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 Effects of Cardiac Rehabilitation for Individuals With Transient Ischemic Attack (NCT00929994), a registered phase not stated study. The primary outcome is Functional Walk Test.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00929994 |
| Phase | Phase not stated |
| Condition | Transient Ischemic Attack |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Toronto Rehabilitation Institute |
| Results posted | Yes |
2. Clinical Question
The study asks whether adding formal cardiac rehabilitation to standard care may be associated with changes in cardiovascular fitness and functional capacity among people who have experienced a transient ischemic attack or minor stroke. It also proposes examining depressive symptoms and cognition. The primary outcome is the Functional Walk Test, described as six-minute walk distance in meters.
Population
People with transient ischemic attack. The primary-outcome population is described as participants who completed the 6 month intervention. The registry summary also refers to people with minor stroke.
Intervention
Cardiac rehabilitation, described as a resistance and aerobic exercise program lasting 6 months after a 3 month non intervention period.
Comparator
A like-for-like control comparison is not described. Allocation is not stated, and the registry record identifies the study as not a randomized comparison.
Primary question
How does six-minute walk distance, a measure of functional walking capacity, vary across the recorded assessment times in the participants described for the primary outcome?
The registry hypothesis concerns the addition of cardiac rehabilitation to standard care, but the recorded arm description focuses on the exercise sequence. It does not establish how participants were allocated or describe a concurrent control arm that would support a direct treatment comparison. Consequently, the question that can be framed from the registered details is descriptive: what walking distances were recorded over time in the stated population? Whether the observed course can be attributed to rehabilitation, rather than other influences, cannot be established from the registry entries alone.
3. Trial Design
The study is registered as completed and lists an enrollment of 20. The sponsor is Toronto Rehabilitation Institute. The registry records a start date of 2010-03 and a primary completion date of 2014-11. The condition listed is transient ischemic attack.
The intervention is classified as behavioral and named Cardiac Rehabilitation. The Exercise arm description specifies a 3 month non intervention period followed by a 6 month exercise program combining resistance and aerobic training. Although the study hypothesis discusses adding rehabilitation to standard care, details of standard care are not reported in the registry record.
The registry record states that this was not a randomized comparison and that allocation is not stated. It also cautions that the arms are not a like-for-like control comparison. These design details matter because a change within an exercise group does not by itself estimate the difference between rehabilitation and a comparable alternative. Without an interpretable concurrent comparison and a stated allocation process, other changes over time cannot be separated from any effect associated with the intervention.
The primary outcome is Functional Walk Test, with assessments listed at baseline, 3 months, and 6 months. The timeframe identifies the measure as Six Minute Walk Distance. The primary-outcome population is described as participants who completed the 6 month intervention, rather than all enrolled participants. The registry lists 4 outcome measures and 5 analyses. Further details about the allocation process, control conditions, and analysis plan are not reported 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.
Overall Study
| Stage | Exercise |
|---|---|
| STARTED | 20 |
| COMPLETED | 14 |
| NOT COMPLETED | 6 |
Reasons for not completing this period:
| Reason | Exercise |
|---|---|
| Withdrawal by Subject | 1 |
| medical issue unrelated to intervention | 4 |
| employment | 1 |
Analysis population for the primary outcome, as defined in the registry: Transient Ischemic Attack participants who completed the 6 month intervention.
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 | Exercise |
|---|---|---|
| Participants analysed | 20 | |
| Age, Continuous | years | 65 (SD 11.2) |
| Sex: Female, Male: Female | Participants | 13 |
| Sex: Female, Male: Male | Participants | 7 |
| Region of Enrollment: Canada | participants | 20 |
6. Primary Endpoint
The registry lists the primary outcome as Functional Walk Test, measured over Baseline, 3 months, 6 months (Six Minute Walk Distance).
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | meters |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the Functional Walk Test, expressed in meters. Its description is the longest distance a person can walk for a duration of 6 minutes. It is therefore a continuous measure: participants can have different distances across a range of values, rather than being classified only as having or not having an event.
Walking distance is used in this study as an indicator of functional walking capacity. The registry hypothesis concerns cardiovascular fitness and functional capacity, making the walk test relevant to the stated research question. A repeated measurement can describe how walking performance changes across assessment times. The registry lists baseline, 3 months, and 6 months, with the measure identified as Six Minute Walk Distance.
