E-Visit for COPD and Smoking Cessation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for E-Visit for COPD and Smoking Cessation (NCT04155073), a randomized na study. The primary outcome is Evidence-based Cessation Treatment Utilization.

2. Clinical Question

The trial asks whether this electronic-visit approach can be tested as a way to deliver smoking cessation treatment to adults at risk for COPD while also supporting early detection and accurate diagnosis. The record describes a pilot randomized controlled trial comparing the electronic visit with treatment as usual. Its stated primary objective is to provide effect-size estimates for a larger randomized trial, rather than to establish a definitive treatment effect.

The primary measure focuses on reported use of smoking cessation medication. It does not, by itself, measure whether a participant quit smoking, whether COPD was detected, or whether a diagnosis was accurate. Those are distinct outcomes, and the registry does not give a group comparison for any of them in the posted results described in the record. The registry lists acceptability and feasibility as a secondary outcome, but does not report its result.

The clinical question is therefore best read as a pilot evaluation of an electronic care pathway and its potential to inform later research. The posted information identifies the comparison and the intended outcome, but does not establish the size, direction, or precision of a difference in medication use between groups.

3. Trial Design

The record describes a randomized, parallel-group pilot trial. Participants were assigned to the COPD and smoking cessation electronic visit or to treatment as usual. Masking is listed as none, so the study is recorded as open-label. The registry lists the phase as not applicable.

The electronic-visit group was invited to complete an initial online visit focused on cigarette smoking, quitting smoking, and respiratory symptoms. Participants were also invited to complete a follow-up electronic visit one month later. If needed, the intervention could include a home spirometry test with instruction. The treatment-as-usual group received information about the state quitline and the importance of quitting smoking, along with a recommendation to contact a primary care provider to discuss quitting.

The trial summary describes the work as development, refinement, and pilot testing. The stated primary objective was to estimate effects for a larger randomized trial. That objective is important when interpreting the trial: estimates from a pilot can help describe what was observed, but the record does not state that the trial was designed or powered to provide a definitive comparison.

Enrollment is recorded as 125. The trial start date is 2019-12-12, and primary completion is recorded as 2021-03-12. The status is completed. Completion describes the registry status; it does not establish that every planned outcome or analysis is reported. The record lists three outcome measures and no analyses. It does not report the allocation procedure, allocation concealment, group sizes for the primary outcome, a sample-size justification, or the statistical analysis plan.

The registry record also does not give details about participant flow, adherence to the electronic visits, use of home spirometry, or the extent to which participants received their assigned intervention. Without those details, the design can be described, but fidelity and the practical delivery of the intervention cannot be assessed from the 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

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 Evidence-based Cessation Treatment Utilization, measured over Baseline through Month 3.

The primary endpoint is titled Evidence-based Cessation Treatment Utilization. It is measured as a count of participants, and the description says that participants in both groups are queried about use of a smoking cessation medication since the last assessment. The timeframe is baseline through Month 3.

A participant count can communicate how many people meet an outcome definition. For a comparison between randomized groups, interpretation generally also depends on the number assessed in each group and on a clearly specified outcome definition. The registry record does not state the exact medication list, the response rule used to classify medication use, or the group-specific primary outcome counts and denominators. It also does not report a single comparison for this endpoint.

Medication use is used as a measure of engagement with evidence-based cessation treatment. It is not equivalent to successful quitting, and it does not directly measure COPD detection or diagnostic accuracy. A medication-use result would need to be interpreted alongside its definition, follow-up completeness, and the precision of the group comparison.

The registry notes that the primary outcome includes several categories or time points and is not reduced to one comparison. As a result, the posted record does not establish which particular time point or category should be treated as the sole primary contrast. Neither an effect estimate nor a confidence interval for the primary endpoint is reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The study is recorded as a randomized parallel-group trial without masking. In a parallel design, participants are assigned to one of the comparison groups and followed in that group. Randomization is intended to reduce systematic differences at the start of a study. It does not ensure that measured outcomes are complete or that a particular comparison is precise. The record does not describe the randomization sequence or allocation concealment, so those implementation details cannot be assessed.

What does the primary count represent?

The outcome is defined as a count of participants reporting use of a smoking cessation medication since the last assessment. Counts are a direct way to express how many people meet a definition. In a group comparison, a count alone is generally incomplete because the number assessed in each group also matters. A proportion expresses the count relative to the relevant group denominator, while an effect estimate can express a difference or another contrast between groups. The registry does not report the primary counts, denominators, or a selected comparison, so none of those quantities can be interpreted for this trial.

