Nashville - Hypertension Management Model: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Nashville - Hypertension Management Model (NCT04232124), a na na study. The primary outcome is Change in Systolic and Diastolic Blood Pressure.

2. Clinical Question

The study was intended as a smaller-scale implementation of a model previously used in Los Angeles. Its stated purpose was to assess feasibility and the success of implementing a collaborative care partnership in another geographic setting, while recruiting regular patrons with uncontrolled hypertension and evaluating a hypertension intervention. The registry identifies blood pressure change as the primary outcome, but does not report the numerical change or a statistical analysis of it.

The clinical question is therefore descriptive and implementation-focused, not a comparison of the model against a control intervention. A change between baseline and follow-up can describe what happened in the participating group, but without a concurrent comparator it cannot isolate the intervention’s effect from other explanations for change over time. The registry record also does not report participant-level characteristics or follow-up completeness, so the extent to which the observed group would represent a broader population cannot be assessed from this record.

3. Trial Design

The study, titled “Nashville - Hypertension Management Model,” is registered as NCT04232124. Vanderbilt University Medical Center is listed as the sponsor. The registry lists the study as completed, with a start date of 2020-02-15 and a primary completion date of 2021-07-15. Enrollment is listed as 30.

This was a single-group behavioral intervention study. The intervention is named the Hypertension Management Model, and the registry describes the project as implementing a smaller-scale version of the Los Angeles Barber–Pharmacist Model in Nashville. The stated implementation aims included recruiting regular patrons with uncontrolled hypertension, conducting a research protocol and evaluating a hypertension intervention, and creating a local registry of potential subjects. Further details of the intervention procedures are not reported in the registry record.

Allocation is listed as NA, masking as none, and phase as NA. With one group and no randomized comparison, the design is not a controlled trial of the intervention against a separate alternative. The primary outcome is change in systolic and diastolic blood pressure from baseline to 6 months. The registry defines the change as the baseline value minus the 6-month value. This direction matters when interpreting a reported estimate: it is a baseline-minus-follow-up quantity, rather than follow-up minus baseline.

The registry identifies one outcome measure and no analyses. It does not report the recruitment flow, the number of participants with measured blood pressure at follow-up, or whether every enrolled participant contributed to the endpoint analysis. A completed study status does not by itself establish complete follow-up or clarify which participants were included in an analysis. The analysis population and handling of incomplete measurements are not reported in the registry record.

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: Change in BP from baseline to 6 months

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.

Population: Adults 35 - 79 years old, non-Hispanic black males, patron of one of the participating barbershops with Systolic BP \> 140 on 2 screening visits.

6. Primary Endpoint

The registry lists the primary outcome as Change in Systolic and Diastolic Blood Pressure, measured over Baseline to 6 months.

The primary endpoint is change in systolic and diastolic blood pressure from baseline to 6 months, measured in mmHg. The registry describes the endpoint as a mean of a continuous measure with standard deviation as the dispersion measure. It defines change as baseline minus the value at 6 months. Thus, an estimate would describe the average within-participant change over the specified interval, with its direction determined by that subtraction order.

Systolic and diastolic pressure capture different components of a blood pressure reading. Considering both can give a more complete description of how blood pressure measurements changed in the group. The registry names both components in one primary outcome title, but does not report whether they were analyzed as separate endpoints, how any multiplicity was handled, or the statistical procedure used.

Change from baseline is commonly used to describe the amount of movement in a continuous measure over follow-up. In general, reporting the mean alongside a standard deviation helps distinguish the average change from the variability among participants. The registry record does not include the mean change, its standard deviation, a confidence interval, or a test result. It therefore does not permit a numerical assessment of the magnitude or precision of the endpoint change.

The endpoint is an outcome measure, not by itself evidence that the intervention caused any observed change. In a single-group study, change over time can also reflect factors unrelated to the intervention. Without a reported result and a control group, neither the size of any change nor its causal interpretation can be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the endpoint as a continuous measure summarized by a mean and standard deviation. A mean describes the average value across observations. A standard deviation describes how dispersed individual observations are around that average. General statistical interpretation: an average alone does not show how similar or varied participants’ measurements were, while a standard deviation does not describe the uncertainty in the estimated average in the same way as a confidence interval.

What does baseline-minus-follow-up mean?

The registry defines blood pressure change as the baseline value minus the 6-month value. This specifies the direction of the subtraction. General explanation: subtraction order determines the sign of a change score, so the estimate should be interpreted using the stated convention rather than assuming that change means follow-up minus baseline. The registry does not report the resulting mean changes or their standard deviations.

What would a confidence interval add?

General explanation: a confidence interval gives a range of values compatible with the data and the statistical method used, and conveys uncertainty around an estimate. It is not a guarantee that the true value lies in the particular interval. For this study, a confidence interval for the mean change would help show how precisely the average change was estimated. No confidence interval is reported in the registry record, so precision cannot be evaluated from the posted outcome information.

