This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Chronic Obstructive Pulmonary Disease (COPD) Maintenance Treatment Patterns in China (NCT04853238), a registered phase not stated study. The primary outcome is Number of Participants Who Received COPD Prescription for Maintenance Treatment at Baseline.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04853238 |
| Phase | Phase not stated |
| Condition | Pulmonary Disease, Chronic Obstructive |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 1507 |
| Arms in the primary outcome | n/a |
| Lead sponsor | GlaxoSmithKline |
| Results posted | Yes |
2. Clinical Question
Population
Participants with chronic obstructive pulmonary disease (COPD) in Tier 2 and Tier 3 hospitals in China were enrolled in a prospective observational cohort study. The registry record lists enrollment of 1507 participants. It describes three clinical cohorts: participants presenting with stable disease, participants with a moderate acute exacerbation not requiring hospitalization, and participants requiring hospitalization for an acute exacerbation.
Intervention
No treatment was assigned by the study. The registry describes the intervention as a prospective observational cohort study, so the clinical focus is on recorded care rather than a randomized treatment intervention. The primary outcome concerns prescriptions for COPD maintenance treatment at baseline, including several medication classes and treatment combinations.
Comparator
The cohorts distinguish participants by clinical presentation, but the registry record does not describe a randomized comparison or state how allocation would occur. The three cohorts should therefore be read as descriptive groups, not as treatment and control arms that are necessarily comparable. The record does not report a prespecified between-cohort contrast for the primary outcome.
Primary question
At baseline, how many participants received a prescription for COPD maintenance treatment, and how were those prescriptions distributed across the listed treatment categories? The outcome is a participant count at baseline, not a measure of change over time or a comparison of treatment effects. The registry record does not report the category counts, so the distribution cannot be characterized from the posted results described in the record.
3. Trial Design
This was a prospective observational cohort study of COPD management in China. The registry describes its purpose as gaining an understanding of COPD management and physicians’ treatment strategies in participants at Tier 2 and Tier 3 hospitals. It lists GlaxoSmithKline as the sponsor and records the study as completed. The recorded start date is 2021-04-27, the primary completion date is 2022-11-03, and enrollment is 1507.
The study describes three cohorts based on clinical presentation: stable disease; a moderate acute exacerbation not requiring hospitalization; and an acute exacerbation requiring hospitalization. These categories organize participants by status, but the record does not establish that they form comparable groups for estimating a treatment effect. Allocation is not stated, and the registry explicitly identifies the study as not being a randomized comparison.
The primary outcome is the number of participants who received a prescription for COPD maintenance treatment at baseline, defined as Day 1. The record also lists secondary outcomes concerning baseline lung function, exacerbation history, medication history, symptom scores, hospitalization by DECAF risk group, comorbidities, and socioeconomic characteristics. In total, 16 outcome measures are listed. The registry record lists 0 analyses.
The primary outcome description says the analysis data set included enrolled participants, excluding those who did not enter the study because they did not meet protocol-defined eligibility criteria. It further says that only participants measured and analyzed contributed data to the reported outcome. The description is truncated, and the number included in the primary outcome analysis is not reported in the registry record. The protocol details and statistical analysis plan are also 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.
Before assignment: A total of 1507 participants were enrolled in the study (Enrolled Population: All participants who passed screening \[met eligibility criteria\] and entered the study).
Overall Study
| Stage | Cohort 1: Participants Presenting With Stable Disease | Cohort 2: Participants Presenting With a Moderate Acute Exacerbation Not Requiring Hospitalization | Cohort 3: Participants Requiring Hospitalization for an Acute Exacerbation |
|---|---|---|---|
| STARTED | 802 | 71 | 634 |
| Analysis Data Set | 797 | 71 | 615 |
| COMPLETED | 772 | 68 | 561 |
| NOT COMPLETED | 30 | 3 | 73 |
Reasons for not completing this period:
| Reason | Cohort 1: Participants Presenting With Stable Disease | Cohort 2: Participants Presenting With a Moderate Acute Exacerbation Not Requiring Hospitalization | Cohort 3: Participants Requiring Hospitalization for an Acute Exacerbation |
|---|---|---|---|
| Death | 4 | 0 | 2 |
| Lost to Follow-up | 16 | 2 | 37 |
| Poor adherence, unable to cooperate with investigator to complete test | 1 | 1 | 10 |
| Withdrawal by Subject | 6 | 0 | 21 |
| Physician Decision | 0 | 0 | 2 |
| Violation of inclusion/exclusion criteria | 3 | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: Analysis data set which included all participants from enrolled population excluding those who did not enter the study as they did not meet Protocol-defined eligibility criteria. Only those participants who were measured and analyzed (i.e., contributed data reported in the table) were included in the 'Overall Number of Participants Analyzed' field.
