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 Mindfulness-Based Cognitive Therapy Intervention to Treat Depression in Individuals With a Traumatic Brain Injury (NCT00745940), a randomized na study. The primary outcome is Beck Depression Inventory - II.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00745940 |
| Phase | NA |
| Condition | Depression, Traumatic Brain Injury |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | None (open label) |
| Enrollment | 105 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Lakehead University |
| Results posted | Yes |
2. Clinical Question
Population
People with depression who have experienced a traumatic brain injury. The registry record does not give further eligibility details or a more specific description of the population included in the outcome analysis.
Intervention
Mindfulness-based cognitive therapy adapted for traumatic brain injury, labelled MBCT for TBI. The record describes a ten-week intervention drawing on elements of mindfulness-based stress reduction and a mindfulness-based cognitive therapy manual.
Comparator
A control group that waited. The registry record does not describe additional control activities or indicate that the control group received an attention-matched intervention.
Primary question
Whether Beck Depression Inventory-II scores changed after the ten-week intervention, and whether the intervention group had fewer depression symptoms than the control group. The investigators also hypothesized that improvement would remain at a three-month follow-up, but the registry record does not report an analysis of that follow-up.
3. Trial Design
This was a randomized, controlled, multi-site trial sponsored by Lakehead University. The registry describes the design as a crossover model and reports no masking. A crossover design generally means participants receive different conditions in sequence, so interpretation can depend on the order and timing of those conditions. The registry record does not give the sequence details, crossover timing, or information about any washout period.
The record reports enrollment of 105. That is the registered enrollment, not a statement of how many participants contributed data to the primary endpoint. The number included in each outcome analysis, and the handling of participants who did not complete an assessment, are not reported in the registry record.
The intervention was a behavioral program adapted to address issues associated with traumatic brain injury. The control group waited. The investigators described a ten-week intervention and expected to assess depression symptoms after it. Baseline data were collected before the intervention, with post-intervention data collected ten weeks later. The investigators’ stated hypothesis also anticipated that improvement would be maintained at the three-month follow-up assessment.
The record identifies the trial as completed. It gives a start date of 2009-11 and a primary completion date of 2012-05. Those dates describe the registered study timeline; they do not establish when an analysis was conducted or whether all planned assessments were completed. The registry record does not report the randomization procedure, allocation concealment, recruitment details, or the statistical plan.
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 | MBCT Intervention Group | MBCT Control Group |
|---|---|---|
| STARTED | 57 | 48 |
| COMPLETED | 38 | 38 |
| NOT COMPLETED | 19 | 10 |
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.
Population: We initially had 57 MBCT Intervention group participants and 48 Control group participants. 29 participants (28%) did not complete the study - 17 prior to their respective arm starting and 8 during the intervention. Thus, for our analysis we had 38 in each arm.
| Characteristic | Unit | MBCT Intervention Group | MBCT Control Group | Total |
|---|---|---|---|---|
| Participants analysed | 38 | 38 | 76 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 38 | 38 | 76 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Age, Continuous | years | 47.10 (SD 12.03) | 45.81 (SD 14.80) | 46.46 (SD 13.06) |
| Sex: Female, Male: Female | Participants | 19 | 15 | 34 |
| Sex: Female, Male: Male | Participants | 19 | 23 | 42 |
| Region of Enrollment: Canada | participants | 38 | 38 | 76 |
6. Primary Endpoint
The registry lists the primary outcome as Beck Depression Inventory - II, measured over Baseline data were collected prior to the intervention and post-intervention data were collected 10 weeks later..
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary outcome was the Beck Depression Inventory-II (BDI-II), a self-report measure of depression symptom severity. The record describes it as a 21-question inventory. Each item offers statements in increasing severity about a symptom, and responses are combined into a score. The inventory covers cognitive-affective features, such as sadness and loss of pleasure, as well as somatic features, such as changes in sleep and appetite.
The registered endpoint is a mean score, with standard deviation as the measure of dispersion. In general, a mean describes the average score in a group, while a standard deviation describes how spread out scores are around that average. The BDI-II is used to quantify symptom severity, making it possible to compare average scores across assessment times or study groups.
