A Comprehensive Care Programme for Patients With Chronic Obstructive Pulmonary Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Comprehensive Care Programme for Patients With Chronic Obstructive Pulmonary Disease (NCT01108835), a randomized na study. The primary outcome is Hospital Readmission.

2. Clinical Question

The clinical question focuses on healthcare use following discharge after an acute exacerbation, rather than on all people living with COPD. Hospital readmission is the registered primary outcome, while quality of life, mortality, lung function and exercise capacity are identified as secondary outcomes. This distinction matters when interpreting the results: the primary comparison addresses readmissions, and secondary measures provide additional, but not equivalent, information about the programme’s effects.

The registry record identifies the programme as a comprehensive care intervention and the comparison as usual care. It does not specify the particular professional roles involved, the frequency or duration of contacts, or whether care was delivered according to a fixed protocol. The clinical question can therefore be stated clearly at the level of intervention category and outcome, but the record does not allow a detailed description of the care contrast.

3. Trial Design

The registry record describes a randomized, single-masked, parallel-group trial with an enrollment of 180 participants. The two groups were the Comprehensive Care arm and the Control Group. The posted outcome summaries report 90 participants in each arm. The record lists the study phase as not applicable and identifies the Chinese University of Hong Kong as the sponsor.

The study status is completed. The recorded start was 2010-04, and the primary completion was 2015-07. These dates describe the registry timeline; they do not by themselves specify when each participant was enrolled, how long recruitment lasted, or whether follow-up continued beyond the registered primary completion.

The intervention is named Comprehensive care programme and described as comprehensive care involving multidisciplinary input. The comparator is described as usual care. The registry identifies single masking but does not say which people were masked. It also does not report how the random sequence was generated, whether allocation was concealed, or how the parallel groups were maintained during follow-up. Those details should not be inferred from the design labels alone.

The primary outcome was mean hospital readmissions over 12 months. The registry also lists quality of life, mortality, lung function and exercise capacity as secondary outcomes. Numerical secondary results are posted for quality of life, mortality and lung function; a numerical exercise-capacity result is not reported in the registry record. The record does not describe the settings, baseline characteristics, or analysis population in enough detail to determine how representative the participants were or exactly who contributed to each analysis.

Although the design is randomized, the statistical analysis plan and details of the original design assumptions are not reported in the registry record. In particular, the record does not state the trial’s planned sample-size justification, analysis model, or whether any interim analyses were planned. The planning illustrations calculated from the posted effect are separate from those unreported original design decisions.

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

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 Hospital Readmission, measured over 12 months.

The primary endpoint is titled Hospital Readmission and is measured as the mean number of hospital readmissions over 12 months. The registered description concerns hospital admission among COPD patients discharged after an episode of acute exacerbation. The posted arm summaries report means and standard deviations, so the primary comparison is expressed as a difference between group means.

Hospital use was chosen in keeping with the stated study objective: assessing whether a comprehensive care programme could decrease admissions for COPD. The registry background notes the substantial use of healthcare resources associated with COPD and identifies admission costs as an important source of public hospital expenditure. This makes readmission a directly relevant measure of healthcare utilization for the population described in the record.

A mean difference describes the average separation between the groups; it does not show how many individuals were readmitted, how admissions were distributed across participants, or whether any particular patient had a readmission. The standard deviations describe variation in the recorded measure within each group, but the registry record does not provide a distribution of individual counts or explain how readmissions were defined, verified, or handled if a participant had more than one admission.

The endpoint is reported over a fixed 12-month timeframe. The record does not specify whether the measure includes only COPD-related admissions or all hospital readmissions, nor does it report a clinical threshold for a meaningful difference. Those omissions limit interpretation of the endpoint’s precise operational definition and of the clinical importance of the observed mean contrast.

7. Results Posted in the Registry

• Comprehensive Care: mean 1.12 versus 1.70 on control; difference -0.58 (95% CI -1.07 to -0.09), standardized effect d = -0.35; z-test p = 0.020.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Quality of Life

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Comprehensive Care Programme: mean -6.90 versus -0.10 on control; difference -6.80 (95% CI -11.33 to -2.27), standardized effect d = -0.44; z-test p = 0.003.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Comprehensive Care Programme than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Mortality

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Comprehensive Care: 11.1% (10/90) versus 13.3% (12/90) on control; risk difference -2.2 percentage points (95% CI -11.8 to 7.3), risk ratio 0.83 (0.38–1.83); unadjusted two-proportion z-test p = 0.649.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Comprehensive Care and the control. The interval gives the range of effects that remain compatible with the data.

