Investigating the Effect of Telmisartan (Micardis®) on the Average 24h Blood Pressure of Therapy-naive and Therapy-experienced Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Investigating the Effect of Telmisartan (Micardis®) on the Average 24h Blood Pressure of Therapy-naive and Therapy-experienced Patients (NCT00879411), a registered phase not stated study. The primary outcome is Efficacy (Change of Systolic Blood Pressure).

2. Clinical Question

In practical terms, the study was intended to describe blood-pressure change during Micardis use among patients with different prior treatment experience. The record does not establish that any observed change would be attributable to the drug: it identifies no randomized allocation and explicitly cautions that the arms are not a like-for-like control comparison. Without a numerical primary outcome estimate and information about how participants entered each arm, the registry record does not permit a quantitative assessment of the magnitude or precision of change, or a controlled treatment-effect interpretation.

3. Trial Design

The registry describes a practical experience report investigating Micardis® and average 24-hour blood pressure among therapy-naive and therapy-experienced patients with hypertension. The listed sponsor is Boehringer Ingelheim. The record lists enrollment of 670, a start date of 2009-04, primary completion of 2010-01, and status as completed. These administrative details describe the study record; they do not supply outcome estimates.

The primary outcome is a continuous measure: mean change from baseline in 24-hour systolic blood pressure at week 8, expressed in mm Hg. The outcome population is ITT, and the dispersion measure is identified as standard deviation. The listed timeframe is baseline to 8 weeks. The registry also lists Overall Tolerability Scale as a secondary outcome and indicates three outcome measures in total. The record does not describe the remaining outcome measures in detail.

The registry explicitly notes that the study is not a randomized comparison, that allocation is not stated, and that its arms are not a like-for-like control comparison. This matters because differences between groups, if any, cannot automatically be interpreted as differences caused by treatment. The record does not describe a control condition or give enough information to determine how treatment experience or other participant characteristics relate to any arm assignments.

Several design details needed to understand conduct and analysis are not reported in the registry record. These include eligibility criteria, recruitment methods, the number assigned to each arm, treatment dose and schedule, adherence procedures, blinding, and the handling of changes in treatment. A sample-size justification and protocol-level analysis plan are also not reported in the registry record. Consequently, the design can be described only at the level of the practical experience report and the registry’s stated outcome definitions.

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: Intention to Treat (ITT)

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 Efficacy (Change of Systolic Blood Pressure), measured over baseline to 8 weeks.

The primary endpoint is change from baseline in 24-hour systolic blood pressure at week 8. It is measured in mm Hg and summarized as a mean, with standard deviation identified as the measure of dispersion. The outcome is assigned to the ITT population, meaning the registry defines the target analysis population using that label; it does not describe exactly how participants were included or how missing measurements were handled.

A change score expresses how a measurement at follow-up differs from its baseline value. In general, using change can describe the direction and magnitude of within-participant movement over the specified period, while the mean provides a summary across participants. The standard deviation describes the spread of individual change values around that mean; it is not itself a measure of precision for the mean.

Twenty-four-hour systolic blood pressure is the specific clinical measurement named in the registry. The record’s week-8 timeframe makes the endpoint a short-term assessment relative to the stated baseline. The registry does not report the numerical mean change, standard deviation, number of participants with evaluable measurements, confidence interval, or test result. Therefore, the endpoint definition is available, but the observed result and its precision cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry classifies the primary outcome as continuous and identifies the summary as a mean with standard deviation. Those labels describe the type of data and intended summary, but do not provide the observed values. The endpoint is change from baseline in 24-hour systolic blood pressure at week 8, measured in mm Hg, in the ITT population. Numerical outcome results are not reported in the registry record.

What does a mean change describe?

In general, a mean change is the arithmetic average of participants’ follow-up measurements relative to their baseline measurements. It gives a summary of the group’s average movement on the outcome scale. A mean does not show whether all participants changed similarly: different individual patterns can produce the same average. The direction and size of this study’s mean change cannot be described because the registry does not report its value.

The standard deviation describes how spread out individual measurements or changes are around the mean. A larger spread indicates more variability in participant-level values, while a smaller spread indicates values are more closely clustered. Standard deviation is not the same as a standard error or confidence interval: those address uncertainty in an estimated mean, whereas standard deviation describes variation among observations. The registry names standard deviation as the dispersion measure but does not report its numerical value.

What would a confidence interval add?

In general, a confidence interval presents a range of values compatible with an estimate under the assumptions of the analysis. Its width communicates precision: a narrower interval generally indicates greater precision, while a wider interval indicates less precision. It does not resolve design limitations or establish that a result is causal. No confidence interval for the primary endpoint is reported in the registry record, so its precision cannot be evaluated.

What can an analysis population label establish?

The primary population is labeled ITT. In general, intention-to-treat analysis refers to analyzing participants according to their assigned treatment group, regardless of treatment adherence or changes, when a randomized assignment exists. This record states that the study is not a randomized comparison and that allocation is not stated. The label alone therefore does not establish how participants were classified, what data were included, or how the stated population was operationalized. Those details are not reported in the registry record.

