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 Translating the DPP Into the Community (NCT00302042), a randomized na study. The primary outcome is Change in Weight.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00302042 |
| Phase | NA |
| Condition | Prediabetic State, Overweight, Obesity |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 92 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Northwestern University |
| Results posted | Yes |
2. Clinical Question
Population
The registry describes a study concerning prediabetes, overweight, and obesity. It does not report the participant eligibility criteria, age range, or other demographic details in the posted results. The study’s stated purpose was to develop preliminary data about the reach, effectiveness, and consistent implementation of a community-based adaptation of the Diabetes Prevention Program.
Intervention
The intervention combined brief counseling with a group diabetes-prevention lifestyle program in the community. The registry describes the program as a group-based adaptation of the Diabetes Prevention Program intended for delivery by YMCA staff in YMCA facilities. The reported primary outcome concerns weight change; the registry also lists physical activity, community program participation, and dietary composition as secondary outcomes.
Comparator
The active comparator was brief counseling alone for prediabetes. Both study groups therefore received brief counseling, while the intervention group also received the group lifestyle program. The registry does not give further detail about counseling content or the frequency and duration of program sessions.
Primary question
The primary outcome asks how mean weight changed from baseline to 6 months in each group, expressed as percentage change in weight. The posted results report a mean change of -6.0 for brief counseling plus group lifestyle and -2.0 for brief counseling alone. These are arm-specific estimates, not a reported estimate of the between-group contrast. The registry record does not report a formal comparison between the groups or a p-value.
3. Trial Design
The registry describes a randomized, parallel-group study with no masking. It was marked completed. The study start is recorded as 2005-05 and primary completion as 2007-08. The enrollment entry is 92; the results list 39.0 participants for the group-lifestyle arm and 38.0 for the brief-counseling-alone arm. The registry does not explain the relationship between these figures or report how many participants contributed data to each outcome analysis.
The experimental arm paired brief counseling with a group-based community lifestyle program intended to translate the Diabetes Prevention Program into YMCA settings. YMCA staff were to deliver the program in YMCA facilities. The active comparator received brief counseling alone. The registry’s description emphasizes preliminary assessment of reach, effectiveness, and implementation, but the posted primary result is a continuous weight-change measure.
The primary outcome is described as change in weight, measured as percentage change from baseline to 6 months. The reported value is the mean for each arm, with a 95% confidence interval. The registry also lists physical activity level, community program participation, and change in dietary composition as secondary outcomes. It does not provide posted numerical results for those secondary outcomes in the information recorded.
The record does not report the randomization sequence, allocation concealment procedures, eligibility details, masking beyond the designation of no masking, or the statistical analysis plan. It also does not report whether the analysis followed an intention-to-treat approach. Those omissions limit what can be established about trial conduct and the interpretation of the arm-specific results.
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 | Experimental: 1: Brief Counseling Plus Group Lifestyle | Active Comparator: 2: Brief Counseling Alone |
|---|---|---|
| STARTED | 46 | 46 |
| COMPLETED | 39 | 38 |
| NOT COMPLETED | 7 | 8 |
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 | Experimental: 1: Brief Counseling Plus Group Lifestyle | Active Comparator: 2: Brief Counseling Alone | Total |
|---|---|---|---|---|
| Participants analysed | 46 | 46 | 92 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 45 | 43 | 88 |
| Age, Categorical: >=65 years | Participants | 1 | 3 | 4 |
| Age, Continuous | years | 56.5 (SD 9.7) | 60.1 (SD 10.5) | 58.3 (SD 10.1) |
| Sex: Female, Male: Female | Participants | 23 | 28 | 51 |
| Sex: Female, Male: Male | Participants | 23 | 18 | 41 |
| Region of Enrollment: United States | participants | 46 | 46 | 92 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Weight, measured over Baseline, 6 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | percentage of change in weight |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change in weight, expressed as percentage change in weight from baseline to 6 months. The registry defines the change as the 6-month value minus the baseline value and summarizes the outcome using a mean. A negative mean therefore indicates a decrease in the measured weight relative to baseline, as expressed on this percentage-change scale.