The endpoint description specifies a period from baseline through Month 3 and refers to use since the last assessment. Repeated assessments can yield multiple values over time. A statistical plan should clarify whether the intended result is based on use at a particular assessment, use during a period, or a pattern across assessments. The record notes several categories or time points but does not reduce them to one comparison. The chosen definition can affect what an estimate means, so it should not be assumed from the endpoint title alone.

What would a confidence interval tell a reader?

In general, a confidence interval describes the statistical uncertainty around an effect estimate. Its width reflects the information available and the variability of the data under the analysis. A narrow interval indicates greater precision than a wide interval, but neither width nor interval location can be evaluated without a reported estimate and interval. The registry record does not report a confidence interval for the primary comparison. A p-value, even if reported, would not replace the effect estimate and its interval: it addresses compatibility with a particular null hypothesis under a specified analysis, rather than showing the range of plausible effect sizes.

For a binary outcome such as whether a participant reported medication use, a comparison could be expressed using group proportions or another prespecified effect measure. The appropriate method depends on the outcome definition, denominators, follow-up, and analysis plan. No particular effect measure or statistical model is reported in the registry record. It would not be appropriate to infer one from the endpoint title or to reconstruct a comparison without the underlying counts.

How should planning illustrations be understood?

Planning sample sizes are conditional calculations, not results observed in trial participants. The record describes planning illustrations based on a fraction of an observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. It specifies that non-time-to-event illustrations are expressed as participants per arm, while time-to-event illustrations use a total number of events. These are general planning assumptions, not evidence that the trial achieved a particular power.

The record does not give numerical planning values or the observed effect used to produce them. The assumptions alone cannot determine a required sample size. Planning based on an estimated effect also carries uncertainty because the estimate itself may be unstable, particularly in a pilot. A design for a later study would need a clearly defined endpoint and comparison, an effect size considered important for planning, a variance or event-rate assumption appropriate to the outcome, and any allowance for attrition or other design features. Those elements are not all reported in the registry record.

Power is a design quantity associated with a specified effect, significance threshold, sample size, and model assumptions. It is not a probability that a treatment works, and it should not be calculated after the fact from an observed result and described as observed power. In this trial, the registry does not report the primary effect estimate or the numeric planning illustrations, so no trial-specific power conclusion is available.

What does the analysis record leave unresolved?

The registry lists no analyses. It therefore does not identify the model, effect measure, handling of repeated assessments, adjustment variables, or inferential procedure used for the primary endpoint. Nor does it report whether the analysis followed randomized assignment or used another analysis population. These are not details that can be inferred from a randomized design alone.

In general, analysis choices should follow the outcome and design. If observations are repeated over time, the method should account for the fact that observations from the same participant are related. If the analysis instead reduces the outcome to one participant-level measure, the definition of that measure should be clear. If outcome data are missing, assumptions and sensitivity analyses can affect how much confidence a reader places in the result. These are general statistical considerations; the registry does not state how this trial addressed them.

The record's description of the primary outcome as involving several categories or time points is particularly relevant. Selecting one comparison in advance can clarify the main inferential question and help distinguish it from secondary or exploratory analyses. Without a reported selection and analysis plan, readers cannot determine how multiple possible comparisons were prioritized or whether any multiplicity procedure was used.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists three outcome measures, identifies evidence-based cessation treatment utilization as the primary outcome, and names acceptability and feasibility as a secondary outcome. It also notes that the primary outcome has several categories or time points and is not reduced to one comparison. No analyses are listed, and the record does not report a multiplicity plan.

In general, multiplicity arises when several outcomes, time points, categories, or contrasts are examined. Considering many comparisons can increase the chance of a chance finding if results are interpreted without an appropriate plan. A prespecified primary comparison and a clear distinction between confirmatory and exploratory analyses help readers understand which results carry the main evidential weight. The registry record does not establish how this issue was handled in this trial.

Missing-data methods and the extent of missing follow-up are not reported in the registry record. The record also does not state the analysis population, such as whether participants were analyzed according to their randomized assignment, or how deviations from assigned care were handled. These details matter because the availability and handling of outcome data can affect a group comparison.

The record does not report whether there were interim analyses, how outcomes were collected, or whether sensitivity analyses were conducted. No assumptions about these procedures should be inferred. Without outcome-level denominators and a description of missingness, readers cannot assess how complete the primary outcome data were or how robust any result would be to alternative missing-data assumptions.

11. 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 0% reporting threshold.

The registry reports serious adverse event figures separately for the electronic-visit group and the treatment-as-usual group. For the electronic-visit group, 85 participants are recorded as at risk for serious adverse events and 0 as affected; 85 are recorded as at risk for other adverse events and 0 as affected; deaths are recorded as 0. For the treatment-as-usual group, 40 are recorded as at risk for serious adverse events and 0 as affected; 40 are recorded as at risk for other adverse events and 0 as affected; deaths are recorded as 0.