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.
Population: Baseline Characteristic data are reported for Analysis data set which included all participants from enrolled population excluding those who did not enter the study as they did not meet Protocol-defined eligibility criteria.
| Characteristic | Unit | Cohort 1: Participants Presenting With Stable Disease | Cohort 2: Participants Presenting With a Moderate Acute Exacerbation Not Requiring Hospitalization | Cohort 3: Participants Requiring Hospitalization for an Acute Exacerbation | Total |
|---|---|---|---|---|---|
| Participants analysed | 797 | 71 | 615 | 1483 | |
| Age, Continuous | Years | 67.1 (SD 8.15) | 68.3 (SD 8.40) | 69.1 (SD 8.28) | 68.0 (SD 8.27) |
| Sex: Female, Male: Female | Participants | 94 | 5 | 69 | 168 |
| Sex: Female, Male: Male | Participants | 703 | 66 | 546 | 1315 |
| Race/Ethnicity, Customized: Asian-Chinese | Participants | 797 | 71 | 615 | 1483 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants Who Received COPD Prescription for Maintenance Treatment at Baseline, measured over At Baseline (Day 1).
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is a count of participants who received a prescription for COPD maintenance treatment at baseline, with baseline defined as Day 1. It includes an overall maintenance-treatment category and categories for LAMA, LABA, LABA/LAMA, ICS/LABA, triple therapy including ICS/LABA/LAMA or SITT, MITT, theophylline, MITT or SITT, and N-acetyl cysteine/carbocysteine. The registry describes participants as potentially belonging to more than one treatment category. Consequently, category counts need not add up to the number analyzed.
A participant count describes how many people were recorded in a category at the specified assessment. It can characterize prescribing patterns in the observed cohort, but it does not by itself measure adherence, treatment duration, clinical response, or a change in treatment over time. Nor does a count alone indicate whether a prescription was appropriate or whether one treatment was better than another.
This endpoint is useful for describing the maintenance therapies recorded in clinical practice at the study’s baseline assessment. Its interpretation depends on knowing the analyzed population and the category counts. The registry record names the endpoint and its timing, but the category counts and the analyzed denominator are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the study’s descriptive focus: maintenance-treatment prescriptions at baseline among participants with COPD in Chinese Tier 2 and Tier 3 hospitals. It identifies 1507 enrolled participants and three cohorts defined by clinical presentation. However, it does not report the primary outcome counts by treatment category. Thus, the posted registry information does not establish which categories were most common or how prescribing differed across the cohorts.
The primary outcome is a count, and its description explicitly allows participants to be counted in more than one medication category. Those categories are therefore not mutually exclusive. A reader should not interpret their counts as a partition of all participants or expect them to sum to the analyzed population. The number analyzed for this outcome is not reported in the registry record, which also limits interpretation of any category count that might be reported elsewhere.
The study is observational, and allocation is not stated. Cohort membership reflects clinical presentation rather than a documented randomized assignment. Differences between cohorts could reflect differences in patient characteristics or circumstances as well as differences in prescribing. The registry record does not report an adjusted comparison, a causal estimate, or a statistical analysis plan that would support attributing any differences to a particular treatment strategy.
The registry lists 16 outcome measures and 0 analyses. It does not report inferential estimates, confidence intervals, p-values, or adjusted models for the primary outcome. A confidence interval, in general, describes the precision of an estimate under the assumptions of the method used; without a reported estimate and interval, the precision of the primary outcome cannot be assessed. The absence of a listed analysis is not evidence that there were no analyses outside the registry record, but such analyses are not reported in the registry record.
Serious adverse event counts are listed for the three cohorts, along with other adverse event counts and deaths. These are descriptive counts with cohort-specific numbers at risk. They do not establish that an event was caused by a treatment, and the registry information does not provide a randomized safety comparison. The listed serious-event terms and percentages are also not accompanied by their denominators in the record.
The study can therefore be read as a registry record of an observational effort to describe COPD management and treatment patterns. It does not, on the available registry information, quantify the distribution of baseline prescriptions or estimate treatment effectiveness. Conclusions should remain within those limits.