Weight change is a continuous outcome: it can take a range of values rather than representing only whether a participant did or did not cross a threshold. Reporting a mean gives a group-level summary, while a 95% confidence interval describes uncertainty around that estimate under the analysis used. The registry does not specify the exact calculation of the percentage change or give details about the measurement procedure.
In this study, the endpoint gives a numerical description of weight change in each assigned group. It is not, by itself, a direct estimate of the difference between the groups. A comparative conclusion would require a between-group estimate and its uncertainty, or another reported inferential comparison. Such a result is not reported in the registry record.
The endpoint was selected within a study intended to evaluate a community-delivered lifestyle program. The registry’s stated background links the intervention to lifestyle change, but the primary outcome is weight change rather than diabetes incidence or a clinical diagnosis. The record does not report a primary outcome result for diabetes development.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
For brief counseling plus group lifestyle, the reported mean percentage change in weight from baseline to 6 months was -6.0, with a 95% confidence interval from -7.3 to -4.7. For brief counseling alone, the reported mean was -2.0, with a 95% confidence interval from -3.3 to -0.6. These values describe the observed arm-specific summaries; they do not constitute a reported estimate of the treatment contrast.
A confidence interval conveys uncertainty around an estimated mean under the methods used to construct it. It is not a range that contains every participant’s result, nor does it show the distribution of individual changes. The registry does not report the underlying individual-level data, a standard deviation, or a standard error. It also does not specify the precise interval-construction method, so the intervals should be interpreted as posted rather than reconstructed.
The arm-specific estimates do not answer, on their own, whether the groups differed statistically. A direct comparison would ordinarily report a contrast between group means, together with its uncertainty and an inferential result if one was planned. The registry record does not report such a contrast, a p-value, or any other formal test for the primary outcome. Accordingly, the posted results support describing the mean change within each group, but not assigning a statistical significance conclusion to the difference between groups.
The results also need to be read in light of the record’s enrollment and arm entries. Enrollment is listed as 92, while the arm-specific result entries list 39.0 and 38.0. The registry does not explain these entries or identify the number included in a complete-case analysis. They should not be combined to infer a total analyzed population or used to infer why outcome data may be absent.
The study was described as a pilot intended to develop preliminary data about reach, effectiveness, and consistent implementation. The primary result is therefore one component of a broader stated evaluation aim. The registry lists secondary outcomes for activity, program participation, and diet, but numerical results for those outcomes are not reported in the registry record. The record also does not provide implementation measures or enough detail to assess whether delivery was consistent with the intended program.
These findings describe this study’s recorded outcome summaries. They do not establish how the program would perform in other communities, whether the groups were comparable on all relevant baseline characteristics, or whether changes persisted beyond 6 months. Those questions require information not reported in the registry record.
9. Statistical Methods Explained
The posted primary outcome is a continuous measure summarized as a mean for each study arm. The registry reports a 95% confidence interval alongside each mean. The primary outcome timeframe is baseline to 6 months, and the change is defined as the later measurement minus the baseline measurement. The record does not specify further details about the statistical model or how the intervals were calculated.
What does a mean summarize?
In general, a mean is an average that combines the observed values into one group-level summary. It can describe the central level of a continuous outcome, but it does not show the range or shape of individual results. A mean can be affected by unusually high or low observations. Without participant-level data or other distribution summaries, the registry’s mean and confidence interval cannot show how variable individual weight changes were.
What does a confidence interval communicate?
In general, a confidence interval represents uncertainty around an estimated quantity, based on the analysis and assumptions used to calculate it. A narrower interval indicates greater precision for that estimate than a wider interval, while the interval does not guarantee that the true value lies within its particular endpoints. The posted intervals are for the mean in each arm. They are not intervals for the difference between the arms, and they should not be treated as such.
The registry does not identify whether the reported interval calculation used a particular distributional assumption, adjustment, or model. It does not report a standard deviation or standard error. Consequently, a reader cannot independently reproduce the intervals from the posted summaries alone. No reconstructed result is needed to describe the registry’s reported values.
How should a group comparison be assessed?
