Effect of Brovana and Tiotropium in Chronic Obstructive Pulmonary Disease (COPD): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effect of Brovana and Tiotropium in Chronic Obstructive Pulmonary Disease (COPD) (NCT00773786), a randomized phase 4 study. The primary outcome is Change From Baseline in Forced Expiratory Volume in 1 Second (FEV1) at 1 Week.

2. Clinical Question

The study was intended as short-term proof-of-concept work: its summary describes examining whether an anticipated additional bronchodilator effect might be accompanied by a meaningful change in exercise capacity. Exercise endurance appears in the official title and summary, but the listed primary endpoint is FEV1. The registry lists change in forced vital capacity (FVC) and inspiratory capacity as secondary outcomes. It also lists three outcome measures overall. The recorded information therefore identifies the clinical question and planned outcome domains, but does not establish what the observed results were or how precisely any treatment contrast was estimated.

3. Trial Design

This was a randomized, quadruple-masked, phase 4 crossover study, marked completed in the registry. The record lists enrollment of 20 participants with COPD. Its official title describes a double-blind study, while the design fields specify quadruple masking. The study began in 2008-10, with primary completion in 2009-05. Trinity Health Of New England is listed as the sponsor.

In a crossover design, participants receive more than one treatment condition, allowing measurements under the different conditions to be compared within the same people. This can help account for stable differences between participants. The record identifies arformoterol and placebo as the two interventions, and describes each as twice daily for 1 week; the arformoterol was administered via nebulizer. The study summary says it would evaluate short-term, 1-week administration of Brovana. The treatment order, the timing and details of treatment transitions, and whether a washout period was used are not reported in the registry record.

Randomization is reported, but the method used to generate the treatment sequence and how allocation was implemented are not reported in the registry record. The record does not describe who was masked beyond the masking designation, nor does it explain how masking was maintained. It lists baseline and 1-week measurements for the primary endpoint, with FEV1 measured 2 hours post dose. The registry also lists secondary changes in FVC and inspiratory capacity at 1 week.

Enrollment is not the same as the number of participants with complete measurements or included in each analysis. Completion by participants, exclusions, and analysis populations are not reported in the registry record. Nor are protocol details such as sample-size justification, planned interim analyses, or a detailed statistical analysis plan. The completed status describes the trial’s registry status; it does not by itself tell readers whether all planned outcomes were measured or analyzed.

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 (1 Week)

Washout (1 Week)

Second Intervention (1 Week)

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 From Baseline in Forced Expiratory Volume in 1 Second (FEV1) at 1 Week, measured over baseline and 1 week.

The primary endpoint was change from baseline in forced expiratory volume in 1 second (FEV1) at 1 week, measured in liters. The registry defines change as the 1-week value minus the baseline value and specifies that FEV1 was measured 2 hours after dosing. The outcome is described as a mean, with standard error as the dispersion measure. Numerical means, standard errors, and a treatment comparison are not reported in the registry record.

FEV1 measures the volume of air exhaled during the first second of a forced breath. In this study, the endpoint was selected to assess a short-term change in lung function under the two treatment conditions. The study summary describes the rationale as examining whether an anticipated additional bronchodilator effect of Brovana added to tiotropium would be accompanied by a meaningful improvement in a patient-centered outcome, exercise capacity. FEV1 is the registered primary outcome, whereas exercise endurance is named in the official title and summary; the distinction matters when interpreting what the primary analysis was meant to address.

As a general statistical point, a change score expresses how a measurement differs from its baseline value. A treatment contrast in change would compare the change under one condition with the change under the other. The registry gives the endpoint definition and timing but does not provide the observed changes, their uncertainty, or the estimated contrast. It is therefore not possible to assess the direction, magnitude, or precision of the primary result from the reported record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a crossover design compare?

In general, a crossover study compares treatment conditions using measurements from the same participants under each condition. Because participants serve as their own comparison, stable characteristics that differ between people may be less influential in the treatment contrast than in a comparison of separate groups. This benefit depends on appropriate design and analysis. The registry identifies this trial as randomized and crossover, with arformoterol and placebo as the interventions. The order in which participants received them, any washout period, and the statistical model used for the crossover comparison are not reported in the registry record.

A crossover analysis may need to consider whether outcomes vary by treatment period or sequence, and whether effects from one period could carry into another. These are general methodological considerations, not claims about what happened in this study. The record does not report whether period, sequence, or carryover effects were assessed, or how repeated measurements were handled.

What does the primary endpoint measure?

The primary outcome is a continuous measure: change in FEV1, in liters, from baseline to 1 week. The registry defines change as the 1-week measurement minus baseline and states that the FEV1 measurement was taken 2 hours post dose. It describes the summary parameter as a mean and the dispersion as standard error. No numerical mean, standard error, or treatment contrast is reported in the registry record.