Why does the comparison structure matter?

In general, randomization helps balance measured and unmeasured participant characteristics across comparison groups, on average. A nonrandomized comparison can be affected by differences in treatment selection, prior care, health status, or other factors. The registry expressly states that this was not a randomized comparison, allocation is not stated, and arms are not a like-for-like control comparison. Accordingly, any between-arm contrast would need careful interpretation, and the registry record does not provide enough information to assess such a contrast.

Within-group change and between-group difference answer different questions. A within-group change describes movement over time in a group. A between-group contrast compares changes or outcomes across groups and may help separate treatment-associated change from other time-related influences when the design supports that interpretation. The registry’s primary endpoint is described as change from baseline, but no numerical estimate or comparator definition is reported. It is therefore not possible to assess either the observed change or a treatment contrast.

What are the planning assumptions?

The registry includes a planning illustration based on the observed effect, rather than the trial’s own design. It specifies a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect expressed as a stated fraction of the observed effect. The general purpose of such an illustration is to show how a hypothetical future study’s required sample size can depend on the effect size and statistical assumptions. It is not an observed-power calculation and does not establish that this study was designed with those assumptions.

The planning description distinguishes participants per arm for outcomes other than time-to-event outcomes; time-to-event illustrations use a total event count. That convention does not provide this trial’s actual group sizes or observed event count. The registry record does not report a trial-specific sample-size justification, and the numerical outcome estimate on which the planning illustration is based is not reported in the record. The illustration therefore cannot be used to infer the study’s design rationale or the precision of its primary result.

Over-dispersion is a general concern when observed variability exceeds what a statistical model assumes. When that occurs, methods that rely on an overly narrow variance assumption can understate uncertainty. For a continuous endpoint summarized by a mean and standard deviation, the actual distribution and variability can matter to inference. The registry does not report sufficient numerical outcome information or a detailed model to assess distributional assumptions, over-dispersion, or robustness.

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("Telmisartan, Hydrochlorothiazide")
n   <- c(537)
m   <- c(8.6)
sp  <- c(17.8)
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  Telmisartan, Hydrochlorothiazide  537  8.600  17.800  7.091  10.109

11. Multiplicity, Missing Data and Analysis Populations

The registry lists three outcome measures and names Overall Tolerability Scale as a secondary outcome. It does not report a multiplicity strategy, such as a prespecified hierarchy or adjustment across multiple outcomes. In general, testing several outcomes can increase the chance of at least one apparently unusual result when each is assessed separately. A multiplicity plan explains how investigators intended to interpret that collection of tests. Because such a plan is not reported in the registry record, it is not possible to determine whether or how multiplicity was addressed.

The registry identifies the primary outcome as mean change in 24-hour systolic blood pressure from baseline to week 8 in the ITT population. It does not provide a detailed statistical analysis plan, an analysis model, a test, a confidence interval method, or rules for handling protocol deviations. The record lists no analysis records. Accordingly, the endpoint definition should not be mistaken for a complete analysis specification.

Missing-data methods and the extent of missing outcome data are not reported in the registry record. The enrollment figure is 670, but the number with available baseline and week-8 measurements is not reported. In general, missing follow-up measurements can affect both the composition of the analyzed group and the estimated mean change. The effect depends on why data are missing and on the methods used; these cannot be assessed without participant flow and analysis details.

The ITT label does not reveal how missing observations were handled or whether every enrolled participant contributed to the endpoint estimate. Nor does the completed status establish that all planned data were collected. The registry record does not report a missing-data sensitivity analysis, an imputation method, or the number included in each analysis population. These omissions limit assessment of how representative the reported endpoint would be, even if its numerical result were available.

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 a safety group titled “Telmisartan, Hydrochlorothiazide.” For that group, 701 are listed at risk for serious adverse events and 0 are listed as affected. The same at-risk count, 701, and affected count, 0, are listed for other adverse events. The death count is not reported in the registry record, and no top serious adverse event terms are listed.

These are registry counts, not a complete account of safety. A count of 0 affected in the listed group means that the record reports zero affected participants for the stated category and denominator; it does not establish that all possible events were captured or that no events occurred outside the recorded definition or observation period. The registry does not provide detailed event definitions, follow-up duration for safety, collection methods, or a narrative explaining ascertainment.

The listed at-risk count of 701 is distinct from the overall enrollment figure of 670. The registry record does not explain this difference, so it should not be interpreted as evidence of an error or assigned a cause. It also does not report a comparison safety group suitable for a like-for-like contrast. These counts should therefore be read as descriptive registry entries, not as comparative evidence of risk.

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

The record establishes that a practical experience report investigated Micardis® and average 24-hour blood pressure among therapy-naive and therapy-experienced patients with hypertension. It defines a primary endpoint: mean change from baseline in 24-hour systolic blood pressure at week 8, in mm Hg, for an ITT population. It also identifies standard deviation as the dispersion measure. These details clarify what the study set out to measure.

