Smart Telehealth Exercise Intervention to Reduce COPD Readmissions: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Smart Telehealth Exercise Intervention to Reduce COPD Readmissions (NCT03089853), a randomized na study. The primary outcome is Rate of All-cause Readmissions.

2. Clinical Question

3. Trial Design

The registry describes a randomized, parallel-group study with no masking. It lists the study as completed and names the University of Alabama at Birmingham as sponsor. The listed start date is 2016-07-14, and the primary completion date is 2019-08-31. The registry lists the phase as NA.

The posted results include 4 participants in the Intervention Arm and 3 in the Usual Care Arm, for enrollment of 7. The study summary had described intended enrollment of up to 40 participants, with about 30 assigned to Smart TeleHealth and NMES and 10 to usual care. The posted enrollment is therefore much smaller than the enrollment described in the summary. The reason for that difference is not reported in the registry record.

Participants assigned to the intervention were to receive NMES for 30 minutes daily for 2 weeks, followed by home pulmonary rehabilitation exercises delivered using a smart phone for an additional 10 weeks. The comparator description specifies a protocolized regimen of 5 days of systemic steroids, with a different regimen allowed if the treating physician determined it was appropriate and with the change documented. The registry does not report further details about treatment adherence or the delivery of these components.

Random allocation is intended to make treatment groups comparable on average, but the small posted enrollment means that chance imbalances can remain substantial. With no masking, participants and study staff would know which arm was assigned; the registry does not report whether outcome assessment was masked. Additional information about sequence generation, allocation concealment, site procedures, or the reasons for the final enrollment is not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: We were unable to analyse because of the small sample size.

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 Rate of All-cause Readmissions, measured over Up to Day 30.

The primary endpoint is the rate of all-cause readmissions within 30 days following an index hospitalization for a COPD exacerbation. The registry describes the outcome in terms of participants and records the number of participants with readmission events for each arm. All-cause readmission includes a return to hospital regardless of the stated cause, as distinct from counting only a return attributed to COPD. This can capture the overall burden of hospital readmission during the defined follow-up period.

Readmission is a clinically relevant outcome because it reflects whether participants return to hospital after discharge. The registry’s study hypothesis linked the intervention to reduced systemic inflammation and improved functional capacity, with the further proposed aim of reducing readmissions. Those are hypotheses and proposed mechanisms, not results established by the posted data.

The registry reports zero participants with readmission events in the Intervention Arm, which included 4 participants, and zero in the Usual Care Arm, which included 3 participants. It states that the outcome could not be analysed because of the small sample size. No comparative estimate or measure of uncertainty for this endpoint is reported in the registry record. The observed counts therefore describe only the participants included in these posted results; they do not quantify how precisely the groups may differ beyond this small study.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the study as randomized, unmasked, and parallel-group. In a randomized study, assignment is intended to reduce systematic differences in participant characteristics between groups. Randomization does not guarantee that groups will be similar in every respect, particularly when enrollment is small. A parallel design means participants are assigned to one arm rather than being described as receiving each treatment in sequence. The registry does not report details of the randomization sequence or allocation concealment.

What do the posted event counts represent?

The primary outcome is a binary event at the participant level: whether an all-cause readmission occurred within 30 days following the index hospitalization. The registry records zero event participants in each arm, with 4 participants in the Intervention Arm and 3 in the Usual Care Arm. Such counts are useful for describing what happened in the enrolled sample. By themselves, they do not estimate the uncertainty around a comparison or establish that the underlying event probabilities are the same.

In general, an inferential comparison uses observed data to estimate how groups may differ beyond the study participants, while accounting for sampling uncertainty. A confidence interval expresses a range of effect estimates compatible with the data under the method’s assumptions. A wider interval indicates less precision. The registry does not report a comparative estimate or confidence interval for this primary outcome. No p-value or other formal test result is reported either. The absence of these results should not be replaced with an informal conclusion based only on the matching observed counts.

Why does the small sample matter?

With few participants and no recorded events, the data provide limited information about event frequency and between-group differences. Statistical methods for binary outcomes may also behave differently when events are rare or absent, and some methods cannot produce a stable estimate in that setting. Which method was planned or attempted is not reported in the registry record. The record’s stated reason for not analysing the primary outcome is the small sample size; no further methodological explanation is reported.

For general context, the precision of an estimate depends on the amount of information in the data, including the number of participants and the number of observed events. Adding participants can improve precision, but the degree of improvement depends on the outcome frequency and the analysis method. No precision calculation or sample-size justification for the trial is reported in the registry record. Any sample-size planning illustration associated with observed data should be distinguished from the trial’s original design: such an illustration is not the same as a prospective justification, and it is not observed power.

