Early Parenting Intervention Comparison: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Early Parenting Intervention Comparison (NCT01517867), a randomized na study. The primary outcome is Change in Child Behavior Problems.

2. Clinical Question

3. Trial Design

The registry describes a randomized, parallel-group trial with no masking. It lists an enrollment of 161 and identifies the study as completed. The study compared the Chicago Parent Program with Parent-Child Interaction Therapy in a mental health clinic serving young children with behavior problems. The record gives a start date of 2011-09 and a primary completion date of 2017-02.

The Chicago Parent Program was a 12-session group-based parenting skills training program. Parent-Child Interaction Therapy was individually tailored for parents and children with behavior problems. Both were categorized as behavioral interventions. The registry's description frames the purpose as comparing the effectiveness of the two programs; it does not describe a usual-care or untreated comparison arm.

The primary outcome was change in child behavior problems, assessed using the Child Behavior Checklist at baseline and first follow-up, which could be up to 2 years. The registry describes the outcome population as participants who started treatment and were discharged, regardless of whether they completed the full treatment. Follow-up data were collected from 42 participants in the Chicago Parent Program arm and 34 in the Parent-Child Interaction Therapy arm. The record notes that follow-up data were not collected from the remaining participants, without explaining the individual reasons.

The record lists Aggregate Cost as a secondary outcome and reports 2 outcome measures, but it does not provide a numerical primary-outcome comparison in the material described. It lists 0 analyses. The registry record does not report the randomization procedure, allocation concealment, the planned statistical analysis, or whether the study used interim analyses. Those details should not be inferred from the randomized label alone.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: First follow-up data collected from 42 participants in Chicago Parent Program and 34 participants in Parent-Child Interaction Therapy who started treatment and were discharged, regardless of whether they completed the full treatment. Did not collect follow-up data from remaining participants who enrolled in study but never attended any treatment.

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 Change in Child Behavior Problems, measured over baseline, first follow-up (up to 2 years).

The primary endpoint is change in child behavior problems measured with the parent-report Child Behavior Checklist. The registry specifies assessment at baseline and first follow-up, with the follow-up timeframe described as up to 2 years. The measure's raw score ranges from 0 to 198, and lower scores are described as better for the child.

A continuous score can retain gradations in reported behavior rather than reducing the outcome to a simple category. A change score is intended to describe how the measure differs between the baseline assessment and follow-up. Comparing changes between randomized groups can address whether the groups' average measured trajectories differed, provided the analysis and missing-data handling are appropriate. That general interpretation does not substitute for the trial's actual analysis, which is not reported in the registry record.

The measure is parent-reported, so the endpoint reflects reports from parents rather than a directly observed outcome as described in the record. The record does not provide details about the questionnaire's administration, scoring beyond its raw-score range and direction, or the clinical meaning of a particular change. It also does not report arm-specific baseline scores, follow-up scores, mean changes, or uncertainty estimates. Without those results, the endpoint's comparative result cannot be characterized.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean change represent?

For a continuous outcome, a mean is an average across the observations included in an analysis. A mean change summarizes the average difference between a participant's later and earlier measurements, if the analysis defines change in that way. A comparison of average changes then contrasts the groups' summaries. This can be useful when the research question concerns whether groups followed different average trajectories.

The registry identifies the outcome parameter as a mean and its dispersion as a standard deviation. A standard deviation describes variation among individual measurements around their group mean; it is not the uncertainty in the estimated mean. The standard deviation can help readers understand how dispersed the scores are, while a standard error or confidence interval is more directly related to precision of an estimated group mean or contrast. The registry record does not report the primary outcome means, standard deviations, or confidence interval.

Why is the contrast important?

Within-arm change and between-arm difference answer different questions. A group may have a change over time, but that alone does not establish that its change differs from the other group's. A comparative analysis should estimate the contrast relevant to the study question, with a clear definition of direction and time point. The registry names a change outcome at first follow-up, but the numerical contrast and the analysis definition are not reported in the registry record.

In general, randomized allocation is intended to make treatment groups comparable at the start of a study, on average. The usefulness of the randomized comparison depends on carrying out allocation as intended and analyzing participants in a manner appropriate to that design. A label of randomized does not reveal the sequence-generation method, concealment procedures, or the analytic population. Those details are not reported in the registry record.

How should uncertainty be understood?

A point estimate is the single numerical summary of an estimated effect. A confidence interval presents a range of values compatible with the observed data under the statistical model and its assumptions. It helps readers distinguish an estimate that is precise from one that is uncertain. A p-value, when used, addresses compatibility of the data with a specified null model; it does not give the probability that a treatment works, nor does it express the size or clinical importance of an effect. Neither a confidence interval nor a p-value for the primary comparison is reported in the registry record.