In general, a randomized comparison is most directly described by an estimate of the between-group contrast. That estimate answers how far apart the group outcomes are on the selected scale. Its confidence interval shows uncertainty about the contrast, and a test may provide additional inferential information when appropriate. A comparison should not be inferred solely from the arm-specific means and their separate confidence intervals. The registry record does not report a primary-outcome contrast, its confidence interval, or a p-value.
The study is recorded as randomized, parallel, and unmasked. Random allocation is intended, in general, to support comparability between groups at the time of assignment, but it does not ensure identical groups in every realized trial. The registry does not describe sequence generation or allocation concealment, nor does it report baseline characteristics. The masking designation is none; the record does not give further information about masking of outcome assessors or analysts.
What do the planning assumptions mean?
The record describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The scenario is defined in terms of detecting a stated fraction of the observed effect. In general, such calculations explore how much information a future study might need under chosen assumptions; they are not evidence about the power achieved by this completed study. The planning assumptions do not establish the design rationale used for the trial. The registry does not report its original sample-size justification, and no planning count is stated in this record.
In general, a planning calculation depends on the target effect, variability, statistical test, allocation, and assumptions about the outcome and analysis. Altering the assumed effect changes the planning requirement. A calculation based on a fraction of an observed effect is therefore an illustrative scenario, not a prospective guarantee and not a substitute for an independently justified design. The record does not state whether these planning scenarios informed the original trial design.
The record lists no posted analyses beyond the arm-level primary outcome values. It does not describe a statistical model, covariate adjustment, handling of repeated measurements, or sensitivity analyses. Nor does it state whether any interim analyses occurred. These details are not reported in the registry record, so the results should be interpreted at the level of the summaries actually documented.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary outcome and three secondary outcomes: physical activity level, rate of community program participation, and change in dietary composition. It does not report a multiplicity procedure, such as an adjustment to account for testing several outcomes. In general, examining multiple outcomes can increase the chance of at least one apparently unusual finding when each is tested separately. Without the analysis plan and results for the secondary outcomes, the extent to which multiplicity was addressed cannot be assessed.
The primary result is reported for each arm, but the registry does not explain the analysis population, the extent of missing outcome data, or how missing observations were handled. It does not report whether the analysis included all randomized participants, only participants with observed measurements, or another population. The enrollment entry is 92, and the arm-level result entries are 39.0 and 38.0; the record does not reconcile those figures or state the outcome-specific denominators.
In general, missing outcome data can affect an estimate when the likelihood of having an observed measurement is related to the outcome or other participant characteristics. Methods such as imputation or sensitivity analysis can examine the influence of assumptions about missing values, but the registry does not report their use. The reasons for missing data and the pattern of follow-up are also not reported in the registry record.
The record does not specify an intention-to-treat approach, per-protocol approach, or another analysis-population definition. It also does not report a statistical analysis plan. As a result, the posted arm-specific means and intervals can be described, but the handling of missing observations and the scope of the analysis cannot be independently assessed.
11. What the Result Does, and Does Not, Mean
The results show that the recorded mean percentage change in weight was -6.0 in the group receiving brief counseling plus group lifestyle and -2.0 in the group receiving brief counseling alone over baseline to 6 months. The 95% confidence intervals describe uncertainty around those arm-specific means: -7.3 to -4.7 and -3.3 to -0.6, respectively. They do not quantify uncertainty around a direct comparison between the groups.
The registry record does not report a formal between-group estimate, a p-value, or another test of the primary outcome. The arm-specific summaries should therefore not be treated as proof of a statistically significant difference. They also do not by themselves establish that the group program caused the observed changes. The fact that the study was randomized is relevant to its design, but the record does not provide enough analysis detail to assess the comparative result fully.
The outcome is weight change over the recorded 6-month period. It is not a measure of diabetes incidence, long-term maintenance, or every aspect of lifestyle change. Although the study’s stated aims include reach and implementation, the registry does not report numerical implementation results in the information recorded. Numerical findings for the listed secondary outcomes are also not reported in the registry record.
