Safety Study Comparing Phenylephrine HCL Extended Release Tablets 30 mg and Placebo (Study CL2007-07)(P07529)(COMPLETED): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety Study Comparing Phenylephrine HCL Extended Release Tablets 30 mg and Placebo (Study CL2007-07)(P07529)(COMPLETED) (NCT00874120), a randomized phase 3 study. The primary outcome is Average Systolic Blood Pressure (SBP) Readings for a 5-hour Range Around the Time of Maximum Concentration (Tmax)..

2. Clinical Question

This is a question about the measured blood-pressure outcome under the study conditions, rather than a broad question about every possible effect of the treatment. The endpoint focuses on readings around the time of maximum concentration, defined in the registry as approximately 2 hours before to approximately 2 hours after that time, including it. It is not a comparison of all blood pressure readings over every period of the study.

Because this was a crossover study, participants received both treatment conditions. The comparison therefore concerns readings during the phenylephrine period versus readings during the placebo period in the same study population. The sequence descriptions indicate that some participants received phenylephrine first and others placebo first. The registry record does not report details of how the sequence was incorporated into the statistical model.

The posted means are 118.3 mmHg for phenylephrine and 118.6 mmHg for placebo. The sponsor-reported ANOVA gives a residual error term from the ANOVA of -0.5, with a 95% confidence interval from -2.0 to 1.1 and p = 0.548 in the registry record. A simple unadjusted recalculation gives a mean difference of -0.3 and a 95% confidence interval from -2.881 to 2.281. These are different analyses, and each should be interpreted with its method and uncertainty in view.

3. Trial Design

The registry describes a randomized, double-blind, placebo-controlled, two-way crossover study. It is listed as Phase 3 and completed. The sponsor was Bayer. The study title identifies phenylephrine HCl extended-release tablets 30 mg and placebo, and the official title specifies ambulatory blood pressure as the outcome area. The registry lists 116 participants enrolled.

According to the brief summary, participants were randomized on Day 1 to a 7-day period of active treatment or placebo. After a 6-8 day washout period, participants entered a second 7-day period of double-blind treatment with the other agent. Thus each participant was scheduled to receive both treatment conditions, with treatment order varied between participants. This arrangement allows a within-participant comparison, while the washout is intended to separate treatment periods. Whether the washout was sufficient to address any carryover effect is not established by the posted results.

Ambulatory blood pressure monitoring was to begin on Day 7 of each treatment period, following administration of the study drug. The primary endpoint timeframe is stated as 24 hours after the final dose of each 7-day treatment period. The endpoint description defines the analysis window around maximum concentration as approximately 2 hours before to approximately 2 hours after maximum concentration, including that time.

The primary population was per protocol. It included 100 participants who completed both treatment periods and had 24-hour ambulatory blood pressure monitoring data for systolic blood pressure for each study drug. The registry reports 46 participants in the phenylephrine-then-placebo sequence and 54 in the placebo-then-phenylephrine sequence. The brief summary says 116 subjects were randomized with the aim of obtaining 98 completed subjects. These counts describe different aspects of the record: randomized enrollment, the stated completion target, and the per-protocol analysis population.

The registry reports ANOVA as the method for comparing treatments and says a 95% two-sided confidence interval on the treatment difference would also be presented. Further detail about the model, treatment of period or sequence, protocol deviations, or the original sample-size rationale is 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.

First Intervention

Reasons for not completing this period:

Wash-out Period

Second Intervention

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The per-protocol population included 100 participants who completed both treatment periods and have 24-hour Ambulatory Blood Pressure Monitoring (ABPM) data for SBP measurements for each study drug, 46 participants who received phenylephrine followed by placebo and 54 participants who received placebo followed by phenylephrine.

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 Average Systolic Blood Pressure (SBP) Readings for a 5-hour Range Around the Time of Maximum Concentration (Tmax)., measured over 24 hours after final dose of each 7-day treatment period..

