both arm descriptions, the intended contrast is between these therapy variants as delivered with exposure, rather than between therapy and no treatment.
Primary question
The study’s stated purpose is to compare the efficacy of cognitive therapy and acceptance and commitment therapy for generalized social anxiety disorder. The primary measure is the Social Phobia and Anxiety Inventory social phobia subscale, assessed at baseline and post-treatment at 12 weeks. The registry record does not report a single reduced comparison or numerical results for that measure, so the direction and size of any between-arm difference cannot be described from this record.
3. Trial Design
This was a randomized, parallel-group trial with no masking reported. The registry lists an enrollment of 88 and identifies Drexel University as the sponsor. The study start is recorded as 2010-01, primary completion as 2015-01, and status as completed. The phase is listed as NA.
The two behavioral interventions were cognitive therapy and acceptance and commitment therapy. The arm descriptions specify cognitive therapy and exposure in one arm and acceptance and commitment therapy and exposure in the other. This means both arms included exposure; interpretation of a contrast should therefore focus on the difference between the therapy variants as implemented, not treat exposure as unique to one arm. Further details about treatment delivery, dose, fidelity, and concomitant care are not reported in the registry record.
Random allocation can support a fair comparison by reducing systematic differences between groups at the time of assignment, on average. That general benefit depends on how allocation was generated and preserved. The sequence-generation and allocation-concealment procedures are not reported in the registry record. Masking is listed as none; the record does not specify which parties, if any, were aware of treatment assignment. For behavioral interventions, participant and therapist masking may be difficult, but the details in this trial are not reported in the registry record.
The primary outcome description identifies the SPAI social phobia subscale and gives baseline and post-treatment (12 weeks) as the timeframe. The record also lists Outcomes Questionnaire and Behavioral Assessment Test as secondary outcomes. It reports three outcome measures in all, but does not supply their numerical results or a single primary comparison. The registry marks the primary outcome as having several categories or time points and not being reduced to one comparison.
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
| Stage | Cognitive Therapy | Acceptance and Committment Therapy |
|---|---|---|
| STARTED | 40 | 48 |
| COMPLETED | 17 | 28 |
| NOT COMPLETED | 23 | 20 |
Reasons for not completing this period:
| Reason | Cognitive Therapy | Acceptance and Committment Therapy |
|---|---|---|
| Lost to Follow-up | 23 | 20 |
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.
| Characteristic | Unit | Cognitive Therapy | Acceptance and Committment Therapy | Total |
|---|---|---|---|---|
| Participants analysed | 40 | 48 | 88 | |
| Age, Continuous | years | 30.05 (SD 10.25) | 29.90 (SD 11.66) | 29.97 (SD 10.98) |
| Sex: Female, Male: Female | Participants | 18 | 27 | 45 |
| Sex: Female, Male: Male | Participants | 22 | 21 | 43 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 5 | 10 | 15 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 5 | 8 | 13 |
| Race (NIH/OMB): White | Participants | 22 | 21 | 43 |
| Race (NIH/OMB): More than one race | Participants | 8 | 9 | 17 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Social Phobia and Anxiety Inventory (SPAI) - Social Phobia Subscale, measured over baseline (pre-treatment; immediately prior to beginning treatment); post-treatment (12 weeks).
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary measure is the Social Phobia and Anxiety Inventory (SPAI) social phobia subscale, expressed in units on a scale. Its description says it assesses social anxiety symptoms in the presence of strangers, authority figures, members of the opposite sex, and people in general. Scores range from 32 to 192, with higher scores reflecting more severe social anxiety symptoms.
The measure is relevant to the study’s stated question because the trial concerns treatments for social anxiety disorder and the scale addresses social anxiety symptoms. The registry specifies a mean and standard deviation as the summary format, with assessments at baseline before treatment and post-treatment at 12 weeks. Repeated assessment can describe participants’ scores at different stages, while an arm comparison can examine whether the groups’ outcomes differ. These are distinct questions: within-arm change alone does not establish a between-arm difference.
The registry record does not provide the group means, standard deviations, participant counts contributing to each assessment, or a specified numerical contrast for this endpoint. It also does not state which assessment or contrast was selected as the single primary analysis. The measure’s stated range and direction help interpret a reported score, but cannot establish an outcome in the absence of the scores themselves.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the trial’s randomized, parallel design and the intended comparison of two therapy variants, each combined with exposure. It also identifies the primary symptom measure and its assessment schedule. It does not report the primary outcome values or a single reduced comparison. Consequently, the record alone does not support a statement about which arm had a higher or lower post-treatment score, the size of any difference, or the precision of an estimated difference.