9. Statistical Methods Explained
The registry identifies the study as a prospective observational cohort study. That design follows participants and records features of their care without describing randomized assignment to treatments. In general, observational data can describe what was recorded in a clinical setting. They can also show associations, but associations may reflect differences among people or their circumstances rather than an effect of treatment. A randomized comparison is not reported for this study, and allocation is not stated.
What does a participant count represent?
The primary outcome is a count: the number of participants with a prescription in a specified maintenance-treatment category at baseline. A count is different from a rate over time, a mean score, or a treatment-effect estimate. To interpret a count, readers need to know which participants were eligible for the analysis and how many contributed data. The registry outcome description refers to measured and analyzed participants, but the analyzed denominator is not reported in the registry record.
The treatment categories may overlap. The registry specifically notes that one participant could have received more than one maintenance treatment and could therefore be counted in multiple categories. General interpretation of overlapping categories requires treating each category as its own descriptive count rather than as one mutually exclusive group in a single distribution. The total across categories need not equal the number analyzed.
What can the cohort structure tell us?
The three cohorts classify participants by presentation: stable disease, a moderate acute exacerbation not requiring hospitalization, and an exacerbation requiring hospitalization. Such groupings can help describe the clinical context in which treatment patterns were recorded. In general, group comparisons in an observational study can be affected by differences in participant characteristics, severity, prior treatment, or other factors. Whether these were measured or adjusted for is not reported in the registry record. No like-for-like control comparison is identified.
How should precision and statistical tests be read?
In general, a confidence interval gives a range of values compatible with an estimate under the assumptions of its statistical method. A narrow interval indicates greater precision than a wide interval, while neither interval alone establishes causation. A p-value, in general, measures how unusual data would be under a specified statistical hypothesis and model; it does not describe the size or clinical importance of an association. The registry record lists 0 analyses and does not report confidence intervals or p-values for the primary outcome. It is therefore not possible to assess inferential precision or evidence from those measures using the registry information.
The outcome is a participant count, so the basic endpoint is not a repeated-event count or a time-to-event endpoint. General methods for over-dispersed event counts address variability greater than a particular count model expects. Whether over-dispersion was evaluated is not reported in the registry record, and the record does not provide a model specification that would justify applying such a method to this endpoint.
What is known about planning?
The registry record does not report the trial’s sample-size justification. The planning illustration described for the statistical material uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of an observed effect. It is described as a planning illustration, not as the study’s own design or an observed-power calculation. The effect estimate and numerical planning results are not reported in the registry record. Because the study is not a randomized comparison and allocation is not stated, equal allocation between two arms should not be mistaken for the actual cohort structure. In general, a planning sample size depends on the effect size and model assumptions; an illustration does not establish that the study was designed or conducted according to those assumptions.
For general interpretation, a study’s analysis plan would specify how outcomes are defined, how participants with missing measurements are handled, which populations are analyzed, and how multiple tests are addressed. Those details are not reported in the registry record. Without them, readers cannot determine whether a particular statistical procedure was prespecified or how sensitive results might be to alternative assumptions.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 16 outcome measures, including the primary count of participants prescribed maintenance treatment and secondary measures covering lung function, prior exacerbations, medication history, symptom scores, hospitalization risk grouping, comorbidities, and socioeconomic characteristics. It lists 0 analyses. A large set of outcomes can raise multiplicity concerns when many hypotheses are tested: in general, repeated testing can increase the chance of finding apparently notable results by chance. Whether any multiplicity adjustment or hierarchy of outcomes was planned is not reported in the registry record. No outcome-level analysis results or p-values are reported there to evaluate.
Missing-data handling is also not reported in the registry record. The primary outcome description says the analysis data set included enrolled participants apart from those who did not enter the study because they did not meet protocol-defined eligibility criteria, and says only measured and analyzed participants contributed data. It does not give the resulting denominator or describe how missing measurements were handled. Imputation, complete-case analysis, and other approaches are not specified in the registry record.