The primary endpoint is the average systolic blood pressure reading, in mmHg, across a 5-hour range around the time of maximum concentration. The registry defines that interval as approximately 2 hours before to approximately 2 hours after maximum concentration, including maximum concentration. Measurements were taken using 24-hour ambulatory blood pressure monitoring, with the endpoint timeframe stated as 24 hours after the final dose of each treatment period.

Systolic blood pressure is the pressure recorded during the heart’s contraction. As a continuous measure, it can be summarized with a mean and a measure of spread. The posted summaries give a mean and standard deviation for each treatment condition. Comparing average readings condenses the repeated measurements in the specified time window into a treatment-level summary, making it possible to estimate and describe the average contrast between phenylephrine and placebo.

The endpoint’s time window is a specific feature of the question: it concentrates on readings around the stated time of maximum concentration rather than treating all measurements during the full monitoring period as the primary outcome. The registry says the parameters would be compared using ANOVA and that a 95% two-sided confidence interval for the difference between treatments would be presented.

Why this particular measure and window were selected, and whether additional endpoint definitions were considered, are not reported in the registry record. The posted primary result should therefore be read as an estimate for this defined average systolic blood pressure outcome and timeframe, not as a summary of every blood pressure measure or every possible treatment effect.

7. Results Posted in the Registry

• Phenylephrine: mean 118.30 versus 118.60 on control; difference -0.30 (95% CI -2.88 to 2.28), standardized effect d = -0.03; z-test p = 0.820.

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: it is an average systolic blood pressure measurement in mmHg. A continuous outcome can take a range of values, and a mean describes its central level. The standard deviation describes how dispersed individual observations are around that mean. These summaries are useful for describing the observed measurements, but the mean difference and its uncertainty are needed to assess the treatment comparison.

What does the ANOVA result represent?

The registry identifies analysis of variance, or ANOVA, as the method for comparing the active treatment and placebo. In general, ANOVA is a framework for comparing means while representing variation in an outcome. For a crossover study, an analysis may account for the fact that the same participants receive both conditions and may include other design features. The registry does not report enough detail to specify which terms were included in this ANOVA or how the crossover structure was represented.

The reported analysis is labelled as a residual error term from the ANOVA, with an estimate of -0.5, a 95% confidence interval from -2.0 to 1.1, and p = 0.548. The record does not provide a fuller description of the contrast coding or model output. It is therefore important not to treat the label as interchangeable with every possible way of calculating a raw difference between the posted treatment means. The sponsor’s estimate and the simple unadjusted estimate arise from different statistical approaches.

What is the unadjusted recalculation?

The recalculated mean difference uses the posted treatment means and summary measures in a simple unadjusted comparison. It is -0.3 mmHg, with a 95% confidence interval from -2.881 to 2.281 and p = 0.82. The calculation does not use participant-level observations, does not adjust for other variables, and does not incorporate the within-person pairing of a crossover design. It is a useful check on the scale and direction of the treatment summaries, but it is not a reanalysis of the original crossover data.

That distinction matters because treatment-period measurements from one participant are often related. If a participant tends to have higher readings in both periods, accounting for that shared tendency can affect the estimated variability of the treatment contrast. General statistical principle: the efficiency of a paired comparison depends on the within-participant relationship. The posted group-level means and standard deviations do not disclose that relationship, so it cannot be recovered from those summaries alone.

What does the confidence interval add?

A confidence interval communicates uncertainty around an estimated contrast. In general, a 95% confidence interval is produced by a procedure that, under its assumptions, would cover the fixed underlying parameter in 95% of repeated samples. It is not a statement that there is a 95% probability that this particular interval contains the true value. A broad interval indicates less precision than a narrow one, while inclusion of zero means that no difference is among the values compatible with the interval at that confidence level.