What can be inferred from randomization?

Randomization supports a causal comparison when the trial is sufficiently informative and the analysis respects the assigned groups, but it cannot compensate for sparse outcome data. In this study, the registry reports assignment to an intervention arm and a usual-care arm, but it does not report an analysis population or explain how participants were handled after randomization. Whether the analysis followed intention-to-treat principles is not reported in the registry record. The registry also does not report adjustment for prognostic factors or details of missing outcome handling.

The trial is unmasked according to the registry. Lack of masking can potentially affect behavior, co-interventions, or outcome ascertainment, depending on how outcomes are collected. The primary endpoint is a recorded readmission, but further information about how readmissions were ascertained or verified is not reported in the registry record. It would therefore be inappropriate to assume either that ascertainment was affected or that it was protected from possible bias.

How should the broader outcome set be read?

The registry lists 8 secondary outcomes, including changes in FEV1, dyspnea measures, COPD-related quality of life, quadriceps strength, a 30-second chair test, and systemic and muscle inflammation. The number of analyses posted is 0. A listed outcome is not the same as a reported result: without outcome values, estimates, or analysis details, no statistical conclusion about these secondary measures can be drawn. The record does not report the planned statistical methods, handling of multiple outcomes, or any interim analyses. Those omissions limit assessment of how the full analysis strategy was specified and whether results across outcomes were interpreted with appropriate caution.

Overall, the available statistical information supports a descriptive reading of the reported counts and the registry’s statement that the primary outcome could not be analysed. It does not support a precise estimate of treatment effect, a formal test of group differences, or conclusions about the listed secondary outcomes.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Intervention Arm", "Usual Care Arm")
n      <- c(4, 3)
events <- c(0, 0)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Intervention Arm  4  0  0.0  0.0  60.2  0.0  49.0  0.5  52.2
ARM  Usual Care Arm  3  0  0.0  0.0  70.8  0.0  56.1  0.6  60.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 8 secondary outcomes in addition to the primary readmission endpoint. These cover lung function, dyspnea, COPD-related quality of life, muscle strength and function, and inflammation. The number of analyses posted is 0, and the registry does not report numerical results or statistical analyses for those secondary outcomes. Their inclusion in the outcome list should not be mistaken for evidence that they changed or for evidence of a treatment effect.

When a study examines multiple outcomes, the chance of at least one apparently unusual finding can increase if each outcome is tested separately. General approaches include identifying a primary outcome in advance, defining a hierarchy, or adjusting interpretation for multiple comparisons. The analysis plan for multiplicity is not reported in the registry record. It is therefore not possible to determine whether multiplicity was addressed in a prespecified way.

Missing-data handling is also not reported in the registry record. The posted arm sizes are 4 and 3, but the record does not explain whether any participants had missing outcome information, how follow-up completeness was assessed, or how missing observations were treated. The record does not report an analysis population definition, including whether participants were analysed according to randomized assignment. No conclusions about these procedures should be inferred from the posted event counts alone.

The registry says the primary outcome could not be analysed because of the small sample size. The reason for not posting analyses of secondary outcomes, any planned handling of missing values, and any prespecified analysis hierarchy are not reported in the registry record. These gaps matter because they limit the ability to assess the completeness and robustness of the reported results.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The safety figures describe participants with serious adverse events, participants with other adverse events, and deaths. In the Intervention Arm, 4 participants were at risk for serious adverse events and zero were affected; 4 were at risk for other adverse events and zero were affected; deaths were zero. In the Usual Care Arm, 3 participants were at risk for serious adverse events and zero were affected; 3 were at risk for other adverse events and zero were affected; deaths were zero. No serious adverse event terms are listed.

These counts mean that no such events were recorded among the participants represented in the posted safety data. They do not establish that an event is impossible or exclude less common harms, particularly given the small numbers of participants. The registry record does not report additional detail about adverse-event definitions, collection procedures, severity grading, or the duration of safety follow-up. The safety counts should therefore be read as a limited description of the posted observations, not as a complete characterization of safety.

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

The result establishes only what was recorded in this small enrolled sample: zero participants in the Intervention Arm and zero in the Usual Care Arm had an all-cause readmission recorded for the primary endpoint. The registry lists 4 participants in the intervention arm and 3 in usual care, and explicitly states that the primary outcome could not be analysed because of the small sample size.