Lung Function

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Comprehensive Care: mean 0.80 versus -0.50 on control; difference 1.30 (95% CI -0.95 to 3.55), standardized effect d = 0.17; z-test p = 0.257.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Comprehensive Care and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes broaden the focus beyond hospital readmissions to quality of life, mortality, lung function and exercise capacity. Numerical results are posted for quality of life, mortality and lung function. A numerical result for exercise capacity is not reported in the registry record. This pattern means that the secondary evidence is incomplete across the outcomes named in the record.

Across the posted secondary comparisons, the estimates do not all point in the same numerical direction, and their uncertainty differs. The quality-of-life comparison has an interval that does not include zero, while the mortality and lung-function intervals include no difference. The quality-of-life scale’s scoring direction is not reported, so the sign alone cannot be described as better or worse. The registry record does not provide a threshold for clinical importance for these secondary outcomes.

The secondary results add context to the primary finding but do not answer the primary readmission question directly. They represent different kinds of outcomes, measured on different scales or as counts, and their estimates should not be treated as interchangeable. The absence of a reported exercise-capacity result also prevents a complete account of every secondary outcome named in the record.

All secondary p-values are unadjusted, and the registry record does not report a multiplicity plan. In general, examining several outcomes creates more opportunities for apparently notable results to arise by chance. Without a stated plan to control the overall error rate or prioritize secondary tests, an isolated unadjusted result carries less evidential weight than it would under a prespecified, multiplicity-aware analysis. The secondary findings are most appropriately considered exploratory or supportive, rather than definitive confirmation of the primary result.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Quality of Life
• Mortality
• Lung Function
• Exercise Capacity

9. Statistical Interpretation

10. Statistical Methods Explained

The registry record reports the primary endpoint as a mean with standard deviation, and the posted group summaries use that form. The comparison is a mean difference: the Comprehensive Care group mean minus the Control Group mean. With that ordering, a negative difference means the posted average is lower in Comprehensive Care, while a positive difference means it is higher. This sign convention describes the arithmetic direction; it does not by itself establish clinical importance.

What do the means and standard deviations describe?

In general, a mean is an average across the participants included in a group’s summary. A standard deviation describes how dispersed individual observations are around that average. The group means alone do not show the shape of the observations, whether values are concentrated near the average, or whether a small number of participants had many admissions. The standard deviations offer information about spread but do not supply the individual-level distribution.

The primary endpoint is a count of readmissions summarized as a mean. In general, count outcomes may be unevenly distributed or show more variability than a simple statistical model assumes. Over-dispersion means the data vary more than the model’s assumed distribution would predict; when that occurs, uncertainty estimates from an unsuitable model can be too narrow. The registry record does not report a model for the primary endpoint, an assessment of its distribution, or whether over-dispersion was considered. It is therefore not possible to say which count-data method, if any, was used by the trial investigators.

How should the mean difference be read?

The calculated mean difference is a contrast between the two posted group averages, not a change from baseline and not a ratio. Here the contrast is ordered as Comprehensive Care minus Control Group. The reported negative estimate therefore points to a lower average in the Comprehensive Care group. Because the comparison is unadjusted, it does not account for covariates or other factors beyond the arm-level summaries used in the calculation.

In general, a confidence interval gives a range of values compatible with the observed data under the statistical procedure used. It reflects sampling uncertainty and should be read together with the point estimate. An interval that crosses zero is compatible with no mean difference under that procedure; an interval wholly on one side of zero indicates that the corresponding unadjusted comparison does not include zero. The confidence level and the precise interval method are not reported in the registry record, so the interval should not be assigned an unreported level or attributed to a specific model.

What does the p-value add?