The listed endpoint is a continuous measure summarized using means and standard deviations. Those summaries can describe the distribution of scores within each arm at a time point. To interpret treatment contrast, however, the relevant estimate would need to compare arms using a defined approach, such as a post-treatment contrast or a contrast in change from baseline. The registry does not report which approach was planned or used. Nor does it report an effect estimate, confidence interval, p-value, or analysis result for this endpoint.
A confidence interval, in general, gives a range of values compatible with the data and the method used to calculate it. Its width conveys precision: a narrower interval indicates more precise estimation under that method, while a wider interval indicates greater uncertainty. Without an estimate and interval, neither the magnitude nor the precision of a primary treatment contrast can be assessed from the registry record. A p-value, if reported, would address compatibility with a specified null model; it would not by itself describe the size or practical importance of an effect. No such p-value is reported.
The timepoints matter. A baseline score describes symptoms before treatment, while a post-treatment score describes the measure at the stated 12-week assessment. Comparing change within each arm is not equivalent to directly comparing the randomized arms. A between-arm estimate is needed to address whether outcomes differed between assigned treatments. Because the record does not reduce its multiple timepoints or categories to one comparison, it is not possible to identify a primary numerical contrast from the registry entry.
The absence of numerical results should not be mistaken for evidence that the interventions had equal outcomes, nor for evidence that one was better. The record reports zero analysis entries, and its note says the primary outcome has several categories or time points and was not reduced to one comparison. The underlying results, analysis population, and estimates are not reported in the registry record. Any interpretation beyond the design and outcome definitions would therefore require information not contained in the record.
9. Statistical Methods Explained
What does randomization contribute?
Randomization assigns participants to treatment groups by chance rather than by a treatment choice based on their characteristics. In general, this helps make the groups comparable at the point of assignment, including on characteristics that were not measured. It does not guarantee identical groups, especially in a finite trial, and it does not remove the need to report how the random sequence was created or how assignments were concealed. Those procedures are not reported in the registry record. The design is listed as randomized, parallel, and unmasked.
In a parallel design, participants are assigned to one treatment arm and outcomes are compared across arms. Here, the two listed approaches are cognitive therapy with exposure and acceptance and commitment therapy with exposure. Since both arm descriptions include exposure, an arm contrast would concern the treatment packages as described. It would not isolate the effect of exposure separately from the therapy variant.
How should a continuous endpoint be read?
The SPAI social phobia subscale is a continuous score, summarized in the record by a mean and standard deviation. A mean describes the average score in a group. A standard deviation describes how spread out individual scores are around that group mean; it is not the uncertainty of the mean or of a treatment contrast. The score range is 32 to 192, and higher scores represent more severe symptoms according to the endpoint description.
General statistical explanation: an estimate of a between-arm difference would describe the observed separation between the groups on a defined scale and at a defined time or across defined timepoints. Its standard error and confidence interval would express uncertainty in that estimated contrast. The registry entry does not provide means, standard deviations, a contrast estimate, or an interval, so none can be interpreted for this trial from the record.
Why does the choice of contrast matter?
The registry lists baseline and post-treatment (12 weeks), but the same endpoint can yield more than one statistical question. One approach could compare post-treatment scores between arms. Another could compare the change from baseline between arms. A repeated-measures analysis could use scores at both timepoints together. These approaches can target different quantities and may rely on different assumptions. The registry record does not identify which contrast or model was used, and it explicitly notes that the primary outcome has multiple categories or timepoints and was not reduced to one comparison.
General statistical explanation: adjusting for baseline can sometimes improve precision when baseline measurements are related to the outcome, but the method and assumptions must be specified. A change score and a baseline-adjusted post-treatment comparison are not automatically interchangeable. No baseline-adjustment method, repeated-measures model, covariate set, or missing-data method is reported in the registry record.
What do confidence intervals and p-values add?
General statistical explanation: a confidence interval communicates both an estimated effect and the uncertainty around it, conditional on the analysis assumptions. It helps readers distinguish a precise estimate from one that remains compatible with a broad range of possible effects. A p-value summarizes how unusual data would be under a specified null hypothesis and model. It does not show the probability that a treatment is effective, and it does not quantify clinical importance.
