Preventing Diabetes in the Deep South: Extending Partnerships and Adapting Interventions to Reach Rural Communities at High Risk.: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Preventing Diabetes in the Deep South: Extending Partnerships and Adapting Interventions to Reach Rural Communities at High Risk. (NCT04343872), a randomized na study. The primary outcome is Change in Body Weight.

2. Clinical Question

3. Trial Design

The registry identifies this as a randomized, single-masked, factorial trial and lists the study status as completed. It records a planned enrollment of 36 and gives a start date of 2020-12-10 and a primary completion date of 2022-12-31. The sponsor is the University of Alabama at Birmingham. The study is described as a pilot conducted through a rural primary-care network, with the broader aim of assessing feasibility for a larger diabetes-prevention trial.

The intervention descriptions identify two groups. Both received a lifestyle modification program facilitated by Peer Coach services; one group also received a metformin recommendation. The registry’s factorial classification is not accompanied by an explanation of the factors or the allocation scheme, so the factorial structure cannot be reconstructed from the record. Details about the single masking are also not reported in the registry record, including who was masked and how masking was maintained.

The registry lists 36 enrolled participants, while the primary outcome summaries report 23 participants in the lifestyle-only group and 4 in the lifestyle-plus-metformin-recommendation group. These outcome counts do not by themselves explain participant flow or account for everyone enrolled. The adverse-event groups have different reported numbers at risk. Reasons for these differences, group assignment counts, withdrawals, and follow-up completeness are not reported in the registry record.

The intervention is described as behavioral in the registry, including the metformin therapy entry. The record’s wording distinguishes a metformin recommendation from documented receipt of medication. It does not report medication use, adherence, intervention attendance, or implementation details. These gaps matter when interpreting a pilot that is intended to inform future research: the record identifies the broad comparison, but does not give enough detail to assess how consistently the interventions were delivered or received.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Participants lost to follow-up

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.

6. Primary Endpoint

The registry lists the primary outcome as Change in Body Weight, measured over 12 months.

The primary endpoint is change in body weight from baseline to 12 months, measured in pounds. It is a continuous outcome, and the registry reports a mean and standard deviation for each group. A change score expresses how a participant’s weight at follow-up differs from their baseline weight; a negative mean indicates a decrease in weight on average among the participants represented in that group’s summary.

Weight is a direct, quantifiable measure that can be summarized across participants and compared between study groups. In a diabetes-prevention study, it can describe one aspect of response to a lifestyle program, but it is not itself a measure of diabetes incidence. The posted primary endpoint therefore addresses weight change, not whether participants developed diabetes or whether diabetes was prevented.

The outcome description specifies a 12-month timeframe. The record also labels the outcome population as participants lost to follow-up. That wording makes it difficult to determine whether the reported means represent all participants with available follow-up, a particular subset, or another analysis population. The interpretation should remain tied to the reported summaries rather than assume a specific missing-data approach.

The registry reports no confidence limits for the group means and no comparative estimate. Thus the means describe observed average changes, while the standard deviations describe variation among the reported participants. They do not, by themselves, quantify the uncertainty in the difference between groups.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the reported mean represent?

The primary outcome is continuous: change in body weight in pounds from baseline to 12 months. A mean summarizes the average recorded change among the observations included in a group’s summary. A negative value indicates that the average follow-up weight was lower than the average baseline weight for the participants represented by that change summary. It does not mean that every participant had a decrease, nor does it describe the distribution of individual responses.

The registry reports a mean of -3.6 pounds for lifestyle modification alone and a mean of -4.4 pounds for lifestyle modification with a metformin recommendation. These values are group summaries; they do not show the outcomes for individual participants. The meaning of a mean depends on which participants were included and how missing measurements were handled. The registry’s description of the outcome population as participants lost to follow-up does not clarify those details.

What does the standard deviation describe?

A standard deviation describes the spread of observed values around their mean. The reported standard deviations are 11.87 pounds and 3.21 pounds for the two groups, respectively. They show that the recorded changes were not all identical within each group. A standard deviation is not the uncertainty range for the group mean and is not a confidence interval for the treatment comparison.

General statistical explanation: a confidence interval expresses the range of estimates compatible with the data under a specified statistical method. Its width reflects both the amount of information and the variability in the observations, as well as assumptions of the method. No confidence interval is posted for the group means or for a comparison between groups, so the precision of a comparative effect cannot be assessed from the registry results.

Why is a direct comparison important?

When a trial is intended to compare groups, a formal analysis estimates the difference between their outcomes and quantifies uncertainty around that estimate. Separate group means do not provide that uncertainty on their own. They also do not account for any adjustment or modeling strategy that might have been specified. The registry lists zero analyses and does not report an inferential result for the primary endpoint. The statistical plan, including any adjustment factors or model specification, is not reported in the registry record.

General statistical explanation: random assignment can support a comparison by helping distribute measured and unmeasured characteristics across groups, but the resulting estimate still depends on following the design and analyzing participants appropriately. The record identifies the allocation as randomized; it does not describe the randomization sequence, concealment, or analysis strategy. Those details cannot be assumed.

