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 Trial of Low and High Intensity Strategies to Maintain BP Control (NCT00760552), a randomized na study. The primary outcome is Blood Pressure Change.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00760552 |
| Phase | NA |
| Condition | Hypertension |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 249 |
| Arms in the primary outcome | n/a |
| Lead sponsor | US Department of Veterans Affairs |
| Results posted | Yes |
2. Clinical Question
Population
Veterans with uncontrolled hypertension receiving care in the VA setting. The study description says participants first took part in a 6-month intensive pharmacist-based intervention. The arm descriptions identify VA patients with uncontrolled hypertension, but do not add further participant characteristics.
Intervention
Continued pharmacist intervention intended to sustain blood pressure control. The described approach includes medication assessment, a plan to intensify treatment if indicated, adherence strategies, and follow-up pharmacist visits.
Comparator
A one-time patient and provider education intervention, described as the lower-intensity approach after the initial pharmacist intervention. The registry lists high- and low-intensity intervention names, but does not map the numbered arm descriptions to those names.
Primary question
Over the 2-year follow-up after randomization, how does blood pressure compare between participants assigned to continued pharmacist intervention and those assigned to the one-time education approach? The endpoint description specifies blood pressure measurements from baseline through 30 months post-baseline, but numerical between-group results are not reported in the registry record.
3. Trial Design
This was a randomized, parallel-group trial with no masking. The registry lists the phase as not applicable. It records enrollment of 249 and identifies hypertension as the condition. The sponsor was the US Department of Veterans Affairs. The record lists a start date of 2009-11, primary completion in 2013-12, and status as completed.
The study description places randomization after an initial 6-month intensive pharmacist-based intervention for veterans with uncontrolled hypertension. Participants were then assigned to continued intervention or a one-time patient and provider education intervention, with blood pressure compared over a 2-year follow-up period. The listed intervention names are High Intensity Intervention, Low Intensity Intervention, and All- 6 month pharmacist intervention. The arm descriptions themselves both say VA patients with uncontrolled hypertension; they do not specify which numbered arm corresponds to each post-randomization strategy.
The planned blood pressure schedule includes baseline and assessments at 6, 12, 18, 24, and 30 months post-baseline. The primary endpoint description also calls the final assessment 24 months after randomization. This timing is consistent with the stated initial intervention followed by follow-up, but the registry record does not provide a participant-level schedule or detail deviations from the planned visits.
The record gives no numerical outcome summaries for the randomized comparison. It also does not report the allocation sequence method, concealment procedures, or additional operational details. Those details should not be inferred from the randomized, parallel, and unmasked design labels.
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.
Before assignment: 249 total were enrolled. 122 had controlled BP and did not participate in the trial. of the 127 who participated, 4 dropped prior to randomization.
Overall Study
| Stage | Arm 1 | Arm 2 |
|---|---|---|
| STARTED | 61 | 62 |
| COMPLETED | 48 | 52 |
| NOT COMPLETED | 13 | 10 |
Reasons for not completing this period:
| Reason | Arm 1 | Arm 2 |
|---|---|---|
| Death | 2 | 0 |
| Lost to Follow-up | 11 | 10 |
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 | Arm 1 | Arm 2 | Total |
|---|---|---|---|---|
| Participants analysed | 61 | 62 | 123 | |
| Age, Continuous | years | 63.6 (SD 11.2) | 66.0 (SD 10.3) | 64.8 (SD 10.8) |
| Sex: Female, Male: Female | Participants | 1 | 2 | 3 |
| Sex: Female, Male: Male | Participants | 60 | 60 | 120 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 57 | 57 | 114 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 4 | 5 | 9 |
| Region of Enrollment: United States | participants | 61 | 62 | 123 |
6. Primary Endpoint
The registry lists the primary outcome as Blood Pressure Change, measured over Measured at Baseline, and 6,12,18,24, and 30 months post baseline..
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | mmHg |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is blood pressure change, expressed in mmHg and described as a mean of a continuous measure. Blood pressure was to be measured using a standard protocol following American Heart Association guidelines, with an Omron HEM 907 device. Assessments are specified at baseline and 6, 12, 18, 24, and 30 months post-baseline. The final assessment is described as 24 months after randomization.