As a general explanation, a mean summarizes the central value of a continuous outcome across observations. A standard error describes the precision of an estimated mean, rather than the spread of individual participants’ values. A confidence interval for a treatment contrast would help convey the uncertainty around the estimated difference between conditions. Such an interval is not reported in the registry record. Without the outcome values and their uncertainty, readers cannot determine how large or precise the estimated effect was.

What can be inferred from the analysis fields?

The registry lists three outcome measures and zero analyses. The first figure describes the number of outcome measures, not the number with reported results. The second indicates that no analysis entries are listed in the record. These fields do not supply estimates or tests for the primary endpoint. They also do not identify a particular statistical model, adjustment strategy, or analysis population. Those details are not reported in the registry record.

In general, statistical inference for a treatment contrast uses an estimate together with a measure of uncertainty, such as a confidence interval or p-value. A p-value assesses compatibility between data and a specified null model; it does not measure the size or clinical importance of an effect. Since no outcome comparison or p-value is reported in the registry record, neither statistical significance nor the precision of a treatment estimate can be evaluated from these entries.

How should sample-size planning be read?

The registry describes a planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It states that the effect to detect is a specified fraction of the observed effect, and distinguishes participants per arm for most outcomes from total events for time-to-event outcomes. Numerical planning outputs are not reported in the registry record.

As a general point, a planning calculation estimates how much information a future study might need under specified assumptions. It is not a measure of the probability that a completed study’s result is true, nor is it observed power. A planning illustration based on an observed effect also depends on that effect estimate, which is not reported in the registry record. The calculation assumptions described in the record do not establish the trial’s original design rationale or its planned analysis. Sample-size justification is not reported in the registry record.

Why does over-dispersion matter in general?

Over-dispersion is a general concern for count outcomes when variability exceeds what a statistical model assumes. It can affect uncertainty estimates and tests if not handled appropriately. The primary endpoint in this record is a continuous FEV1 change, not a count outcome, and no outcome analysis is listed. The registry does not report whether over-dispersion was relevant to any other analysis. This concept therefore cannot be used to infer anything about the trial’s results or methods.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome, change from baseline in FEV1 at 1 week, and two secondary outcomes: change from baseline in FVC and change from baseline in inspiratory capacity at 1 week. It reports three outcome measures overall and zero analyses. Numerical results and inferential tests for these outcomes are not reported in the registry record.

As a general statistical consideration, testing several outcomes or making several comparisons can increase the chance of finding at least one apparently unusual result even when there is no underlying effect. Researchers may address this through a prespecified hierarchy, adjustment, or other strategy. The multiplicity strategy, any hierarchy among outcomes, and any planned contrasts are not reported in the registry record. Without those details or reported analyses, it is not possible to assess how multiple outcomes were handled.

Missing-data handling is also not reported in the registry record. Enrollment of 20 participants does not establish how many completed both treatment conditions, contributed measurements at each time point, or entered an analysis. Reasons for missing measurements, imputation methods, and sensitivity analyses are not reported. The analysis populations—such as whether analyses included all randomized participants or only participants with complete measurements—are not reported in the registry record.

These omissions limit interpretation independently of whether numerical outcomes might be available elsewhere. Readers cannot determine which participants contributed to an estimate, how incomplete observations were treated, or whether the statistical conclusions account for multiple outcomes. No conclusions about analysis choices should be inferred from the completed status or the number of registered outcome measures.

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.

The registry lists safety figures for arformoterol and placebo. For each intervention group, 20 participants are recorded as at risk for serious adverse events, and 0 as affected. The corresponding figures for other adverse events are also 20 at risk and 0 affected in each group. No serious adverse event terms are listed.

These entries should be read as the counts recorded in the registry, not as proof that an intervention has no risk. The record does not explain how adverse events were collected, how long participants were monitored, or whether the group counts represent people, treatment periods, or another reporting unit in this crossover study. A zero count in the posted results does not rule out events that were not captured or reported.

Deaths are marked as null for both groups, rather than reported as zero. Therefore, death counts are not reported in the registry record; they should not be interpreted as no deaths. The registry also does not give detail about non-serious event types or the completeness of safety follow-up. The listed figures describe the recorded safety entries but do not support a broader conclusion about safety.

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

The record identifies a short-term randomized crossover study of arformoterol (Brovana) and placebo in COPD, with 20 participants enrolled. It specifies a primary endpoint of FEV1 change from baseline at 1 week, measured 2 hours after dosing. It also lists FVC and inspiratory capacity changes as secondary outcomes. These details make the intended comparison and measurement schedule clear.