Statistical evidence should not be reduced to whether a threshold is crossed. The size of an effect, its uncertainty, the measurement scale, and the study context all matter. In this trial, the scale's direction is described, but no numerical effect or uncertainty estimate is available in the registry record. As a result, these general principles cannot be applied to determine the comparative result.

What do planning illustrations mean?

General sample-size planning asks how many participants per arm might be needed to detect an assumed effect at a chosen significance level and power, subject to modeling assumptions. Such a calculation depends on the target effect, variability, allocation, statistical test, and other design choices. It is a planning exercise, not a result observed in the trial and not a measure of the probability that the completed study detected an effect.

The stated planning assumptions describe a two-sided significance level of 0.05, equal allocation, and a normal approximation. The effect to detect is described as a fraction of the observed effect. These are planning illustrations based on the observed effect, not the trial's own design. The record does not report a protocol-based sample-size justification. Any sample-size illustration should therefore be read as conditional on its assumptions, not as evidence about the trial's actual design rationale or an observed finding.

Why can variability matter?

For a continuous outcome, greater variation among participants generally makes it harder to estimate a group average precisely, all else being equal. Standard deviations describe observed spread, while confidence intervals reflect uncertainty in estimated quantities. If data have more variation than a simple model assumes, model-based uncertainty can be understated. In settings with over-dispersion, methods that account for the extra variability may be needed. That is a general statistical point; the registry does not report an over-dispersion assessment or a model for this outcome.

Because the primary outcome values and analysis are absent, no recalculated contrast or independent check of the sponsor's analysis is possible from the registry information described. There is also no reported sponsor analysis to compare against a recalculation. The interpretation should remain at the level of the design and outcome definition, rather than implying an estimated effect.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 2 outcome measures and identifies Aggregate Cost as a secondary outcome. It does not describe the statistical plan for testing multiple outcomes, any hierarchy among outcomes, or any adjustment for multiplicity. When a study examines several outcomes or analyses, the chance of at least one apparently unusual result can increase if each is assessed separately. Whether and how that issue was addressed is not reported in the registry record.

The record lists 0 analyses, and the primary-outcome information does not include a numerical comparison. It therefore does not report which analysis population was used, whether the analysis followed randomized assignment, or how any departures from assignment were handled. The outcome population is described as participants who started treatment and were discharged, whether or not they completed the full treatment. That description does not establish that the analysis included everyone randomized.

Follow-up observations are described for 42 participants in the Chicago Parent Program arm and 34 in the Parent-Child Interaction Therapy arm. The record says follow-up was not collected from the remaining participants. It does not state why each observation was missing, whether missingness was related to participant characteristics or outcomes, or whether any imputation or sensitivity analysis was performed. Missing outcomes can affect both the precision and the interpretation of a comparison, particularly if the observed participants differ systematically from those without follow-up.

These omissions do not show that the analysis was inappropriate; they mean that its handling cannot be evaluated from the registry record. The registry also does not report prespecified procedures for interim analyses or outcome multiplicity. Such procedures should not be inferred from the absence of posted analyses.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry reports no serious adverse events, no other adverse events, and no deaths in either arm. For the Chicago Parent Program arm, the listed at-risk counts are 81 for serious adverse events and 81 for other adverse events; the corresponding affected counts are 0 and 0, and deaths are 0. For Parent-Child Interaction Therapy, the listed at-risk counts are 80 for serious adverse events and 80 for other adverse events; the corresponding affected counts are 0 and 0, and deaths are 0.

These are registry-reported counts, not proof that an event was impossible or that no event occurred outside the registry's reporting and observation process. The record does not provide event descriptions, ascertainment details, or a time-at-risk analysis. The serious-event terms list is empty, so no specific serious adverse event is named. The figures should be read as the counts reported for these categories and groups, without extrapolating beyond the registry information.

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

The record establishes that a randomized, parallel-group comparison was conducted between the Chicago Parent Program and Parent-Child Interaction Therapy for families of young children with behavior problems. It identifies the primary outcome as change in a parent-reported measure of child behavior, gives the score direction, and describes follow-up as baseline and first follow-up up to 2 years. These details clarify what the trial set out to compare.

What the registry information does not establish is whether the measured average change differed between programs, which program had the lower follow-up scores, how large any difference was, or how precise an estimate might be. Arm-specific results and an inferential comparison are not reported in the registry record. The lack of a posted estimate cannot be interpreted as evidence of no effect, equivalence, or a benefit for either program.

