PRO-POWER: Hypertension With Risk Factors for a Duration of 24 Weeks With Micardis 80mg/Micardis Plus 80mg/12.5mg: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for PRO-POWER: Hypertension With Risk Factors for a Duration of 24 Weeks With Micardis 80mg/Micardis Plus 80mg/12.5mg (NCT00936208), a registered phase not stated study. The primary outcome is Change in Diastolic Blood Pressure From Baseline at Week 24.

2. Clinical Question

3. Trial Design

PRO-POWER is described as an observational cohort study lasting 24 weeks. Its stated aim was to evaluate safety, efficacy and cardiovascular-risk protection in people with essential hypertension who also had at least one other contributing cardiovascular risk factor. The registry lists an enrollment of 3184 and gives the status as completed. The recorded study start is 2009-05, and the primary completion is 2010-11.

The registry identifies two groups: Micardis 80mg and Micardis Plus 80mg / 12.5mg. It does not state how treatment was selected or how participants entered each group. In particular, allocation is not stated, and the registry warns that the groups are not a like-for-like control comparison. This is important for interpretation: an observational comparison does not, by itself, separate a treatment association from differences in participant characteristics, clinical decisions or other factors.

The primary outcome uses a Full Analysis Set defined as patients with blood-pressure data available at both baseline and Week 24. The record does not report the number included in that analysis or the amount of missing blood-pressure data. It names secondary assessments involving the Framingham Score, the IRIS II Score and urinary microalbuminuria. The registry lists seven outcome measures overall, but it does not give results for the primary outcome or these secondary assessments in the information recorded. No protocol details, treatment-selection criteria or statistical analysis plan are 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.

Before assignment: 3184 patients were enrolled but treatment was unknown in 89 patients. Therefore, 3095 patients were analysed.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Full Analysis Set (FAS): Patients with Blood Pressure data available at baseline and at week 24

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 Diastolic Blood Pressure From Baseline at Week 24, measured over Baseline and Week 24.

The primary endpoint is change in diastolic blood pressure from baseline at Week 24, measured in mmHg. Diastolic pressure is the lower blood-pressure reading, recorded as the heart relaxes between beats. The registry defines change as the Week 24 measurement minus the baseline measurement. Under that definition, a negative change represents a lower Week 24 reading than at baseline, while a positive change represents a higher reading.

The endpoint is expressed as a mean, with standard deviation identified as the measure of dispersion. A mean describes the average change across the analysed participants; the standard deviation describes how spread out individual changes are around that average. These are different summaries: a mean change alone does not show whether individual participants had similar changes or widely varying changes.

Repeated measurement makes it possible to describe within-participant change over the stated follow-up. It does not, in an observational study, establish that an observed change was caused by a particular treatment. Blood pressure may change for reasons other than treatment, and the registry does not describe adjustment for such factors. The specified analysis population includes only patients with blood-pressure data at both baseline and Week 24. The registry record does not report the mean change, standard deviation, confidence interval or group comparison for this endpoint, so the size and precision of the outcome cannot be evaluated from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean change represent?

The endpoint is a continuous measurement expressed in mmHg. For each participant with both required measurements, change is the Week 24 value minus the baseline value. The mean of these individual changes gives an average change for the analysed group. It is not the same as comparing two unrelated group averages, and it does not show the distribution of individual responses. The standard deviation is a measure of that distribution’s spread.

These are general statistical interpretations of a mean and standard deviation. The registry identifies both summaries for the endpoint but does not report their numerical values. It therefore is not possible to describe the observed average or how variable participant changes were.

What would a confidence interval add?

In general, a confidence interval communicates the uncertainty around an estimated quantity. A narrower interval indicates greater precision under the assumptions of the method used; a wider interval indicates less precision. It is not a guarantee that the true value lies within the particular interval. No confidence interval for the primary outcome is reported in the registry record, and no interval method is specified.

A p-value, in general, describes how compatible data are with a specified null model and its assumptions. It does not measure the size or importance of an effect, and it does not establish causality. The registry record does not report a p-value or a testing procedure for the primary outcome. Without an estimate and its uncertainty, a conclusion about statistical significance would not be warranted.

Why does the observational design matter?

In a randomized comparison, random assignment is intended to balance measured and unmeasured characteristics on average. This study is described as observational, and the allocation method is not stated. The registry explicitly cautions that its groups are not a like-for-like control comparison. In general, treatment choice in an observational cohort may be related to participant characteristics, disease history or clinical judgment. Those factors can also be related to the outcome, creating confounding.