What can a single-group design estimate?

A single-group study can describe measurements in its participants and changes between time points. General explanation: a before-and-after comparison does not, on its own, distinguish an intervention-related change from other changes occurring over time. A separate, comparable control group can help address that question, but this study is listed as single-group, with allocation NA and masking none. The record does not describe a randomized or concurrent control comparison. Accordingly, any reported within-group change would not be a randomized treatment contrast.

How should the planning illustration be understood?

The registry’s sample-size assumptions describe a planning illustration based on the observed effect, not the trial’s own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. The record says time-to-event displays use total events, while other displays use participants per arm. These are planning assumptions, not evidence that the study randomized participants or enrolled two arms. The numerical illustration results are not reported in the registry record.

General explanation: a sample-size calculation asks how many observations a hypothetical design would need to detect an effect under specified assumptions. It does not describe what the study actually observed, and it is not observed power. A planning calculation based on an observed effect also depends on that effect estimate, which may be uncertain. Because the numerical sample-size outputs and endpoint estimate are not reported in the registry record, their implications cannot be assessed.

Why does variability matter?

General explanation: greater variability in a continuous outcome makes it harder to estimate a group average precisely when the sample size is unchanged. The standard deviation is one way to describe this variability. The registry names standard deviation as the dispersion measure but does not report its value for the primary endpoint. Over-dispersion is relevant when observed variability is greater than a statistical model assumes; in general, that can make model-based uncertainty estimates too small if the model does not account for the extra variability. The registry record does not report a model or an over-dispersion assessment, so there is no basis to say whether this issue arose.

What is not specified about the analysis?

The registry lists no analyses. It does not describe the statistical test or model, covariate adjustment, confidence-interval method, or handling of repeated measurements. It also does not report whether systolic and diastolic pressure were tested separately or how their joint presence in the primary outcome title was addressed. These details are necessary to reproduce or fully assess an analysis and are not reported in the registry record.

The registry lists one outcome measure, but that listing alone does not establish how many statistical tests were performed or whether any adjustment for multiple testing was planned. General explanation: when multiple outcomes or tests are considered, the chance of at least one apparently unusual result can increase, depending on the testing strategy. Multiplicity procedures can address that issue, but none is described in the record. With no posted outcome estimates or analysis details, statistical significance and estimation precision cannot be assessed.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure, titled “Change in Systolic and Diastolic Blood Pressure,” and lists no analyses. The title includes two blood pressure components, but the record does not explain whether systolic and diastolic change were treated as separate statistical tests, combined in a single analysis, or handled by another strategy. A multiplicity plan or adjustment is not reported in the registry record. It is therefore not possible to determine how the testing of the two components was addressed.

The number of outcomes listed does not establish the number of analyses actually conducted. The record does not describe the analysis plan, any secondary analyses, or whether analyses were selected after examining the data. These details are not reported in the registry record, so the risk of selective emphasis cannot be evaluated.

Missing-data information is also not reported. Although enrollment is listed as 30, the registry does not state how many participants had a baseline measurement, how many had a 6-month measurement, or how many were included in the primary endpoint analysis. It does not describe whether incomplete measurements were excluded, imputed, or handled with a model that used available observations. No reasons for missing follow-up or sensitivity analyses are reported.

The analysis population is not reported in the registry record. The record therefore does not clarify whether the endpoint was analyzed among all enrolled participants, only those who completed follow-up, or another defined group. These omissions prevent assessment of whether missingness could have affected the estimated change and limit reproducibility of any analysis.

11. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: seizure (3.3%), transient ischemic attack (3.3%), hyperglycemia (3.3%).

The registry lists safety information for male participants who received the Hypertension Management Model. The group has 30 participants at risk for serious adverse events and 3 reported as affected; for other adverse events, 30 are listed at risk and 6 as affected. The death count is 0. The registry lists Seizure, Transient Ischemic Attack, and hyperglycemia among the serious adverse-event terms, each with a reported value of 3.3%.

These figures should be read as descriptive safety reporting for the study group. The record does not provide event timing, duration, severity details beyond the serious-event classification, or a narrative about relatedness to the intervention. It also does not report a comparison group. Consequently, the counts cannot establish whether an event was caused by the model or indicate how event occurrence compares with another group.

The top-term percentages are registry-reported values and do not substitute for participant-level information or an event-level account. The record does not clarify whether affected-participant counts correspond one-to-one with event counts. General explanation: adverse-event counts and the number of participants experiencing an event can differ when a participant has multiple events. The available figures should not be used to infer details that the registry does not report.

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

The study addresses an implementation question: whether a smaller-scale version of a collaborative barbershop–pharmacist hypertension management approach could be carried out in Nashville. Its stated aims include recruitment of regular patrons with uncontrolled hypertension, delivery and evaluation of an intervention, and creation of a local registry of potential subjects. The single-group design is consistent with describing experience in the participating group, but cannot by itself provide a randomized comparison against another approach.