What the registry record does not report is the numerical result of the primary comparison. It does not provide the means, standard errors, effect estimate, confidence interval, or p-value for FEV1. Numerical results for the secondary outcomes are also not reported. The record therefore cannot establish whether the measured changes favored either treatment condition, how large any difference was, or how precisely it was estimated. It also cannot show whether any result met a threshold of clinical importance.

The study summary describes an aim to examine whether an anticipated additional bronchodilator effect might lead to a meaningful improvement in exercise capacity. This is a statement of the study’s rationale, not a finding. Exercise endurance appears in the study title and summary, while FEV1 is the registered primary endpoint. The record does not report a numerical exercise endurance result or an analysis of that outcome.

More generally, a completed trial status does not supply missing outcome estimates or determine whether a comparison was statistically persuasive. A planning illustration is not observed power, and no such planning output is numerically reported in the registry record. The short-term, 1-week treatment description also does not support conclusions about longer-term effects. In the absence of reported results, this record describes the research question and design but does not answer the treatment-effect question.

13. Why This Trial Matters Statistically

This trial is statistically notable for its crossover design and its focus on short-term changes in continuous lung-function measures. In a crossover study, measurements from the same participant under different treatment conditions can support a within-participant comparison. This design can be informative when treatment effects and measurement timing are well defined, and when the analysis appropriately accounts for the repeated observations. The record identifies the design but does not report the treatment sequence, washout details, or analysis method.

The primary endpoint is explicitly defined as change from baseline in FEV1 after 1 week, with measurement 2 hours post dose. Clear endpoint timing and a stated change-score definition are useful for interpreting what a reported estimate would represent. The registry also distinguishes the primary outcome from secondary outcomes in FVC and inspiratory capacity. However, it reports no numerical outcome results and lists zero analyses, so the statistical comparison itself cannot be evaluated.

The record’s proof-of-concept framing also highlights a general distinction between a small, short-term study and a definitive estimate of effects. A study may be designed to generate preliminary information, but the interpretation still depends on the size and uncertainty of its observed estimates. Those values are not reported in the registry record. Enrollment of 20 participants alone does not reveal the precision of an effect estimate or the adequacy of the analysis.

Finally, the record describes a sample-size planning illustration based on the observed effect, but does not report its numerical outputs. Such calculations are planning aids, not observed power or evidence of an effect. The statistical importance of the record is therefore largely in its design features and in the limits of what can be inferred when outcome estimates, analysis details, and missing-data information are absent.

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 most important limitation for interpreting this record is that numerical efficacy results are not reported. Although the primary FEV1 endpoint and two secondary lung-function outcomes are identified, the record provides no observed means, treatment contrasts, uncertainty estimates, or inferential tests. It is therefore not possible to assess effect direction, magnitude, or precision.

Important crossover details are also absent. The treatment sequence, washout procedures, and approach to period or carryover effects are not reported in the registry record. The statistical method for comparing repeated measurements is not reported, so readers cannot determine how the crossover structure was incorporated into an analysis.

The record lists enrollment of 20 participants but does not report how many completed each treatment condition or contributed endpoint data. Participant flow, exclusions, missing measurements, analysis populations, and missing-data methods are not reported. Baseline characteristics and details of participant eligibility are also not reported, limiting assessment of who was studied.

The intervention descriptions specify twice-daily treatment for 1 week, with nebulized administration for arformoterol. Further details about background tiotropium use, treatment transitions, and adherence are not reported. The stated short-term duration limits what can be inferred about outcomes beyond the described period. The record also does not report an analysis plan, a sample-size justification, or a multiplicity strategy. These limitations leave both the statistical conduct and the results unavailable for independent interpretation from the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Effect of Brovana and Tiotropium in Chronic Obstructive Pulmonary Disease (COPD) — NCT00773786.
• Registry record last updated 2019-08-06; status last verified 2013-12.
• Results first posted 2015-06-03.
• 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

The registry record describes a completed, randomized, quadruple-masked, phase 4 crossover study in COPD, sponsored by Trinity Health Of New England. Enrollment was 20. The study began in 2008-10 and reached primary completion in 2009-05.

Participants were assigned to treatment conditions involving arformoterol (Brovana) and placebo, each described as twice daily for 1 week; arformoterol was administered via nebulizer. The primary outcome was change from baseline in FEV1 at 1 week, measured 2 hours after dosing. Change in FVC and inspiratory capacity were listed as secondary outcomes.

Numerical outcome estimates, inferential analyses, treatment sequence, missing-data methods, and analysis populations are not reported in the registry record. Safety entries list 0 serious and 0 other adverse events affected in each group, with 20 at risk for each category; death counts are not reported.