The record describes the study as a pilot focused on a community adaptation delivered by YMCA staff in YMCA facilities. These results should be understood in that context rather than assumed to apply to other delivery settings or populations. The registry does not report enough detail about participant characteristics, missing observations, or the analysis population to establish how representative the outcome summaries are.
In general, statistical uncertainty and practical importance are different considerations. A confidence interval describes precision for an estimate under its analysis, while judging importance requires context about the outcome and intended use. The registry does not state a threshold for meaningful weight change, and no such threshold can be inferred from the posted means alone.
12. Why This Trial Matters Statistically
This trial addresses a statistical and implementation question: whether a structured lifestyle program originally associated with the Diabetes Prevention Program could be adapted for delivery in community settings by YMCA staff. The registry describes a group-based adaptation and a brief-counseling comparator, making the primary outcome relevant to evaluation of a community-delivered intervention rather than only a program delivered in a specialized research setting.
Statistically, the record illustrates why arm-specific summaries and comparative estimates answer different questions. A mean and its confidence interval describe the outcome within an arm. A direct treatment comparison requires a contrast and uncertainty for that contrast. The registry reports the first type of information for weight change, but not the second. That distinction prevents the arm summaries from being overread as a formal test of the intervention effect.
The study also has multiple stated aims. The registry lists reach, effectiveness, and consistent implementation as areas of interest, while the posted primary outcome is weight change and the secondary outcomes concern activity, participation, and diet. These domains are related but not interchangeable: a weight result alone does not describe program reach or consistency of delivery. Numerical results on the listed secondary outcomes and direct implementation measures are not reported in the registry record.
The completed study’s pilot framing matters for interpretation. A pilot can generate preliminary information in a specific delivery context, but its posted summary does not, on its own, resolve broader questions about comparative efficacy, implementation across communities, or longer-term outcomes. The available record is most informative when its scope is kept clear: it documents arm-level mean weight changes and intervals for a community translation study, while leaving important comparative and implementation details unreported.
13. 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 provides limited detail about the participants. It lists prediabetic state, overweight, and obesity as conditions, but does not report eligibility criteria, participant characteristics, recruitment flow, or baseline weight values. The enrollment entry is 92, while the arm-level outcome entries list 39.0 and 38.0. The record does not explain the relationship between these figures or provide outcome-specific denominators.
The primary outcome is reported as an arm-specific mean with a 95% confidence interval, but the registry does not provide a between-group contrast or inferential test. It also does not report the statistical model, interval calculation method, adjustment variables, analysis population, or handling of missing observations. These omissions constrain interpretation of both the estimates and their precision.
Because the study was unmasked, participants and staff were not masked according to the registry designation. The record does not explain whether outcome assessment or analysis was masked. Details of random sequence generation and allocation concealment are not reported. The registry also does not provide session-level information, adherence measures, or evidence about consistency of program delivery, despite the stated interest in implementation.
The outcome timeframe ends at 6 months for the primary measure. Longer-term weight results, diabetes incidence results, and numerical results for the listed secondary outcomes are not reported in the registry record. The record also does not state the original sample-size justification or whether interim analyses were conducted. These limitations mean that the posted information supports a focused description of the recorded weight summaries, not a complete evaluation of all trial aims.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Translating the DPP Into the Community — NCT00302042.
- Registry record last updated 2017-07-18; status last verified 2014-08.
- Results first posted 2013-07-12.
- 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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17. Record Summary
NCT00302042, titled “Translating the DPP Into the Community,” is recorded as a completed randomized, parallel-group study with no masking. The registry lists Northwestern University as sponsor, a start of 2005-05, primary completion in 2007-08, and enrollment of 92.
The intervention combined brief counseling with a group lifestyle program adapted from the Diabetes Prevention Program for YMCA delivery. The active comparator was brief counseling alone. The primary outcome was mean percentage change in weight from baseline to 6 months, reported with a 95% confidence interval. The recorded means were -6.0 for the group-lifestyle arm and -2.0 for brief counseling alone.
The registry lists physical activity level, community program participation, and dietary composition as secondary outcomes, but numerical results for them are not reported in the registry record. A direct primary-outcome comparison, analysis population, missing-data approach, and detailed statistical plan are also not reported.