The follow-up data description also calls for caution. Outcome observations are described for participants who started treatment and were discharged, with full treatment completion not required, and the registry notes that follow-up was not collected from the remaining participants. The record does not explain the missing observations or describe an analysis addressing them. Consequently, the representativeness of the observed outcome data and the potential influence of missingness cannot be assessed.

The posted safety counts show 0 affected participants in each listed adverse-event category and 0 deaths in each arm, as recorded. Those counts do not answer the primary effectiveness question and do not provide detailed information about event collection or follow-up. Aggregate Cost is listed as a secondary outcome, but no cost result is described in the registry information.

In short, the registry describes the trial question, intervention formats, outcome, and selected safety counts, but does not report numerical primary-outcome results. Any claim about comparative effectiveness, clinical importance, or precision would go beyond what the registry record reports.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of the difference between a clearly stated research question and a fully interpretable set of results. The registry identifies a randomized comparison of two behavioral parenting programs and specifies a continuous, parent-reported outcome. It also states the direction of the score, which is essential for interpreting any eventual estimate: lower raw scores are described as better for the child.

The record also highlights why the analysis population and follow-up process matter. The primary outcome description concerns participants who started treatment and were discharged, regardless of full treatment completion, while follow-up data were not collected from the remaining participants. Without a reported analysis population and a clear account of missing-data methods, readers cannot determine how closely the observed outcome comparison corresponds to the randomized groups as a whole.

Another statistical lesson is that a study's design label cannot replace its results. Randomization is relevant to the intended comparison, but it does not supply the effect estimate, uncertainty interval, or analysis details. Those are needed to assess both the size and precision of any difference. Here, the registry record does not report the numerical primary comparison, so the underlying question remains unanswered by the posted outcome information.

The trial also makes the distinction between outcome reporting and safety reporting visible. The registry includes zero counts in the listed adverse-event categories, but those figures do not provide the comparative outcome estimate. Conversely, an effectiveness estimate would not by itself describe safety. Each result requires its own outcome definition and context.

For researchers, the case underscores the value of transparent reporting of group summaries, comparative estimates, uncertainty, analysis populations, and missing-data handling. Without those elements, even a randomized design may not yield a result that can be evaluated from the registry record alone.

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 trial-specific limitation of the registry information is that it does not report numerical results for the primary outcome. There are no arm-specific means or changes, no comparative estimate, and no uncertainty interval or p-value in the primary-outcome information described. The comparative outcome therefore cannot be assessed for direction, magnitude, or precision.

Follow-up was collected from 42 participants in the Chicago Parent Program arm and 34 in the Parent-Child Interaction Therapy arm. The registry says the outcome population included people who started treatment and were discharged, whether or not they completed the full treatment, and that follow-up data were not collected from the remaining participants. The reasons for missing follow-up and the methods used to address it are not reported. The extent to which the observed follow-up data represent the randomized groups cannot be determined from the record.

The record states that masking was none. It does not explain who knew assignment at different stages, how the parent-report outcome was administered, or whether expectations may have influenced reporting. These are uncertainties, not proof of bias. Details of the randomization procedure and allocation concealment are also not reported.

The registry does not report a protocol-based sample-size justification, the primary statistical model, the analysis population, multiplicity procedures, or interim-analysis methods. It lists 0 analyses. The secondary outcome Aggregate Cost is named, but no result is described. These reporting gaps prevent a fuller appraisal of the intended and performed analyses.

Finally, registry-reported zero adverse-event counts should be understood within the information recorded: detailed event ascertainment and follow-up are not described. The record's completed status does not resolve these limitations in the available outcome reporting.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Early Parenting Intervention Comparison — NCT01517867.
• Registry record last updated 2018-05-03; status last verified 2018-04.
• Results first posted 2018-04-02.
• 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

The registry record describes a completed, randomized, parallel-group trial with no masking, comparing the Chicago Parent Program with Parent-Child Interaction Therapy for families of young children with behavior problems. Enrollment was 161. The listed study dates are 2011-09 for start and 2017-02 for primary completion.

The primary outcome was change in parent-reported Child Behavior Checklist scores at baseline and first follow-up, described as up to 2 years. Raw scores range from 0 to 198, with lower scores described as better. Follow-up data were collected from 42 participants in the Chicago Parent Program arm and 34 in the Parent-Child Interaction Therapy arm. The registry record does not report numerical primary-outcome results or an analysis, and lists 0 analyses. Aggregate Cost is listed as a secondary outcome.

For both arms, the registry reports 0 serious adverse events, 0 other adverse events, and 0 deaths. These counts do not replace the absent comparative outcome estimate.