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 Study of Impact of Behavioral Intervention- Exercise, Nutrition, Education- on Body Mass Index (BMI) (NCT00132132), a randomized na study. The primary outcome is Change in BMI (Body Mass Index).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00132132 |
| Phase | NA |
| Condition | Obesity |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 30 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Steward St. Elizabeth's Medical Center of Boston, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The registry describes a population aged 10-20 years with a BMI greater than or equal to 85%. Obesity is listed as the condition. The planned enrollment was 30, but the primary outcome population is narrower: participants who attended at least one intervention session and completed the final assessment. The record does not give further participant characteristics.
Intervention
The behavioral education program meets monthly for a 4 hour session. Its described components include exercise, education on medical aspects and nutrition, and empowerment. The registry’s brief summary characterizes the study as long term, but does not give a more specific duration for the program or a full account of attendance.
Comparator
The Standard of Care/Control group receives education on physical activity and nutrition in a primary care office setting. The record does not give further detail about the content, frequency, or delivery of this education. The comparison is between the behavioral program and this control condition, not between the program and an absence of education.
Primary question
The primary outcome is mean change in BMI, measured in kg/m^2, from baseline to 12-15 months. The clinical question is whether the recorded change differs between the intervention and control groups in the stated per protocol population. The registry does not report the numerical change, a between-group estimate, or its confidence interval, so the direction and precision of any difference cannot be assessed.
3. Trial Design
This is a randomized, parallel-group study with no masking reported. The registry identifies two groups: a Behavioral Program group and a Standard of Care/Control group. The study is listed as completed, with enrollment of 30. Its start is recorded as 2005-08 and its primary completion as 2008-02. The phase is listed as NA. The sponsor is Steward St. Elizabeth's Medical Center of Boston, Inc.
The intervention is a behavioral education program with monthly 4 hour sessions. The stated elements include exercise, education on medical aspects and nutrition, and empowerment. The control condition consists of education on physical activity and nutrition in a primary care office setting. The registry calls the project long term but does not report a detailed schedule for all study activities. The listed outcome timeframe is baseline and 12-15 months.
Random allocation is intended to make the groups comparable, on average, with respect to factors that could influence BMI. It does not guarantee that the groups are identical at baseline, especially in a study with limited enrollment. No masking is reported, so participants and those delivering the program may have known group assignment. The record does not say whether outcome assessors or analysts were masked.
The primary outcome is described for a per protocol population: subjects who attended at least one intervention session in addition to their final assessment. This is not necessarily the same population as everyone randomized. The registry does not report the number included in the primary analysis, the number completing follow-up by group, or details of participant flow. Accordingly, enrollment should not be read as the analyzed sample size.
The record reports two outcome measures and four analyses, but it does not provide a full statistical analysis plan. It does not report the randomization method, allocation concealment, or the intended approach to missing measurements. Those omissions limit assessment of how the planned design was carried through in the reported analyses.
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 | Behavioral Program | Standard of Care/Control |
|---|---|---|
| STARTED | 15 | 15 |
| COMPLETED | 8 | 13 |
| NOT COMPLETED | 7 | 2 |
Reasons for not completing this period:
| Reason | Behavioral Program | Standard of Care/Control |
|---|---|---|
| Lost to Follow-up | 7 | 2 |
Analysis population for the primary outcome, as defined in the registry: Per protocol analysis: subjects who attended at least one intervention session in addition to their final assessment
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 | Behavioral Program | Standard of Care/Control | Total |
|---|---|---|---|---|
| Participants analysed | 15 | 15 | 30 | |
| Age, Categorical: <=18 years | Participants | 14 | 14 | 28 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 | 1 | 2 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 7 | 11 | 18 |
| Sex: Female, Male: Male | Participants | 8 | 4 | 12 |
| Region of Enrollment: United States | participants | 15 | 15 | 30 |
6. Primary Endpoint
The registry lists the primary outcome as Change in BMI (Body Mass Index), measured over Baseline, 12-15 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | kg/m^2 |
| Endpoint classification | Continuous Endpoint |
BMI is a measure derived from a person’s weight relative to height. The primary endpoint is the mean change in BMI, in kg/m^2, with the timeframe described as baseline and 12-15 months. Tracking change over time gives a way to describe whether BMI was higher or lower at follow-up than at baseline. A comparison between groups can then estimate how the average change differed between the behavioral program and standard-of-care education.
