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 Home Pulmonary Rehabilitation for COPD (NCT03480386), a randomized na study. The primary outcome is Change in Quality of Life.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03480386 |
| Phase | NA |
| Condition | Chronic Obstructive Pulmonary Disease (COPD), Emphysema |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 375 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Mayo Clinic |
| Results posted | Yes |
2. Clinical Question
Population
People with chronic obstructive pulmonary disease (COPD) were the intended population; emphysema is also listed among the conditions. The primary-outcome description specifies an intent-to-treat analysis. Eligibility details and the characteristics of enrolled participants are not reported in the registry record.
Intervention
The intervention was a home-based pulmonary rehabilitation program. The arm description says participants would receive 12 weeks of home pulmonary rehabilitation with health coaching. The brief summary describes the study as testing technology and coaching intended to help people with COPD become more physically active in daily life.
Comparator
The comparison group received 12 weeks of usual care. Further details about what usual care included are not reported in the registry record, so the contrast cannot be characterized beyond the arm description.
Primary question
The primary outcome concerns change in health-related quality of life from baseline to 3 months, measured with the Chronic Respiratory Questionnaire (CRQ). The registry describes emotional and physical summary scores. Numerical between-group results for these scores are not reported in the registry record, so the size and precision of any difference cannot be described.
3. Trial Design
The registry identifies this as a randomized, parallel-group trial with no masking. Its status is completed, and the enrollment is 375. The listed study start is 2019-01-01 and the primary completion date is 2022-02-16. The phase is recorded as NA. Mayo Clinic is identified as the sponsor.
Participants were assigned to one of two arms: a pulmonary rehabilitation program intervention or usual care. The intervention description specifies 12 weeks of home pulmonary rehabilitation with health coaching, while the comparison arm is described as 12 weeks of usual care. The brief summary frames the study around physical activity in daily life and describes new technology and health coaching as the approach under study. Details of the technology, coaching procedures, and usual-care content are not reported in the registry record.
A parallel-group design compares groups followed over the same study period rather than crossing participants between treatments. Randomization is intended to support a fair comparison by distributing baseline characteristics without relying on researchers to choose the assignment. That rationale is general; the registry record does not report the randomization procedure, allocation concealment, or whether any adjustments were planned.
No masking was recorded. This means the registry does not describe participants or study personnel as blinded to the assigned arm. Whether outcome assessors were masked is not reported in the registry record. The registry does not report the target population eligibility criteria, study sites, detailed recruitment procedures, or the planned statistical analysis beyond the primary-outcome and missing-data descriptions.
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
| Stage | Pulmonary Rehabilitation Program Intervention | Usual Care |
|---|---|---|
| STARTED | 188 | 187 |
| COMPLETED | 143 | 142 |
| NOT COMPLETED | 45 | 45 |
Reasons for not completing this period:
| Reason | Pulmonary Rehabilitation Program Intervention | Usual Care |
|---|---|---|
| Did not complete measures at 3-months | 17 | 14 |
| No baseline measures | 11 | 14 |
| Death | 0 | 5 |
| Withdrawal by Subject | 12 | 8 |
| Lost to Follow-up | 2 | 1 |
| Complicating disease | 0 | 1 |
| Disease progression | 3 | 0 |
| Became ineligible | 0 | 2 |
Analysis population for the primary outcome, as defined in the registry: Intent-to-treat analyses, if a month three measure is missing for any reason, it will be described as not changing from baseline.
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.
| Characteristic | Unit | Pulmonary Rehabilitation Program Intervention | Usual Care | Total |
|---|---|---|---|---|
| Participants analysed | 188 | 187 | 375 | |
| Age, Continuous | years | 69.335 (SD 9.530) | 68.676 (SD 9.530) | 69 (SD 9) |
| Sex: Female, Male: Female | Participants | 101 | 111 | 212 |
| Sex: Female, Male: Male | Participants | 87 | 76 | 163 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 2 | 1 | 3 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 181 | 181 | 362 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 5 | 5 | 10 |
| Race/Ethnicity, Customized: White | Participants | 177 | 180 | 357 |
| Race/Ethnicity, Customized: Black or African American | Participants | 3 | 5 | 8 |
| Race/Ethnicity, Customized: Asian | Participants | 2 | 0 | 2 |
| Race/Ethnicity, Customized: American Indian/Alaska Native | Participants | 2 | 0 | 2 |
| Race/Ethnicity, Customized: Native Hawaiian/Other Pacific Islander | Participants | 1 | 0 | 1 |
| Race/Ethnicity, Customized: More than One Race | Participants | 3 | 2 | 5 |
| Region of Enrollment: United States | participants | 188 | 187 | 375 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Quality of Life, measured over Baseline, 3 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | score on a scale |
| Endpoint classification | Continuous Endpoint |
The primary outcome is described as change in quality of life, measured with the Chronic Respiratory Questionnaire (CRQ) at baseline and 3 months. The questionnaire measures physical and emotional aspects of chronic respiratory disease. Scores range from 1 to 7, with higher numbers indicating better health-related quality of life.