The endpoint is specified as a mean with standard deviation. A mean describes the central level of the measured distances, while a standard deviation describes how spread out individual distances are around that mean. These summaries can help characterize group measurements, but they do not by themselves show whether a change is attributable to the intervention or how precisely a change has been estimated.
Numerical endpoint values, standard deviations, and estimates of change are not reported in the registry record. The stated primary-outcome population is participants who completed the 6 month intervention; the record does not give further details about how that population was defined or how incomplete measurements were handled.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the endpoint and its assessment schedule, but it does not report numerical Functional Walk Test results. There are no recorded means, standard deviations, estimates of change, confidence intervals, or significance tests in the available details. As a result, the direction and size of any change in walking distance, and the precision of such a change, cannot be assessed from the registry record.
The study hypothesis proposes that adding cardiac rehabilitation to standard care will lead to long-term improvements in cardiovascular fitness and functional capacity. That is a proposed research question, not a finding. The record also proposes examining depressive symptoms and cognition. It does not report numerical results for those outcomes either. The presence of an outcome or hypothesis does not establish that a measured difference occurred.
The design information places an important limit on interpretation. The registry states that the study was not a randomized comparison, that allocation is not stated, and that the arms are not a like-for-like control comparison. A change from baseline within the Exercise arm, if reported elsewhere, would describe the participants' measurements over time. It would not alone establish what would have happened to comparable participants without the rehabilitation program. Time, practice with testing, other care, and participant characteristics can also be relevant to changes observed during follow-up; the registry record does not provide information that separates these influences.
The primary-outcome population is described as participants who completed the 6 month intervention. That wording makes the results population important: measurements among completers may not represent every person enrolled if some participants did not complete the program. The number of completers and the handling of missing observations are not reported in the registry record, so the extent of any such issue cannot be evaluated.
The sample-size assumptions describe a planning illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The illustration varies the effect to detect as a stated fraction of the observed effect. These are planning assumptions, not a report of the trial's original design justification. The registry record does not report that justification, and the observed effect values needed to interpret the illustration are not reported in the registry record. Such planning quantities are not observed power and do not substitute for outcome estimates or uncertainty intervals.
Overall, the registered details support a description of the intended intervention, population, and endpoint, but not a conclusion about the observed effect or its precision. A treatment comparison cannot be inferred from the stated design information alone.
9. Statistical Methods Explained
The registry identifies the primary measure as continuous, summarizes it using a mean and standard deviation, and lists measurements at baseline, 3 months, and 6 months. The record does not report the numerical outcome summaries or a detailed statistical analysis plan. The concepts below explain how such statistics are generally interpreted; they do not describe analyses confirmed to have been used in this study.
What does a mean describe?
For a continuous outcome such as walking distance, the mean is the arithmetic average of the recorded participant measurements in the group and at the assessment time being summarized. It gives a concise description of the group's average distance. A mean is not a description of every participant: individuals may have measurements above or below it, and a few unusually high or low values can influence it.
The registry specifies standard deviation as the measure of dispersion. In general, standard deviation describes how much individual measurements vary around the mean. A larger spread means participant measurements are more dispersed; a smaller spread means they are more clustered. Standard deviation is not the same as uncertainty in the estimated mean. In general, the standard error and a confidence interval are used to express uncertainty about an estimate, while the standard deviation describes variability among observations.
How should a confidence interval be read?
In general, a confidence interval gives a range of values compatible with the data and the statistical procedure used, expressing uncertainty around an estimate. A narrower interval indicates greater precision under the method's assumptions; a wider interval indicates less precision. The interval does not guarantee that the true value lies within its endpoints, nor does it resolve limitations in the study design. No confidence interval for the primary outcome is reported in the registry record.
A p-value, in general, measures how surprising data at least as incompatible with a specified null hypothesis would be if that hypothesis and the model assumptions were true. It is not the probability that the null hypothesis is true, and it does not measure clinical importance or precision. Interpretation depends on the question being tested, the analysis method, and the study design. A p-value for the primary outcome is not reported in the registry record.
What is different about measurements over time?
Repeated measurements on the same participant are generally related: a participant's distance at one assessment may be associated with their distance at another. Statistical methods for repeated observations can account for this within-person relationship. Treating every measurement as if it came from a different person can misrepresent the amount of independent information. The registry lists repeated assessment times but does not report which statistical method, if any, was used to account for the relationship among a participant's measurements.