In general, a p-value describes how unusual data at least as incompatible with a specified null hypothesis would be if that null hypothesis and the test assumptions were true. It is not the probability that the null hypothesis is true, and it does not measure the size or importance of a difference. The primary p-value is unadjusted. The registry record does not report the test used, its assumptions, or whether the investigators used a different inferential analysis.

The posted primary p-value accompanies a mean difference whose interval lies below zero. These statistics summarize the same unadjusted contrast from different perspectives: the estimate gives the direction and magnitude, the interval conveys uncertainty, and the p-value describes compatibility with a null comparison under a particular test. They do not establish that the analysis was prespecified, adjusted, or the only analysis conducted.

What is and is not reported about the analysis?

The record contains arm-level means, standard deviations and sample sizes, but no reported analysis entries. It does not state whether the investigators used an intention-to-treat population, a per-protocol population, a covariate-adjusted model, or another analysis population. The method used to manage missing outcome data, if any, is not reported in the registry record. Nor are the model specification, software, diagnostics, or treatment of repeat admissions described.

The available mean-difference calculation is an unadjusted re-calculation from the posted summaries. It is useful for describing the numerical contrast based on the data recorded, but it cannot reconstruct an analysis that requires participant-level data or adjustment variables. The registry indicates no discrepancy between the arm summaries and this calculation; nevertheless, the absence of a reported investigator analysis limits what can be concluded about the trial’s original inferential approach.

Why can planning assumptions differ from the trial analysis?

The planning illustrations use a two-sided significance level of 0.05, equal allocation between the arms and a normal approximation. They consider effects set at stated fractions of the observed effect. These are assumptions for the planning illustrations, not reported assumptions for the original trial design. In general, the normal approximation is a simplifying basis for estimating sample requirements; it is not evidence that the original investigators used a normal model for the readmission outcome.

General statistical practice distinguishes such planning calculations from an observed treatment effect. The calculations describe how many participants per arm might be needed under the specified assumptions to detect an effect of a chosen size with a stated power. They cannot show the probability that the completed trial detected an effect, and they do not repair the lack of a reported original sample-size justification. The original design assumptions are not reported in the registry record.

11. Confidence Intervals and Precision

The primary mean difference is -0.58 readmissions, with an interval from -1.068 to -0.092. The estimate is negative, and both interval limits are also negative. In the unadjusted comparison, this places the full reported interval on the side corresponding to a lower mean in the Comprehensive Care arm. The interval is important because the point estimate alone would not describe how uncertain the estimated difference is.

In general, an interval summarizes sampling uncertainty under a statistical method and its assumptions. It is not a guarantee that the true effect falls within the stated limits, and it does not describe the range of individual participants’ outcomes. The registry record does not report the interval’s confidence level or the method used to calculate it, so interpretation should stay with the limits that are posted rather than assume an unreported procedure.

The interval’s lower and upper limits are separated by a meaningful span relative to the point estimate. This indicates that the estimate is not precise enough to identify a single value for the underlying mean difference. The limits remain on the same side of zero, but the registry record provides no threshold for what would count as a clinically important difference. Statistical separation from zero and clinical importance are distinct questions.

The unadjusted p-value is 0.02. It is consistent with the interval’s placement but does not add information about the effect’s practical importance. Because no investigator-reported analyses are listed, and because the inferential method and confidence level are not specified, the precision assessment is limited to the posted summary-statistic comparison. The record does not provide a more detailed uncertainty analysis or adjusted estimate.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm, not total participants and not total events. They use a two-sided significance level of 0.05, equal allocation between the two arms and a normal approximation. The assumed effect to detect is set at 100%, 75% or 50% of the observed effect. These assumptions describe the planning illustration; the trial’s original sample-size assumptions are not reported in the registry record.

The 80% power column gives the estimated participants per arm under which the planning calculation would have an 80% chance of detecting the chosen effect at the stated significance level, if the planning assumptions and effect were correct. The 90% power column uses a higher target probability of detection and therefore calls for more participants under otherwise matching assumptions. For example, at 100% of the observed primary effect, the illustration gives 131 participants per arm for 80% power and 175 participants per arm for 90% power.

Each row changes the assumed effect size. Planning for 75% or 50% of the observed effect means aiming to detect a smaller difference than the full observed estimate. Smaller effects are harder to distinguish from random variation, so the planning calculations require more participants per arm. The figures are therefore conditional illustrations, not a recommendation about the appropriate design for a future study.

