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 Latinos Combating Diabetes (NCT01831921), a randomized na study. The primary outcome is Hemoglobin A1c.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01831921 |
| Phase | NA |
| Condition | Pre Diabetes, Obesity, Metabolic Syndrome |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 225 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Wake Forest University Health Sciences |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns Latino participants in and around Forsyth County, North Carolina, with prediabetes, obesity, or metabolic syndrome. The registry record reports enrollment of 225 participants. The primary-outcome description says retention at clinic assessment visits is presented as the number analyzed at each time-point, but those counts are not reported in the registry record.
Intervention
The intervention was a group-based lifestyle weight-loss program. It promoted healthy eating, increased physical activity, and weight loss, with sessions delivered by Latino Health Advisors, described as lay community members. The arm description states that the program aimed at modest weight loss of 5-7% and that sessions took place at churches and other community locations. Further details about the sessions are not reported in the registry record.
Comparator
The comparison was enhanced usual care. Participants were to receive two individual sessions with a registered dietitian and monthly newsletters focused on existing community resources. The brief summary describes the counseling as helping participants make healthier lifestyle choices. Additional detail about the content or delivery of these resources is not reported in the registry record.
Primary question
The primary outcome was mean hemoglobin A1c, measured in percent HbA1c. The registry record says the mean in both groups would be assessed at 6, 12, 18, and 24 months. The statistical question is whether the groups’ outcome profiles differ over the stated follow-up times. Numerical group means, between-group estimates, uncertainty intervals, and tests of that question are not reported in the registry record, so the direction and precision of any observed difference cannot be described.
In general, a randomized comparison is designed to assess differences between assigned groups while limiting systematic differences at the start of follow-up. That design feature does not itself establish whether the groups differed on the primary outcome. Interpretation still depends on the observed outcome data, the analysis method, and how missing observations were handled; those details are not reported in the registry record.
3. Trial Design
The registry record describes Latinos Combating Diabetes as a randomized, parallel-group trial with single masking. The phase is listed as NA. The record names Wake Forest University Health Sciences as sponsor, reports enrollment of 225, gives a start of 2014-01, and lists primary completion as 2017-06-30. The study status is COMPLETED.
Participants were assigned to Lifestyle Weight-Loss or Enhanced Usual Care. The lifestyle program used group sessions promoting healthy eating, increased physical activity, and weight loss; Latino Health Advisors delivered the sessions. The enhanced usual-care group received individual counseling with a registered dietitian and access to existing community resources, including monthly newsletters. The intervention descriptions do not give a complete schedule or full account of every activity.
Assessment visits were planned at baseline, 6, and 12 months. The primary outcome timeframe also includes 18 and 24 months. The record says follow-up on all participants was at least 12 months and that 18- and 24-month data were collected for participants randomized early in recruitment. These descriptions do not establish how many participants contributed data at each visit; those counts are not reported in the registry record.
Single masking is recorded, but who was masked and how masking was maintained are not reported in the registry record. The method used to generate the random allocation, whether allocation was concealed, and any stratification or blocking procedures are also not reported in the registry record. No sample-size justification or detailed protocol is included in the registry record. The planned enrollment should therefore be distinguished from the number with observed primary-outcome data at each time-point.
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 | Lifestyle Weight-Loss | Enhanced Usual Care |
|---|---|---|
| STARTED | 150 | 75 |
| 6 Months | 122 | 63 |
| 12 Months | 120 | 62 |
| 18 Months | 90 | 49 |
| COMPLETED | 66 | 36 |
| NOT COMPLETED | 84 | 39 |
Analysis population for the primary outcome, as defined in the registry: Participant retention at clinic assessment visits is presented below as the number analyzed at each time-point. Follow-up on all participants was at least 12 months; for those participants randomized early in the recruitment process, 18 and 24 month data was collected.