A mean summarizes the center of a set of measurements. It is useful for describing an average change, but it does not show how much individual participants varied, whether the distribution was uneven, or whether a small number of measurements had substantial influence. The registry specifies a 95% confidence interval as the dispersion measure for the endpoint. In general, a confidence interval expresses the statistical uncertainty around an estimate under the analysis assumptions; it is not a range containing all individual participant outcomes.
The endpoint is stated for a per protocol population consisting of participants who attended at least one intervention session and had a final assessment. That definition makes attendance and follow-up part of the analysis population. The registry does not report the actual mean changes, the difference between group means, or the confidence interval values. It is therefore possible to describe what the endpoint was intended to measure, but not the size or precision of the observed result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record defines a randomized comparison of a behavioral education program with standard-of-care education, with mean BMI change as the primary outcome. It does not report numerical outcome estimates. In particular, the record does not state the mean change in either group, the difference in change between groups, or the 95% confidence interval. No direction or magnitude of a comparative result can therefore be inferred from the endpoint description alone.
The brief summary says the researchers anticipate that the intervention group will experience a decrease in BMI of approximately five points. This is an anticipated effect, not a reported result. It should not be read as evidence that the decrease occurred, nor as the observed difference between groups. The record does not report whether the observed data supported, differed from, or were too imprecise to assess that anticipation.
A confidence interval would help show the precision of a between-group estimate. A narrow interval would indicate greater precision under the analysis assumptions, while a wide interval would indicate more uncertainty. Without the estimate and its interval, the registry record does not support a judgment about how compatible the data are with effects of different sizes. A p-value is also not reported, and statistical significance cannot be determined.
The planned enrollment was 30, and the safety listing gives 15 at risk in each group. Those entries do not establish how many participants were included in the primary analysis. The endpoint population excludes people without at least one intervention session and a final assessment, according to its stated definition. The numbers who met that definition, and the reasons any participants may have been excluded, are not reported in the registry record.
Even if a numerical group difference were available, interpretation would require attention to its uncertainty, the analysis population, and the handling of missing measurements. The record does not report the statistical test or model used for the primary outcome, any adjustment for baseline BMI, or whether the analysis followed the randomized assignment regardless of attendance. These details matter because different analysis choices can produce estimates with different interpretations.
The registry lists two outcome measures and four analyses, but does not describe their relationship or any hierarchy among them. It also does not report a multiplicity strategy. This makes it impossible to tell from the record whether the primary result was selected from a larger set of comparisons or whether inferential error was controlled across analyses. These are limits on interpretation, not evidence that a particular analysis was inappropriate.
The study status is completed, but completion status alone does not convey the outcome. The endpoint specification, intervention description, and group labels establish what was intended to be evaluated; they do not establish the numerical effect. The most defensible reading is therefore that the registry describes a randomized study of BMI change but does not report enough outcome statistics to assess the observed comparative effect or its precision.
9. Statistical Methods Explained
The registry identifies the study as randomized and parallel, with no masking. These design labels describe how participants were assigned and how the groups were organized; they do not specify the statistical method used to analyze BMI. The record does not report a primary-outcome model, a test statistic, or a detailed analysis plan. The explanations below describe general statistical concepts and do not imply that a particular method was used in this study.
What does a mean change describe?
For a continuous outcome such as BMI, a mean change describes the average difference between a participant’s follow-up and baseline measurements within the analyzed group. A comparison of mean changes between groups focuses on the contrast in average trajectories, rather than on whether each group changed in isolation. In a randomized study, a between-group contrast is generally more informative about the effect associated with assignment than a before-and-after change in only the intervention group. That interpretation still depends on the analysis population and methods.