This is not observed power. It is a planning calculation based on the observed effect and stated assumptions, and it does not tell whether the completed trial had a particular probability of detecting an effect. The original trial’s design justification and assumptions are not reported in the registry record.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -0.580; pooled standard deviation σ = 1.670.
2. n = 2 × (1.96 + 0.842)² × 1.670² / -0.580² = 130.2, rounded up to 131 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -0.58                      # observed difference in means
sigma <- 1.67011975618517                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(1108835)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 131 (80% power), 175 (90% power)
 75% of observed effect: n per arm = 232 (80% power), 310 (90% power)
 50% of observed effect: n per arm = 521 (80% power), 697 (90% power)
power.t.test: 131.1 
Simulated power at n = 131 per arm: 0.803 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry record lists several secondary outcomes in addition to the primary readmission outcome, but it does not report a multiplicity strategy. It is not reported whether the investigators defined a hierarchy of outcomes, adjusted secondary p-values, or identified a single secondary endpoint as confirmatory. In general, when several hypotheses are tested, the chance of at least one apparently notable result can increase. An unadjusted secondary p-value should therefore be interpreted cautiously unless the analysis plan explains how the set of tests was handled.

The registry record lists no reported analyses. It does not describe an analysis population, such as whether all randomized participants were included according to assigned group, or whether exclusions were made. The posted summaries give 90 participants in each arm, but those counts do not establish how every participant was handled or whether the same analysis population was used for every outcome.

Missing-data methods are not reported in the registry record. The record does not state whether outcome data were complete, how missing measurements were identified, or whether any imputation, weighting or sensitivity analysis was used. Without that information, it is not possible to assess whether missing outcomes could have affected the reported means or comparisons. The available summaries should not be taken as evidence that no data were missing.

The registry record also does not report whether analyses were prespecified, whether there were interim analyses, or what original sample-size assumptions were used. These are separate reporting questions: the absence of a reported plan does not establish that no plan existed, but it prevents readers from checking how closely the posted results follow one. The reported unadjusted comparisons should be understood in light of these unresolved analysis and reporting details.

15. 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 0% reporting threshold.

The safety summaries list 90 participants at risk for serious adverse events in each arm. The posted count of participants affected by a serious adverse event is 0 in the Comprehensive Care group and 0 in the Control Group. The count for other adverse events is also 0 in each group, with 90 participants at risk in each arm. No serious adverse-event terms are listed.

These are the counts recorded in the registry safety fields. They do not describe event timing, severity grading beyond the serious-versus-other categories, relatedness assessments, or how events were collected. The registry record does not provide those details, so the zero counts should be read as the posted safety summaries rather than as a complete account of adverse-event monitoring.

The safety fields do not report a death count. Mortality is listed separately as a secondary outcome, but that should not be substituted for the missing safety death field. The record does not provide enough information to reconcile the distinct safety and mortality reporting fields or to make broader claims about safety.

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

The primary posted summaries show a lower mean number of hospital readmissions in the Comprehensive Care arm than in the Control Group over 12 months. The unadjusted calculated mean difference is -0.58, and its interval lies below zero. This describes the group-level result in the registry record; it does not mean that every participant in the programme group had fewer admissions or that each individual experienced the same change.

The randomized design is relevant because random assignment is intended to support a fair comparison between groups. However, the registry record does not report allocation procedures, participant characteristics, analysis populations, missing-data handling, or an investigator-reported analysis. These omissions limit assessment of how the randomization was implemented and how the posted summary comparison was derived.

The numerical result does not by itself establish clinical importance. The registry record does not report a minimum important difference or explain the operational details used to count readmissions. Nor does the mean summarize the distribution of admissions among individuals. The reported standard deviations indicate variation, but without individual-level data it is not possible to describe who experienced admissions or how that variation arose.

The secondary outcomes do not provide a uniform or complete body of evidence: numerical results are not reported for exercise capacity, and the record does not describe a multiplicity plan for the other secondary comparisons. They should not be used to make a broader claim than the outcomes and methods reported support. A favorable direction in one measure does not establish a consistent effect across all domains.

