Veteran Peer Coaches Optimizing and Advancing Cardiac Health: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Veteran Peer Coaches Optimizing and Advancing Cardiac Health (NCT02697422), a randomized na study. The primary outcome is Change in Systolic Blood Pressure (SBP).

2. Clinical Question

The trial asked whether a community-based peer health coach intervention could improve systolic blood pressure among Veterans with high blood pressure and at least one other cardiovascular disease risk factor. The intervention was intended to support health behavior changes associated with cardiovascular risk, including healthy diet, regular to moderate-intensity physical activity, and smoking cessation. Coaches were to deliver brief health messages and discuss goal setting and action planning.

The primary outcome was change in systolic blood pressure, measured in mm Hg. The registry describes readings taken using standard procedures and a blood pressure monitor, with the mean of 3 measurements used for each mean systolic blood pressure score. It defines a greater reduction as a better outcome. The record also set out secondary outcomes covering cardiovascular risk, tobacco use, health-related quality of life, and health service use. The results available in the registry record do not provide a complete numerical account of every listed secondary outcome.

3. Trial Design

This was a randomized, parallel-group trial with no masking. The registry records 264 participants enrolled: 134 in the peer health coach intervention group and 130 in the control group. The trial is marked completed. Its recorded start date is 2017-05-30, and its primary completion date is 2022-01-06. The phase is listed as NA.

Participants assigned to the intervention group were to receive a home-visit peer health coach intervention. The control group received no study intervention and continued usual primary care. The study description says the intervention would address health behaviors such as diet, physical activity, and smoking cessation through brief messages, goal setting, and action planning. It also names assessment of intervention facilitators, barriers, and costs as study purposes; results for those topics are not reported in the registry record.

The primary outcome was change in systolic blood pressure from baseline to follow-up at one year. Blood pressure readings were collected using a monitor and standard procedures, and the mean of 3 readings formed the mean systolic blood pressure score. Other listed outcomes include the Framingham Cardiovascular Risk Score, body mass index, current tobacco use, low-density lipoprotein cholesterol, mental and physical health-related quality-of-life scores, hospitalizations, and emergency room visits.

The registry record describes the allocation as randomized, but details of sequence generation, allocation concealment, recruitment settings, participant characteristics, and adherence to the intervention are not reported in the registry record. Masking is recorded as none. Details about the duration or number of coaching visits are not reported in the registry record, so the intervention’s actual intensity cannot be characterized from the listed design information.

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:

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 Systolic Blood Pressure (SBP), measured over Baseline to follow-up at 1 year.

The primary endpoint is change in systolic blood pressure from baseline to follow-up at one year, expressed in mm Hg. Systolic blood pressure is the upper blood pressure reading. In this trial, the registry describes a mean score based on 3 readings taken with a blood pressure monitor using standard procedures. The change score captures how the measured value shifted between baseline and the one-year assessment.

The registry’s direction for interpreting the endpoint is that an increased reduction indicates a better outcome. The intervention group’s posted mean change was -3.32 mm Hg, with a 95% confidence interval from -6.88 to 0.23. The control group’s posted mean change was -0.4 mm Hg, with a 95% confidence interval from -4.2 to 3.39. These are separate arm-level estimates, not an estimate of the difference between groups. The sponsor’s recorded regression analysis reports p = 0.05 for the group comparison, but the estimated between-group contrast and its confidence interval are not reported in the registry record.

General: Repeated measurements can reduce the influence of short-term variation in a clinical measurement. A confidence interval describes uncertainty around an estimated quantity under the assumptions of the analysis; it does not show the range of individual participants’ readings. The arm-level intervals should not be mistaken for a confidence interval for the treatment contrast.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: systolic blood pressure change is measured on a numeric scale in mm Hg. The registry reports mean change and 95% confidence intervals for each randomized group. It also records a linear regression analysis for the comparison between groups, but does not report the regression coefficient, its confidence interval, or the model’s adjustment variables. Thus, the arm-specific means describe changes within each group, while the regression analysis is the recorded method for assessing the group comparison.

What does a mean change represent?