The registry names mean as the summary parameter and gives a 95% confidence interval as the dispersion measure. A mean is sensitive to the values contributing to it, so it can be affected by unusually high or low measurements. A confidence interval reflects uncertainty in an estimated mean or contrast under the model and assumptions used. It does not describe the spread of individual BMI values. The interval’s width is relevant to precision, while its location relative to a value of no group difference is relevant to the range of effects compatible with the data.
Why does the analysis population matter?
The primary outcome population is defined as participants who attended at least one intervention session and also had a final assessment. This is a per protocol definition, based on participation and follow-up rather than merely randomized assignment. A per protocol analysis can describe outcomes among those meeting the stated conditions, but it may not preserve the full comparability created by randomization if inclusion is related to participant characteristics or outcomes. This is a general concern, not evidence that such bias occurred in this study.
An analysis based on all randomized participants, by contrast, generally retains participants according to their assigned group regardless of adherence. The registry does not report whether such an analysis was conducted. It also does not report how many participants had a final assessment or met the per protocol definition. Consequently, the population actually contributing to the BMI estimates and the degree of attrition cannot be evaluated from the record.
What does randomization contribute?
Randomization assigns participants to groups by chance and is intended to reduce systematic differences in prognostic factors at the start of a study. It supports a causal interpretation of a group contrast when allocation is implemented appropriately and analyses preserve the randomized comparison. Randomization does not eliminate random baseline imbalance, ensure adherence, prevent missing data, or conceal group assignment. The registry states that allocation was randomized, but does not give the sequence-generation or allocation-concealment procedures.
Masking can reduce the possibility that knowledge of assignment influences behavior, assessment, or analytic decisions. No masking is reported in the registry. That does not establish which people knew assignments or whether the outcome assessment was especially susceptible to influence. The record does not report masking of outcome assessors or analysts, so those details remain unknown.
How should the confidence interval be read?
In general, a confidence interval is a range of values produced by a statistical procedure intended to reflect uncertainty about an underlying quantity. Its interpretation relies on the procedure’s assumptions and repeated use of that procedure, rather than on a claim that the observed interval contains every participant’s true change. For a between-group mean difference, the interval helps readers assess both the plausible direction and the precision of the estimate. A p-value, if reported, would address compatibility with a specified null hypothesis under the test assumptions; it would not measure clinical importance or the probability that a hypothesis is true.
The registry specifies a 95% confidence interval but does not give its endpoints. It also does not report a p-value for the primary outcome. Thus the stated interval type cannot be used to judge uncertainty in the observed BMI effect. No recalculated estimate can be produced from the registry entries because the group outcome summaries are not reported in the registry record.
What assumptions are relevant to planning illustrations?
The planning illustration is described as a calculation based on the observed effect, not as the trial’s original design justification. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. For time-to-event tables, the description refers to total events, while other planning outputs refer to participants per arm. This study’s primary outcome is continuous, so the general distinction is that participant counts per arm are used for non-time-to-event planning illustrations.
Such calculations are conditional illustrations: they show how planning requirements would depend on assumptions about an effect and variability. They are not observed power, and they do not establish that the original study was designed around the same assumptions. The record does not report the numeric planning outputs or a sample-size justification for the trial. Nor does it report numeric outcome summaries from which the observed effect could be independently assessed. No conclusion about adequacy of the trial’s planned enrollment follows from the stated illustration assumptions alone.
What cannot be established from the registry description?
The method used to compare BMI changes, any adjustment for baseline values, the variance assumptions, and the treatment of missing outcomes are not reported in the registry record. The record also does not explain whether the 95% confidence interval is for within-group change or the between-group contrast. Those details are important because a confidence interval for change within each group answers a different question from an interval for the difference between groups. Without the numerical results and analysis specification, the comparative effect and its precision remain unassessable.
