Home Blood Pressure Telemonitoring and Case Management to Control Hypertension: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Home Blood Pressure Telemonitoring and Case Management to Control Hypertension (NCT00781365), a randomized na study. The primary outcome is Blood Pressure Control.

2. Clinical Question

The clinical question concerns a combined care approach: participants were offered home measurement and transmission of blood pressure readings, together with pharmacist case management. The comparator was usual care, rather than no care. The primary outcome was the proportion meeting a blood pressure control definition at baseline, 6 months, 12 months, and 18 months. The record does not report outcome percentages, between-group estimates, confidence intervals, or a p-value, so the magnitude and precision of any difference cannot be described from the registry record.

3. Trial Design

The trial is listed as randomized, parallel-group, and unmasked, with phase recorded as not applicable. Its status is completed. The registry reports enrollment of 450, identifies HealthPartners Institute as sponsor, and lists hypertension as the condition. The recorded start is 2009-03 and the primary completion is 2012-10. Those dates describe the registry record and do not supply further details about recruitment or follow-up.

The intervention was named “Telemonitors and pharmacy management.” The control group was described as receiving usual care from primary care physicians at HealthPartners Medical Group clinics. Participants assigned to the telemonitoring intervention were to receive a home blood pressure telemonitor and work with a clinical pharmacist case manager. The registry description says they would use the device to read and send blood pressure measurements to the pharmacist case manager. Further operational details are not reported in the registry record.

The registry lists the design as parallel and randomized, but its accompanying analysis note identifies a cluster-randomized design and warns that a simple individual-level re-analysis would be misleading. These statements make the unit of randomization important to interpretation. The record does not describe which entities were randomized, how clusters were formed, or how clustering was handled in the sponsor’s analysis. Those details are not reported in the registry record.

Blinding is listed as none. In general, an unmasked design means that participants and care providers may know which group is assigned; the record does not specify which people were aware of allocation or how outcome assessment was conducted. The registry does not report the randomization procedure, allocation concealment, sample-size justification, protocol deviations, or a detailed analysis plan. The recorded enrollment is a trial-level figure and does not by itself explain how participants were distributed across groups or how many contributed data to the primary outcome.

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: Participants were assigned to treatment group based on their primary care clinic location. Clinics were randomized to treatment or control (cluster randomization).

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 Blood Pressure Control, measured over Baseline, 6 months, 12 months, 18 months.

The primary endpoint is blood pressure control, expressed as the percentage of participants meeting the specified threshold at baseline, 6 months, 12 months, and 18 months. Control is defined as blood pressure below 140/90 mmHg, with a lower threshold of below 130/80 mmHg for participants with kidney disease or diabetes. The endpoint therefore classifies each participant at each assessment according to whether the applicable threshold is met.

Using a percentage makes the outcome interpretable as the share of participants whose blood pressure meets the registry’s definition of control at a given time. It can be compared between the intervention and usual-care groups and across the listed assessment times. The definition’s alternate threshold matters: the same measured blood pressure may be classified differently depending on whether a participant has kidney disease or diabetes. The registry record does not report how those conditions were determined for this endpoint or how missing measurements were handled.

In general, a binary endpoint simplifies a continuous measurement into categories, which can make a target-oriented outcome easier to communicate. It also discards information about how far a participant’s blood pressure lies above or below a threshold. The registry gives the endpoint definition and timepoints, but does not report the observed percentages or an estimated comparison between groups. The clinical and statistical size of any difference therefore cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the primary endpoint represent?

The endpoint is binary at the participant level: at each stated assessment, a participant either meets the blood pressure control definition or does not. The group outcome is expressed as a percentage of participants. The registry specifies assessments at baseline, 6 months, 12 months, and 18 months and defines different thresholds for participants with and without kidney disease or diabetes. Numerical results at any of these times are not reported in the registry record.

General: A binary outcome can be summarized as a proportion or percentage, and a group comparison can describe how those proportions differ. The choice of threshold affects classification. Categorizing a continuous measurement can make a target easier to understand, but it also removes detail about the actual measurement and the distance from the cutoff. These are general properties of threshold-based outcomes, not additional findings from this trial.

What would a confidence interval add?

The primary outcome is described as a percentage with a 95% confidence interval. No numerical confidence interval is reported in the registry record. General: A confidence interval communicates the uncertainty around an estimate under the assumptions of the statistical method. A narrower interval indicates greater precision; a wider interval indicates less precision. It is not a guarantee that the true value lies within the particular interval, and it does not by itself establish the importance of an effect. Here, without the estimate and interval, precision cannot be evaluated.

For a comparison between groups, the estimated difference and its confidence interval would help distinguish a precisely estimated contrast from one with substantial uncertainty. The registry record does not give a between-group estimate, so no conclusion about direction or magnitude is available. A p-value is also not reported for the primary endpoint.

Why does the cluster-randomized note matter?

The trial is listed as randomized and parallel, and the analysis note specifically identifies a cluster-randomized design. General: In cluster randomization, groups of participants rather than necessarily each participant individually are assigned. Participants within one cluster may share providers, settings, or other influences, so their outcomes may be correlated. When that correlation is present, the amount of independent information is less than a calculation that treats every participant as unrelated would imply. A suitable analysis accounts for the clustering when estimating uncertainty.