Accordingly, the posted primary statistics indicate a difference in average readmissions between the randomized groups, with uncertainty that remains on the negative side of zero under the reported unadjusted comparison. The record does not establish the mechanism behind that difference, its clinical value, or how it would generalize to settings and participants not described in the registry record.

17. Why This Trial Matters Statistically

This trial addresses a statistical question with direct relevance to healthcare utilization: whether a comprehensive care programme is associated with a different average number of hospital readmissions after discharge for an acute COPD episode. The primary endpoint matches the stated objective of evaluating admissions, rather than relying only on measures of symptoms or physiology. The registry background also identifies hospital use as an important resource concern.

The posted result illustrates why an estimate should be read alongside its uncertainty. The mean difference is -0.58 readmissions, and the interval runs from -1.068 to -0.092. The estimate’s direction is clear under the stated subtraction order, while the range communicates that the exact size of the difference remains uncertain. The registry does not report a clinical-importance threshold, so statistical separation from zero cannot settle the practical importance of the result.

The trial also highlights the value of reporting complete statistical methods. Randomization and equal group sizes are documented, but the record does not report the analysis model, analysis population, missing-data approach, or original sample-size assumptions. Such details help readers judge whether an analysis is appropriate for a count outcome, whether all randomized participants are represented, and whether the primary comparison followed a planned strategy.

Finally, the secondary outcomes show why multiple outcomes require transparent planning and interpretation. The registry names several clinical domains, yet the numerical reporting is incomplete and the multiplicity strategy is not reported. The primary result remains the central statistical finding, while secondary comparisons are best treated cautiously. This combination of a clear primary contrast and incomplete analysis detail makes the record useful for examining both effect estimation and the limits of registry-based interpretation.

18. 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.

Several details needed to evaluate the trial’s conduct and applicability are not reported in the registry record. These include participant baseline characteristics, detailed eligibility criteria, study setting, and further information about the comprehensive care programme and usual care. The record therefore defines the broad clinical comparison but does not establish how closely the intervention or participants resemble those in other settings.

The masking designation is single, but the record does not identify who was masked. It also does not describe sequence generation or allocation concealment. These omissions limit assessment of the randomization procedures and of possible influences on outcome measurement. The registry record does not explain how readmissions were defined or verified, or whether the endpoint included admissions for causes other than COPD.

The statistical reporting is limited. No investigator-reported analyses are listed, and the original analysis plan, sample-size justification, analysis population and missing-data methods are not reported. The posted primary contrast is an unadjusted re-calculation from summary statistics, so it cannot account for covariates or reproduce an analysis requiring participant-level data. The record does not state whether interim analyses were planned or conducted.

Reporting is also incomplete across outcomes. Exercise capacity is named as a secondary outcome, but a numerical result is not reported in the registry record. The quality-of-life scale’s scoring direction and clinical-importance threshold are not stated. The safety summary does not provide event details or a safety death count, while mortality appears as a separate secondary outcome. These limitations do not erase the posted comparisons, but they constrain their interpretation and the conclusions that can be drawn from the registry record alone.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: A Comprehensive Care Programme for Patients With Chronic Obstructive Pulmonary Disease — NCT01108835.
• Registry record last updated 2017-08-23; status last verified 2017-07.
• Results first posted 2017-03-30.
• 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.

22. Record Summary

The registry record describes a completed randomized, single-masked, parallel-group trial sponsored by the Chinese University of Hong Kong. Enrollment was 180, with posted summaries for 90 participants in each arm. The comparison was multidisciplinary comprehensive care versus usual care for patients with COPD discharged after an acute exacerbation.

The primary endpoint was mean hospital readmissions over 12 months. The posted means were 1.12 for Comprehensive Care and 1.7 for the Control Group. The unadjusted calculated mean difference was -0.58, with an interval from -1.068 to -0.092 and an unadjusted p-value of 0.02. The record lists quality of life, mortality, lung function and exercise capacity as secondary outcomes, but does not report a numerical exercise-capacity result.

The registry record does not list investigator-reported analyses or the original sample-size and analysis assumptions. The primary comparison is therefore best read as an unadjusted calculation from the posted arm summaries, with the reporting limitations considered alongside the result.