A mean change is the average difference between a participant’s follow-up and baseline measurements, summarized over a group. The sign indicates direction according to the scale and the subtraction convention. Here the registry explicitly states that an increased reduction in mean systolic blood pressure indicates a better outcome. A group mean does not show the distribution of individual changes: participants may have values above and below the average. The record does not report the standard deviation for the primary outcome.

How should the confidence intervals be read?

General: A confidence interval expresses the statistical uncertainty associated with an estimate under a specified method and its assumptions. It is not a range containing a fixed proportion of individual observations, and it is not a guarantee that the true quantity lies inside the interval. The primary outcome’s intervals are reported separately by arm. Because the target question is the difference between randomized groups, the interval for that contrast would be the most direct description of the comparison’s precision. That interval is not reported in the registry record.

What does the reported p-value tell us?

The sponsor’s primary analysis is listed as linear regression, with p = 0.05. General: A p-value measures how incompatible data are with a specified null model, conditional on the model and its assumptions. It does not measure effect size, clinical importance, or the probability that a hypothesis is true. The registry does not provide enough detail to identify the exact null formulation, regression specification, or any covariate adjustment. The p-value is also rounded in the record, so it should not be interpreted as more precise than reported.

What are the recalculated comparisons?

For selected secondary outcomes, the unadjusted recalculations compare the posted group summaries without the sponsor’s regression model. For binary current tobacco use, the recalculation uses group counts to obtain an unadjusted risk difference and related measures. For the continuous hospitalization and emergency room outcomes, it uses group means and standard deviations to form unadjusted mean comparisons. These recalculations are descriptive checks from summary statistics; they do not reproduce an adjusted model or account for participant-level information unavailable in the summaries.

General: Regression can account for covariates or outcome structure specified in a model, whereas a simple comparison of summaries does not. The methods may therefore yield different estimates or p-values. The registry does not report enough detail to determine why the sponsor’s reported p-values differ from the unadjusted recalculations for some outcomes. The discrepancy indicator is false, but that does not supply omitted model details or make the methods equivalent.

Why does over-dispersion matter for counts?

General: Count outcomes such as hospitalizations and emergency visits can be skewed, with many participants having few events and a smaller number having more. A mean and standard deviation summarize the outcome, but may not capture all features of its distribution. Over-dispersion occurs when count variability exceeds what a simple count model assumes; if not addressed where relevant, standard errors and uncertainty estimates can be poorly calibrated. The registry identifies linear regression for the sponsor’s count-outcome analyses and does not report diagnostics or an alternative count model. It is therefore not possible to assess from the record how the outcome distribution or over-dispersion was handled.

What do the planning illustrations mean?

The planning illustrations for selected secondary outcomes use the observed effect as a starting point and show participant counts per arm for hypothetical detectable effects at different fractions of that observed effect. Their stated assumptions are a two-sided significance level of 0.05, equal allocation, and a normal approximation. They are not the trial’s original sample-size justification, and the registry does not report the trial’s sample-size assumptions or justification. These illustrations are planning scenarios, not observed power and not evidence that the trial had a particular probability of detecting an effect. The assumptions and the hypothetical effect size affect the resulting sample-size estimates.

For the primary endpoint, the registry record does not report a comparable planning illustration in the listed results. It also does not report an interim-analysis plan, a detailed analysis plan, missing-data methods, or the population used for the primary analysis. Those omissions limit the ability to evaluate how the recorded regression result was specified and whether all randomized participants were included in it.

10. Analyses Reported by the Sponsor

For the primary endpoint, the sponsor’s recorded analysis is linear regression and reports p = 0.05. The registry gives no estimated between-group regression contrast or confidence interval, and it does not provide the model specification. The arm-level mean changes and confidence intervals therefore cannot be used to reconstruct the sponsor’s primary estimate from the registry record.

For selected secondary outcomes, recalculations from posted summary statistics are unadjusted. The sponsor’s recorded methods differ: logistic regression for current tobacco use and linear regression for hospitalizations and emergency room visits. Their reported p-values are p = 0.90 for tobacco use and p = 0.05 for each of the two visit outcomes. The unadjusted recalculations produce p = 0.169, p = 0.626, and p = 1.0, respectively.