The registry warns that a simple individual-level re-analysis would be misleading and says the sponsor’s own analysis takes precedence. The record does not describe the randomization unit, cluster count, cluster sizes, correlation assumptions, or sponsor’s statistical method. No cluster-adjusted primary estimate is reported in the registry record. It is therefore not possible to assess whether or how the sponsor’s analysis accounted for clustering.

What can the planning illustrations tell readers?

The planning assumptions describe an illustration based on an observed effect, with two-sided significance level 0.05, equal allocation, and a normal approximation. They specify that the effect to detect is a stated fraction of the observed effect. For time-to-event outcomes, the illustration is defined in terms of total events; other outcomes are described in terms of participants per arm. The primary outcome described for this trial is a percentage, not a time-to-event outcome.

General: A planning calculation asks how much information would be needed under stated assumptions to detect a target effect with a chosen statistical power. Such an illustration is not the same as the original trial’s design justification, and it does not establish what power the completed trial achieved. The registry explicitly distinguishes the illustration from the trial’s own design. The trial’s sample-size justification and original power assumptions are not reported in the registry record. The calculated planning values are not repeated in this explanation.

When an illustration uses a fraction of an observed effect, it depends on the observed effect being available and on the assumed design and analysis being appropriate. For a cluster-randomized study, an illustration that does not reflect clustering could misrepresent the required information. The stated analysis note cautions against simple individual-level re-analysis; details needed to judge how the planning illustration addresses clustering are not reported in the registry record. These sample-size illustrations must not be interpreted as observed power or as evidence that the trial did or did not detect an effect.

What analysis details remain unknown?

The registry record does not describe the statistical model for the primary endpoint, adjustment variables, handling of repeated measurements, missing-data procedures, or analysis population. It also does not report interim analyses, a multiplicity procedure, or a detailed prespecified statistical plan. General: These choices can affect how estimates and uncertainty are calculated. Without them, readers should not infer a particular method from the endpoint format alone. No model, test, or adjustment should be attributed to the trial unless it is documented in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary endpoint, blood pressure control, assessed at baseline, 6 months, 12 months, and 18 months. It also reports three outcome measures overall, but the other measures and their analytic roles are not described in the information available for this account. The registry does not state whether one timepoint was designated as the principal comparison, whether comparisons across time were jointly tested, or whether any multiplicity adjustment was planned. A multiplicity strategy is not reported in the registry record.

General: When several outcomes, timepoints, or subgroup comparisons are examined, the chance of at least one apparently unusual result can increase if each is tested separately. Prespecifying a primary contrast and an approach to multiple comparisons can clarify which findings are confirmatory and how uncertainty should be interpreted. The registry does not provide enough information to determine what strategy, if any, was used.

Missing-data handling is also not reported in the registry record. The record does not give the number of participants with blood pressure measurements at each timepoint, reasons for unavailable measurements, or whether participants were analyzed according to their original group assignment. It does not describe imputation, complete-case analysis, or sensitivity analyses. General: Missing outcome data can affect an estimated percentage if participants with unavailable measurements differ from those with observed measurements. The direction and extent of any such effect cannot be determined without the relevant information.

The analysis population for the primary outcome is not reported in the registry record. The safety denominators do not establish how many participants contributed to each efficacy assessment. The registry also does not report interim analyses or a detailed statistical analysis plan. These absences limit assessment of whether the reported analyses, if any, follow a prespecified approach.

11. Safety Results

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

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: myocardial infarction (3.6%), spinal decompression/fusion (2.7%), cerebrovascular accident (stroke) (2.3%), anemia (1.8%), overdose, toxicity, or withdrawal (1.8%).

The registry reports serious adverse-event counts of 37 among 222 participants at risk in usual care and 30 among 228 participants at risk in the telemonitoring intervention. It separately reports other adverse-event counts of 8 among 222 at risk in usual care and 5 among 228 at risk in the telemonitoring intervention. These are counts in the registry’s safety entries; they are not the primary blood pressure outcome.

The listed serious-event terms and percentages are myocardial infarction, 3.6%; spinal decompression/fusion, 2.7%; cerebrovascular accident (stroke), 2.3%; anemia, 1.8%; overdose, toxicity, or withdrawal, 1.8%; and chest pain, non-cardiac, non-specific, 1.8%. The registry information does not attribute these listed terms to a particular arm in the posted safety listing, so they should not be read as arm-specific comparisons.

The record does not report death counts. It also does not give additional detail about event timing, duration, severity criteria, or the number of participants who experienced more than one event. General: Event counts and participant counts are not interchangeable when a participant can experience multiple events. The entries should be read as registry safety summaries, not as a complete causal assessment or a comparison adjusted for the trial design.

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

The registry record establishes that a randomized, parallel-group trial compared home blood pressure telemonitoring with pharmacist case management against usual care, and that blood pressure control was the primary endpoint. It also defines the thresholds and assessment times. These details identify the clinical question and the outcome the trial was intended to evaluate.

