Cognitive-Behavioral Treatment for Anxiety Disorders in Children With Autism Spectrum Disorders: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Cognitive-Behavioral Treatment for Anxiety Disorders in Children With Autism Spectrum Disorders (NCT01178385), a randomized phase 2, phase 3 study. The primary outcome is Pediatric Anxiety Rating Scale (Measures the Severity of Anxiety Symptoms).

2. Clinical Question

The clinical question is about a behavioral intervention adapted for children with autism spectrum disorders who also have anxiety. The registry summary explains the rationale: anxiety may add distress and impairment, and treatment approaches used for typically developing young people may need adaptation for children with autism. The trial was designed to compare the adapted cognitive-behavioral approach with continued usual care.

The comparison is between assigned treatment strategies, not a comparison of a single medication or a single uniform usual-care program. The record describes the intervention as a structured family CBT program and usual care as ongoing services selected in the context of participants' providers. As a result, the groups differ in the treatment strategy being evaluated, while the specific services received under usual care may vary.

The trial record names anxiety severity as the primary endpoint and identifies two additional severity measures. It does not report outcome values, group summaries, an estimated treatment contrast, or uncertainty around that contrast. The clinical question can therefore be stated from the design, but the registry record cannot answer whether the groups differed on anxiety severity.

3. Trial Design

The registry record describes a randomized, parallel-group trial with single masking and phase listed as PHASE2 and PHASE3. Its status is completed. The sponsor is the University of South Florida. The recorded enrollment is 45. Separately, the brief summary describes a proposed study in 46 youth; both figures appear in the record, and it does not explain the difference.

Participants were assigned to cognitive-behavioral therapy or treatment as usual. The cognitive-behavioral arm is described as a modified family CBT program called Behavioral Interventions for Anxiety in Children with Autism. Its description specifies 16 weekly sessions. In the treatment-as-usual arm, participants were instructed to continue prior interventions as recommended by their providers. The examples span behavioral, psychosocial, family-based, and pharmacological care, so usual care is not described as one standardized treatment.

The primary outcome was scheduled after an average of 16 weeks, at post-treatment. The record does not specify the exact timing for each participant or provide an account of adherence to the planned treatment schedule. The start date is recorded as 2010-04 and primary completion as 2012-12. These are registry dates, not outcome-assessment dates for any individual participant.

Random allocation supports a comparison of assigned groups, while the parallel design means the two treatment strategies were evaluated in separate groups. “Single” masking is recorded, but the registry record does not identify which people involved in the trial were masked or explain how masking was maintained. It also does not report the randomization procedure, allocation concealment, or the statistical plan. Those details cannot be inferred from the design labels alone.

The record identifies a primary anxiety scale and two secondary severity measures: the Anxiety Disorders Interview Schedule Highest Anxiety Clinician Severity Rating and the Clinical Global Impression - Severity Scale. It lists no analysis records and does not report the results for these measures. The trial's completed status therefore indicates registry completion, not that interpretable outcome estimates are available 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: Seventy-one youth were assessed for eligibility. Twenty-six were excluded because they did not meet eligibility criteria (Did not meet IQ criteria (n=6); Did not meet anxiety criteria (n=9); Parent unwilling or unable to accompany child to all sessions (n=4); No autism spectrum disorder diagnosis (n=7)).

Overall Study

Reasons for not completing this period:

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 Pediatric Anxiety Rating Scale (Measures the Severity of Anxiety Symptoms), measured over After an average of 16 weeks (Post-treatment).

The primary endpoint is the Pediatric Anxiety Rating Scale, a measure of anxiety symptom severity. It is recorded as a continuous measure summarized by a mean and standard deviation, with the assessment scheduled after an average of 16 weeks, at post-treatment. The scale ranges from 0 (minimum score) to 25 (maximum score). Higher scores indicate more severe anxiety symptoms, and lower scores indicate less severe anxiety. The measure has no subscales according to the registry record.