The primary outcome was intended to measure the mean change in systolic and diastolic blood pressure from baseline to 6 months. The registry defines the change as baseline minus follow-up and names standard deviation as the measure of dispersion. However, the endpoint values and analyses are not reported in the registry record. The direction, size, and precision of any blood pressure change therefore cannot be stated from the recorded outcome information.

Even if a within-group change were reported, it would not by itself show that the intervention caused that change. General explanation: a before-and-after comparison can reflect influences apart from the intervention, and a single-group design cannot separate those influences through a concurrent randomized comparison. The registry record also does not provide follow-up completeness or an analysis population, limiting interpretation of who contributed to the endpoint.

The safety record includes adverse-event counts and listed serious-event terms, but no comparator or detailed causal assessment. Those figures describe events recorded among participants receiving the model; they do not establish a comparative safety effect.

The record can therefore support a description of the study’s purpose, design, endpoint definition, enrollment, and recorded safety counts. It does not support a conclusion about whether the model changed blood pressure, how precisely change was estimated, or whether the intervention caused any change. Nor does study completion alone establish that the implementation aims were met; feasibility results are not reported in the registry record.

13. Why This Trial Matters Statistically

This study is statistically informative as an example of how an implementation-focused, single-group design differs from a randomized comparison. It examines a model intended for a specific geographic setting, with a primary endpoint defined as blood pressure change from baseline to 6 months. Such a design can describe experience among participants, but its structure does not isolate the intervention’s contribution to change over time.

The endpoint definition makes the subtraction order explicit. That detail matters because the direction of a change estimate depends on whether baseline or follow-up is subtracted first. The registry also identifies the mean and standard deviation as the summary and dispersion measures, respectively. Together, those quantities would help describe average change and participant-to-participant variability, while a confidence interval would help convey estimation uncertainty. The outcome values and confidence interval are not reported in the registry record.

The record also illustrates why enrollment and analysis populations should not be treated as interchangeable. Enrollment is listed as 30, but the number with complete measurements and the population included in endpoint analysis are not reported. Without those details, it is not possible to judge the extent or possible influence of missing follow-up.

Finally, the planning assumptions are not a substitute for the study’s design or results. The assumptions describe a hypothetical two-arm planning illustration based on an observed effect, while the registered study is single-group. Keeping design, planning calculations, and observed results distinct is essential to sound interpretation. Here, the lack of reported endpoint estimates means neither an effect size nor its precision can be evaluated.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The primary limitation for interpreting efficacy is the absence of numerical outcome results in the registry record. Although the endpoint and time frame are defined, the record does not report mean systolic or diastolic change, standard deviations, confidence intervals, or test results. The size and precision of any change therefore cannot be assessed.

The single-group design provides no randomized control comparison. Any baseline-to-follow-up change could have explanations other than the intervention, and the record does not support a causal attribution. The absence of masking is recorded as none; further details about measurement procedures are not reported in the registry record.

The listed enrollment is 30, but the number contributing data at 6 months and the endpoint analysis population are not reported. Missing-data methods, reasons for missing measurements, and sensitivity analyses are also not reported. This leaves uncertainty about follow-up completeness and how incomplete observations may have been handled.

The intervention is described as a Nashville implementation of a smaller-scale Los Angeles barbershop–pharmacist model, but the registry record does not provide enough detail to assess implementation fidelity, participant exposure, or the extent to which the intended model was delivered. It also does not report numerical findings for feasibility or recruitment aims. Generalizability beyond the participating group cannot be evaluated from the record, which lacks detailed participant characteristics.

Safety interpretation is limited by the lack of a comparator and by the absence of event timing, relatedness assessments, and further event-level detail. The recorded counts are descriptive and do not establish causation or comparative risk.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Nashville - Hypertension Management Model — NCT04232124.
• Registry record last updated 2024-01-22; status last verified 2023-04.
• Results first posted 2024-01-22.
• 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.

18. Record Summary

NCT04232124 is a completed, single-group behavioral study sponsored by Vanderbilt University Medical Center, with enrollment listed as 30. Its purpose was to implement a smaller-scale version of a Los Angeles barbershop–pharmacist hypertension management approach in Nashville and assess feasibility and implementation.

The primary outcome was change in systolic and diastolic blood pressure from baseline to 6 months, defined as baseline minus the 6-month value and described using a mean and standard deviation. Allocation is listed as NA, masking as none, and the registry lists no analyses.

The registry records 3 serious adverse events, 6 other adverse events, and 0 deaths among 30 male participants who received the model. Numerical primary outcome results, analysis details, follow-up completeness, and the analysis population are not reported in the registry record. The available record therefore describes the study’s design and outcome definition, but does not establish the magnitude or precision of blood pressure change.