The registry describes score categories ranging from minimal, with scores from 0-13, to severe, with scores from 29-63. These categories help characterize scores, but the registry record does not report group means, standard deviations, changes, or a between-group estimate. The specific primary comparison and its statistical uncertainty are therefore not available in the posted results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The key interpretive limitation is that the registry record does not report numerical results for the primary outcome. It identifies the BDI-II as the primary measure and gives the assessment timing, but it does not report an effect estimate, confidence interval, or p-value. Without those results, the direction, size, and precision of any difference between the intervention and control conditions cannot be evaluated.
The investigators’ stated hypothesis was that participants receiving the ten-week intervention would have fewer depression symptoms than participants in the control group, with improvement maintained at the three-month follow-up. A hypothesis is a planned expectation, not an outcome. The registry record does not provide results that establish whether the observed data were consistent with that expectation. It also does not report an analysis of the three-month follow-up.
The record lists no analyses. It also indicates that the primary outcome has several categories or time points and was not reduced to a single comparison. As a result, there is no one reported primary contrast to interpret. Even if a difference in average scores were available, a complete interpretation would require knowing the comparison, the participants contributing data, and the uncertainty around the estimate. Those details are not reported in the registry record.
Enrollment of 105 indicates the registered enrollment, not the number contributing to the endpoint at each assessment. Participant counts for the outcome analyses are not reported. This matters because missing follow-up data can affect both precision and interpretation, particularly if missingness differs between groups or relates to symptom severity. The record does not report how missing data were handled.
Accordingly, the posted results do not support a conclusion about the magnitude or precision of an intervention effect. That is not evidence that there was no effect; it reflects the absence of a reported primary-outcome analysis in the registry record. The design and research question are described, but the comparative outcome data needed for statistical interpretation are not.
9. Statistical Methods Explained
Randomization assigns participants to study conditions by chance. In general, this helps limit systematic differences between groups at the outset, though its success depends on implementation and does not ensure that every group characteristic will be identical. This trial is registered as randomized, but the method used to generate the allocation sequence and the approach to conceal allocation are not reported in the registry record.
What does the crossover design imply?
In a crossover trial, participants may experience more than one condition in a planned sequence, and comparisons can use information from the same participant under different conditions. This can be useful when within-person change is meaningful. It also creates design considerations: outcomes may be influenced by the order of conditions, changes over time, or effects that persist from an earlier condition into a later one. These are general features of crossover studies, not evidence that any particular issue occurred in this trial. The registry record labels the model as crossover but does not report the sequence, period structure, washout, or analysis approach.
How should a continuous outcome be read?
The primary endpoint is a continuous measure summarized as a mean with standard deviation. In general, the mean describes the center of a group’s scores, while the standard deviation describes their spread. A comparison of means can describe an average difference, but an estimate alone does not show how precisely it is known. A confidence interval is a range of values compatible with the data and the statistical model; a narrow interval indicates greater precision than a wide one. No mean comparison or confidence interval is reported in the registry record.
The BDI-II measures symptom severity through responses to multiple items. A mean difference would express an average score contrast, but its interpretation depends on the scale, the study’s comparison and the interval around the estimate. The registry’s description of score categories provides context for severity, but does not replace the missing trial results or establish the clinical meaning of a particular change.
Why do the reported analyses matter?
The registry record lists no analyses and does not report a statistical analysis plan. It therefore does not specify whether the primary comparison would use change from baseline, post-intervention scores, a model accounting for repeated measurements, or another approach. These are not interchangeable descriptions: they can address different contrasts and rely on different assumptions. The analysis used, the covariates included, and any adjustments for the crossover structure are not reported in the registry record.
In general, repeated observations from one person are related rather than independent. Statistical methods for repeated measures account for that relationship instead of treating every observation as unrelated. Crossover analyses may also need to distinguish treatment effects from period or sequence effects. These are general methodological considerations; the registry record does not identify the model or assumptions used for this trial.
What can planning calculations tell readers?