10. Multiplicity, Missing Data and Analysis Populations
The registry reports two outcome measures and four analyses. It does not describe how those analyses relate to one another, which analyses were primary or secondary, or whether a hierarchy was prespecified. The primary outcome entry identifies change in BMI, but its timeframe includes baseline and 12-15 months, and the registry indicates that the primary outcome has several categories or time points and was not reduced to one comparison. The record therefore does not establish a single numerical comparison for interpretation.
Multiplicity arises when multiple outcomes, time points, groups, or analyses are examined. In general, testing many comparisons can increase the chance that at least one result appears notable by chance. Statistical approaches can address this concern, but the registry does not report whether any adjustment or other multiplicity strategy was used. This absence does not show that no strategy existed; it means that the strategy is not reported in the registry record.
Missing-data information is also limited. The primary population requires both at least one intervention session and a final assessment, but the registry does not state how many participants lacked follow-up, why measurements were unavailable, or what method was used to handle missing BMI values. It does not report whether participants with partial follow-up contributed to any analyses.
The per protocol definition is relevant because attendance and availability of a final assessment determine inclusion in the stated primary population. The record does not provide a separate intention-to-treat analysis or a comparison of results under different missing-data assumptions. Without participant flow and analysis details, it is not possible to assess whether missingness or exclusions could have affected the estimated group contrast.
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 |
|---|---|---|---|
| Behavioral Program | 0 | 15 | 0.0% |
| Standard of Care/Control | 0 | 15 | 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 |
|---|---|
| Behavioral Program | 0 of 15 |
| Standard of Care/Control | 0 of 15 |
The registry lists serious and other adverse-event counts separately for the Behavioral Program and Standard of Care/Control groups. For each group, 15 participants are listed as at risk for serious adverse events, with 0 affected. For other adverse events, each group also lists 15 at risk and 0 affected. These are the recorded counts for the categories shown; they do not provide the BMI outcome or establish the effect of the intervention.
The serious-event and other-event entries refer to separate categories. Their at-risk counts should not be added together, because doing so would combine listings rather than describe a distinct participant total. The record gives no serious adverse-event terms. Death counts are null for both groups; a null entry is not a reported zero and should not be interpreted as confirmation that no deaths occurred.
Zero recorded affected participants is a count in the registry entry, not proof that an event is impossible or that all potential harms were captured. The registry does not provide further detail about event definitions, collection procedures, timing, or the duration of safety follow-up. The listed counts should therefore be read narrowly as the reported adverse-event figures, with those reporting details in mind.
12. What the Result Does, and Does Not, Mean
The registry describes a completed randomized study comparing a behavioral education program with education on physical activity and nutrition in a primary care office setting. It identifies mean change in BMI as the primary outcome and gives a timeframe of baseline and 12-15 months. These details explain the intended comparison, but they are not outcome evidence by themselves.
The record does not report numerical BMI changes, a between-group estimate, a confidence interval, or a primary-outcome p-value. As a result, it does not establish whether BMI changed more in one group, how large any difference was, or how precisely it was estimated. The anticipated decrease of approximately five points in the intervention group is stated as an expectation in the study summary, not as an observed result.
The study’s planned enrollment was 30, while the primary endpoint is defined for a per protocol population requiring attendance at at least one intervention session and a final assessment. The record does not report how many participants entered that analysis. The safety entries list 15 at risk in each group, but those entries do not supply the missing BMI results or identify the primary analysis population.
Even a reported difference would need to be interpreted alongside its confidence interval, analysis population, missing-data handling, and the multiplicity of outcomes and analyses. These details are not reported. The absence of this information prevents a statistical assessment of the comparative effect; it should not be mistaken for evidence of either benefit or no effect.
More broadly, a study of this design can inform a group-level comparison in the population and setting studied, but the registry description alone cannot establish how broadly any result would apply. The record does not provide enough participant characteristics, implementation details, or outcome statistics to judge generalizability. Its contribution in this form is to identify the question, intervention, comparator, and intended endpoint, while leaving the observed result and its uncertainty unreported.
