Assessment of Chronic Obstructive Pulmonary Disease (COPD) Therapy From the Physicians Perspective Using Tiotropium as an Example: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Assessment of Chronic Obstructive Pulmonary Disease (COPD) Therapy From the Physicians Perspective Using Tiotropium as an Example (NCT01036763), a registered phase not stated study. The primary outcome is Success of Treatment With Tiotropium According to Physician's Assessment.

2. Clinical Question

3. Trial Design

The registry record describes an assessment of COPD therapy from physicians’ perspectives, using tiotropium as an example. The sponsor is Boehringer Ingelheim. The study start is recorded as 2010-01, primary completion as 2010-08, and status as COMPLETED. These administrative details describe the registered study but do not provide its outcome estimates.

The study summary concerns documentation of therapy with Spiriva Respimat or Spiriva (tiotropium 18 mcg capsules) in patients with COPD requiring long-acting bronchodilators. Its stated aim is to describe the outcome parameters physicians considered important when judging whether treatment was successful. The summary also describes collecting physicians’ and patients’ assessments of efficacy and tolerability. The record does not provide further details of how these assessments were elicited, whether standardized instruments were used, or how treatment exposure was managed.

The primary outcome is the number of participants assessed as having successful treatment, with evaluation over 6 - 12 weeks. The outcome description names pulmonary function, dyspnoe, health-related quality of life, exercise capacity, and prevention of exacerbations as parameters used in the physician’s decision. The record also lists Physician's Global Evaluation at Visit 1 and Physician's Global Evaluation at Visit 2 as secondary outcomes. The results of those evaluations are not reported in the registry record.

The registry identifies the study as not a randomized comparison and states that allocation was not stated. The adverse-event entry lists Spiriva 18 Microgram/Spiriva Respimat, but the record does not describe a like-for-like control group. This matters because treatment outcomes observed without a randomized comparator cannot, on their own, separate treatment effects from differences in patient characteristics, clinical practice, or the course of COPD. Further design details, including recruitment methods, sites, blinding, and the analysis plan, 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: All patients who were documented to have taken at least one dose of Spiriva®18 Microgram/Spiriva® Respimat® and had COPD requiring long-acting anticholinergics

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 Success of Treatment With Tiotropium According to Physician's Assessment, measured over 6 - 12 weeks.

The primary endpoint is a count of participants whose treatment was judged successful by a physician. Its timeframe is 6 - 12 weeks. The physician’s decision was to draw on several clinically relevant parameters: pulmonary function, dyspnoe, health-related quality of life, exercise capacity, and prevention of exacerbations. The registry does not specify how these components were combined, whether any one component was required, or what threshold qualified as success. Those details are not reported in the registry record.

A physician-assessed endpoint can capture a clinical judgment that draws on several aspects of a patient’s condition. It can therefore address a question broader than a single physiological or symptom measure. At the same time, such an outcome depends on the definition and consistency of the assessment. Without a specified scoring rule, decision threshold, or information about assessor training, readers cannot tell how comparable judgments were across physicians or patients. These methodological details are not reported in the registry record.

The count format indicates that the intended outcome is the number of participants meeting the success criterion, rather than a continuous change score. The registry lists the outcome unit as participants and the parameter as NUMBER. However, it does not report the number judged successful, the number assessed for this outcome, or an accompanying estimate of uncertainty. Thus, the endpoint’s intended meaning is described, but its observed result cannot be interpreted from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a binary participant outcome in concept: each participant would either meet the physician’s definition of treatment success or not. The registry describes the result as a number of participants, rather than reporting a continuous score. For a binary outcome, an analysis commonly presents the event count and the number assessed, and may also report a proportion with an uncertainty interval. Those quantities help readers distinguish the observed count from the precision of an estimate. The registry record does not report the primary count, its denominator, a proportion, or an uncertainty interval.

A confidence interval expresses uncertainty around an estimate under the assumptions of the analysis. A narrower interval indicates greater precision, while a wider interval indicates less precision. An interval is not a guarantee that the true value lies within its limits, and it does not correct for bias, poor measurement, or a missing comparator. Because no primary estimate or confidence interval is reported in the registry record, the precision of the physician-assessed result cannot be evaluated.

For a comparative treatment question, interpretation would ordinarily depend on a clearly defined comparison and an analysis appropriate to the outcome and design. Here, the registry states that the study is not a randomized comparison and that allocation was not stated. It does not describe a like-for-like control comparison. A difference between groups, if one had been reported, could be confounded by differences in who received treatment or by other aspects of care. Randomization can help balance measured and unmeasured characteristics on average, but the registry does not describe random allocation for this study. No comparative effect estimate is reported.

The endpoint itself is based on a physician’s assessment informed by pulmonary function, dyspnoe, health-related quality of life, exercise capacity, and prevention of exacerbations. In general, a composite or overall judgment requires a clear rule for how its components contribute to the final classification. Different rules can yield different classifications, especially if one component improves while another does not. The registry description does not give a formal algorithm, weighting scheme, or success threshold. Those methodological details are not reported in the registry record, so the endpoint’s reproducibility cannot be assessed from the description alone.