It does not establish that the intervention reduces readmissions, that the groups have equal readmission outcomes, or that either approach is preferable. Identical observed event counts in very small groups do not provide a precise estimate of the difference that might occur in a larger population. No comparative effect estimate or confidence interval is reported in the registry record, so the magnitude and precision of any possible difference are unknown.

The finding also does not determine whether the proposed biological and functional pathways occurred. The registry’s study summary describes a hypothesis involving inflammation and functional capacity, while its secondary outcome list includes measures relevant to those ideas. Results for those secondary outcomes are not reported in the registry record. The primary readmission counts cannot substitute for measurements of inflammation, lung function, dyspnea, quality of life, or muscle function.

Likewise, zero recorded adverse events in these participants should not be interpreted as proof that no adverse events could occur. The observed safety counts are limited to the participants and reporting represented in the registry. Further information about adverse-event monitoring and follow-up is not reported in the registry record.

The registry result is therefore best understood as an incomplete and descriptive account of a small randomized study. It records no primary events in either arm but provides insufficient information for a comparative statistical conclusion. It does not settle the intervention’s effect on readmission or the other outcomes listed.

14. Why This Trial Matters Statistically

This trial is statistically instructive because it separates a neutral-looking event count from a conclusive comparison. Both arms have zero recorded primary events, but the study includes only 7 participants and the registry says the primary outcome could not be analysed because of the small sample size. Matching counts are not evidence of equivalence when the data are too sparse to estimate a difference with useful precision.

The record also illustrates the distinction between planned and posted enrollment. The study summary describes enrollment up to 40 participants, while the posted results include 7. That difference is important context for interpreting the amount of information available. The reason the final enrollment was lower is not reported in the registry record, so the statistical consequences can be described without attributing a cause.

Another important point is that a registry can list outcomes without presenting results for them. This record names secondary measures spanning symptoms, lung function, quality of life, strength, physical function, and inflammation, but reports 0 analyses. The proposed biological rationale therefore remains distinct from evidence in the posted results.

Finally, the record does not report several elements needed to fully evaluate the statistical plan, including the sample-size justification, the handling of missing data, the analysis population, and the approach to multiple outcomes. Their absence limits the conclusions that can be drawn from the registry, even when the recorded arm-level counts are clear. Careful interpretation recognizes both what was observed and the uncertainty that remains.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The most immediate limitation is the small posted enrollment: 7 participants, with 4 in the Intervention Arm and 3 in the Usual Care Arm. The registry states that the primary outcome could not be analysed because of the small sample size. With no readmissions recorded in either arm, the results do not provide a reported comparative estimate or quantify its precision.

The study summary described enrollment up to 40 participants, with about 30 assigned to Smart TeleHealth and NMES and 10 to usual care. Why the posted enrollment was 7 rather than the planned maximum is not reported in the registry record. The sample-size justification and any statistical assumptions used in planning the trial are also not reported. The registry does not provide a basis for determining whether the final enrollment was anticipated or how it affected the original design.

The record lists 8 secondary outcomes but posts 0 analyses. As a result, it is not possible to assess the intervention’s reported results for lung function, dyspnea, quality of life, muscle function, or inflammation. A statistical plan, multiplicity approach, interim analyses, missing-data procedures, and analysis population are not reported in the registry record.

The study was unmasked, but further information about outcome ascertainment, adherence, follow-up completeness, and co-interventions is not reported in the registry record. These details would help readers assess the possibility of bias and the extent to which the delivered intervention matched its description. The registry’s safety data also provide only event counts, without further reported detail on definitions or monitoring. These limitations constrain interpretation and do not justify conclusions beyond the posted observations.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Smart Telehealth Exercise Intervention to Reduce COPD Readmissions — NCT03089853.
• Registry record last updated 2022-03-22; status last verified 2022-03.
• Results first posted 2020-09-22.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry record describes a completed randomized, parallel-group, unmasked study sponsored by the University of Alabama at Birmingham. It enrolled 7 participants and compared home Smart TeleHealth pulmonary rehabilitation with NMES against usual care after hospitalization for a COPD exacerbation.

The primary endpoint was all-cause readmission within 30 days following the index hospitalization. The registry reports zero readmissions in the Intervention Arm of 4 participants and zero in the Usual Care Arm of 3 participants. It states that the primary outcome could not be analysed because of the small sample size. No comparative estimate is reported.

The registry lists 8 secondary outcomes and reports 0 analyses. It also records zero serious adverse events, zero other adverse events, and zero deaths in both arms. The posted data are descriptive and do not establish a comparative effect on readmission or the listed secondary outcomes.