The primary outcome results are not reported in the registry record. Consequently, the record does not establish the percentage meeting the control definition in either group, the difference between groups, or the precision of a comparative estimate. It cannot support a statement about whether the intervention increased or decreased blood pressure control or by how much. Completion status and enrollment do not supply those missing results.

The registry does report safety counts and a list of serious adverse-event terms with percentages. Those entries are distinct from the primary outcome and should be interpreted with their reported denominators and limitations. The listed terms are not presented as a clear arm-by-arm comparison in the record, and death counts are not reported.

General: A trial result is best interpreted using the estimated effect together with its uncertainty, the design and analysis, and the completeness of outcome reporting. A design description alone does not answer whether an intervention changed an outcome. Likewise, a planning illustration based on an observed effect is not a substitute for a reported trial estimate and does not indicate observed power. The registry’s note about cluster randomization is especially relevant to uncertainty: an individual-level analysis that ignores clustering can misstate precision.

Accordingly, the defensible reading is limited to the trial’s design, intended endpoint, and posted safety information. The registry record does not report enough primary-outcome data or analytic detail to assess the size, direction, or precision of the primary comparison.

13. Why This Trial Matters Statistically

This trial raises a useful statistical question about a care intervention whose components include home blood pressure measurement, remote transmission, and pharmacist case management. The endpoint is a threshold-defined percentage measured at several follow-up times. That setup illustrates why readers need both a clear outcome definition and the actual group estimates to interpret a clinical trial.

The record also highlights the importance of the unit of randomization. Although the design fields identify a randomized parallel trial, the analysis note identifies cluster randomization and cautions against simple individual-level re-analysis. General: Cluster allocation can induce dependence among participants in the same cluster, which affects the calculation of uncertainty. Recognizing the unit of randomization is therefore part of assessing whether the reported analysis is appropriate, not merely a technical detail.

Another statistical issue is the distinction between a planning illustration and the trial’s original design. The registry describes illustrations based on an observed effect and stated assumptions, while noting that they are not the trial’s own design justification. Such planning values cannot be treated as observed power or as a substitute for results. The original sample-size justification is not reported in the registry record.

Finally, completion and enrollment do not answer the efficacy question. Without the primary endpoint estimates, confidence intervals, and analysis details, readers cannot judge the observed contrast or its precision. The record’s safety entries are informative as posted summaries, but they do not fill that gap. Statistically, the most important lesson is that design labels and endpoint definitions must be read alongside outcome estimates, denominators, and analysis methods; several of those elements are not reported in the 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.

The principal limitation of interpretation is that numerical results for the primary endpoint are not reported in the registry record. There are no group percentages, comparative estimates, confidence intervals, or primary-outcome p-values. The three listed outcome measures are not fully described in the available record, limiting assessment of the outcome hierarchy and the role of secondary measures.

The analysis note identifies a cluster-randomized design, but the registry design fields also describe a randomized parallel-group study. The record does not explain the randomization unit or provide cluster information. It cautions that a simple individual-level re-analysis would be misleading and says the sponsor’s own analysis takes precedence, but the sponsor’s primary-outcome estimate and analysis method are not reported in the registry record.

The record does not report participant characteristics, eligibility criteria beyond the hypertension condition, group-specific enrollment for the primary outcome, or endpoint availability by timepoint. Missing-data methods and analysis populations are not described. The outcome definition uses different thresholds for participants with kidney disease or diabetes, but the record does not explain how those conditions were classified or provide results by threshold category.

Blinding is listed as none, but details about who knew allocation and how measurements were assessed are not reported in the registry record. Randomization procedures, allocation concealment, protocol deviations, sample-size justification, interim analyses, multiplicity handling, and a detailed statistical plan are also not reported. These omissions restrict assessment of risk of bias, precision, and the extent to which analyses followed prespecified methods.

Safety information is limited to the posted counts, denominators, and listed serious-event terms and percentages. Death counts are not reported, and the listing does not supply the detail needed to interpret event timing or arm-specific rates for the named terms.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Home Blood Pressure Telemonitoring and Case Management to Control Hypertension — NCT00781365.
• Registry record last updated 2017-04-13; status last verified 2017-03.
• Results first posted 2014-07-14.
• 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

NCT00781365 is a completed randomized, parallel-group, unmasked trial sponsored by HealthPartners Institute. It lists hypertension as the condition, enrollment of 450, a start of 2009-03, and primary completion of 2012-10. The intervention was home blood pressure telemonitoring with pharmacy management; the comparator was usual care from primary care physicians at HealthPartners Medical Group clinics.

The primary endpoint was the percentage with controlled blood pressure at baseline, 6 months, 12 months, and 18 months, using the registry’s stated thresholds. Numerical primary-outcome results and the sponsor’s detailed analysis are not reported in the registry record. The record notes a cluster-randomized design and cautions against simple individual-level re-analysis.

Safety entries report serious and other adverse-event counts by group, as well as selected serious-event terms and percentages. Death counts are not reported. Further details about analysis populations, missing data, multiplicity, and sample-size justification are not reported in the registry record.