For the sponsor-reported ANOVA estimate, the confidence interval extends from -2.0 to 1.1. For the simple unadjusted recalculation, it extends from -2.881 to 2.281. Both intervals include zero, and their endpoints are not identical because the analyses differ. The registry does not give a prespecified threshold for a difference that would be considered important, so the intervals cannot be judged against such a threshold from this record.

How should the p-values be read?

A p-value measures how incompatible the observed data, or data more extreme, would be with a specified null model, if the model assumptions hold. It is not the probability that the null hypothesis is true, nor is it a direct measure of the size or clinical importance of an effect. The sponsor-reported p-value is 0.548 in the registry record; the recalculated unadjusted p-value is 0.82. Both are above 0.05, but a p-value above that threshold is not proof of no effect. Interpretation also depends on the estimate, interval, design, and analysis assumptions.

General statistical principle: a study may fail to produce strong evidence of a difference because the underlying contrast is small, because estimates are imprecise, or because both conditions apply. The interval is useful for seeing the range of effect sizes compatible with the analysis. It should be considered alongside the trial’s population and endpoint rather than reduced to a binary significant-or-not label.

Why does over-dispersion matter?

General explanation: over-dispersion occurs when variability in the data is greater than a statistical model expects. It is especially relevant to some count outcomes, where a simple model may assume that the mean and variance have a particular relationship. If actual variability is larger, standard errors can be underestimated and confidence intervals can be too narrow unless the model accounts for the extra variation. The primary outcome in this study is a continuous blood pressure measure, and the registry record does not report an over-dispersion issue. This concept is included as a general distinction, not as a finding about this trial.

The registry reports one primary outcome measure and one analysis, with no secondary outcomes posted. Its description says that a 95% two-sided confidence interval would be presented and identifies ANOVA. The exact statistical plan, model specification, handling of missing measurements, and any interim analyses are not reported in the registry record. Those details should not be inferred from the outcome summaries.

10. Confidence Intervals and Precision

Precision concerns how tightly the data locate the treatment contrast. The sponsor-reported ANOVA estimate is -0.5, with a 95% confidence interval from -2.0 to 1.1. The simple unadjusted recalculation is -0.3 mmHg, with a 95% confidence interval from -2.881 to 2.281. Both intervals cross zero. Thus neither result pins the treatment difference to one direction, and the estimates remain compatible with no difference as well as with values on either side of zero.

The interval widths also show why an absence of statistical significance is not the same as evidence that the treatments produce exactly equal readings. A confidence interval does not list every possible value with equal support, and its interpretation relies on the assumptions of the analysis. In general, more precise data yield narrower intervals, while greater variability or less information tends to yield wider intervals.

The sponsor’s interval is tied to the reported ANOVA quantity, whereas the recalculated interval comes from an unadjusted summary-statistic comparison. Their different estimates and limits should not be treated as a contradiction without knowing the model and data structure behind the ANOVA. In particular, the recalculation does not account for participant-level pairing in the crossover design. The registry record does not provide the individual observations or enough model detail to independently reproduce the sponsor’s interval.

The posted standard deviations are 9.24 for phenylephrine and 9.38 for placebo, with 100 listed for each treatment summary. The per-protocol description identifies 100 participants who completed both treatment periods. In a crossover study, those treatment summaries refer to observations from the same participants rather than two distinct sets of 100 people. The shared participants and their correlation are relevant to precision, but that correlation is not reported.

No clinical importance threshold is stated in the registry record. Consequently, the confidence intervals can describe statistical uncertainty but cannot establish whether all values they include would be considered unimportant or meaningful in a clinical context. The sponsor-reported estimate and the recalculation both support a cautious reading: the observed means are close, yet the available summaries do not eliminate uncertainty about the treatment contrast.

11. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm for the stated power targets, not total events. This is a continuous-outcome comparison, and the illustration uses equal allocation between two arms. Its listed assumptions are a two-sided significance level 0.05, a normal approximation, equal allocation, and an effect to detect set to the stated fraction of the observed effect. The original trial’s sample-size assumptions and justification are not reported in the registry record.