13. Why This Trial Matters Statistically
This trial is statistically interesting because it pairs a randomized comparison with a continuous outcome measured over time. BMI change can be summarized as a mean, and comparing change between groups is a direct way to frame the difference associated with the two assigned conditions. The registry specifies that framework but does not report the numerical estimates needed to complete the interpretation.
The study also illustrates why the analysis population matters. The primary outcome is defined for participants who attended at least one intervention session and had a final assessment. Randomization supports comparability at assignment, while restricting analysis according to attendance and follow-up can change which participants contribute to the estimate. Without analysis counts or a separate analysis by randomized assignment, readers cannot assess that distinction empirically.
Unmasked delivery is another feature relevant to interpretation. Participants and program staff may have known the assigned condition, although the registry does not state who was masked or how outcomes were assessed. For an outcome with a defined measurement scale, the numerical measure may appear objective, but study conduct and missingness can still affect what is observed. The record does not report details that would resolve those questions.
Finally, the registry lists multiple outcomes and analyses but does not describe a multiplicity plan, and it does not report the primary estimate or confidence interval. These omissions show why endpoint labels and design descriptions are not substitutes for results and methods. A complete statistical interpretation needs the contrast, its uncertainty, the analysis population, and enough information to understand how the estimate was obtained.
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 most consequential limitation of the registry record for statistical interpretation is that numerical primary-outcome results are not reported. Mean changes by group, a between-group estimate, confidence interval endpoints, and a p-value are absent. The record therefore does not permit assessment of effect direction, magnitude, or precision.
The primary outcome population is described as participants who attended at least one intervention session and had a final assessment, but the number included is not reported. Participant flow, follow-up completeness, reasons for missing assessments, and the method for handling missing BMI values are also not reported in the registry record. This prevents evaluation of whether the analyzed population differed from the randomized groups.
The registry does not report a detailed statistical analysis plan, the method used to compare changes, or whether baseline BMI was accounted for in the analysis. It reports two outcomes and four analyses but does not explain their hierarchy or describe any multiplicity strategy. The endpoint timeframe names baseline and 12-15 months, while the record notes that the primary outcome has several categories or time points and was not reduced to one comparison. That leaves the exact comparison underlying any primary estimate unclear.
Randomization is reported, but the method of sequence generation and allocation concealment is not. No masking is reported, and the record does not say whether assessors or analysts were masked. These are limits on what can be judged from the record, not proof of flaws in study conduct.
Finally, the population description and intervention details are limited. The record gives the age range and BMI threshold wording, but does not provide fuller baseline characteristics or detailed implementation information. These omissions constrain appraisal of comparability and generalizability. The stated anticipated decrease is not a substitute for an observed estimate.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study of Impact of Behavioral Intervention- Exercise, Nutrition, Education- on Body Mass Index (BMI) — NCT00132132.
- Registry record last updated 2015-05-21; status last verified 2015-05.
- Results first posted 2012-06-27.
- 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
NCT00132132 is a completed, randomized, parallel-group study sponsored by Steward St. Elizabeth's Medical Center of Boston, Inc. The registry records a start of 2005-08, primary completion in 2008-02, and enrollment of 30. Masking is listed as none, and phase is listed as NA.
The study compares a behavioral education program, delivered in monthly 4 hour sessions, with education on physical activity and nutrition in a primary care office setting. The primary endpoint is mean change in BMI in kg/m^2, with a 95% confidence interval and a timeframe of baseline and 12-15 months. Its stated analysis population requires at least one intervention session and a final assessment.
The registry record does not report numerical BMI results or the details needed to assess their precision. It lists two outcome measures and four analyses, without reporting a multiplicity strategy or missing-data approach. Serious and other adverse-event entries list 0 affected in each group; death counts are null. The study description and endpoint are available, but the comparative BMI result is not reported in the registry record.