These differences do not by themselves establish an error. A regression analysis may use a different model or information than a simple summary-statistic comparison. Since model details and sponsor estimates are not reported, the reason for each difference cannot be determined from the registry record. The discrepancy indicator is false. The sponsor’s own analysis is not replaced by a recalculation; the recalculation is a separate, unadjusted check and should be interpreted as such.

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists multiple secondary outcomes and records 9 posted secondary outcomes and 10 analyses. The listed outcome areas include cardiovascular risk, body mass index, tobacco use, low-density lipoprotein cholesterol, mental and physical health-related quality of life, hospitalizations, and emergency room visits. The statistical plan for handling multiple outcomes or comparisons is not reported in the registry record. It is not reported whether outcomes were ordered in a testing hierarchy or whether any multiplicity adjustment was used.

That omission matters because testing several outcomes can increase the chance of at least one result appearing notable under a null hypothesis. General: Multiplicity procedures control or describe that increased error risk, but their relevance depends on the planned questions and analysis strategy. Without the trial’s prespecified plan, the secondary p-values should be treated as exploratory rather than as a set of independent confirmations. The record does not state whether secondary analyses were prespecified in detail.

Missing-data methods are not reported in the registry record. The posted group sizes are 134 and 130, but the record does not explain whether all randomized participants contributed data at follow-up, how missing one-year measurements were handled, or whether any imputation or sensitivity analyses were performed. The analysis population for the primary outcome is not reported; the record does not specify whether analyses followed an intention-to-treat, per-protocol, or other population definition.

The registry record also does not report a detailed statistical analysis plan, a sample-size justification for the trial, or an interim-analysis plan. These details are relevant to understanding how the primary and secondary analyses were selected, whether any decisions were made after viewing accumulating results, and how the reported p-values relate to prespecified hypotheses. Their absence does not demonstrate that a particular method was or was not used; it means the record does not allow those features to be assessed.

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 registry reports 0 serious adverse events in the peer health coach intervention group, among 134 participants at risk, and 0 in the control group, among 130 participants at risk. It also reports 0 other adverse events in each group. Deaths are recorded for 2 participants in the intervention group and 1 in the control group. No serious adverse event terms are listed.

These entries are counts in the registry record. They do not describe causes, timing, severity beyond the serious-event classification, or whether deaths were considered related to the intervention. Such details are not reported in the registry record. The record also does not provide event narratives or additional context for interpreting the death counts.

General: Zero reported events does not establish that an intervention has no risk. Event counts are interpreted in the context of how events were defined, collected, monitored, and attributed, as well as the size and follow-up of the study. Because the registry record does not provide those details, the figures should be read as the recorded counts rather than as a complete safety assessment.

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

The posted primary outcome describes average change in systolic blood pressure within each randomized group over baseline to one-year follow-up. The intervention group’s mean change was -3.32 mm Hg and the control group’s was -0.4 mm Hg. The sponsor reports p = 0.05 for a linear regression comparison. Together, these registry entries describe the available primary result, but the registry record does not give the regression contrast or its confidence interval. The size and precision of the between-group difference therefore cannot be directly read from the record.

The arm-level confidence intervals extend across zero, which indicates uncertainty around each group’s mean change. They are not intervals for the difference between groups. A p-value of 0.05 is not a measure of the probability that the intervention caused a change, and it does not establish how important a difference would be. The registry does not report a threshold for interpreting clinical importance.

The trial was randomized, which is a design intended to support comparisons between groups. However, details about allocation procedures, analysis populations, missing data, adherence, and the regression model are not reported in the registry record. Those omissions make it harder to evaluate the robustness of the reported comparison. The result should be described as a reported trial analysis, not as a complete account of all methodological choices.

The secondary outcomes cover other cardiovascular risk measures, quality of life, and health-service use. The available numerical recalculations for selected secondary measures are unadjusted and are not interchangeable with the sponsor’s regression analyses. The record does not report the multiplicity strategy, so isolated secondary p-values warrant caution.