The 80% power column describes an illustrative design intended to have an 80% chance of detecting the selected effect under the planning assumptions, if that effect and assumptions were correct. The 90% power column describes the corresponding illustration for a 90% chance. These are design-planning concepts, not guarantees about a particular study or its result. They do not mean that the completed trial had an 80% or 90% probability of finding an effect.

The rows use different fractions of the observed effect: 100%, 75%, and 50%. As the target effect becomes smaller, more participants per arm are needed under the same assumptions, because smaller differences are harder to distinguish from random variation. For example, the displayed planning requirements increase from 15,119 to 26,878 to 60,476 participants per arm for 80% power across those effect assumptions. The 90% column likewise increases from 20,240 to 35,982 to 80,960 participants per arm.

The curve conveys the same relationship between the effect size chosen for planning and the number of participants required. These figures are not observed power and are not a retrospective measure of the likelihood that this trial detected a treatment difference. They are planning illustrations calculated from the observed effect under the stated assumptions. The trial used a crossover design, while the illustration is described in terms of equal allocation between two arms; it should not be mistaken for the study’s original design calculation or a tailored crossover sample-size analysis.

12. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -0.300; pooled standard deviation σ = 9.310.
2. n = 2 × (1.96 + 0.842)² × 9.310² / -0.300² = 15,118.9, rounded up to 15,119 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -0.299999999999997                      # observed difference in means
sigma <- 9.31026315417561                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(874120)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 15,119 (80% power), 20,240 (90% power)
 75% of observed effect: n per arm = 26,878 (80% power), 35,982 (90% power)
 50% of observed effect: n per arm = 60,476 (80% power), 80,960 (90% power)
power.t.test: 15119.8 
Simulated power at n = 15,119 per arm: 0.796 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

13. Analyses Reported by the Sponsor

The sponsor-reported analysis is the ANOVA result in the registry: a residual error term of -0.5, with a 95% confidence interval from -2.0 to 1.1 and p = 0.548. The simple recalculation from the posted summary statistics gives a mean difference of -0.3, a 95% confidence interval from -2.881 to 2.281, and p = 0.82. The registry record does not mark a discrepancy between the posted analysis and the recalculation.

The recalculation is deliberately unadjusted. It uses summary statistics rather than participant-level data and does not incorporate the within-person relationship expected in a crossover trial. The sponsor’s ANOVA may reflect a model-based analysis, but the model terms and contrast coding are not reported in the registry record. The two estimates therefore should be presented as results from distinct approaches, not forced into numerical agreement.

The sponsor’s result is the trial-reported inferential analysis; the recalculation is a transparent descriptive check, not a replacement for it. Both estimates are near zero and both confidence intervals include zero. Their different p-values do not change the basic limitation that the registry does not provide enough detail to reproduce the ANOVA or to assess all of its assumptions.

Because the discrepancy indicator is false, the record does not identify a conflict requiring the recalculation to be set aside on that basis. Still, the sponsor’s own analysis remains the appropriate result to cite as the reported trial analysis, while the unadjusted calculation should be clearly labelled as such.

14. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure and one analysis, and it reports no secondary outcomes. That limits what can be assessed from the posted results: there is no set of multiple posted outcome tests to review for multiplicity. Whether the broader study protocol included additional outcomes or analyses is not reported in the registry record.

Multiplicity arises when several hypotheses, outcomes, timepoints, or subgroups are tested. General statistical principle: with many tests, the chance of at least one apparently unusual result can increase unless the analysis plan addresses that issue. The registry does not report whether any adjustment or hierarchical strategy was planned, and no such method should be inferred from the single posted primary analysis.

The record gives a per-protocol analysis population of 100 participants who completed both treatment periods and had 24-hour ambulatory blood pressure monitoring data for systolic blood pressure for each study drug. It also reports randomized enrollment of 116 in the brief summary and says the study aimed to obtain 98 completed subjects. The record does not give a participant flow accounting for every randomized participant, reasons for non-completion, or a comparison of included and excluded participants.