The record does not report a detailed analysis-population definition beyond that outcome description, nor does it state whether different populations were used for different outcomes. The enrolled population is listed as 1507, but enrollment does not establish how many participants contributed data to each outcome. The impact of missing data or exclusions therefore cannot be assessed from the registry information.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Cohort 1: Participants Presenting With Stable Disease | 5 | 797 | 0.6% |
| Cohort 2: Participants Presenting With a Moderate Acute Exacerbation Not Requiring Hospitalization | 1 | 71 | 1.4% |
| Cohort 3: Participants Requiring Hospitalization for an Acute Exacerbation | 4 | 615 | 0.7% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Cohort 1: Participants Presenting With Stable Disease | 4 of 797 |
| Cohort 2: Participants Presenting With a Moderate Acute Exacerbation Not Requiring Hospitalization | 0 of 71 |
| Cohort 3: Participants Requiring Hospitalization for an Acute Exacerbation | 2 of 615 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Cohort 1: Participants Presenting With Stable Disease | 2 of 797 |
| Cohort 2: Participants Presenting With a Moderate Acute Exacerbation Not Requiring Hospitalization | 0 of 71 |
| Cohort 3: Participants Requiring Hospitalization for an Acute Exacerbation | 0 of 615 |
Most frequent serious adverse event terms
| Event term | Organ system | Cohort 1: Participants Presenting With Stable Disease | Cohort 2: Participants Presenting With a Moderate Acute Exacerbation Not Requiring Hospitalization | Cohort 3: Participants Requiring Hospitalization for an Acute Exacerbation |
|---|---|---|---|---|
| Chronic obstructive pulmonary disease | Respiratory, thoracic and mediastinal disorders | 3 of 797 | 1 of 71 | 2 of 615 |
| Cardiac arrest | Cardiac disorders | 1 of 797 | 0 of 71 | 0 of 615 |
| Death | General disorders | 0 of 797 | 0 of 71 | 1 of 615 |
| Intestinal perforation | Gastrointestinal disorders | 0 of 797 | 0 of 71 | 1 of 615 |
| Fall | Injury, poisoning and procedural complications | 1 of 797 | 0 of 71 | 0 of 615 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Cohort 1: Participants Presenting With Stable Disease | Cohort 2: Participants Presenting With a Moderate Acute Exacerbation Not Requiring Hospitalization | Cohort 3: Participants Requiring Hospitalization for an Acute Exacerbation |
|---|---|---|---|---|
| Cataract | Eye disorders | 1 of 797 | 0 of 71 | 0 of 615 |
| Conjunctivitis | Infections and infestations | 1 of 797 | 0 of 71 | 0 of 615 |
| Urinary retention | Renal and urinary disorders | 1 of 797 | 0 of 71 | 0 of 615 |
Serious events with the highest arm-level rate: chronic obstructive pulmonary disease (1.4%), death (0.2%), intestinal perforation (0.2%), cardiac arrest (0.1%), fall (0.1%).
The registry lists serious adverse events by cohort with participants at risk and participants affected. In the stable-disease cohort, 5 of 797 participants were affected; in the moderate acute exacerbation cohort not requiring hospitalization, 1 of 71 was affected; and in the cohort requiring hospitalization, 4 of 615 were affected. Other adverse events are listed for 2 of 797, 0 of 71, and 0 of 615 participants, respectively. Deaths are listed as 4, 0, and 2 across those cohorts.
The registry also lists serious-event terms and percentages: chronic obstructive pulmonary disease, 1.4%; death, 0.2%; intestinal perforation, 0.2%; cardiac arrest, 0.1%; and fall, 0.1%. The denominators and the relationship between these terms and the cohort-level counts are not reported in the registry record. The listed counts and terms are descriptive; they do not establish that a treatment caused an event. Because this is not a randomized comparison, the cohort figures should not be read as a like-for-like comparative safety estimate.
12. What the Result Does, and Does Not, Mean
The study’s stated purpose is to describe COPD management and physicians’ treatment strategies in Tier 2 and Tier 3 hospitals in China. Its primary endpoint is suited to describing the number of participants prescribed maintenance treatments at baseline. The study also lists outcomes intended to describe participant characteristics, prior exacerbations and treatment, symptom measures, and comorbidities. In principle, these measures can contribute to a picture of care and disease burden in the observed cohort.
The registry information does not report the primary treatment-category counts or the analyzed denominator. It therefore does not show how often each maintenance-treatment category was recorded. Nor does it report a statistical analysis comparing cohorts on the primary endpoint. The record’s 0 listed analyses means the posted registry information does not provide an inferential analysis to interpret; it should not be taken as proof that no analysis was conducted outside the record.