In general, a trial result is one piece of evidence tied to its population, measurements, follow-up, and analysis. This record does not establish how the intervention would perform in other populations or settings. It also does not report enough detail to determine the costs, barriers, facilitators, or delivered intervention intensity, despite naming those as study aims. No treatment recommendation follows from these registry results alone.

14. Why This Trial Matters Statistically

This trial is statistically useful as an example of why the arm-level outcome summaries, the randomized-group comparison, and the sponsor’s reported analysis should be kept distinct. The posted means describe change within each arm. The primary question concerns a comparison between arms, for which the sponsor reports a regression p-value but not the estimated contrast or its confidence interval. Without those quantities, readers cannot directly evaluate the magnitude and precision of the primary group difference.

The record also illustrates how an unadjusted calculation based on summary statistics can differ from a regression analysis. The recalculations use posted group-level numbers, while the sponsor’s analyses are identified as linear or logistic regression. Model details are absent, so the differences cannot be attributed to a specific adjustment or modeling decision. The two kinds of results should be read as distinct analyses, not as competing versions of an identical calculation.

Another statistical issue is the set of secondary outcomes. Several domains were included, but the registry does not report the multiplicity approach or a complete set of model estimates. This affects how confidently isolated secondary findings can be treated as confirmatory. Similarly, the missing-data and analysis-population details leave uncertainty about who contributed to the reported results.

The trial’s sample-size planning illustrations for selected secondary outcomes are based on observed effects and explicit hypothetical assumptions. They are useful as planning scenarios, but are not the trial’s original design justification and do not represent observed power. Keeping those purposes separate prevents retrospective planning calculations from being misread as evidence about the trial’s ability to detect its primary effect.

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 trial-specific reporting limitations constrain interpretation. The primary group contrast, its confidence interval, and the linear regression specification are not reported in the registry record. The primary arm-level means and intervals do not supply those missing quantities. The registry also does not report primary-outcome standard deviations or details about how the one-year analysis population was defined.

The record identifies randomization but does not describe sequence generation or allocation concealment. Masking is recorded as none. Participant characteristics beyond the broad target description, recruitment setting, intervention adherence, and completeness of follow-up are not reported in the registry record. Details about the number, duration, and delivery fidelity of peer-coach visits are also not reported, limiting assessment of what intervention participants actually received.

Missing-data handling, the sample-size justification, interim analyses, and a detailed statistical analysis plan are not reported. The multiplicity approach for the range of secondary outcomes is likewise not reported. These omissions prevent assessment of whether the analyses followed prespecified methods and how missing observations or multiple comparisons were addressed.

The sponsor’s model-based p-values are presented without effect estimates or confidence intervals for the comparisons. For selected secondary outcomes, the available recalculations are unadjusted and use summary statistics; they cannot recover participant-level analyses or identify why results differ from regression outputs. The record identifies study aims around intervention costs, facilitators, and barriers, but does not report those findings in the information summarized. These limitations are specific to the detail available in the registry record and should not be taken as proof that omitted procedures or analyses were not performed.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Veteran Peer Coaches Optimizing and Advancing Cardiac Health — NCT02697422.
• Registry record last updated 2024-08-09; status last verified 2024-06.
• Results first posted 2024-08-09.
• 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

NCT02697422, “Veteran Peer Coaches Optimizing and Advancing Cardiac Health,” is recorded as a completed randomized, unmasked, parallel-group trial sponsored by the VA Office of Research and Development. It enrolled 264 participants: 134 assigned to home-visit peer health coaching and 130 assigned to no study intervention with usual primary care.

The primary outcome was change in systolic blood pressure from baseline to one-year follow-up. Posted mean changes were -3.32 mm Hg in the intervention group and -0.4 mm Hg in control. The sponsor’s linear regression comparison reports p = 0.05, but its estimated contrast and confidence interval are not reported in the registry record.

Secondary outcomes address cardiovascular risk, tobacco use, quality of life, and health-service use. The record does not report the multiplicity strategy, missing-data methods, or analysis populations. Selected recalculations from summary statistics are unadjusted and should be distinguished from the sponsor’s regression analyses.