Missing-data methods are not reported in the registry record. In particular, the record does not explain how incomplete monitoring, missing readings, or other unavailable measurements were handled, or whether any imputation was used. The requirement for complete data in both treatment periods defines the stated per-protocol population, but does not describe the handling of missing data outside that population.

The registry identifies the per-protocol population, but an intention-to-treat analysis is not reported. Additional analysis populations, sensitivity analyses, and protocol-deviation rules are not reported in the registry record. These omissions matter because analysis population and missing-data choices can affect both the estimand and uncertainty, especially when a participant must contribute information from both periods for the stated per-protocol comparison.

The study is described as randomized and double-blind, but those design labels do not supply the missing details about sequence allocation, masking assessment, model specification, period effects, carryover effects, interim analyses, or prespecified multiplicity handling. These items should be treated as unknown rather than assumed absent or present.

15. 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 posted serious adverse event figures list 114 participants at risk in the phenylephrine group and 111 at risk in the placebo group. The number affected by a serious adverse event is reported as 0 in each group. The registry also lists 114 and 111 participants at risk for other adverse events, respectively, and reports 0 affected in each group for those entries.

These figures describe the adverse-event counts recorded in the registry, not an estimate of comparative risk with a confidence interval. The at-risk counts differ from the 100 participants in the per-protocol efficacy population, and the record does not explain the relationship between the safety populations and the per-protocol population. The group labels in the safety listing should be read as displayed, not as proof that each listed group represents a distinct set of participants in this crossover study.

A zero count in a posted field means that no affected participants are recorded for that category in that entry. It does not establish that the underlying risk is exactly zero or exclude events not captured in the record. The registry does not report deaths in the displayed safety fields, and it provides no top serious adverse event terms. The duration and broader scope of safety follow-up beyond the described treatment periods are not reported in the registry record.

These counts are descriptive safety information only. They should not be used to make medical decisions or to claim that one treatment is safer than the other. The record does not provide a comparative safety analysis, detailed event descriptions, or enough information to characterize rare events.

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

The results describe a specific comparison: average systolic blood pressure in a defined 5-hour window around maximum concentration, after the final dose of each 7-day treatment period, among the per-protocol participants with monitoring data for both treatments. The posted means are 118.3 mmHg with phenylephrine and 118.6 mmHg with placebo. The sponsor-reported ANOVA estimate is -0.5 with a 95% confidence interval from -2.0 to 1.1; the simple unadjusted recalculation is -0.3 mmHg with a 95% confidence interval from -2.881 to 2.281.

Both confidence intervals include zero. The registry’s results therefore do not show a statistically clear difference under the reported analysis or the simple recalculation. That does not prove there is no difference, and it does not establish that the treatments are equivalent. The intervals leave uncertainty about the magnitude and direction of the contrast. The registry does not state a clinical threshold for interpreting the size of that contrast.

The evidence is limited to the selected outcome, time window, treatment conditions, and analysis population. It does not answer questions about other blood pressure outcomes, other timepoints, other populations, or longer-term outcomes. The registry reports no secondary outcome results. The absence of posted results for other outcomes should not be interpreted as evidence about them.

The study’s crossover design means that participants were intended to receive both treatment conditions, with a washout between periods. That structure can support a within-participant comparison, but the available group-level summaries do not show the relationship between each participant’s readings under the two treatments. The recalculation does not use that pairing; the ANOVA is the sponsor-reported comparison, but its detailed specification is unavailable in the registry record.

The safety entries record zero affected participants for serious adverse events in both displayed groups, with the stated at-risk counts. Those entries are limited registry data and do not amount to a complete assessment of all possible safety outcomes. Taken together, the record supports a careful description of the posted primary result and its uncertainty, rather than a broad claim about treatment effects or safety.