No confidence interval, p-value, or effect estimate for the primary outcome is reported in the registry record. It is therefore not possible to assess statistical precision, the compatibility of the data with a null hypothesis, or the magnitude of a treatment difference. A numerical conclusion should not be inferred from the randomized design or from the outcome’s measurement range.
What is over-dispersion, and is it relevant?
General statistical explanation: over-dispersion arises when observed variability is greater than a statistical model expects. It is particularly relevant to some count outcomes, where a model that understates variability can produce confidence intervals that are too narrow and p-values that overstate evidence. The primary endpoint in this record is a continuous scale summarized by a mean and standard deviation, not a count outcome. The registry does not report a model or diagnostic assessment, so there is no basis for claiming that over-dispersion was assessed or affected the analysis.
How should planning calculations be distinguished from results?
General statistical explanation: a sample-size planning calculation asks how many participants might be needed under assumptions about an effect, variability, significance level, allocation, and statistical method. Such a calculation is not an observed trial result and does not establish the probability that a completed study detected a real effect. The registry’s stated planning assumptions describe a two-sided significance level of 0.05, equal allocation, a normal approximation, and an effect defined as a fraction of the observed effect. Any resulting sample size would be an illustration under those assumptions, not the trial’s own design justification. The registry record does not report a sample-size justification or the numerical planning assumptions beyond those listed.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists three outcome measures and names Outcomes Questionnaire and Behavioral Assessment Test as secondary outcomes. The primary SPAI social phobia subscale is described at baseline and post-treatment (12 weeks), and the registry notes that the primary outcome has several categories or timepoints and was not reduced to one comparison. Multiple outcomes, timepoints, or possible contrasts can create multiplicity: when many hypotheses are examined, the chance of at least one apparently notable result can increase. General statistical practice may address this through a prespecified primary contrast, adjustment procedures, or careful interpretation of exploratory findings. The registry record does not report a multiplicity strategy or identify one primary comparison for analysis.
The record lists zero analysis entries. It does not report an analysis plan, the model used, the handling of missing observations, or the population included in each analysis. It is therefore not possible to determine whether all randomized participants were analyzed as assigned, whether participants were excluded, or whether missing data were imputed or otherwise handled. The number with outcome data at each timepoint is also not reported in the registry record.
General statistical explanation: missing outcome data can affect both the amount of information available and the interpretation of a comparison. The direction of any resulting bias depends on why data are missing and on the assumptions used in analysis. A complete-case analysis, imputation, and likelihood-based methods can produce different results under different conditions. Without the amount and pattern of missingness and the stated analysis method, the likely impact cannot be assessed for this trial.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Cognitive Therapy | 0 | 40 | 0.0% |
| Acceptance and Committment Therapy | 0 | 48 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Cognitive Therapy | 0 of 40 |
| Acceptance and Committment Therapy | 0 of 48 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Cognitive Therapy | 0 of 40 |
| Acceptance and Committment Therapy | 0 of 48 |
The adverse-event record lists zero serious adverse events among 40 participants at risk in the Cognitive Therapy arm and zero among 48 participants at risk in the Acceptance and Commitment Therapy arm. It lists zero other adverse events among 40 and 48 participants at risk, respectively. Deaths are listed as zero in both arms.
These figures describe the registry’s recorded event counts and the stated at-risk groups. A zero count means no events of that category are listed in the record for those groups; it does not establish that no symptoms, unwanted experiences, or events of any kind occurred. The registry does not report event definitions, collection procedures, duration of safety follow-up, or additional context for the adverse-event entries. The figures should therefore be read as the reported counts, not as a comprehensive account of all possible harms or as proof of absence of risk.
General statistical explanation: when an event is uncommon, a zero observed count can still be compatible with some underlying event risk. The amount of uncertainty depends on the number observed and the information available about follow-up and event ascertainment. No further safety analysis or uncertainty estimate is reported in the registry record.
12. What the Result Does, and Does Not, Mean
The registry record gives useful information about the question the trial was designed to address: a randomized comparison of cognitive therapy with exposure and acceptance and commitment therapy with exposure for generalized social anxiety disorder. It identifies a symptom scale, its direction and range, and assessments at baseline and post-treatment at 12 weeks. These details describe the intended comparison and the kind of outcome measured.