A symptom-severity scale is used to represent the degree of anxiety in a form that can be compared between randomized groups. A mean describes the average score in a group, while a standard deviation describes the spread of individual scores around that average. A treatment comparison would ordinarily need to report group summaries and a contrast between them, with uncertainty around the contrast, to show both the estimated difference and its precision.

The scale's stated direction is important when interpreting any future or posted results: a lower mean represents lower recorded anxiety severity. A difference in score would describe the scale outcome, not every aspect of functioning or the experience of each child. The registry record does not report the primary endpoint values, the between-group contrast, or its confidence interval. It therefore supports a description of what the endpoint measures, but not a conclusion about the observed treatment effect.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Random allocation is intended to make treatment assignment independent of participants' measured and unmeasured characteristics on average. It creates a sound basis for comparing the groups as assigned, provided the allocation process is implemented appropriately and outcomes are analyzed in a way that respects that assignment. The registry record identifies the trial as randomized, but does not report the method used to generate the sequence or conceal allocation before assignment. Those implementation details are not reported in the registry record.

What does the parallel design mean?

In a parallel-group design, participants are assigned to one of the treatment strategies and outcomes are compared across the groups. This differs from a crossover design, in which participants receive more than one intervention in sequence. Here, the named arms are cognitive-behavioral therapy and treatment as usual. The registry record does not provide a crossover or repeated-treatment comparison.

The treatment-as-usual strategy allows participants to continue interventions recommended by their providers. This is clinically recognizable as ongoing care, but it can encompass different services. Such variation matters statistically because the contrast is between the structured CBT program and the usual-care approach as implemented, not between CBT and one specified standard regimen. The record does not quantify the services received or describe how they were distributed between participants.

How should a continuous outcome be understood?

The Pediatric Anxiety Rating Scale is a continuous measure, and the registry identifies the mean and standard deviation as its summary statistics. A mean is a measure of the group's central tendency. A standard deviation describes how dispersed individual scores are around the mean; it is not the uncertainty in the estimated mean and is not a range containing all participants. The endpoint's score range and direction are stated in the registry record, but its observed summaries are not reported.

A between-group analysis of a continuous endpoint commonly estimates a difference in means, possibly with adjustment for prespecified covariates. An unadjusted difference compares the groups' observed average scores directly. An adjusted estimate accounts for variables included in the model and answers a conditional comparison under that model. These are general statistical distinctions; the registry record does not report which approach was used for this trial, or any estimated contrast.

What does a confidence interval add?

A confidence interval presents uncertainty around an estimated treatment contrast. A relatively narrow interval indicates greater precision than a wide interval, given the same scale and method. Its interpretation depends on the analysis assumptions and the data included. A confidence interval can help distinguish an estimate that is precise from one that remains compatible with a broad range of effects. The registry record reports no interval for the primary endpoint, so its precision cannot be assessed.

A p-value, when reported, addresses how compatible the data are with a specified null model under the statistical test's assumptions. It does not measure the probability that a treatment has no effect, and it does not describe the clinical importance of an estimate. A p-value alone would not convey the size or precision of a difference. No primary-outcome p-value or statistical test is reported in the registry record.

Why does masking matter?

Masking can reduce the influence of expectations on treatment delivery, outcome assessment, or reporting. The registry labels the study single-masked, but does not identify who was masked. That omission matters when interpreting a symptom-severity endpoint, especially if assessment involves clinical judgment. It is not appropriate to assume that participants, therapists, assessors, or analysts were masked without a description in the record.

In general, planning calculations estimate the sample size that might be needed to detect an effect under specified assumptions. The record's planning description refers to a two-sided significance level of 0.05, equal allocation, a normal approximation, and an effect defined as a stated fraction of the observed effect. Such calculations are planning illustrations, not observed power and not evidence that the trial was designed around those assumptions. The numerical planning results and a trial-specific sample-size justification are not reported in the registry record.