Planning sample-size illustrations are not observed trial results and are not observed power. The stated assumptions describe illustrations using a two-sided significance level of 0.05, equal allocation between arms, a normal approximation, and an effect to detect defined as a stated fraction of the observed effect. In general, a planning calculation estimates the number of participants needed under specified assumptions; changing the target effect or assumptions changes the planning requirement. Such a calculation cannot establish that a study found an effect, nor can it substitute for an estimate and confidence interval from the actual data.
The numerical planning outputs and the observed effect used to construct them are not reported in the registry record. They should therefore not be treated as evidence about the size or precision of the trial’s result. Any sample-size illustration is a planning aid, not a measure of the study’s achieved power.
What is missing from the statistical record?
The record does not report an endpoint analysis, an analysis population, outcome-specific participant counts, or a method for handling missing data. It also does not report the randomization procedure, masking beyond the designation of none, or whether any interim analyses were conducted. The absence of these details limits assessment of how the data were analyzed and how robust an estimate would be. It does not establish that a particular method was or was not used; those details are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists the BDI-II as the primary outcome and names secondary measures: the Patient Health Questionnaire (PHQ-9), the depression subscale of the Symptom Checklist-90 Revised, and the awareness and acceptance subscales of the Philadelphia Mindfulness Scale. It also reports five outcome measures overall. The registry record does not give results for these measures or specify how many comparisons were planned for each measure, time point, or study condition.
Multiplicity arises when several outcomes, time points, or comparisons are examined. In general, making many statistical tests can increase the chance of obtaining at least one apparently notable result by chance. A statistical plan may address this through a prespecified primary comparison or an adjustment procedure. The record does not report a multiplicity strategy, so it is not possible to assess how any multiple comparisons were handled.
The record identifies baseline and post-intervention assessment timing for the primary endpoint and describes a three-month follow-up hypothesis. It does not report which time points were analyzed or how results across time points would be combined or compared. It also does not provide analysis-population definitions, outcome-specific denominators, or a missing-data method. Thus, the number contributing to the primary analysis and the consequences of incomplete follow-up are not reported in the registry record.
These omissions matter for both interpretation and reproducibility. In general, the analysis population and missing-data approach help clarify which participants contributed to an estimate and what assumptions support it. Without those details or a reported estimate, readers cannot assess the sensitivity of the findings to missing observations or multiplicity.
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 |
|---|---|---|---|
| MBCT Intervention Group | 0 | 57 | 0.0% |
| MBCT Control Group | 0 | 48 | 0.0% |
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 |
|---|---|
| MBCT Intervention Group | 0 of 57 |
| MBCT Control Group | 0 of 48 |
The registry lists serious adverse event figures for the MBCT intervention group and the MBCT control group. Each group has a reported at-risk count, and the recorded serious adverse event count is 0 in both. The record also lists 0 other adverse events in each group. These are the counts recorded in the registry; they should not be interpreted as proof that no adverse experiences occurred outside the reported categories or reporting process.
The death entries are null, so deaths are not reported in the registry record. A null entry is different from a reported count of 0. The record does not describe the safety surveillance procedures, event definitions, duration of monitoring, or the completeness of adverse-event ascertainment. It also does not provide further detail about the recorded at-risk groups or explain their relationship to outcome-analysis populations.
These figures describe what the registry reports, not a comparative safety analysis. No statistical comparison of adverse events is reported, and the posted data do not establish a difference in safety between groups.
12. What the Result Does, and Does Not, Mean
The record identifies a clinically relevant research question: whether an adapted mindfulness-based cognitive therapy program changes depression symptom scores in people who have experienced traumatic brain injury. It describes a randomized, unmasked, crossover trial, a waiting control group, and the BDI-II as the primary outcome. Those details clarify the intended study question and broad design.
They do not establish what happened to participants’ scores. The registry record does not report primary-outcome results, an effect estimate, a confidence interval, or a p-value. It therefore does not show the size or direction of a difference, or how precisely such a difference could be estimated. The investigators’ stated hypothesis and the registered completion status are not substitutes for outcome data.