The registry describes two summary scores: an emotional summary made up of the mastery and emotional domains, and a physical summary made up of the dyspnea and fatigue domains. It states that the reported measure is the difference between baseline and 3 months on these summaries. The registry gives 0.5 points as the minimal clinically important difference for this tool. This threshold is a stated interpretation guide for the CRQ, not a treatment effect estimate.
Quality of life is used as an outcome because the trial description concerns both physical and emotional aspects of chronic respiratory disease, rather than activity alone. The registry also lists changes in self-management abilities, physical activity, daily step counts, depression, sleep quality, and anxiety, as well as social support and meaning in life. Those outcomes are not substitutes for the primary CRQ measure. Numerical results for the primary summaries are not reported in the registry record, so the observed change and its uncertainty cannot be evaluated from the recorded outcome description.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies change in CRQ quality-of-life scores as the primary outcome and names baseline and 3 months as the assessment times. It describes both emotional and physical summary scores. However, numerical estimates for these outcomes are not reported in the registry record. There is therefore no reported mean change, between-group contrast, or confidence interval to interpret for the primary outcome. The posted outcome description alone cannot establish the direction, magnitude, or precision of a difference between the intervention and usual-care groups.
The CRQ score range is 1 to 7, with higher scores indicating better health-related quality of life. The registry states that 0.5 points is the minimal clinically important difference. That benchmark can help readers interpret a reported CRQ effect, but it does not supply the missing effect estimate. Without the estimate and its confidence interval, it is not possible to assess whether the observed difference was close to, below, or above that benchmark, or how compatible the data are with effects of different sizes.
A confidence interval communicates uncertainty around an estimate. In general, a narrower interval indicates greater precision, while a wider interval leaves more uncertainty about the magnitude of the effect. Neither the estimate nor its confidence interval for the primary CRQ summaries is reported in the registry record. A p-value is also not reported for those results, so statistical evidence against a no-difference model cannot be assessed from this record.
The registry lists secondary outcomes covering self-management, physical activity, daily step counts, depression, social support, meaning in life, sleep quality, and anxiety. It records 10 outcome measures and 8 analyses. Numerical results for those secondary outcomes are not reported in the registry record. The available information therefore does not support conclusions about how the arms compared on those outcomes or whether results were consistent across measures.
The safety record lists 15 serious adverse events in each arm. It lists 0 other adverse events in each arm, and deaths of 0 in the intervention arm and 5 in usual care. These are descriptive counts. They do not, by themselves, establish whether an event was caused by an intervention or whether the observed counts differ beyond what could occur by chance. No comparative safety estimate or uncertainty interval is reported in the registry record.
Overall, the registry documents the design, outcome definitions, and selected event counts, but does not report the numerical primary-outcome results. Interpretation must therefore remain limited to those recorded details rather than an estimate of treatment effect.
9. Statistical Methods Explained
The analysis described in the registry is based on a continuous outcome: CRQ scores summarized as means with 95% confidence intervals. General statistical interpretation of these quantities can help explain what a complete report would communicate, but the numerical primary-outcome estimates are not reported in the registry record.
What does a mean describe?
A mean is a measure of the central value of observations. For a continuous score such as the CRQ, it condenses the scores in a group into a single average. A change score represents how the measurement differs between the stated assessment times. Here, the registry describes baseline and 3 months and says the reported changes concern the emotional and physical CRQ summaries. The registry does not report the actual means or changes for either arm.