The phrase “fraction of the observed effect” also requires an outcome estimate to be meaningful. No primary effect estimate is reported in the registry record. A planning illustration should therefore be read as a conditional scenario based on its stated assumptions, not as a new finding about this trial. No recalculated comparison can be described because the necessary endpoint summaries and sponsor analysis are not reported.

10. Multiplicity, Missing Data and Analysis Populations

The trial record lists the Pediatric Anxiety Rating Scale as the primary outcome and identifies two secondary measures of anxiety severity. When a study evaluates multiple outcomes or performs multiple comparisons, the chance of at least one apparently notable result can increase if no adjustment or hierarchy is used. A prespecified primary endpoint can help focus interpretation, while secondary outcomes can provide complementary evidence. The registry record does not report a multiplicity strategy, an outcome hierarchy beyond identifying the primary measure, or how results across measures were to be interpreted.

The record does not report the statistical analysis plan, analysis populations, or the handling of missing outcome data. It is therefore not possible to determine whether the primary analysis followed intention-to-treat principles, used a per-protocol population, or applied another approach. The endpoint's post-treatment timing is described as after an average of 16 weeks, but the record does not report how many participants had an assessment at that time or how missing measurements were addressed.

Missing data can affect a comparison when the availability of measurements is related to treatment assignment or participants' outcomes. Statistical methods for missing data make assumptions, and those assumptions should be described so readers can judge their plausibility. The registry record does not report reasons for missingness, imputation methods, sensitivity analyses, or a comparison of participants with and without observed outcomes. No conclusion about the robustness of the primary result to missing data is possible because neither the result nor the relevant methods are reported.

The registry record lists zero analysis records. It does not report a primary-outcome estimate or a multiplicity-adjusted result. These omissions mean that the available record describes the planned outcome framework but does not permit assessment of the analysis population, multiplicity control, or missing-data handling.

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 5% reporting threshold.

The safety fields report serious adverse events affecting 0 participants in the cognitive-behavioral therapy group, with 24 at risk, and 0 participants in the treatment-as-usual group, with 21 at risk. For other adverse events, the record reports 0 affected in each group, with 24 at risk in the cognitive-behavioral therapy group and 24 at risk in the treatment-as-usual group. These are the counts recorded for the listed fields; they are not measures of anxiety improvement.

The registry record does not list serious adverse-event terms. Death counts are recorded as null rather than as a numeric count, so deaths are not reported in the registry record. A zero in an affected field means that the record reports no affected participants for that field; it does not establish that no events could occur outside the reporting scope or observation period. The registry record does not describe the safety observation window, event definitions, or whether events were assessed systematically.

Safety counts should be interpreted with their at-risk denominators and with awareness that the denominators differ across fields and arms. They do not establish a causal safety comparison, and the registry record does not provide a statistical analysis of these counts. The figures also do not provide information about the primary anxiety outcome.

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

The record establishes that a randomized, parallel-group trial was conducted to compare a family-based cognitive-behavioral program with treatment as usual for children with autism spectrum disorders and anxiety. It identifies anxiety severity on the Pediatric Anxiety Rating Scale as the primary outcome and describes the scale's range and direction. It also identifies two secondary severity measures and reports selected adverse-event counts.

The record does not establish whether cognitive-behavioral therapy was associated with lower, higher, or similar anxiety scores compared with treatment as usual. It contains no reported primary-outcome means, treatment contrast, confidence interval, or test result. The completed status cannot fill this gap, and the absence of outcome values should not be interpreted as evidence of no effect.

Even if outcome estimates were available, a score comparison would address the measured anxiety-severity endpoint at the reported assessment time. It would not automatically establish effects on social, adaptive, or school functioning, nor would it represent every child's experience. The registry summary gives background about those areas, but no results for them are reported in the record.

The treatment contrast also has a specific meaning: a structured CBT program compared with ongoing provider-recommended care. Because usual care could include different services, the comparison would not isolate CBT against a single standardized alternative. The record does not report treatment adherence, concurrent care by group, or the extent to which the intended intervention was delivered.

