Effects of Mometasone Furoate/Formoterol Combination Versus Mometasone Furoate Alone in Persistent Asthmatics (Study P04073AM1)(COMPLETED): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effects of Mometasone Furoate/Formoterol Combination Versus Mometasone Furoate Alone in Persistent Asthmatics (Study P04073AM1)(COMPLETED) (NCT00383552), a randomized phase 3 study. The primary outcome is Mean Area Under the Time Curve From 0 to 12 Hours (AUC(0-12 Hours)) of Change From Baseline to Week 12 in Forced Expiratory Volume (Liters) in 1 Second (FEV1).

2. Clinical Question

The study asked whether a mometasone furoate/formoterol combination was associated with a different change in lung function than mometasone furoate alone among people with persistent asthma previously treated with low-dose inhaled glucocorticosteroids. The primary endpoint was the mean area under the curve for change in forced expiratory volume in one second over 0 to 12 hours at Week 12. The registry also describes time to first severe asthma exacerbation during the 26-week treatment period, along with several secondary outcomes.

3. Trial Design

This was a Phase 3, randomized, double-blind, double-dummy, placebo-controlled, parallel-group study of asthma treatments. The registry describes it as multi-center. It was completed, with an enrollment of 746. The study started in 2006-09, and primary completion was in 2008-08.

The double-blind treatment period lasted 26 weeks. Before that period, participants received open-label mometasone furoate metered dose inhaler, 100 mcg twice daily, for 2 to 3 weeks during a run-in. The listed treatment groups were mometasone furoate/formoterol fumarate, mometasone furoate alone, formoterol alone, and placebo. The stated primary comparison was the combination against mometasone furoate alone, even though other groups were part of the study.

Randomization assigns participants to treatment groups by chance, while masking is intended to limit the influence of treatment knowledge on participant or study assessments. In a double-dummy design, treatment assignments can be masked when study treatments differ in their presentation or dosing. These are general descriptions of the design terms; details about how randomization was generated, how masking was maintained, and how allocation was concealed are not reported in the registry record.

The registry lists efficacy outcomes involving lung function, severe asthma exacerbation, asthma control, quality of life, nocturnal awakenings, and body mass index subgroups. It does not report a single consolidated primary comparison result. The trial's detailed protocol, allocation procedures, and reasons for the selected design are 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.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Efficacy analyses were based on randomized participants with Baseline and any post-baseline data (intent-to-treat principle).

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 Mean Area Under the Time Curve From 0 to 12 Hours (AUC(0-12 Hours)) of Change From Baseline to Week 12 in Forced Expiratory Volume (Liters) in 1 Second (FEV1), measured over Baseline to Week 12.

The primary endpoint measures the change in FEV1, the volume of air forcibly exhaled in one second, across a 12-hour period after dosing, summarized as an area under the curve. It concerns the change from baseline to Week 12 and is expressed in liters * hours. For each participant, the baseline reference was the average of two predose FEV1 measurements. Changes from that reference were calculated at serial measurements during the 12-hour period, and the area under the resulting curve was used for the endpoint.

An area-under-the-curve measure can represent both the size and persistence of changes over a specified observation period. As a general statistical concept, it can capture a pattern across repeated measurements rather than relying on a single measurement time. The endpoint therefore describes an average lung-function change across the period, not just a reading at one moment. The registry says the comparison was between mometasone furoate/formoterol and mometasone furoate alone, and that the reported parameter was a least-squares mean with pooled standard deviation.

The registry does not report the primary estimate, its uncertainty, or a single result for the comparison. It is therefore not possible to describe the size, direction, or precision of the observed difference from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry labels the primary endpoint as a continuous measure and reports a least-squares mean with pooled standard deviation. The endpoint is an area under the curve of change in FEV1 from baseline to Week 12. The following explains the statistical terms in general; the detailed analysis model is not reported in the registry record.

What does a least-squares mean represent?

A least-squares mean is generally an estimate derived from a statistical model, rather than a simple arithmetic average of all observed values. Depending on the model, it may account for specified covariates or features of the design. The registry identifies the measure as a least-squares mean but does not state the model, covariates, estimation method, or exact contrast calculation. It is therefore not possible to determine which adjustments were made or to reproduce the estimate from the registry description.

For a two-group comparison, the central quantity of interest is commonly a difference between group estimates. Its sign indicates which group has the higher estimated value under the chosen coding, and its size expresses the contrast in the endpoint's units. However, a single contrast and its direction are not reported. The registry's outcome description alone cannot establish whether the combination group's value was higher or lower than the mometasone furoate group's value.

Why is a standard deviation useful?

A standard deviation describes the spread of individual observations around a group mean. It is not the same as the uncertainty of the estimated group mean or of a between-group contrast. That uncertainty also depends on factors such as the analysis population and the number of observations contributing to the estimate. The registry says the standard deviation was pooled, meaning that the reported variability measure was combined across the comparison groups under an assumption of shared variability. The pooled standard deviation itself is not reported in the registry record.