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 | Lifestyle Weight-Loss | Enhanced Usual Care | Total |
|---|---|---|---|---|
| Participants analysed | 150 | 75 | 225 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 147 | 71 | 218 |
| Age, Categorical: >=65 years | Participants | 3 | 4 | 7 |
| Age, Continuous | years | 41.6 (SD 9.0) | 41.8 (SD 9.1) | 41.6 (SD 9.0) |
| Sex: Female, Male: Female | Participants | 127 | 64 | 191 |
| Sex: Female, Male: Male | Participants | 23 | 11 | 34 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 150 | 75 | 225 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | Participants | 150 | 75 | 225 |
| Hemoglobin A1c | percent | 6.0 (SD .30) | 5.9 (SD .20) | 5.9 (SD .3) |
| Body Weight | kilograms | 81.9 (SD 14.10) | 80.3 (SD 13.1) | 81.4 (SD 13.80) |
| Systolic Blood Pressure | mmHg | 118.5 (SD 13.8) | 116.5 (SD 14.5) | 117.8 (SD 14.0) |
| Diastolic Blood Pressure | mmHg | 71.9 (SD 8.5) | 69.9 (SD 9.8) | 71.3 (SD 9.0) |
| Fasting Glucose | mg/dL | 97.7 (SD 9.9) | 96.6 (SD 9.6) | 97.4 (SD 9.8) |
| High Density Lipoprotien (HDL) | mg/dL | 45.3 (SD 10.5) | 46.5 (SD 10.9) | 45.7 (SD 10.6) |
| Low Density Lipoprotein (LDL) | mg/dL | 109.9 (SD 28.50) | 106.7 (SD 28.10) | 108.8 (SD 28.40) |
| Triglycerides | mg/dL | 142.1 (SD 68.70) | 140.1 (SD 61.60) | 141.4 (SD 66.30) |
| Total Cholesterol | mg/dL | 183.6 (SD 33.10) | 181.3 (SD 36.6) | 182.8 (SD 34.30) |
6. Primary Endpoint
The registry lists the primary outcome as Hemoglobin A1c, measured over 6, 12, 18, and 24 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | percent HbA1c |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is mean hemoglobin A1c, expressed in percent HbA1c. It is assessed in both groups at 6, 12, 18, and 24 months. In general, hemoglobin A1c is a laboratory measure used to describe glycemic status. Reporting a group mean gives a summary of the outcome level, while the standard deviation describes how much individual measurements vary around that mean.
Repeated assessment can describe how the group outcomes develop across follow-up, rather than focusing on a single visit alone. A meaningful comparison would need to account for the fact that measurements from the same participant across visits are related. General longitudinal methods can represent both change over time and differences between assigned groups, but the registry record does not report which method was used.
The endpoint description identifies the measure and assessment times, but no numerical means, standard deviations, group contrasts, confidence intervals, or p-values are reported in the registry record. Thus, the endpoint’s role is clear, but the observed level, between-group difference, and precision cannot be evaluated from the registry information. The record also does not identify a single time-point as the sole primary comparison; the outcome is specified across 6, 12, 18, and 24 months.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the trial’s main comparison and its primary outcome, but it does not provide numerical primary-outcome results. The endpoint is mean hemoglobin A1c in each group at 6, 12, 18, and 24 months. Without those values or a reported contrast between groups, there is no basis in the registry record for describing whether the groups’ observed outcomes were higher, lower, or similar at any assessment time.
Precision is also not available. In general, a confidence interval describes a range of values compatible with an estimate under the assumptions of the analysis; its width conveys uncertainty. No confidence intervals or other uncertainty estimates for the primary outcome are reported in the registry record. The number enrolled does not substitute for such information, because the primary-outcome description refers to participants analyzed at each time-point and the number contributing data at those times is not reported.
The registry record lists 11 outcome measures and names secondary measures including body weight, systolic and diastolic blood pressure, fasting glucose, total cholesterol, HDL, LDL, and triglycerides. Numerical results for these measures are not reported in the registry record. A count of listed outcomes cannot establish whether they changed, whether differences occurred between groups, or how reliable any such estimates would be.
The record lists zero analyses. That means the registry record does not contain analysis entries that can be used to explain the reported statistical findings. It does not supply a test statistic, a p-value, an effect estimate, or an adjusted analysis for the primary outcome. The planned sample-size illustration is described as based on an observed effect and a stated fraction of that effect, but the primary outcome is not reduced to one comparison in the record. Its assumptions therefore should not be read as observed evidence or as a substitute for trial results.