17. Why This Trial Matters Statistically

This trial is statistically instructive because a crossover design and group-level summaries create an important distinction between the trial analysis and a simple recalculation. The same participants were scheduled to receive phenylephrine and placebo. A comparison that uses each participant as their own reference can use information about within-person change, but that information is not available from the posted means and standard deviations alone.

The record reports an ANOVA result and also provides enough summary statistics for a basic unadjusted recalculation. Their estimates and intervals are not identical. This illustrates why an analysis label, model specification, and design structure matter: the numbers cannot be interpreted as though every analysis uses the same assumptions or information. The recalculation is useful as a check, but it should not be presented as reproducing the sponsor’s crossover analysis.

The results also show why statistical significance and precision are different questions. Both reported intervals include zero, but neither interval proves equality. The estimate identifies the observed direction and scale, while the interval communicates remaining uncertainty. Without a prespecified clinical threshold, statistical uncertainty cannot be translated into a judgment about the importance of every value in the interval.

Finally, planning calculations based on an observed effect can generate very large participant requirements when the target effect is made smaller. Those values are illustrative, depend on stated assumptions, and are not observed power or the original study’s design justification. Keeping planning scenarios separate from the completed trial’s evidence prevents a retrospective calculation from being mistaken for a property of the observed result.

18. 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 registry record leaves important analysis details unspecified. It names ANOVA but does not give the model terms, contrast coding, treatment of period and sequence, or the way the crossover structure was handled. The sponsor-reported estimate is labelled as a residual error term from the ANOVA, and the record does not provide enough detail to reconstruct its interpretation beyond the reported estimate, interval, and p-value.

The primary analysis population is per protocol and requires completion of both treatment periods and available 24-hour monitoring data for each study drug. The record does not explain reasons for exclusion, participant flow after randomization, missing-data handling, or results from an intention-to-treat population. This limits assessment of how the analysis population relates to all randomized participants.

The simple recalculation uses posted summary statistics and does not account for within-participant pairing. That is a specific limitation for a crossover design. The registry does not report the participant-level treatment differences or their variability, so an unadjusted recalculation cannot recover the precision of a paired analysis.

The study description includes a 6-8 day washout, but the record does not report analyses of carryover or period effects, or evidence supporting the washout duration. It also does not provide the original sample-size justification, the full statistical analysis plan, interim-analysis details, or a clinical importance threshold for the primary endpoint.

The safety entries are limited to the counts posted for the listed groups. They do not give detailed event narratives, comparative estimates, or fuller follow-up information. The record reports one primary endpoint and one analysis and no secondary results, limiting assessment of a broader outcome profile. These are limitations of the available registry record; they do not establish that the unreported procedures or analyses were not performed.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Safety Study Comparing Phenylephrine HCL Extended Release Tablets 30 mg and Placebo (Study CL2007-07)(P07529)(COMPLETED) — NCT00874120.
• Registry record last updated 2015-03-11; status last verified 2015-02.
• Results first posted 2010-07-05.
• 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.

22. Record Summary

NCT00874120 is a completed Phase 3 randomized, double-blind, placebo-controlled crossover study sponsored by Bayer. The registry lists 116 participants enrolled. The brief summary describes two 7-day treatment periods separated by a 6-8 day washout, with each participant receiving phenylephrine HCl extended-release tablets 30 mg and placebo.

The primary endpoint was average systolic blood pressure in mmHg in a 5-hour range around maximum concentration, measured 24 hours after the final dose of each treatment period. The per-protocol population included 100 participants with both treatment periods completed and monitoring data for both treatments.

The sponsor-reported ANOVA estimate was -0.5, with a 95% confidence interval from -2.0 to 1.1 and p = 0.548. A simple unadjusted recalculation gave a mean difference of -0.3 mmHg, with a 95% confidence interval from -2.881 to 2.281 and p = 0.82. Both intervals include zero; the recalculation does not replace the sponsor’s analysis. The registry reports zero affected participants for the posted serious adverse event entries in both groups.