As a general concept, pooling can be useful when a common within-group variability is a reasonable working assumption. If the groups have meaningfully different variability, a common pooled value may not describe each group well. The registry does not report diagnostic checks or other details that would show how this assumption was assessed. A standard deviation also does not by itself provide a confidence interval or establish whether a contrast is statistically distinguishable from zero.

How should the area-under-the-curve outcome be understood?

The registry describes baseline as the average of two predose FEV1 measurements. Serial measurements during the following 12-hour period were expressed as changes from that baseline, and the area under those changes was calculated. In general, this approach uses information across repeated measurements and summarizes the accumulated change over the observation window. The unit, liters * hours, reflects a volume measure summarized across time. The registry does not report the serial measurement schedule, the precise numerical integration procedure, or how measurements missing during that period were handled.

Because this is a continuous endpoint, the statistical analysis would ordinarily summarize a distribution of measured values and estimate a group contrast. That general description does not establish which particular statistical test or model was used. The registry does not report whether assumptions about the outcome distribution were examined, how repeated measurements were incorporated in the model, or whether any transformation was used.

What can be inferred from the analysis population statement?

The stated efficacy population includes randomized participants who had baseline and any post-baseline data, described as following the intent-to-treat principle. This defines eligibility for the efficacy analysis in broad terms, but it does not state how many participants contributed to this endpoint or how incomplete observations were treated. The term intent-to-treat can refer to analyzing participants according to assigned group, but the registry's specific population wording requires baseline and post-baseline data. It does not establish that every randomized participant was included in every analysis.

These distinctions matter because the estimate can depend on which measurements are available and how missing observations are addressed. General approaches include analyzing observed data under stated assumptions, imputing missing values, or using a model designed for incomplete repeated measurements. The registry record does not identify the approach, its assumptions, or any sensitivity analysis. No numerical primary estimate or uncertainty interval is reported, so the method terms in the record cannot be used to reconstruct the trial result.

What does a planning calculation mean?

Any sample-size illustrations associated with the statistical output are planning calculations based on an observed effect and stated assumptions, not observed trial findings. The stated assumptions include a two-sided significance level of 0.05, equal allocation for the two arms, and a normal approximation; the target effect is described as a fraction of the observed effect. For continuous outcomes, such illustrations are expressed as participants per arm for 80% power or another stated planning target. Such calculations describe hypothetical planning under assumptions. They are not the trial's actual enrollment, and they are not observed power. The planning outputs and a usable observed primary effect are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists multiple outcomes: the primary lung-function measure, time to first severe asthma exacerbation, and secondary measures involving asthma control, quality of life, nocturnal awakening, trough FEV1, and body mass index subgroups. Testing or estimating several outcomes can raise multiplicity concerns. In general, multiplicity means that interpretation of a collection of statistical tests may differ from interpretation of one test, particularly if no adjustment or hierarchy is specified. The registry record does not report a multiplicity adjustment, testing hierarchy, or a statistical analysis plan that would clarify how these outcomes were prioritized.

The record identifies the efficacy analysis population as randomized participants with baseline and any post-baseline data. It does not report the number analyzed for the primary endpoint, the number excluded from that analysis, or the reasons for any exclusions. The missing-data method, assumptions about incomplete measurements, and sensitivity analyses are not reported in the registry record. Thus, the population definition is informative but does not fully explain how missing observations affected the estimates.

The registry does not report whether there were interim analyses, whether the primary analysis was adjusted for baseline characteristics, or how multiple observations within a participant were handled statistically. These details are not inferable from the design description. Because no single primary comparison result is reported, multiplicity procedures and missing-data methods cannot be connected to a reported estimate or used to assess the robustness of a result.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: pulmonary valve stenosis (0.5%), goitre (0.5%), uterine leiomyoma (0.5%), dysfunctional uterine bleeding (0.5%), pneumothorax (0.5%).

The registry lists serious adverse events and other adverse events separately for the open-label run-in and the double-blind groups. For the open-label mometasone furoate group, 2 of 882 participants at risk were reported with serious adverse events, and 22 of 882 were reported with other adverse events. For the double-blind combination group, the corresponding figures were 4 of 182 and 33 of 182. For mometasone furoate alone, they were 5 of 188 and 37 of 188. For formoterol alone, they were 1 of 188 and 32 of 188. For placebo, they were 1 of 188 and 24 of 188.

These are counts of participants reported as affected, not a measure of the severity or duration of every event. The registry lists pulmonary valve stenosis, goitre, uterine leiomyoma, dysfunctional uterine bleeding, pneumothorax, and deafness among serious event terms, each at 0.5%. The record does not provide enough context to interpret these terms as caused by a treatment. Death figures are not reported in the registry record.

The open-label run-in and double-blind treatment groups have different reporting frames, and the registry does not explain their relationship. These counts alone do not establish comparative risk; interpretation also depends on exposure, follow-up, event definitions, and analysis procedures.