Overall, the registry documents a randomized comparison and identifies the intended measurements, but it does not report the numerical findings needed to assess the size, direction, or precision of the primary contrast. No conclusion about the comparative outcome can be drawn from the record alone. This is a limitation of the available registry reporting, not evidence that the groups had no difference.
9. Statistical Methods Explained
The primary outcome is a continuous measure summarized as a mean with standard deviation. In general, the mean describes the central level of measurements in a group. The standard deviation describes dispersion among individual measurements; it is not the uncertainty around the group mean. A comparison between groups would usually be expressed as a difference in means or another model-based contrast, accompanied by an uncertainty estimate. The registry record does not report such estimates for hemoglobin A1c.
What does a confidence interval communicate?
In general, a confidence interval conveys the precision of an estimate under the assumptions of the chosen statistical method. A narrow interval indicates greater precision than a wide interval, while the values included in the interval show which effects remain compatible with the data and method. It is not a guarantee that the true effect lies within a particular interval. No confidence interval for the primary outcome is reported in the registry record, so its precision cannot be assessed.
How do repeated measurements affect analysis?
The primary outcome is scheduled at 6, 12, 18, and 24 months, and clinic assessments are also described at baseline, 6, and 12 months. In general, measurements from the same participant are correlated: a person’s later measurement is not statistically independent of that person’s earlier measurement. Analyses of longitudinal data can account for this correlation and estimate group differences across time. A model may also address whether group differences change over follow-up. These are general considerations, not a description of the method used in this trial; the statistical model is not reported in the registry record.
There is more than one possible way to summarize a multi-time-point outcome. One analysis might focus on a specified follow-up assessment, while another might estimate a pattern across visits. The estimand, or precise quantity the analysis aims to estimate, depends on the selected contrast, time-point, and population. The registry record names multiple assessment times but does not identify a single comparison or provide an analysis plan that clarifies how those times were to be combined or interpreted.
Why do analysis details matter?
Random allocation defines the assigned groups, but analysis choices affect how the observed data are translated into estimates. For example, an adjusted analysis may account for selected baseline characteristics, while an unadjusted analysis compares groups without such adjustment. General statistical practice requires the selected method and its assumptions to be transparent. Whether the trial used an adjusted or unadjusted method, which covariates were included, and how repeated measurements were modeled are not reported in the registry record. No recalculated comparison can be made from the registry information because group-level outcome summaries are not included.
The planning assumptions describe a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. They also describe detecting a stated fraction of an observed effect. These are planning assumptions, not evidence that a particular effect was observed or that the trial had a particular achieved power. The registry record does not provide a primary-outcome effect estimate that would allow those planning illustrations to be interpreted as a specific clinical contrast. A sample-size calculation is a planning aid based on assumptions; it is not an observed trial result.
When would over-dispersion matter?
In general, over-dispersion is a concern when data vary more than a statistical model expects, particularly for outcomes modeled as counts or proportions. The primary endpoint is continuous and summarized as a mean with standard deviation, so the central considerations include the outcome’s distribution, the validity of the model, repeated-measure correlation, and missing observations. The registry record does not report diagnostic checks or model assumptions. No claim about over-dispersion or a correction for it can be made from the record.
Finally, statistical significance and practical importance are different concepts. A p-value, if reported, would describe how compatible the observed data are with a specified null model; it would not by itself describe the size or clinical relevance of a contrast. An effect estimate and its uncertainty are needed to assess the magnitude and precision of a difference. Neither is reported for the primary outcome in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome is assessed at 6, 12, 18, and 24 months, and the registry record lists 11 outcome measures. Multiple outcomes and time-points can create multiplicity: when many comparisons are examined, the chance of at least one apparently notable result can increase. General approaches include prespecifying a primary contrast, adjusting inference for a family of comparisons, or distinguishing confirmatory from exploratory analyses. The statistical plan, any multiplicity adjustment, and the intended hierarchy of outcomes are not reported in the registry record.
The registry record names body weight, systolic blood pressure, diastolic blood pressure, fasting glucose, total cholesterol, HDL, LDL, and triglycerides as secondary outcomes. It does not report numerical results or analyses for these measures. The listed outcomes should not be interpreted as evidence that a difference was detected. The record also does not reduce the multi-time-point primary outcome to one comparison.