Change from baseline is used to describe how the measured blood pressure differs over time from each participant’s baseline measurement. In a trial comparing strategies to maintain control, repeated measurements can describe whether the groups’ blood pressure patterns differ during follow-up, rather than relying only on a single measurement. This is a general explanation of the endpoint concept; it does not establish that the trial’s groups differed.
The registry record does not report group means, standard deviations, changes from baseline, between-group contrasts, confidence intervals, or test results for this endpoint. It also does not identify a single time point as the sole comparison in the posted results. The endpoint description alone therefore establishes what was intended to be measured, not the magnitude or precision of any treatment contrast.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The study addresses whether a more sustained pharmacist-based strategy is associated with a different blood pressure course than a one-time education approach after an initial intensive intervention. The design and outcome description make that question clear, but the registry record does not report numerical primary-outcome results. No group-specific blood pressure values, changes, standard deviations, between-group estimates, confidence intervals, or p-values are reported. As a result, the size, direction, and precision of the randomized comparison cannot be interpreted from this record.
The outcome is described as blood pressure change, a continuous measure summarized by a mean and standard deviation. A mean contrast could indicate the average separation between strategies at a particular time or over a specified period, depending on the analysis. However, the registry record does not state which contrast or time point was used in an analysis, nor does it report an analysis result. The scheduled assessments should not be mistaken for evidence that each time point has a posted estimate.
The record states that 249 participants were enrolled, but this enrollment figure does not establish how many contributed to any particular endpoint analysis. The safety entries separately give numbers at risk for adverse-event reporting; those figures are not a substitute for outcome-analysis denominators. The number of participants with blood pressure measurements at each follow-up time is not reported in the registry record.
There is also no reported estimate of uncertainty for the primary comparison. In general, a confidence interval communicates the range of values compatible with the data and analysis under its assumptions. Without an estimate and interval, readers cannot judge how precisely a difference was estimated or whether the data are compatible with a range of effects. Absence of a posted result is not evidence that the strategies had the same blood pressure outcomes.
The trial status is completed, but completion does not itself supply an outcome finding. The registry record lists zero analysis entries. It does not report a sponsor analysis for the primary endpoint that could be compared with a simple recalculation. Therefore, no conclusion about benefit, lack of benefit, or comparative effectiveness follows from the numerical information in this record. Interpretation is limited to the research question, measurement plan, trial structure, and separately listed safety counts.
9. Statistical Methods Explained
The trial is described as randomized, parallel, and unmasked. Randomization is a method for assigning participants to strategies by chance, intended to support a fair comparison by reducing systematic differences in assignment. A parallel design means the assigned groups are followed as separate groups rather than participants crossing between strategies as the defining design. These are general explanations of the design terms; the registry record does not describe the sequence-generation or allocation-concealment procedures.
What does a continuous mean endpoint represent?
Blood pressure is treated as a continuous measure, and the primary endpoint is described as a mean in mmHg with standard deviation. A mean summarizes the central level of observed measurements. A standard deviation describes how spread out individual measurements are around that mean; it is not the same as the uncertainty in a group mean or in a between-group contrast. The registry record does not post the means or standard deviations for the primary endpoint.
Change from baseline uses a participant’s baseline value as a reference for later measurements. A group-level comparison of change can address whether average change differs between strategies. Alternatively, an analysis might compare follow-up measurements while accounting for baseline values. These are general analytic possibilities, not a description of the method used in this trial: the statistical analysis plan and the specific primary-outcome model are not reported in the registry record.
Why do repeated measurements matter?
The endpoint schedule includes baseline and multiple follow-up assessments through 30 months post-baseline. Repeated measurements can describe the course of blood pressure over time. They also create analytic choices: an analysis might focus on a particular visit, compare trajectories, or use a model that accounts for measurements from the same participant being related. Measurements from one participant are generally not independent observations. That dependence matters when estimating uncertainty, but the registry record does not say how repeated observations were handled.
Time-specific comparisons can answer different questions from an overall longitudinal comparison. A value at one follow-up visit describes the contrast at that time; a trajectory analysis addresses patterns over the follow-up period. Because the record does not identify a reported contrast or provide numerical results, readers cannot determine which interpretation applies to an outcome estimate.
What can be inferred from the planning assumptions?