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

The record establishes the trial question, design, endpoint definition, and broad efficacy population. It also gives safety counts for an open-label run-in group and the double-blind treatment groups. These details help explain what was intended to be compared and what kinds of outcomes were collected. They do not establish the magnitude or direction of the primary treatment contrast.

The primary endpoint is a continuous measure of change in FEV1 summarized over a 12-hour period at Week 12. The registry does not report a single estimate for the combination versus mometasone furoate comparison, a confidence interval, or a p-value. Therefore, it is not possible to tell from this record whether the observed group estimates differed, how large any difference was, or how precisely it was measured. Absence of that result is not evidence of equivalence or of no effect.

The other listed outcomes cannot fill that gap. Lung function at a different time, asthma control, quality of life, nocturnal symptoms, and time to exacerbation are distinct measures. Each would need its own estimate and uncertainty for meaningful statistical interpretation. Subgroup findings would additionally require information about the subgroup analysis and its precision. Those results are not reported in the registry record in the information available for this analysis.

Safety counts provide a descriptive account of reported events in the listed groups. They do not, by themselves, demonstrate that an event was caused by treatment, nor do they describe the full balance of benefits and harms. The registry's event counts and percentages should be read as reported, without deriving comparative rates or causal conclusions from them.

Overall, the registry supports a description of the study's structure and planned clinical question, but not a conclusion about the primary result. Statistical interpretation of effectiveness would require a reported contrast and an accompanying measure of uncertainty, as well as enough analysis detail to understand the population and handling of missing data.

13. Why This Trial Matters Statistically

This study illustrates why a clearly defined endpoint is not the same as a fully interpretable result. The registry explains how the primary lung-function measure was constructed: baseline-referenced FEV1 changes were summarized over a 12-hour interval and assessed at Week 12. That description tells readers what the outcome was intended to represent. But an endpoint definition cannot show the size or precision of a treatment contrast without the reported estimate and uncertainty.

The registry also distinguishes a main comparison from a larger multi-group study. The primary comparison was the combination inhaler versus mometasone furoate alone, while the listed design includes formoterol and placebo groups as well. Multiple outcomes are named, including a continuous lung-function measure and time to severe asthma exacerbation. Statistically, clear outcome priorities and a transparent approach to multiplicity help readers understand which findings are confirmatory and how a collection of results should be interpreted. Those details are not reported in the registry record.

The record's efficacy population statement is another useful reminder that an analysis population is part of a result's meaning. Restricting an analysis to participants with baseline and post-baseline data may matter when observations are incomplete. Without the number analyzed and the missing-data approach, readers cannot judge how those choices might affect an estimate.

Finally, safety counts are informative as descriptions but are not self-interpreting comparisons. Exposure, follow-up, definitions, and analysis context are all relevant. This trial therefore demonstrates the value of reporting estimates, uncertainty, analysis populations, missing-data methods, and outcome hierarchy alongside endpoint definitions and event counts.

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 key limitation for interpreting efficacy is that the registry does not report a single result for the primary comparison. The primary endpoint description is available, but the estimate, its uncertainty, and a significance test are not reported in a form that permits direct interpretation. The registry indicates that the primary outcome has several categories or time points and is not reduced to one comparison, leaving the precise result structure unclear.

Important analysis details are also absent. The statistical model and covariates underlying the least-squares mean are not reported. The registry does not state the method for handling missing endpoint data, give the number analyzed for the primary outcome, or describe sensitivity analyses. It does not report a multiplicity strategy, analysis plan, or whether interim analyses took place.

The available safety information also has limits. The relationship between the open-label run-in group and the double-blind treatment groups is not explained. The listed event counts do not provide treatment exposure or enough analysis detail to support a causal comparison. Death figures are not reported in the registry record.

Finally, the registry lists several outcomes, but results for those outcomes are not available for interpretation in the information. No protocol-level detail is reported to clarify the planned outcome hierarchy or how the analyses were intended to address multiple comparisons. These limitations restrict what can be concluded from the registry record, and should not be mistaken for evidence that the trial found no difference.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Effects of Mometasone Furoate/Formoterol Combination Versus Mometasone Furoate Alone in Persistent Asthmatics (Study P04073AM1)(COMPLETED) — NCT00383552.
• Registry record last updated 2024-05-17; status last verified 2022-02.
• Results first posted 2011-10-25.
• 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

NCT00383552 was a completed Phase 3 randomized, double-blind, double-dummy, placebo-controlled parallel-group study in persistent asthma. It enrolled 746 participants and compared mometasone furoate/formoterol with mometasone furoate alone as the primary treatment contrast, with formoterol and placebo also listed as groups. The double-blind treatment period lasted 26 weeks and followed an open-label mometasone furoate run-in of 2 to 3 weeks.

The primary endpoint was the mean area under the curve for change from baseline in FEV1 over 0 to 12 hours at Week 12. The registry describes the endpoint calculation and efficacy population but does not report a single primary comparison result or its precision. It also lists secondary outcomes and adverse-event counts. The main statistical limitation is that the record does not permit an estimate of the direction, magnitude, or uncertainty of the primary contrast.