Missing-data handling is important because the primary-outcome description refers to the number analyzed at each time-point, and the record states that some participants had 18- and 24-month data collected based on when they were randomized. The actual assessment counts are not reported in the registry record. The reasons for missing measurements, the method used to handle missingness, and any sensitivity analyses are not reported in the registry record. Without those details, the effect of incomplete follow-up on the estimates cannot be assessed.
The analysis population is also not defined. The registry record does not state whether results were based on all randomized participants, participants with available measurements, or another population. It does not report an intention-to-treat analysis or a per-protocol analysis. Those omissions prevent assessment of how participants were included in any statistical comparison.
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 |
|---|---|---|---|
| Lifestyle Weight-Loss | 4 | 150 | 2.7% |
| Enhanced Usual Care | 1 | 75 | 1.3% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Lifestyle Weight-Loss | 2 of 150 |
| Enhanced Usual Care | 0 of 75 |
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 |
|---|---|
| Lifestyle Weight-Loss | 13 of 150 |
| Enhanced Usual Care | 10 of 75 |
Most frequent serious adverse event terms
| Event term | Organ system | Lifestyle Weight-Loss | Enhanced Usual Care |
|---|---|---|---|
| Inpatient hospitalization for surgery | Surgical and medical procedures | 2 of 150 | 1 of 75 |
| death from non-study related causes (colon cancer) | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1 of 150 | 0 of 75 |
| death from non-study related causes (aneurysm) | Vascular disorders | 1 of 150 | 0 of 75 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Lifestyle Weight-Loss | Enhanced Usual Care |
|---|---|---|---|
| Joint/Musculoskeletal Pain | Musculoskeletal and connective tissue disorders | 13 of 150 | 10 of 75 |
Serious events with the highest arm-level rate: inpatient hospitalization for surgery (1.3%), death from non-study related causes (colon cancer) (0.7%), death from non-study related causes (aneurysm) (0.7%).
The registry record reports serious adverse events for the two groups. In Lifestyle Weight-Loss, 150 were at risk for serious events and 4 were affected; in Enhanced Usual Care, 75 were at risk and 1 was affected. For other adverse events, 150 were at risk and 13 were affected in Lifestyle Weight-Loss, while 75 were at risk and 10 were affected in Enhanced Usual Care. The record lists 2 deaths in Lifestyle Weight-Loss and 0 in Enhanced Usual Care.
These are reported counts, not estimates of comparative risk. No statistical comparison, uncertainty interval, or attribution analysis is reported in the registry record. The counts should be read alongside their group-specific numbers at risk; they do not by themselves establish whether a difference between groups is meaningful or related to an intervention.
The listed serious-event terms include “Inpatient hospitalization for surgery” at 1.3%, “death from non-study related causes (colon cancer)” at 0.7%, and “death from non-study related causes (aneurysm)” at 0.7%. The registry record labels the two deaths as non-study related. The listed terms and percentages should be understood as the registry’s safety reporting, not as a complete description of every event or a causal finding. Further details about event timing, definitions, severity grading, and adjudication are not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The registry record supports a description of the study design, intervention groups, planned assessments, and selected safety counts. It does not provide the numerical primary-outcome findings or statistical analyses needed to estimate a difference in mean hemoglobin A1c. Consequently, it cannot establish from the posted results whether one group had a higher or lower mean at any assessment time, nor how precise a group contrast might be.
That absence of results should not be mistaken for a finding of no difference. A null or non-significant result would require reported estimates and an analysis; neither is present in the registry record. Likewise, a randomized design alone does not show that the intervention produced a particular outcome. The design describes how the comparison was intended to be conducted, while outcome data are needed to characterize what was observed.
Even if an estimated difference were available, interpretation would depend on its size, uncertainty, clinical context, and the analysis population. In general, statistical significance alone does not establish importance, and lack of statistical significance alone does not establish equivalence. No equivalence margin or non-inferiority objective is reported in the registry record.
The safety counts are also descriptive rather than conclusive. They report affected participants and deaths by group, but the registry record does not provide a comparative safety analysis or sufficient detail to assess attribution beyond the listed classification of deaths as non-study related. These figures should not be extended into claims about the overall safety of either program.