A mean can be useful for comparing groups, but it does not describe every participant’s experience. Individual scores can vary around the mean. The spread of those scores and the distribution of changes are not reported in the registry record. Nor are the numerical group contrasts for the emotional and physical summaries. Thus, the outcome definition is available, but the magnitude of the observed results is not.
What does a confidence interval add?
A confidence interval expresses uncertainty around an estimate under the assumptions of the statistical method used. It is not a guarantee that the true value lies within the particular interval. In general, a more precise estimate has a narrower interval, while a less precise estimate has a wider interval. A 95% confidence interval is the dispersion measure named for the primary outcome in the registry. Its endpoints are not reported in the registry record, so precision cannot be evaluated for the primary comparison.
Confidence intervals also help distinguish the point estimate from the range of values that remain compatible with the data and model. If an interval includes effects that would be interpreted differently, the estimate may not settle the practical question. For this CRQ outcome, the registry gives 0.5 points as the minimal clinically important difference. The absent estimate and interval prevent comparison with that benchmark.
Why is the comparison between arms important?
Changes within one arm do not, on their own, identify an effect attributable to the assigned intervention. Participants may change over time for reasons shared across arms. A randomized comparison asks whether the measured outcome differs between the assigned groups, taking the trial’s analysis approach into account. This is a general principle of trial interpretation. The registry describes randomization and a parallel-group structure, but numerical comparative results and details of the analysis model are not reported in the registry record.
The record specifies an intent-to-treat approach for the primary outcome. In general, intent-to-treat analysis retains participants according to their randomized assignment, regardless of what they ultimately receive or complete. That approach aims to preserve the original randomized comparison. The registry also states that if a month three measure is missing for any reason, it will be described as not changing from baseline. How many measurements were missing and how this rule affected the reported estimates are not reported in the registry record.
What can significance testing tell a reader?
A significance test evaluates the compatibility of data with a specified statistical model, often one in which there is no group difference. A p-value is not the probability that the null hypothesis is true, and it does not measure clinical importance. Statistical significance, if reported, would need to be considered alongside the estimated effect, its uncertainty, and the CRQ benchmark. No primary-outcome p-value or numerical estimate is reported in the registry record.
The sample-size assumptions describe planning illustrations based on an observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. Such planning illustrations ask how many participants per arm might be needed to detect a specified fraction of an effect under stated assumptions. They are not observed power and are not a substitute for the trial’s actual effect estimate or confidence interval. The registry record does not report the trial’s own sample-size justification or the numerical planning outputs in the registry record for this analysis.
Why can over-dispersion matter?
General statistical note: over-dispersion occurs when observed variability is greater than a model assumes. If a model underestimates variability, standard errors and confidence intervals can be too small, making results appear more precise than warranted. This issue depends on the type of outcome and model. The primary outcome is described as a continuous mean, and the registry does not report a model specification or a finding of over-dispersion. It would therefore be inappropriate to claim that over-dispersion affected this trial’s analysis.
More broadly, a statistical method should match the outcome structure and account for relevant uncertainty. The registry identifies the outcome scale, summary measure, time frame, and missing-data rule, but does not report enough numerical results or analytic detail to assess model fit, assumptions, or robustness.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 10 outcome measures and 8 analyses. It names secondary outcomes covering self-management abilities, physical activity, daily step counts, depression, social support, meaning in life, sleep quality, and anxiety. The primary outcome description includes both emotional and physical CRQ summary scores. Considering many outcomes or summaries creates a multiplicity issue: the more statistical comparisons made, the greater the opportunity for apparently notable findings to arise by chance. This is a general statistical concern, not a claim about what occurred in this trial.
Whether the trial used a hierarchy of outcomes, adjusted significance thresholds, or another multiplicity approach is not reported in the registry record. The numerical results and p-values for the primary and secondary outcomes are also not reported in the registry record. Without those details, it is not possible to assess how multiplicity was addressed or to distinguish prespecified confirmatory comparisons from exploratory ones.
The primary-outcome population is described as intent-to-treat. The registry states that a month three measure missing for any reason would be described as not changing from baseline. This is a specific missing-data rule: it assigns no change from baseline to a missing month three observation for the stated analysis description. The number of missing measurements, reasons for missingness, and sensitivity analyses are not reported in the registry record.