The record describes planning illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. These are planning assumptions, not reported evidence about the effect or the trial’s original design. No numerical observed effect or illustration values are reported in the registry record, so no planning result can be interpreted from those assumptions alone. Such sample-size illustrations are not observed power and do not establish the probability that the trial detected an effect.
In general, a two-sided test considers departures in either direction from a null value. A significance level is a chosen threshold for the testing procedure, not the probability that a particular conclusion is true. A normal approximation uses a mathematical approximation to calculate a test or planning quantity. These general definitions do not identify what statistical test or model the investigators actually used.
Why can over-dispersion matter?
For count outcomes, over-dispersion means that variability is greater than a simple model assumes; failing to account for it can make uncertainty estimates too small. That concept is not central to the stated primary endpoint, which is continuous blood pressure change, and the record does not report a count-based primary analysis. No over-dispersion adjustment is described for this trial.
Overall, the registry record supplies design labels, an endpoint definition, a measurement schedule, and planning assumptions, but does not report a statistical analysis plan or primary outcome estimates. The general explanations above clarify statistical concepts; they should not be read as claims that a particular model, test, or adjustment was used.
10. Multiplicity, Missing Data and Analysis Populations
The primary endpoint has repeated assessment times: baseline and 6, 12, 18, 24, and 30 months post-baseline. Considering multiple time points can raise a multiplicity question: repeated testing or selecting a favorable time point can increase the chance of a false-positive finding if the analysis does not account for the number and structure of comparisons. This is a general statistical concern, not a claim that such testing occurred in this trial.
The registry record does not report an analysis plan describing a primary follow-up time, a hierarchy of outcomes, or any adjustment for multiple comparisons. It also does not report whether a longitudinal model or separate time-specific analyses were planned or used. The single listed outcome measure does not by itself establish how many statistical comparisons were conducted.
Missing-data methods and analysis populations are also not reported in the registry record. The record does not state how participants with absent blood pressure measurements were handled, whether all randomized participants were included in the primary analysis, or how adherence, withdrawal, or incomplete follow-up affected analysis eligibility. The enrollment figure cannot answer these questions, and the adverse-event at-risk counts are not endpoint-analysis denominators.
Without these details, readers cannot assess how missing observations or the choice of analysis population may have influenced an estimated blood pressure contrast. No assumptions about imputation, last observation carried forward, complete-case analysis, or intention-to-treat analysis should be attributed to the trial from the available record.
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 |
|---|---|---|---|
| Arm 1 | 1 | 61 | 1.6% |
| Arm 2 | 0 | 62 | 0.0% |
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 |
|---|---|
| Arm 1 | 0 of 61 |
| Arm 2 | 0 of 62 |
Most frequent serious adverse event terms
| Event term | Organ system | Arm 1 | Arm 2 |
|---|---|---|---|
| Drug--Participant Hospitalization | General disorders | 1 of 61 | 0 of 62 |
Serious events with the highest arm-level rate: drug--participant hospitalization (1.6%).
The registry lists serious adverse events by arm. For Arm 1, 61 participants are listed as at risk and 1 as affected by a serious adverse event; for Arm 2, 62 are listed as at risk and 0 as affected. The listed serious-event term is “Drug--Participant Hospitalization,” with a reported percentage of 1.6%. The registry lists zero other adverse events for each arm in the figures shown.
These entries are descriptive counts, not a comparative safety analysis. The record does not provide a statistical comparison, confidence interval, or assessment of whether the event was caused by an intervention. The event term alone does not establish its clinical circumstances or relationship to treatment. Death counts are not reported in the registry record.
The at-risk figures are the denominators attached to the adverse-event reporting entries; they should not be treated as the blood pressure analysis denominators. The registry record does not give further detail about the observation period or the rules used to classify adverse events. These safety figures should therefore be read narrowly as the posted serious and other adverse-event counts, without interpreting them as proof of comparative safety.
12. What the Result Does, and Does Not, Mean
The record establishes that the study was designed to compare continued pharmacist-based management with a one-time education approach after an initial 6-month pharmacist intervention in veterans with uncontrolled hypertension. It specifies a blood pressure endpoint, a measurement device and protocol, and scheduled assessments extending through 30 months post-baseline. It also identifies the randomized, parallel, unmasked design and records the trial as completed.