The missing analysis also means that the record cannot establish whether any symptom change persisted at the three-month follow-up. It does not report participant counts for outcome analyses, missing-data handling, or an analysis method for the crossover design. Those details would be needed to judge how the result was estimated and what population it represents.
The absence of reported results should not be read as evidence that the intervention had no effect, nor as evidence that it had an effect. It means that the posted registry information is insufficient to assess either conclusion. The adverse-event entries describe reported counts, while deaths are not reported; these entries do not provide a complete comparative safety assessment.
Overall, the registry record documents the trial’s aim and design but does not provide the statistical results needed to answer its primary question. Interpretation should remain limited to that distinction.
13. Why This Trial Matters Statistically
This trial is statistically notable for the combination of a randomized design and a crossover model. Randomization and crossover address different aspects of study design: randomization concerns assignment to conditions, while crossover concerns the sequence in which conditions may be experienced. In general, a crossover analysis must account for within-participant relationships and possible period or sequence effects. The registry record does not describe the details needed to assess how those considerations were handled.
The outcome is a continuous self-report score, summarized as a mean and standard deviation. This makes the distinction between an average contrast and its uncertainty especially important. A reported estimate would describe the observed comparison; a confidence interval would show its precision. Neither is available in the registry record, so the design cannot be connected to an interpretable estimate of change or group difference.
The record also identifies several secondary measures and a follow-up hypothesis. Multiple outcomes and assessment times can complicate interpretation unless comparisons are clearly prespecified and multiplicity is addressed. The statistical plan and multiplicity approach are not reported in the registry record. Likewise, participant counts for the outcome analysis and missing-data procedures are not reported, limiting assessment of the data contributing to any potential estimate.
These issues illustrate why a completed trial record and a detailed outcome analysis serve different purposes. The record describes the trial’s question, design, and intended measurement, but without an analysis it cannot communicate the estimated effect or its precision. The posted information is therefore useful for understanding the study structure, while leaving the central statistical question unanswered.
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 is the absence of a reported primary-outcome analysis. The registry names the BDI-II and gives its assessment timing, but does not provide group summaries, a comparison, or uncertainty measures. The primary outcome is also described as having several categories or time points and is not reduced to one comparison in the registry record.
The design is labelled crossover, but the record does not describe condition sequence, period structure, or any washout. It also does not report the statistical method used to account for the design. Because masking is recorded as none, participants and study personnel were not masked according to the registry designation; further information about who knew allocations or how outcomes were collected is not reported in the registry record.
Enrollment is reported, but the number contributing to each outcome and assessment is not. The registry does not report an analysis population, reasons for missing observations, or a missing-data method. The randomization procedure and allocation concealment are also not reported. These omissions limit assessment of allocation, attrition, and the assumptions behind any analysis.
The intervention description indicates adaptation for traumatic brain injury, but the record does not provide enough detail to assess adherence or delivery consistency. It also does not report the results for the named secondary measures or the three-month follow-up hypothesis. Finally, the registry’s adverse-event entries do not include event definitions or monitoring details, and deaths are not reported. Together, these limitations restrict conclusions about outcome effects, follow-up, and safety.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Mindfulness-Based Cognitive Therapy Intervention to Treat Depression in Individuals With a Traumatic Brain Injury — NCT00745940.
- Registry record last updated 2014-03-28; status last verified 2014-02.
- Results first posted 2014-02-17.
- 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
NCT00745940 is a completed, randomized, unmasked, crossover trial sponsored by Lakehead University. It enrolled 105 participants and evaluated an adapted mindfulness-based cognitive therapy intervention against a waiting control group in people with depression who had experienced traumatic brain injury.
The primary outcome was mean Beck Depression Inventory-II score, assessed at baseline and ten weeks after the intervention began. The investigators hypothesized that the intervention group would have fewer depression symptoms and that improvement would be maintained at the three-month follow-up. The registry record lists several secondary measures but reports no analyses or primary-outcome results.
The record lists 0 serious and 0 other adverse events in each group; deaths are not reported. Outcome-analysis counts, missing-data methods, the detailed statistical plan, and the numerical effect estimate are not reported in the registry record.