How should the reported counts be read?

The registry lists 36 participants enrolled. The outcome summaries give 23 participants for lifestyle modification alone and 4 for lifestyle modification with a metformin recommendation. The adverse-event summaries give 29 and 7 participants at risk in their respective groups. These are different reported counts for different types of results. The record does not explain how they relate to enrollment, whether all participants were assigned to a group, or why the outcome counts differ from the adverse-event counts.

The primary outcome population is described as participants lost to follow-up. This is an unusual and potentially consequential description because it does not clearly identify whether the reported results use participants with observed 12-month measurements or some other group. The registry does not report a participant flow account, the number with missing weight measurements, reasons for missingness, or a method for handling missing data. No assumption about complete-case analysis, imputation, or another approach is warranted.

What can the planning illustrations tell readers?

The record describes sample-size planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Such illustrations are hypothetical planning calculations, not evidence about the probability that this completed pilot detected an effect. They are not observed power. The record does not report the trial’s own sample-size justification or design assumptions, so the planning illustrations should not be interpreted as the original protocol’s planned sample size.

General statistical explanation: planning calculations depend on assumptions about the effect worth detecting, variability, significance threshold, allocation, and analysis. If an effect estimate comes from a small pilot, it may be unstable; planning for a fraction of an observed effect can illustrate how a future study’s size changes under different assumptions. Such calculations do not establish that the assumed effect is real or clinically important. No numerical planning results are stated in the registry record.

Why might over-dispersion matter?

General statistical explanation: over-dispersion occurs when observed variability is greater than a statistical model expects. For a continuous outcome, a model that understates variability can produce uncertainty estimates that are too narrow. The posted standard deviations describe spread, but the registry does not report a model or an over-dispersion assessment. There is no basis to claim that over-dispersion was present or addressed in this trial.

Overall, the registry permits a descriptive reading of the observed group means and standard deviations. It does not provide the inferential analysis, confidence intervals, full analysis population, missing-data method, or protocol-level statistical plan needed for a detailed assessment of comparative effect and precision.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Receive Lifestyle Modification Alone (DPP)", "Receive Lifestyle Modification With Metformin Ther")
n   <- c(23, 4)
m   <- c(-3.6, -4.4)
sp  <- c(11.87, 3.21)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Receive Lifestyle Modification Alone (DPP)  23  -3.600  11.870  -8.733  1.533
CARM  Receive Lifestyle Modification With Metformin Ther  4  -4.400  3.210  -9.508  0.708

11. Multiplicity, Missing Data and Analysis Populations

The registry records two outcome measures and zero secondary outcomes posted. It does not identify the full set of outcomes in a protocol or statistical analysis plan, nor does it report whether multiple time points, treatment contrasts, or analyses were planned. The approach to multiplicity is therefore not reported in the registry record. Without that information, it is not possible to assess whether any formal adjustment for multiple comparisons was planned or needed.

For the primary outcome, the registry states that the measure is change in body weight from baseline to 12 months, but describes the population as participants lost to follow-up. That wording does not make clear which participants were analyzed. The outcome summaries include 23 participants in the lifestyle-only group and 4 in the lifestyle-plus-metformin-recommendation group. The record does not explain whether these are all assigned participants with available measurements or a different population.

Missing-data information is not reported in the registry record. The record does not give the number of participants missing the 12-month weight measure, reasons for missingness, or the method used to handle missing outcomes. It also does not state whether participants were analyzed according to their randomized assignment, received intervention, or another population definition. These details are important because results can depend on who is included and how absent measurements are treated.

The group summaries should therefore be interpreted as posted descriptive results, with the analysis population uncertain. No assumptions about intention-to-treat analysis, per-protocol analysis, imputation, or complete-case analysis can be made from the registry record.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The adverse-event results report zero serious adverse events among 29 participants at risk in the lifestyle modification alone group and zero among 7 participants at risk in the group receiving lifestyle modification with a metformin recommendation. Deaths are also reported as zero in both groups. The record likewise reports zero other adverse events in each group, using the same group-specific numbers at risk.

These figures describe the events recorded in the registry for the participants counted as at risk. A zero count means no events of that category were reported in those groups; it does not establish that the true risk is zero. In particular, the group receiving the metformin recommendation has a reported count of 7 at risk, so the absence of a recorded event in that group cannot precisely characterize uncommon harms.

The registry does not report the adverse-event collection period, event definitions, severity grading approach, or how events were solicited and assessed. It also does not give a list of serious adverse-event terms, consistent with the reported zero counts. The safety summaries should be read as a limited record of reported events, not as proof that no adverse events could occur or as a complete safety assessment.

13. What the Result Does, and Does Not, Mean

The posted results establish that the registry records mean 12-month body-weight changes of -3.6 pounds for the lifestyle modification alone group and -4.4 pounds for the lifestyle modification with a metformin recommendation group. The corresponding standard deviations are 11.87 pounds and 3.21 pounds. These summaries describe the recorded participants; they do not show individual trajectories or the uncertainty around a comparative effect.