The record lists secondary Physician's Global Evaluation outcomes at Visit 1 and Visit 2. Repeated assessments can be informative about changes over time, but their interpretation depends on when visits occurred, how measures were recorded, and how missing assessments were handled. The registry does not report those details or the secondary outcome results. It also records 7 outcome measures and 0 analyses. The count of registered outcome measures does not establish how many were analyzed, and the absence of listed analyses means no analysis results can be evaluated from this record.

Multiplicity arises when several outcomes, timepoints, or comparisons are examined. In general, testing many questions can increase the chance that at least one result appears notable by chance. Statistical plans may address this through a prespecified primary outcome, a hierarchy, or an adjustment method. The registry identifies a primary outcome and secondary outcomes, but does not report a multiplicity strategy. It would be inappropriate to assume that an adjustment was or was not used; the approach is not reported in the registry record.

The record includes a planning description for sample-size illustrations. 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. It distinguishes time-to-event illustrations, which give the total number of events using the Schoenfeld approach, from other illustrations, which give participants per arm. These are planning assumptions, not a description of the study’s actual allocation or its own design. Such illustrations are not observed power. The registry does not report a sample-size justification for the study itself. The observed effect value referenced in the planning description is not reported in the registry record.

For event-count data, the number observed is only part of the information needed for interpretation. The population at risk, event definition, follow-up period, and completeness of ascertainment also matter. Over-dispersion is a general concern when variability in counts exceeds what a simple statistical model expects; a model that ignores it may understate uncertainty. The primary endpoint is registered as a participant count, but no model or dispersion assessment is reported. It is not possible to determine whether such considerations were relevant to the sponsor’s analysis because the statistical plan and analyses are not reported in the registry record.

Recalculated estimates, when available, are simple unadjusted calculations from posted summary statistics and are not substitutes for a sponsor’s prespecified analysis. No recalculated primary efficacy estimate can be described from this record because the necessary outcome result is not reported. The registry record also does not report a sponsor analysis for the primary endpoint. Accordingly, there is no basis for an adjusted or unadjusted estimate of treatment effect.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 7 outcome measures and 0 analyses. It names a primary outcome and lists Physician's Global Evaluation at Visit 1 and Physician's Global Evaluation at Visit 2 as secondary outcomes. The record does not report results for these outcomes or describe how analyses across outcomes and assessments were handled. A prespecified multiplicity strategy, such as an outcome hierarchy or statistical adjustment, is not reported in the registry record.

Missing-data handling is also not described. The record does not state how missing physician assessments, incomplete follow-up, or participants without an evaluable endpoint were treated. It does not report the number assessed for the primary outcome or whether the endpoint denominator included every participant who met the stated treatment-exposure criteria. Without those details and the primary result, the potential influence of missing observations cannot be assessed.

The primary population is described as patients with COPD requiring long-acting anticholinergics who were documented to have taken at least one dose of the specified tiotropium treatment. The registry does not give further analysis-population definitions, such as rules for excluding participants or handling treatment discontinuation. These details are not reported in the registry record. The record’s stated population should therefore not be assumed to match an intention-to-treat, per-protocol, or other formal analysis set.

These reporting gaps do not show that appropriate procedures were absent; they mean that the registry record does not document them. Without outcome results, analysis-population details, and missing-data methods, readers cannot assess the robustness of the primary finding or the impact of examining multiple outcomes.

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

Serious events with the highest arm-level rate: coronary artery disease (0.1%), dyspnoea (0.1%), condition aggravated (0.1%), osteoporotic fracture (0.1%), metastatic bronchial carcinoma (0.1%).

The registry lists 1264 at risk for serious adverse events and records 5 participants affected. For other adverse events, it lists 1264 at risk and records 0 affected. These are the counts recorded for the tiotropium treatment group. They are descriptive figures and do not compare tiotropium with a control treatment.

The serious-event terms listed are Coronary artery disease, Dyspnoea, Condition aggravated, Osteoporotic fracture, and Metastatic bronchial carcinoma; each is reported as 0.1%. These entries identify terms and reported frequencies, but the registry record does not provide further detail about event timing, severity beyond the serious-event classification, relationship to treatment, or whether events could overlap within participants. No additional counts should be inferred from the term list.

Deaths are not reported in the registry record. The reported 0 for other adverse events should be read as the entry recorded for that category, not as proof that no untoward experiences occurred or that safety was established. In general, a safety count is interpreted in the context of how events were defined, collected, followed, and compared. Those methods are not reported, and the absence of a control group in the registry information limits comparative interpretation.

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

The record identifies a completed study focused on physicians’ assessments of tiotropium treatment in COPD. Its primary question concerns the number of participants judged to have successful treatment during 6 - 12 weeks, based on several clinical parameters. This gives readers a clear description of the intended assessment, but the registry record does not report the resulting count or any estimate of its precision.