Statistical adjustment can sometimes address measured differences, but it cannot automatically remove unmeasured confounding, and its adequacy depends on the variables and methods used. The registry does not report adjusted estimates, covariates, model specifications or a statistical analysis plan. A group difference, if reported elsewhere, could therefore not be interpreted as a causal treatment effect on the basis of this record alone.

How should the planning illustrations be read?

The planning illustrations are described as calculations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between groups and a normal approximation. They consider detecting a stated fraction of the observed effect. The record describes these as planning illustrations, not as the study’s own design calculations. The observed effect itself is not reported in the registry record, so the numerical illustrations cannot be independently interpreted from the recorded outcome information.

In general, such calculations describe the participant numbers a hypothetical future study might require under their assumptions. They are not observed power and do not show that the completed observational study had a particular probability of detecting an effect. Planning estimates are sensitive to the assumed effect size, variability, allocation and analysis method. The registry does not report a sample-size justification or say that these illustrations were used to plan PRO-POWER.

What can safety counts tell readers?

A count of affected participants is a descriptive safety summary. Its interpretation depends on the event definition, the period and completeness of follow-up, and whether events were collected consistently. A zero recorded count means no affected participants are listed in that specific field; it does not by itself establish that no event occurred or that risk is absent. The serious-event entries and their denominators are discussed separately, while deaths are not reported in the registry record.

10. Confidence Intervals for Each Arm

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

R code and output

arm <- c("Micardis 80mg", "Micardis Plus 80mg / 12.5mg")
n   <- c(1462, 1574)
m   <- c(-15.3, -18.3)
sp  <- c(8.6, 8.4)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Micardis 80mg  1462  -15.300  8.600  -15.741  -14.859
CARM  Micardis Plus 80mg / 12.5mg  1574  -18.300  8.400  -18.715  -17.885

11. Multiplicity, Missing Data and Analysis Populations

The registry lists seven outcome measures. Alongside the primary diastolic blood-pressure change, named secondary outcomes include Framingham Score and change in that score, IRIS II Score and change in that score, and change in urinary microalbuminuria. The record does not report numerical results for these outcomes or describe a hierarchy for testing them.

In general, testing multiple outcomes can increase the chance of obtaining at least one apparently notable result by chance. A prespecified primary outcome, a hierarchy, or an adjustment procedure can help clarify how multiple tests are interpreted. Whether any such approach was planned or used is not reported in the registry record. The record lists zero analyses, so it does not provide analysis-level results or testing details from which multiplicity handling could be assessed.

The primary analysis population is defined as the Full Analysis Set: patients with blood-pressure data available at baseline and Week 24. This identifies who qualifies for the stated endpoint analysis, but it does not explain how many participants had complete measurements, whether other analyses used different populations, or how missing measurements were handled. Imputation, sensitivity analyses and reasons for unavailable measurements are not reported in the registry record.

In general, restricting an analysis to participants with complete measurements can be informative if missingness is unrelated to the outcome after accounting for relevant factors. If follow-up availability is related to participant health or outcome, a complete-case estimate may be less representative. The registry record does not provide the information needed to determine which situation applies. It also does not describe interim analyses, missing-data assumptions or a statistical analysis plan.

12. 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 5% reporting threshold.

The registry lists zero participants with a serious adverse event in the Micardis 80mg group, among 1499 at risk, and zero in the Micardis Plus 80mg / 12.5mg group, among 1596 at risk. These are descriptive counts in the serious-event fields. They should be read as the recorded entries, not as proof that serious events were impossible or that the treatments have no safety risks.

The record does not give serious-event terms, event definitions, collection procedures or a detailed account of safety follow-up. It lists no top serious-event terms. Death counts are not reported in the registry record. The absence of a listed term or a reported death count is not equivalent to a verified count of zero.

Because the study is observational and the groups are not described as comparable controls, these entries do not support a causal safety comparison. Differences in who received each treatment, follow-up or event recording could affect comparisons. The safety entries are therefore best treated as limited descriptive information rather than a complete account of risks or evidence that one group is safer.

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

The registry record establishes that PRO-POWER was a completed, 24-week observational cohort study concerning essential hypertension in people with at least one other cardiovascular risk factor. It identifies two treatment groups and specifies change in diastolic blood pressure from baseline at Week 24 as the primary outcome. It also defines the subtraction direction and the population eligible for that analysis.