It is also important to distinguish a within-group change from a between-group contrast. A within-group change compares measurements from the same group over time. A between-group contrast compares the change or outcome between groups. The latter can address a comparative question only when the groups and their allocation support that interpretation. Here, the record states that the study was not a randomized comparison, allocation is not stated, and the arms are not a like-for-like control comparison. The registry does not report a particular adjusted or unadjusted contrast for the primary endpoint.
Why can over-dispersion matter?
In general, over-dispersion occurs when observed variability is greater than a statistical model assumes. If a model understates variability, standard errors may be too small and confidence intervals too narrow, making estimates appear more precise than the data support. Methods that allow for extra variability can improve uncertainty estimates when their assumptions fit the data. The endpoint is continuous and is summarized using a mean and standard deviation; over-dispersion is not identified as an issue in the registry record.
How do the planning assumptions relate to the results?
The registry's sample-size assumptions describe a planning illustration: two-sided significance level 0.05, equal allocation between two arms, a normal approximation, and an effect to detect expressed as a stated fraction of the observed effect. In general, sample-size planning asks how much information would be needed to detect a specified effect under stated assumptions. It depends on the expected effect, variability, allocation, and chosen error criteria. A planning illustration is conditional on those inputs and is not evidence that the planned or observed study had a particular probability of success.
The assumptions state that non-time-to-event illustrations are expressed as participants per arm. They do not establish the study's actual allocation or design. The registry record does not report the trial's own sample-size justification, nor does it provide numerical observed effects or the numerical planning results needed to assess the illustration. Planning counts should not be interpreted as observed power or as proof that the enrolled sample could or could not answer the research question.
The record lists 4 outcome measures and 5 analyses. It does not describe which statistical models, covariates, or hypothesis tests were used. The statistical concepts above therefore provide general context only; the analyses actually conducted are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 4 outcome measures and 5 analyses. When a study examines several outcomes, time points, or statistical contrasts, the chance of at least one apparently unusual finding can increase if each is tested separately without accounting for the collection of tests. In general, a prespecified testing hierarchy or an adjustment for multiple comparisons can address this issue, though choices depend on the study question. The registry record does not report whether multiplicity was addressed, which outcomes were treated as primary or secondary in the analysis, or how the 5 analyses relate to the 4 outcome measures.
Missing data can also affect interpretation. If measurements are absent, the amount and pattern of missingness matter, as do the assumptions and methods used to handle it. Analyses limited to participants with complete observations can describe that subset, but may not represent all enrolled participants if completion is related to measured outcomes or participant characteristics. The primary-outcome population is described as participants who completed the 6 month intervention. The number of participants with measurements at each time, reasons for missing measurements, and methods for handling missing data are not reported in the registry record.
The analysis population is not fully defined in the registry record. It does not state whether all enrolled participants were included in any primary analysis, whether analyses were restricted to intervention completers, or how deviations from the intended intervention were treated. Allocation is not stated, and the registry identifies the study as not a randomized comparison; therefore, an intention-to-treat framework cannot be assumed. Details about prespecified analyses, interim analyses, and adjustments for missing data are not reported in the registry record.
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 |
|---|---|---|---|
| Exercise | 0 | 20 | 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 |
|---|---|
| Exercise | 0 of 20 |
The registry safety figures list 20 people at risk in the Exercise group for serious adverse events, with 0 affected. The other-adverse-event figures also list 20 at risk and 0 affected. The serious adverse event terms list is empty. These are the recorded counts; they should be read as a description of what the registry reports, not as evidence that adverse events are impossible or that every possible event was captured.
The deaths field has no reported value. Deaths are therefore not reported in the registry record; a missing value should not be read as a reported count of zero. The registry entries do not describe the safety-monitoring period, event definitions, ascertainment procedures, or whether reporting was complete. Without those details, the scope and sensitivity of the safety figures cannot be assessed.
Safety counts are also distinct from a comparative safety estimate. The record does not describe a like-for-like control comparison, so these figures do not establish a difference in risk between rehabilitation and an alternative. They describe the recorded Exercise-group counts only.
12. What the Result Does, and Does Not, Mean
The study registration describes a question about cardiac rehabilitation, functional walking capacity, depressive symptoms, and cognition among people with transient ischemic attack or minor stroke. It specifies a behavioral exercise program and identifies six-minute walk distance as the primary outcome. These details explain what the study set out to examine.