The registry does not report the numerical result for that endpoint. It therefore does not show the observed average change, its direction, its magnitude, or its precision. No confidence interval, standard deviation value, or inferential test result is reported in the registry record. The completed status and enrollment figure do not fill this gap.

The record also does not describe a randomized comparison: it says allocation is not stated and the arms are not a like-for-like control comparison. For that reason, the record does not support interpreting a change over time as a causal treatment effect. In general, a before-and-after pattern may reflect treatment as well as other influences, and an unbalanced comparison can be affected by differences between groups. These are general interpretive considerations; the registry does not report which influences were present in this study.

The findings should not be described as showing that treatment works or does not work. The numerical outcome results needed for such a description are not reported in the registry record, and the design information does not establish a controlled causal comparison. The appropriate conclusion is limited to the study’s stated purpose, population description, endpoint, and the record’s missing outcome and analysis details.

The safety entries are similarly descriptive. The record lists 0 affected for serious adverse events and 0 affected for other adverse events in the group with 701 at risk, but does not report the death count or serious-event terms. These entries do not by themselves establish comprehensive event ascertainment or permit a comparative safety interpretation.

14. Why This Trial Matters Statistically

This record is statistically instructive because it distinguishes a clearly named endpoint from a reported result. The primary measure is defined with a scale, summary, dispersion measure, population label, and timeframe: mean change in 24-hour systolic blood pressure, in mm Hg, from baseline to week 8, with standard deviation, in the ITT population. Yet the numerical result itself is not reported in the registry record. A complete endpoint definition does not guarantee that readers can evaluate effect size or precision.

The study also illustrates why design information matters when interpreting change. It is described as a practical experience report, not a randomized comparison; allocation is not stated, and the arms are not a like-for-like control comparison. In general, a mean change can be useful descriptively, but attributing that change to treatment requires a design and analysis that address competing explanations. The registry information does not establish that basis for causal attribution.

Registry readers also need to distinguish planned calculations from trial findings. The record describes a planning illustration using a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and a fraction of the observed effect. It explicitly characterizes this as planning rather than the trial’s own design. Such assumptions can illustrate how planning depends on effect and design choices, but they do not recover missing outcome results or demonstrate observed power.

Finally, the record shows why safety counts need context. It reports zero affected in the listed serious and other adverse-event categories, while the death count is not reported and the at-risk denominator differs from the overall enrollment figure. Without further detail about event definitions, follow-up, and comparison groups, these entries remain descriptive. Careful statistical reading separates what the registry explicitly states from what its omissions prevent readers from concluding.

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 for interpreting the primary endpoint is that its numerical result is not reported in the registry record. The mean change, standard deviation, confidence interval, and test result are absent. The number of participants contributing baseline and week-8 measurements is also not reported, so the endpoint’s precision and observed-data coverage cannot be assessed.

The comparison structure limits causal interpretation. The registry says this is not a randomized comparison, allocation is not stated, and arms are not a like-for-like control comparison. The comparator and the number assigned to each arm are not reported in the registry record. No adjustment strategy for differences among participants is described.

Further design and conduct details are not reported in the registry record, including eligibility criteria, recruitment, dose and schedule, adherence, blinding, and treatment changes. The record does not provide participant flow, reasons for missing data, or methods for handling missing measurements. It also does not report a detailed statistical analysis plan, a sample-size justification, or a multiplicity strategy.

The registry lists three outcome measures but names only Overall Tolerability Scale as a secondary outcome. The other outcome details and numerical results are not reported in the registry record. The record lists no analysis records. For safety, the group has 701 at risk and 0 affected for serious adverse events, and 701 at risk and 0 affected for other adverse events; the death count is not reported. The record does not explain why the at-risk count differs from the enrollment figure of 670 or describe event ascertainment in detail. These limitations constrain interpretation without explaining why any information is absent.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Investigating the Effect of Telmisartan (Micardis®) on the Average 24h Blood Pressure of Therapy-naive and Therapy-experienced Patients — NCT00879411.
• Registry record last updated 2014-03-28; status last verified 2014-02.
• Results first posted 2012-05-15.
• 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

The registry describes a completed practical experience report sponsored by Boehringer Ingelheim, investigating Micardis® and average 24-hour blood pressure among therapy-naive and therapy-experienced patients with hypertension. Enrollment is listed as 670. The start date is 2009-04 and primary completion is 2010-01.

The primary endpoint is mean change from baseline in 24-hour systolic blood pressure at week 8, in mm Hg, among the ITT population; standard deviation is the stated dispersion measure. Overall Tolerability Scale is named as a secondary outcome, and three outcome measures are listed. Numerical primary outcome results and analysis records are not reported in the registry record.

The registry states that the study is not a randomized comparison, allocation is not stated, and the arms are not a like-for-like control comparison. Safety entries list 0 affected for serious and other adverse events among 701 at risk in the named group; the death count is not reported. The record supports a description of the study’s intent and endpoint, but not an assessment of the primary result’s magnitude or precision.