The values do not establish that adding a metformin recommendation caused a greater weight change. The registry does not post a formal comparison, confidence interval, or p-value for the endpoint. The outcome group counts are 23 and 4, and the record does not explain why they differ from one another or from the 36 participants enrolled. It also describes the outcome population as participants lost to follow-up, leaving uncertainty about who contributes to the results.

The study is described as a pilot for assessing feasibility in preparation for a larger diabetes-prevention study. Its primary outcome is body-weight change, not diabetes incidence. The registry record therefore does not establish whether diabetes was prevented, and the posted weight summaries should not be treated as a substitute for that outcome.

The results also do not establish the intervention’s acceptability, adherence, or feasibility, because those measures and their findings are not reported in the registry record. Nor do zero reported adverse events establish the absence of risk; the safety counts are limited by the reported numbers at risk and the lack of detail about monitoring and event definitions.

The appropriately narrow conclusion is descriptive: the registry records average weight decreases in both groups among the participants represented in the outcome summaries, with substantial uncertainty about comparative precision and the analyzed population. Any stronger claim would require analysis and design details that are not reported in the registry record.

14. Why This Trial Matters Statistically

This trial is statistically informative as an example of why a pilot’s descriptive results should be separated from evidence of a comparative effect. The registry identifies a randomized design and a clinically relevant continuous measure, but posts only group means and standard deviations for the primary endpoint. Without a between-group estimate and its uncertainty, readers cannot tell how precisely the data distinguish the two intervention strategies.

The reported outcome counts also illustrate the importance of transparent participant accounting. The registry lists 36 enrolled participants, while the primary outcome summaries include 23 participants in one group and 4 in the other. The adverse-event summaries use 29 and 7 participants at risk. The record does not explain these counts or clearly define the primary outcome population. An explicit account of assignment, follow-up, missing measurements, and analysis inclusion would make the summaries easier to interpret.

The study’s stated role as a pilot also matters. Pilot findings can help characterize implementation and inform future research, but a small outcome dataset may provide imprecise estimates. The registry’s planning illustrations are not observed power and are not the trial’s own design justification. Keeping planning calculations distinct from observed results helps avoid treating an illustrative sample-size scenario as evidence that the pilot was adequately powered to detect a particular effect.

Finally, the registry’s factorial classification is not accompanied by details of the factors or statistical model. Reporting that structure, alongside the analysis plan and missing-data methods, would help readers understand the intended comparisons. The record supports a cautious descriptive reading, while highlighting the value of complete reporting for future trials in rural communities.

15. 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.

Several limitations specific to this record constrain interpretation. Although the trial is classified as randomized and factorial, the registry does not describe the factorial factors, allocation procedure, sequence generation, or concealment. It describes two intervention groups but does not explain how that structure corresponds to the factorial classification. The single-masking designation is not accompanied by details about who was masked or how.

The primary outcome population is worded as participants lost to follow-up, which does not clearly define the analyzed population. The registry lists 36 participants enrolled but reports outcome summaries for 23 participants in one group and 4 in the other. It gives different at-risk counts for adverse events. Participant flow, group assignment counts, reasons for missingness, and the handling of missing outcomes are not reported in the registry record.

No formal primary-outcome comparison, confidence interval, or p-value is posted, and the registry lists zero analyses. The statistical analysis plan and the trial’s own sample-size justification are not reported. Consequently, the precision and inferential basis of a group comparison cannot be evaluated from the posted summaries.

The intervention record describes a metformin recommendation but gives no information about whether participants started medication, adherence, or delivery of the lifestyle program. The registry does not report diabetes incidence as an outcome in the results. Safety reporting also lacks event definitions and a stated observation period. These limitations mean that the available record supports a narrow description of weight-change summaries, not a full assessment of intervention delivery, feasibility, comparative effects, or safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Preventing Diabetes in the Deep South: Extending Partnerships and Adapting Interventions to Reach Rural Communities at High Risk. — NCT04343872.
• Registry record last updated 2024-03-05; status last verified 2024-02.
• Results first posted 2024-03-05.
• 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.

19. Record Summary

NCT04343872 is a completed randomized, single-masked trial classified as factorial, sponsored by the University of Alabama at Birmingham. The registry records 36 participants enrolled and describes a pilot intended to assess feasibility for a larger diabetes-prevention study in rural communities. The two described groups received Peer Coach-facilitated lifestyle modification, with a metformin recommendation added in one group.

The primary outcome is change in body weight from baseline to 12 months. The posted means are -3.6 pounds for lifestyle modification alone and -4.4 pounds for lifestyle modification with a metformin recommendation. The outcome counts are 23 and 4, respectively. No formal comparative analysis or confidence interval is posted. The outcome population is described as participants lost to follow-up, and the record does not clarify the analysis population or missing-data handling.

Zero serious adverse events, other adverse events, and deaths are reported in both groups. The registry does not provide enough detail to interpret these counts as a complete safety assessment. Overall, the record supports a descriptive account of the posted weight summaries but leaves key design, analysis, and participant-flow questions unresolved.