In general, missing-data assumptions matter because participants with unobserved outcomes may differ from those with observed outcomes. Treating missing scores as unchanged can influence estimates if that assumption does not reflect their unobserved outcomes. That is a general limitation of the rule, not evidence that it biased the results. The full statistical analysis plan and further details of the analysis populations are not reported in the registry record.
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 |
|---|---|---|---|
| Pulmonary Rehabilitation Program Intervention | 15 | 188 | 8.0% |
| Usual Care | 15 | 187 | 8.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Pulmonary Rehabilitation Program Intervention | 0 of 188 |
| Usual Care | 5 of 187 |
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 |
|---|---|
| Pulmonary Rehabilitation Program Intervention | 0 of 188 |
| Usual Care | 0 of 187 |
Most frequent serious adverse event terms
| Event term | Organ system | Pulmonary Rehabilitation Program Intervention | Usual Care |
|---|---|---|---|
| Hospitalization- COPD Exacerbation | Respiratory, thoracic and mediastinal disorders | 9 of 188 | 10 of 187 |
| Hospitalization: Aortic Stenosis | Cardiac disorders | 1 of 188 | 0 of 187 |
| Hospitalization: Opioid Hyperalgesia | General disorders | 1 of 188 | 0 of 187 |
| Hospitalization- left Carotid Artery Stent | Vascular disorders | 1 of 188 | 0 of 187 |
| Hospitalization: Debridement of Metatarsal ulcer | Surgical and medical procedures | 1 of 188 | 0 of 187 |
| Hospitalization: Endobronchial valve lung volume reduction sugery | Respiratory, thoracic and mediastinal disorders | 1 of 188 | 0 of 187 |
| Hospitalization: Obstruction Intestinal | Gastrointestinal disorders | 1 of 188 | 0 of 187 |
| Hospitalization: Prostate Cancer | Reproductive system and breast disorders | 0 of 188 | 1 of 187 |
| Hospitalization: Neoplasm of Rectum | Gastrointestinal disorders | 0 of 188 | 1 of 187 |
| Hospitalization: Malignant Neoplasm Brain | Nervous system disorders | 0 of 188 | 1 of 187 |
Serious events with the highest arm-level rate: hospitalization- copd exacerbation (5.3%), hospitalization: prostate cancer (0.5%), hospitalization: neoplasm of rectum (0.5%), hospitalization: malignant neoplasm brain (0.5%), hospitalization: acute diarrhea (0.5%).
The safety record lists 15 serious adverse events among 188 participants at risk in the pulmonary rehabilitation program intervention arm, and 15 among 187 participants at risk in usual care. It lists 0 other adverse events among 188 participants at risk in the intervention arm and 0 among 187 in usual care. The death counts are 0 in the intervention arm and 5 in usual care.
The registry also lists serious-event terms and percentages: Hospitalization- COPD Exacerbation, 5.3%; Hospitalization: Prostate Cancer, 0.5%; Hospitalization: Neoplasm of Rectum, 0.5%; Hospitalization: Malignant Neoplasm Brain, 0.5%; Hospitalization: Acute Diarrhea, 0.5%; and Hospitalization: Pacemaker Cardiac Status Post, 0.5%. The registry record does not provide enough detail to attribute those terms to a particular arm.
These figures are descriptive counts, not proof that an event was caused by an assigned treatment. Event counts also do not show how severity, timing, duration, or participant-level recurrence compared. The registry does not report a comparative safety analysis or uncertainty intervals. The five deaths listed for usual care and none listed for the intervention arm should therefore be read as recorded counts, not as evidence of a causal difference.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized, parallel-group comparison was conducted between a home pulmonary rehabilitation program with health coaching and usual care. It defines a primary quality-of-life outcome using the CRQ at baseline and 3 months, and it describes both physical and emotional summary scores. It also states that higher CRQ scores represent better health-related quality of life and gives 0.5 points as the minimal clinically important difference.
Those details explain what the trial was designed to assess, but they do not tell readers what the primary outcome showed. Numerical changes, between-group estimates, confidence intervals, and p-values for the CRQ summaries are not reported in the registry record. Consequently, neither the direction nor size of any difference can be determined from the outcome description. It is also not possible to assess how precisely an effect was estimated or how it compares with the stated CRQ benchmark.