Those details do not establish which strategy produced a lower mean blood pressure, whether the groups differed, or how large or precise any difference was. Numerical primary-outcome results are not reported in the registry record. A completed status is not an outcome result, and the lack of a posted estimate cannot be interpreted as no difference. The record also does not report a statistical analysis plan or enough information to assess missing blood pressure observations or the primary analysis population.
The findings should not be generalized beyond what the record describes. The participants were veterans with uncontrolled hypertension in a VA context, and both strategies followed an initial intensive intervention. The described comparison is therefore not a direct comparison of starting pharmacist management against no pharmacist management, nor does the record establish effects in other populations or care settings.
The posted safety counts are limited descriptive information. They do not establish a causal relationship between the intervention and an event, and the record does not provide a formal comparison of safety between arms. The most defensible interpretation is that this registry entry documents the trial question and measurement plan but does not provide numerical evidence to answer the primary comparative question.
13. Why This Trial Matters Statistically
Statistically, this trial illustrates the difference between a clearly specified research question and a result that can be evaluated from a registry entry. The design description identifies random assignment to different strategies after an initial pharmacist intervention, while the endpoint description specifies repeated blood pressure measurement. Together, these details clarify what the investigators intended to compare and measure.
The repeated schedule also highlights why an endpoint needs an analysis definition. A continuous outcome measured at several visits can be summarized in different ways, and those choices affect the interpretation of an estimate and its uncertainty. The registry record does not report the analysis method, selected comparison time, or numerical estimate. As a result, the schedule alone cannot stand in for a statistical result.
The planning assumptions are another useful distinction. A planning illustration based on an observed effect is not the same as an original sample-size justification, an analysis result, or observed power. The record does not state the trial’s original sample-size justification, and no numerical planning illustration or primary effect estimate is reported. Keeping these concepts separate avoids treating a design calculation as evidence of what occurred in the trial.
Finally, the trial record demonstrates the limits of interpreting registry safety counts without context. Counts and percentages can describe what was posted, but they do not by themselves establish causal attribution, precision, or a between-group difference. Statistical interpretation depends not only on the design and endpoint but also on outcome estimates, uncertainty, analysis methods, and transparent reporting of missing data and analysis populations. Those primary-outcome details are not reported in this registry record.
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 of this record for statistical interpretation is the absence of numerical primary-outcome results. Although blood pressure change is identified as the primary endpoint and its measurement schedule is described, the registry record does not report group means, standard deviations, changes, contrasts, confidence intervals, or p-values. The primary comparative question therefore cannot be answered from the posted results.
The analysis details are also limited. The record does not report the statistical model, the specific time point used for a primary contrast, handling of repeated measurements, multiplicity procedures, missing-data methods, or analysis population. It does not state the original sample-size justification. These omissions prevent assessment of how well the reported design and analysis, if any, address the intended comparison.
The arm descriptions are identical in their brief wording and do not map the numbered arms to the high- and low-intensity intervention names. The study summary describes the post-randomization strategies, but the record does not provide further arm-level operational detail in those descriptions. This limits interpretation of the exact contrast as represented by the numbered arms.
The record’s enrollment figure is not a count of participants with endpoint measurements at every visit. The number analyzed at each scheduled time and the reasons for any missing measurements are not reported in the registry record. The safety entries do not fill that gap, since their at-risk counts relate to adverse-event reporting.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Trial of Low and High Intensity Strategies to Maintain BP Control — NCT00760552.
- Registry record last updated 2015-04-27; status last verified 2014-11.
- Results first posted 2014-12-17.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry describes a completed, randomized, parallel, unmasked study of veterans with uncontrolled hypertension. After a 6-month intensive pharmacist-based intervention, participants were assigned to continued intervention or a one-time patient and provider education approach. The stated aim was to compare blood pressure over a 2-year follow-up.
The primary endpoint is mean blood pressure change in mmHg, measured at baseline and at 6, 12, 18, 24, and 30 months post-baseline using an Omron HEM 907 device and a standard protocol following American Heart Association guidelines. The record lists enrollment of 249 and a trial start of 2009-11, with primary completion in 2013-12.
Numerical primary-outcome estimates, uncertainty measures, analysis methods, and missing-data procedures are not reported in the registry record. The posted serious adverse-event entries list 1 affected participant in Arm 1 and 0 in Arm 2; these counts do not establish causation or a comparative safety result.