The record does not provide a single reduced primary comparison, group outcome summaries, an effect estimate, a confidence interval, or a p-value. It therefore cannot establish the direction, magnitude, or precision of a difference between the treatment arms. It also cannot show that the treatments had similar results. Lack of a reported estimate is not evidence of equivalence, and the randomized design alone does not supply an outcome result.
General statistical explanation: a treatment contrast is most informative when its target is clear, its estimate is reported with uncertainty, and the analysis population and missing-data handling are described. Statistical evidence and clinical importance are also different considerations. A precise estimate can still be small in practical terms, while an uncertain estimate may leave a range of materially different possibilities open. The registry entry provides neither an estimate nor a threshold for interpreting the scale in practical terms.
The named secondary outcomes broaden the types of outcomes registered for the study, but their results and analysis methods are not reported in the registry record. No conclusion about those outcomes, treatment adherence, or the consistency of results across measures can be drawn from the listed outcome names alone. The safety counts document zero listed serious events, other events, and deaths in the stated groups, but limited detail on event ascertainment means those counts should not be read as a complete safety evaluation.
13. Why This Trial Matters Statistically
This trial is statistically notable for a design that directly compares two behavioral treatment approaches while including exposure in both arm descriptions. That makes the treatment contrast important to define carefully: the randomized comparison concerns the packages as described, rather than an isolated exposure effect. The record also makes clear that the primary measure is a continuous symptom scale, with higher scores indicating more severe social anxiety symptoms.
The registry’s account illustrates why an endpoint description is not the same as a reported result. It gives the scale, score direction, range, and assessment timing, but does not reduce the multiple timepoints or categories to one primary comparison. Without an identified contrast and numerical estimates, readers cannot assess whether the randomized groups differed or how precisely any difference was estimated. This distinction matters for interpreting clinical trials: design information explains how a comparison was intended, whereas results are needed to quantify what happened.
The record also lists secondary outcomes and adverse-event counts, but does not provide analyses for the outcomes or detailed safety methods. This reinforces the value of transparent reporting of analysis populations, missing observations, methods, estimates, and uncertainty. For biostatisticians and clinical researchers, the key lesson is to distinguish the registered question and outcome definitions from the evidence needed to answer that question. The trial’s design is identifiable; its primary statistical result is not reported in the registry record.
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 main limitation for interpreting this trial from the registry record is that no numerical primary outcome results or single primary contrast are reported. Although the SPAI social phobia subscale, its range and direction, and baseline and post-treatment (12 weeks) assessments are described, the record does not provide group means, standard deviations, or an estimate comparing the arms. The note that the outcome has several categories or timepoints and was not reduced to one comparison further limits identification of the intended result.
The analysis details are also sparse. The registry lists zero analysis entries and does not report the statistical model, analysis population, missing-data approach, baseline adjustment, or multiplicity handling. The allocation method and concealment procedures are not reported. Masking is listed as none, but the record does not specify which parties were unmasked. Treatment delivery details, such as session schedule and fidelity, are not reported in the registry record, limiting assessment of how consistently the interventions were implemented.
The registry names two secondary outcomes but supplies no results for them. The adverse-event record lists event counts and at-risk groups, but does not describe the definitions, ascertainment, or duration of safety follow-up. These gaps mean that neither efficacy estimates nor a comprehensive assessment of safety can be reconstructed from the record. They do not show that the trial lacked such procedures; they mean those details are not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Variations of Cognitive Behavior Therapy for Social Anxiety Disorder — NCT00948974.
- Registry record last updated 2018-10-05; status last verified 2017-12.
- Results first posted 2018-10-05.
- 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.
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18. Record Summary
NCT00948974 is a completed, randomized, unmasked, parallel-group study sponsored by Drexel University. The registry lists enrollment of 88, a study start of 2010-01, primary completion of 2015-01, and phase NA. It compares cognitive therapy with exposure against acceptance and commitment therapy with exposure for generalized social anxiety disorder.
The primary outcome is the SPAI social phobia subscale, a continuous measure with scores from 32 to 192; higher scores indicate more severe symptoms. Assessments are described at baseline and post-treatment at 12 weeks. Outcomes Questionnaire and Behavioral Assessment Test are listed as secondary outcomes. The registry does not report a single reduced primary comparison, numerical outcome results, or analysis methods. It lists zero serious adverse events, zero other adverse events, and zero deaths in each arm, with 40 and 48 participants at risk in the respective arms.