The trial also listed outcomes related to physical activity, daily step counts, self-management, mood, social support, meaning in life, and sleep. The numerical findings for these measures are not reported in the registry record. Their presence in the outcome list indicates what was assessed, not what the results were.
The safety counts provide a separate descriptive picture. Serious adverse event counts were 15 in each arm, other adverse event counts were 0 in each arm, and death counts were 0 in the intervention arm and 5 in usual care. Without a comparative analysis, uncertainty estimates, and fuller event context, those counts cannot establish causation or a reliable between-arm safety difference.
In short, the registry supports conclusions about the trial’s design, outcome definitions, stated missing-data approach, and recorded event counts. It does not support a conclusion about whether the intervention changed quality of life or other outcomes. That distinction is important: knowing what a trial set out to measure is not the same as knowing its effect estimate.
13. Why This Trial Matters Statistically
This trial raises an important statistical distinction between a clearly defined question and a reported result. The registry identifies randomization, a parallel-group comparison, two assigned arms, and a primary outcome with a specified instrument and assessment times. Those features help readers understand the intended comparison. Yet without the numerical primary-outcome estimate and its uncertainty, the central statistical question remains unanswered in the registry record.
The CRQ definition is particularly useful for interpretation because it describes the score direction, range, component domains, and the stated minimal clinically important difference of 0.5 points. A meaningful interpretation would consider the estimated between-arm effect and its confidence interval in relation to this benchmark. The benchmark alone cannot show whether participants’ scores changed, whether the arms differed, or how precisely a difference was estimated.
The recorded intent-to-treat approach and rule for missing month three measurements also matter. Missing-data decisions can affect estimates, so transparent reporting of missingness, assumptions, and sensitivity analyses helps readers assess how robust conclusions are. The registry states the rule but does not report the number of missing measures or sensitivity analyses.
Finally, the trial includes multiple secondary outcome areas and more than one CRQ summary. Multiplicity makes clear reporting of prespecified analyses and interpretation especially important. The registry does not report whether multiplicity was addressed. Together, these features illustrate why statistical interpretation depends not just on design and outcome definitions, but also on complete estimates, uncertainty, and analytic transparency.
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 this trial from the registry record is the absence of numerical primary-outcome results. The record describes the CRQ measures and timing, but does not report the mean changes, comparative estimates, confidence intervals, or p-values for the emotional and physical summaries. Without these values, effect size and precision cannot be evaluated.
Further analytic details are not reported in the registry record. These include the sample-size justification, randomization procedure, allocation concealment, statistical model, handling of any outcomes beyond the stated missing-data rule, and use of sensitivity analyses. The registry also does not report the number of missing month three measures or their reasons.
The trial is recorded as unmasked. Whether outcome assessors were masked is not reported in the registry record. Because the intervention involves home rehabilitation and health coaching, participant and personnel masking is not described; details of the intervention delivery and usual-care content are also limited. These gaps make it difficult to assess the exact contrast between arms and the potential for measurement or performance differences.
The registry lists multiple outcome measures and analyses, but does not describe a multiplicity strategy. The numerical results for the listed secondary outcomes are not reported in the registry record. Safety information is limited to selected event counts and terms; comparative safety estimates, event timing, and attribution are not reported. These limitations constrain interpretation of both benefit-related outcomes and safety, and they do not establish that the trial itself lacked analyses or reporting beyond what appears in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Home Pulmonary Rehabilitation for COPD — NCT03480386.
- Registry record last updated 2024-02-13; status last verified 2024-01.
- Results first posted 2024-02-13.
- 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
NCT03480386, titled Home Pulmonary Rehabilitation for COPD, is recorded as a completed randomized, unmasked, parallel-group trial sponsored by Mayo Clinic. Enrollment was 375. The listed study start was 2019-01-01, and primary completion was 2022-02-16.
The intervention arm received 12 weeks of home pulmonary rehabilitation with health coaching; the comparison arm received 12 weeks of usual care. The primary outcome was change in CRQ quality-of-life scores from baseline to 3 months, described as emotional and physical summary scores. The registry states a missing-data rule of describing a missing month three measurement as unchanged from baseline.
Numerical primary-outcome results are not reported in the registry record. Safety counts include 15 serious adverse events in each arm, 0 other adverse events in each arm, and deaths of 0 in the intervention arm and 5 in usual care.