The observational design also sets an important boundary on interpretation. Participants were grouped by clinical presentation, and the registry does not describe randomized treatment assignment. Any differences in recorded prescribing across groups, if available elsewhere, could be associated with patient or clinical differences. They would not by themselves show that a treatment caused a change in outcome. The registry record does not provide a treatment-effect estimate or evidence for choosing one therapy over another.
The serious adverse event and death counts are safety descriptions, not causal findings. They give counts for the cohorts but do not provide a randomized contrast or establish attribution to a particular treatment. In general, descriptive records can help identify patterns worth examining, while causal conclusions require an appropriate design and analysis that address alternative explanations.
The appropriate scope is therefore descriptive: a prospective registry study focused on baseline maintenance-treatment prescriptions and other aspects of COPD care in the specified hospital settings. The posted registry information does not establish treatment effectiveness, comparative safety, or the reasons physicians selected particular prescriptions.
13. Why This Trial Matters Statistically
Statistically, this study illustrates the distinction between an outcome definition and an outcome result. The registry gives a clear primary-outcome concept—a count of participants prescribed maintenance treatment at baseline—and explains that treatment categories can overlap. But it does not report the category counts or the analyzed denominator. Without those values, the endpoint cannot answer the descriptive question it was designed to address in the posted record.
The study also highlights why design matters when interpreting group patterns. Its cohorts are based on clinical presentation, not documented randomized assignment, and allocation is not stated. In general, an observational cohort can describe treatment choices in practice, while comparisons between groups may be influenced by the characteristics that led participants to fall into those groups. Recognizing that distinction prevents descriptive patterns from being mistaken for treatment effects.
The number of outcomes is another statistical consideration. The registry lists 16 outcome measures but 0 analyses. Multiple outcomes can serve different descriptive aims, yet a plan for prioritizing outcomes and interpreting repeated tests is important when inferential claims are made. Multiplicity methods and the analysis plan are not reported in the registry record.
Finally, the record shows the value of transparent outcome reporting. Clear denominators, category counts, missing-data methods, and analysis details are needed to assess how representative and precise a descriptive estimate is. The available record gives the study’s setting, cohort structure, enrollment, endpoint definition, and some safety counts, but leaves the primary endpoint’s numerical findings and key analysis details unreported.
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 main limitation for interpreting the primary endpoint is that its treatment-category counts are not reported in the registry record. The number of participants analyzed for that endpoint is also not reported, so the denominator and completeness of the baseline assessment cannot be assessed. Although enrollment is listed as 1507, the enrolled number should not be treated as the analyzed number for every outcome.
The study is observational, and the registry says allocation is not stated and the study is not a randomized comparison. The cohorts are defined by clinical presentation, so they should not be treated as randomized arms or assumed to be comparable. The registry record does not report adjusted estimates or a statistical plan addressing potential differences between cohorts. It also does not report how participants were selected across hospitals or how representative they are of other settings.
The primary outcome allows participants to be counted in more than one treatment category. This makes the categories overlapping rather than a mutually exclusive breakdown of the cohort. The registry record also does not report the exact analysis population or missing-data procedures in sufficient detail to assess their influence on the endpoint.
Although 16 outcome measures are listed, 0 analyses are listed. The registry record does not report methods for handling multiplicity, a sample-size justification, interim analyses, or the statistical analysis plan. The safety information includes cohort counts and serious-event terms, but does not establish treatment attribution; denominators for the listed event-term percentages are not reported in the record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Chronic Obstructive Pulmonary Disease (COPD) Maintenance Treatment Patterns in China — NCT04853238.
- Registry record last updated 2024-12-06; status last verified 2024-10.
- Results first posted 2024-12-06.
- 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.
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18. Record Summary
This completed prospective observational cohort study concerns COPD maintenance-treatment patterns and related characteristics in China Tier 2 and Tier 3 hospitals. The registry lists GlaxoSmithKline as sponsor, enrollment of 1507, a start date of 2021-04-27, and primary completion on 2022-11-03. Participants were classified into cohorts with stable disease, a moderate acute exacerbation not requiring hospitalization, or an exacerbation requiring hospitalization.
The primary outcome is the number of participants prescribed COPD maintenance treatment at baseline, defined as Day 1. Treatment categories may overlap. The record lists 16 outcome measures and 0 analyses. The primary treatment-category counts and analyzed denominator are not reported in the registry record. Cohort-level serious adverse event counts, other adverse event counts, and deaths are listed, but do not constitute a randomized safety comparison or establish treatment causation.