What the record does not establish is the numerical result. The primary mean change and its standard deviation are not reported, nor are confidence intervals or a statistical comparison. Therefore, the size, direction and precision of the primary outcome cannot be judged from the registry record. The listed secondary outcomes also lack numerical results in the record.

The observational design matters independently of whether results are available. Treatment allocation is not stated, and the registry cautions that the groups are not a like-for-like control comparison. Any contrast between them would not, without further design and analysis information, isolate a causal treatment effect. The record does not report adjustment methods or enough detail to assess possible confounding.

Likewise, the serious-event fields list zero affected participants, but the safety information is limited and deaths are not reported. These entries should not be interpreted as establishing the absence of risk. The registry record supports an account of the study question, design type, outcome definition and selected safety entries; it does not provide enough results or methods detail to determine treatment effectiveness, comparative safety or precision.

In general, a registry record is most informative when it includes outcome estimates, uncertainty intervals, analysis populations, missing-data handling and prespecified analysis methods. Those details would help distinguish the magnitude of an association from its uncertainty and clarify the limits of comparisons. They are not reported in the registry record for this study.

14. Why This Trial Matters Statistically

This study illustrates why the design label and the outcome definition need to be read together. The primary endpoint is a clearly specified continuous measure: mean change in diastolic blood pressure, calculated as the Week 24 value minus baseline. That definition tells readers what quantity was intended for analysis. But a clearly named endpoint is not a substitute for its estimate, uncertainty or supporting analysis details.

The observational design is central to interpretation. The registry names two groups but does not state allocation, and it warns that they are not like-for-like controls. That caution separates a descriptive comparison from a causal claim. Even a precise numerical difference would not by itself show that treatment caused the difference if groups differed in relevant ways.

The record also makes the analysis population explicit: participants with blood-pressure data at both measurement times. This is useful because it identifies the basis for the stated primary analysis, while also raising questions about missing follow-up data and representativeness. The number analysed and the approach to missing data are not reported in the registry record.

Finally, the registry illustrates the importance of complete reporting. It names multiple outcome measures and includes limited serious-event counts, but does not report the primary effect estimate, uncertainty, analysis procedures or death counts. Without these, readers cannot assess the size or precision of the primary outcome, the consistency of secondary findings, or the extent to which the safety record is complete. Statistical interpretation depends not only on the question and design, but also on transparent reporting of estimates and their limitations.

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.

The principal limitation in interpreting this study from the registry record is that the primary outcome result is not reported. The endpoint’s mean change, standard deviation and uncertainty are absent, as are numerical results for the listed secondary outcomes. The record therefore describes what was to be measured but does not permit assessment of the observed changes.

The study is observational, allocation is not stated, and the registry warns that the two groups are not like-for-like controls. This limits causal interpretation of any group contrast. The registry record does not report baseline characteristics, treatment-selection factors, adjustment variables or model details that would help assess confounding.

The primary population includes only people with blood-pressure observations at both baseline and Week 24. The number meeting that definition, reasons for missing measurements and missing-data methods are not reported. As a result, the extent to which the analysed population represents the enrolled cohort cannot be assessed.

Although seven outcome measures are listed, the registry reports zero analyses and does not describe multiplicity procedures, interim analyses or a statistical analysis plan. The serious-event entries are limited to the recorded counts; event definitions and detailed safety reporting are absent, and deaths are not reported. These omissions constrain interpretation of both efficacy-related outcomes and safety.

The record also does not state the sample-size justification or explain whether the planning illustrations informed study design. The listed illustrations are not evidence of observed power. Overall, the information in the registry is insufficient to reconstruct the analysis or to judge the precision and robustness of the study findings.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: PRO-POWER: Hypertension With Risk Factors for a Duration of 24 Weeks With Micardis 80mg/Micardis Plus 80mg/12.5mg — NCT00936208.
• Registry record last updated 2014-04-10; status last verified 2014-03.
• Results first posted 2012-07-02.
• 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

PRO-POWER is recorded as a completed observational cohort study with a duration of 24 weeks and an enrollment of 3184. It concerned people with essential hypertension and at least one other cardiovascular risk factor. The two listed groups are Micardis 80mg and Micardis Plus 80mg / 12.5mg; allocation is not stated, and the registry cautions that the groups are not like-for-like controls.

The primary outcome is mean change in diastolic blood pressure from baseline to Week 24, defined as the Week 24 value minus baseline. The stated analysis population requires blood-pressure data at both times. The registry record does not report the primary result, its variability or uncertainty, secondary outcome results, missing-data methods or analysis details. Serious-event counts are recorded as zero in both groups; deaths are not reported.