The most defensible reading is therefore limited: the registry documents a randomized parallel-group trial of a community lifestyle program versus enhanced usual care, with mean hemoglobin A1c as the primary outcome at multiple follow-up times. The numerical efficacy results and analysis details are not reported in the registry record. Conclusions about comparative effects, their precision, or their clinical importance cannot be drawn from the information recorded.
13. Why This Trial Matters Statistically
This trial is statistically notable for evaluating a community-delivered behavioral program against an active form of enhanced usual care, rather than against no contact. The comparator included individual dietitian counseling and monthly newsletters focused on community resources. That distinction matters when interpreting a randomized comparison: the estimated contrast, if reported, would represent the difference between these two program strategies, not the difference between receiving support and receiving none.
The primary outcome was scheduled across several follow-up times. In general, repeated assessments can reveal whether a group difference is stable, emerges, or changes over time. They also require clear decisions about the target comparison and methods for within-participant correlation. The registry record does not report the analysis strategy, so this aspect of the trial’s statistical interpretation remains unresolved.
The study also places outcome measurement in a community setting, with sessions at churches and other community locations and delivery by Latino Health Advisors. Those are relevant design features for understanding the intervention being evaluated. They do not, by themselves, establish that the program changed hemoglobin A1c or any secondary measure. Such claims require posted outcome estimates and appropriate uncertainty measures.
For researchers, the record illustrates why trial registration and results reporting serve different purposes. Registration identifies planned outcomes and design features; numerical results and analyses are needed to assess the observed evidence. Here the design and intended endpoints are described, but the registry record does not report the primary outcome analyses. The distinction between a clearly named endpoint and an interpretable estimate is central to sound statistical reading.
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.
A central limitation is that numerical results for the primary endpoint are not reported in the registry record. There are no group means, standard deviations, between-group estimates, confidence intervals, or p-values for hemoglobin A1c at the stated assessment times. The direction, magnitude, and precision of the primary comparison therefore cannot be assessed.
The record says retention at clinic assessment visits is presented as the number analyzed at each time-point, but the counts themselves are not reported in the registry record. It also says all participants had at least 12 months of follow-up and that 18- and 24-month data were collected for participants randomized early in recruitment. Without participant counts by visit, reasons for missing assessments, and a missing-data strategy, the completeness of follow-up cannot be evaluated.
The analysis plan is not reported in the registry record. The model for repeated measurements, the target contrast, any baseline adjustment, the analysis population, and multiplicity procedures are not described. The record lists zero analyses, so no statistical results can be checked or compared with a prespecified plan. Sample-size justification is also not reported in the registry record.
Intervention descriptions have limited detail about session content and delivery. The lifestyle program is described as group-based and community-delivered, and the enhanced usual-care description names dietitian sessions and newsletters, but full schedules and adherence information are not reported in the registry record. Masking is listed as single; who was masked and how masking was implemented are not reported. Safety reporting provides counts and selected terms, but event definitions, timing, and comparative analyses are not reported.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Latinos Combating Diabetes — NCT01831921.
- Registry record last updated 2019-08-28; status last verified 2019-08.
- Results first posted 2018-08-28.
- 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
Latinos Combating Diabetes (NCT01831921) is recorded as a completed, randomized, parallel-group, single-masked trial sponsored by Wake Forest University Health Sciences. Enrollment was 225. The record lists a start of 2014-01 and primary completion on 2017-06-30. The phase is listed as NA.
The trial compared a group-based Lifestyle Weight-Loss program delivered by Latino Health Advisors with Enhanced Usual Care that included individual dietitian counseling and community-resource newsletters. The primary outcome was mean hemoglobin A1c, measured in percent HbA1c at 6, 12, 18, and 24 months. Secondary outcomes include body weight, blood pressure, fasting glucose, and lipid measures.
Numerical primary-outcome results, analysis methods, and participant counts at each assessment are not reported in the registry record. Safety counts are reported by group, including serious events, other adverse events, and deaths, but no comparative safety analysis is reported. The registry record therefore describes the study design and intended measures more fully than the statistical evidence from the trial.