The safety fields report zero affected participants for the listed serious and other adverse-event categories, with arm-specific at-risk counts. They do not establish the absence of all harms or provide a statistical comparison. Death counts are not reported in the registry record. Overall, the record supports a description of the trial question and selected design and safety information, but it does not supply the outcome evidence needed to judge the primary treatment comparison.

13. Why This Trial Matters Statistically

This trial raises a practical statistical question about evaluating an adapted behavioral intervention in a population with co-occurring conditions. The comparison is not simply between treatment and no treatment: the control strategy is treatment as usual, which may include a range of provider-recommended services. That makes the estimand—the treatment contrast a study intends to describe—important. A result would need to be interpreted as a comparison of the assigned strategies, rather than as a clean contrast between CBT and one uniform control regimen.

The outcome is a symptom-severity scale with a stated direction and score range. This makes careful reporting of group summaries and an estimated contrast essential. A result's statistical significance alone would not show its magnitude or precision; an effect estimate and confidence interval would be needed to judge those features. The registry record does not report them, so the clinical question remains unanswered by the posted registry information.

The record also illustrates why design labels do not replace methods details. Randomization is identified, but the record does not specify sequence generation, concealment, the identity of the masked party, analysis populations, or missing-data methods. Those details help readers assess whether the intended comparison was preserved in conduct and analysis.

Finally, registry completion and outcome reporting are different matters. A completed status documents the trial's status in the record, but readers need the results and analysis details to assess the primary endpoint. The availability of a clear outcome definition and safety counts is useful, yet it cannot substitute for the unreported treatment estimate. Statistically, the key point is to distinguish what the record says was evaluated from what it reports was observed.

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.

A central limitation of the registry record is that it does not report primary or secondary outcome results. There is no basis in this record for estimating the treatment contrast, its uncertainty, or whether the groups differed on the primary scale. The record also lists zero analysis records, leaving the statistical analysis methods unavailable.

The enrollment information is not internally explained: the registry records enrollment of 45, while the brief summary describes a proposed study in 46 youth. The record does not state why these figures differ or how many participants were included in each outcome analysis. It would be inappropriate to infer the analyzed sample from the enrollment figure or from the safety denominators.

The intervention descriptions indicate a structured CBT program and varied usual care, but do not report treatment receipt, adherence, or concurrent services by group. This limits what could be inferred about the treatment contrast even if endpoint results were reported. The registry also does not identify who was masked, detail allocation procedures, or describe the analysis population.

Other important interpretive details are not reported in the registry record: missing-data methods, outcome-assessment completeness, multiplicity handling, and the rationale for the planned sample size. The safety fields give selected counts, but do not describe event definitions or the observation period; deaths are not reported in the registry record. These limitations concern the registry information available and should not be mistaken for proof that the trial did not collect or analyze such information elsewhere.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Cognitive-Behavioral Treatment for Anxiety Disorders in Children With Autism Spectrum Disorders — NCT01178385.
• Registry record last updated 2013-04-02; status last verified 2012-12.
• Results first posted 2013-04-02.
• 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.

18. Record Summary

NCT01178385 is a completed, randomized, parallel-group, single-masked trial sponsored by the University of South Florida. The registry lists phases PHASE2 and PHASE3, enrollment of 45, a start date of 2010-04, and primary completion of 2012-12. The brief summary describes a proposed study of 46 youth ages 7-11; the record does not explain the difference from the enrollment figure.

The trial compared a family-oriented cognitive-behavioral treatment program with treatment as usual for children with autism spectrum disorders and anxiety. The primary measure was the Pediatric Anxiety Rating Scale after an average of 16 weeks. Two secondary severity measures are listed. Primary and secondary outcome results, analysis methods, and missing-data procedures are not reported in the registry record. The safety fields report zero affected participants in the listed adverse-event categories; death counts are not reported in the registry record.