They do not show whether participants' walking distance increased, decreased, or remained similar. Numerical results for the primary and secondary outcomes are not reported in the registry record. Without estimates and measures of uncertainty, the magnitude and precision of any outcome change cannot be judged. The study hypothesis is not a result, and registration as completed does not itself establish a finding.
The design information further limits causal interpretation. The registry says this was not a randomized comparison, does not state allocation, and warns that the arms are not a like-for-like control comparison. Even if measurements changed over time, those changes would not alone identify the contribution of the intervention. A suitable comparator and clear design details would be important for separating intervention-associated change from other explanations.
The primary-outcome population is described as those who completed the 6 month intervention. Because the number of completers and the handling of incomplete measurements are not reported, it is not possible to determine how well any analysis would represent everyone enrolled. The enrollment is 20, but enrollment alone does not describe the number contributing data at each assessment or the precision of an estimate.
The registry's planning assumptions are illustrative and do not establish the original design rationale or the strength of evidence from the study. They cannot replace reported outcome estimates. The responsible reading is therefore limited: the record identifies the research question, intervention sequence, and intended endpoint, while the observed effects and their uncertainty are not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically noteworthy because its question involves change over time in a continuous functional measure. Six-minute walk distance can be summarized through group means and standard deviations, but interpretation requires more than an average. The amount of participant-to-participant variability, the uncertainty around estimated changes, and the relationship among repeated measurements all matter.
The study also illustrates the distinction between measuring change and estimating a comparative effect. Baseline and follow-up values can describe a participant group, but a comparison intended to attribute differences to an intervention needs a design that supports that attribution. The registry specifically notes that this was not a randomized comparison, allocation is not stated, and the arms are not like-for-like controls. Those features shape what any observed pattern could mean.
Another statistical issue is the analysis population. The primary outcome is described for participants who completed the 6 month intervention. Clear reporting of participant flow and incomplete measurements would help readers understand whose outcomes inform the estimate and whether the findings apply beyond those who completed the program. Such details are not reported in the registry record.
Finally, the record lists multiple outcome measures and analyses, while details of the analysis plan are not reported. Prespecified outcome priorities and transparent handling of multiple analyses help readers distinguish planned questions from exploratory ones. The absence of numerical outcome results means no effect size or precision can be assessed, but the registered design features still clarify which statistical questions are important when interpreting any eventual results.
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 registry record leaves several trial-specific uncertainties. It lists an enrollment of 20, but does not report how many participants contributed primary-outcome measurements at baseline, 3 months, or 6 months. Because the primary-outcome population is described as participants who completed the 6 month intervention, the number of completers and the treatment of participants who did not complete are especially relevant and are not reported.
The record does not state how participants were allocated. It explicitly identifies the study as not a randomized comparison and says the arms are not a like-for-like control comparison. Consequently, the registered details do not establish a controlled causal contrast. The description of the intervention includes a non intervention period followed by an exercise program, but details of standard care and any comparison condition are not reported in the registry record.
Numerical primary and secondary outcome results, measures of uncertainty, and the analysis methods are not reported in the registry record. The record lists 4 outcome measures and 5 analyses but does not explain their relationship or identify methods for multiplicity. It also does not describe handling of missing data, model assumptions, or the analysis population beyond the primary-outcome description.
The follow-up schedule for the primary outcome is listed as baseline, 3 months, and 6 months. Longer-term outcome assessments are not reported in the registry record. Information on blinding, adherence, protocol deviations, and the original sample-size justification is also not reported, so these aspects cannot be evaluated from the registered details.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Effects of Cardiac Rehabilitation for Individuals With Transient Ischemic Attack — NCT00929994.
- Registry record last updated 2019-04-23; status last verified 2019-04.
- Results first posted 2019-04-23.
- 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
NCT00929994 is a completed study sponsored by Toronto Rehabilitation Institute, with enrollment of 20 and transient ischemic attack listed as the condition. The registered intervention is behavioral Cardiac Rehabilitation. The Exercise arm description gives a 3 month non intervention period followed by a 6 month program combining resistance and aerobic training.
The primary outcome is Functional Walk Test, measured as Six Minute Walk Distance in meters at baseline, 3 months, and 6 months. It is described as a mean with standard deviation among participants who completed the 6 month intervention. The registry also lists CES-D and cognition as secondary outcomes, with 4 outcome measures and 5 analyses overall.
The registry identifies the study as not a randomized comparison, with allocation not stated and arms not representing a like-for-like control comparison. Numerical outcome results and details of the statistical analysis plan are not reported in the registry record.