As a result, the posted information cannot establish how often physicians judged treatment successful. It also cannot show whether assessments differed by visit, because results for Physician's Global Evaluation at Visit 1 and Visit 2 are not reported. The outcome description is not a substitute for an observed result, and the completed study status does not supply missing results.

The record does not describe a randomized comparison, and allocation is not stated. Therefore, even if a physician assessment were available, it would not by itself establish that tiotropium caused a change. A causal interpretation would require consideration of the study design, comparison group, outcome measurement, and potential sources of bias. The registry information does not provide a like-for-like control comparison or the analysis details needed to evaluate those issues.

The safety entry reports serious adverse events among the listed treatment group and gives frequencies for named serious-event terms. These descriptive data do not determine whether the treatment caused the events, nor do they allow comparison with another treatment. The entry for other adverse events and the absence of a reported death count should be interpreted within the limits of the event definitions and ascertainment details recorded.

The appropriate conclusion is narrow: the registry describes the study purpose, primary outcome definition, timeframe, secondary outcomes, and safety counts, but it does not report the primary efficacy result. No conclusion that tiotropium did or did not improve outcomes is supported by the primary result in this record. The absence of a reported result is not evidence of no effect; it is a limitation on what can be concluded from the registry record.

13. Why This Trial Matters Statistically

This study raises a useful statistical question about how an overall clinical judgment is defined and analyzed. The primary endpoint combines several kinds of information in a physician’s assessment: pulmonary function, dyspnoe, health-related quality of life, exercise capacity, and prevention of exacerbations. Each may describe a different aspect of COPD. The interpretation of a single success classification therefore depends on how those components inform the judgment and what counts as success.

That question matters because a clinically meaningful endpoint also needs enough methodological detail for readers to understand and reproduce it. A clear decision rule can reduce ambiguity about how assessments are made. The registry describes the domains considered but does not report a scoring rule, threshold, or assessment procedure. Those details are not reported in the registry record, so the consistency of the physician judgments cannot be evaluated.

The study also illustrates the difference between documenting an outcome and reporting an outcome result. The registry identifies the primary endpoint and timeframe, but does not give the count or uncertainty around the assessment. It records 7 outcome measures and 0 analyses, while listing two Physician's Global Evaluation assessments as secondary outcomes. Without results and analysis details, readers cannot evaluate the magnitude, precision, or robustness of any finding.

Finally, the registry’s description of a nonrandomized assessment, with allocation not stated, highlights the distinction between describing outcomes among treated patients and estimating a causal treatment effect. A clinical assessment may be informative about how physicians viewed treatment in the recorded setting, but causal and comparative claims require design and analysis information that is not reported. The record is therefore useful for understanding the intended question and its reporting limits, rather than for drawing a comparative efficacy conclusion.

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 direct limitation is that the primary endpoint result is not reported in the registry record. There is no reported count of participants judged to have successful treatment, no denominator for that outcome, and no estimate of uncertainty. Consequently, neither the frequency of physician-assessed success nor its precision can be evaluated.

The endpoint description names several parameters considered by the physician, but does not state how they were combined or what threshold defined success. The registry does not report whether the assessment followed a standardized instrument or a common decision rule. This leaves uncertainty about how consistently the outcome may have been assigned across assessments.

The record states that the study was not a randomized comparison and that allocation was not stated. It does not describe a like-for-like control group. This restricts causal interpretation and makes it difficult to separate treatment-associated outcomes from other influences. Details about recruitment, treatment administration, follow-up procedures, and co-interventions are not reported in the registry record.

Analysis methods, missing-data procedures, analysis-population definitions, and multiplicity handling are not reported. The registry lists 7 outcome measures and 0 analyses, and results for the secondary physician evaluations are not reported. The safety information is also limited: deaths are not reported, and details of event ascertainment, timing, and treatment relationship are not given. These limitations concern what can be evaluated from the registry record; they do not establish that unreported procedures or results were absent from the study itself.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Assessment of Chronic Obstructive Pulmonary Disease (COPD) Therapy From the Physicians Perspective Using Tiotropium as an Example — NCT01036763.
• Registry record last updated 2014-03-27; status last verified 2014-02.
• Results first posted 2012-03-22.
• 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

NCT01036763 is a completed registry record sponsored by Boehringer Ingelheim. The study start is recorded as 2010-01 and primary completion as 2010-08. It concerns physicians’ assessments of tiotropium therapy in people with COPD.

The primary outcome is the number of participants judged to have successful treatment over 6 - 12 weeks, using clinical parameters that include pulmonary function, dyspnoe, health-related quality of life, exercise capacity, and prevention of exacerbations. The registry also lists Physician's Global Evaluation at Visit 1 and Physician's Global Evaluation at Visit 2. The primary and secondary outcome results are not reported in the registry record.

The record describes the study as not a randomized comparison and states that allocation was not stated. It lists 7 outcome measures and 0 analyses. Safety entries report 5 participants with serious adverse events among 1264 at risk and 0 with other adverse events among 1264 at risk; deaths are not reported. These entries are descriptive and do not provide a treatment comparison.