These are reported counts, not a complete characterization of safety. A zero recorded count means that no event was entered in that category in the registry results; it does not prove that no event occurred or that risk is absent. Interpretation depends on the event definitions, the method and duration of surveillance, and the completeness of reporting. Those details are not reported in the registry record.

The record lists no serious adverse event terms. It does not provide descriptions of individual events, the event collection procedures, or an analysis comparing safety between groups. The group-specific at-risk counts should not be treated as the primary outcome denominators or used to infer the number analyzed for medication use. The safety entries describe what is recorded, while leaving the scope and precision of safety monitoring uncertain.

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

The record establishes that a randomized pilot trial was completed and describes an electronic visit intended to address smoking cessation and early COPD detection. It also identifies treatment as usual as the comparator and names reported medication use as the primary outcome. These details define the research question, but they do not supply the outcome comparison needed to answer it.

No group-specific primary outcome counts, effect estimate, confidence interval, or p-value are reported in the registry record. It is therefore not possible to conclude from the posted information whether medication use differed between the groups, how large any difference was, or how precisely it was estimated. The same restraint applies to the secondary outcome of acceptability and feasibility, for which no result is reported.

The primary endpoint concerns reported smoking cessation medication use. It should not be read as a direct measure of smoking cessation, COPD detection, diagnostic accuracy, or overall health. A result on one measure would not automatically answer questions about the others. The intervention description includes several components, but the record does not report how often each component was completed or whether home spirometry was used.

The trial's stated purpose was to provide effect-size estimates for a larger randomized trial. That aim frames the study as pilot work. In general, a pilot can inform the design and feasibility of later research, but a result from a pilot is not automatically definitive. The registry record does not provide the effect estimate or the numerical planning illustrations needed to assess any proposed next-study assumptions.

The safety entries record zero serious adverse events, zero other adverse events, and zero deaths in each group. Those entries are limited to the event counts recorded and do not demonstrate that risk is absent. The registry does not report the safety-monitoring details needed to interpret the scope of those counts.

In sum, the record supports a description of the trial's question and design, not a conclusion about the intervention's effect. Any claim about the direction, magnitude, precision, or practical importance of the primary comparison would go beyond the results reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically interesting because it combines service development with a randomized pilot comparison. The intervention is not only a single message: it includes an initial electronic visit, an invitation to a follow-up visit one month later, and home spirometry with instruction if needed. The comparator also includes information and a recommendation to seek care. A later evaluation would need a clearly specified outcome and analysis to distinguish the effects of the overall care pathway from the contribution of any one component.

The primary measure is reported medication use over baseline through Month 3, but the registry notes multiple categories or time points without reducing them to one comparison. That makes endpoint definition and prespecification central statistical issues. A clearly chosen primary contrast can help prevent readers from treating many possible comparisons as if they were one unambiguous test.

The stated pilot objective is to estimate effects for a larger randomized trial. Estimation and precision are therefore important: a useful pilot result would need to communicate both the size of the observed effect and the uncertainty around it. The registry record does not report those results, so it cannot support a trial-specific assessment of how informative the estimate was for future planning.

The record also highlights the distinction between design information and analysis information. Random allocation is recorded, but the analysis plan, outcome denominators, missing-data handling, and analysis population are not reported. Those details are needed to judge how a comparison was constructed and how it should be interpreted.

For clinical researchers, the key statistical lesson is that a plausible intervention and a completed randomized design do not substitute for a reported outcome estimate. The effect, its uncertainty, the precise endpoint definition, and the completeness of follow-up are all needed before the comparison can be meaningfully evaluated.

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 results is that the registry record does not report the primary outcome comparison. Group-specific medication-use counts, denominators, an effect estimate, and a measure of uncertainty are not available. As a result, the direction and precision of the primary result cannot be assessed.

The outcome description refers to multiple categories or time points and does not identify a single comparison. The record does not provide the detailed outcome definition, including the medication classification or response rule. This limits the ability to determine exactly what an event in the primary count represents.

The record lists no analyses. It does not describe the statistical model, analysis population, missing-data methods, adjustment variables, or multiplicity plan. It also does not report participant flow, follow-up completeness, adherence to the electronic visits, or use of home spirometry. These omissions prevent assessment of the conduct and analysis of the trial beyond the broad design description.

The trial is described as a pilot intended to estimate effects for a larger study. The registry does not report the sample-size justification or numerical results from planning illustrations. The enrollment entry alone does not establish the precision of a primary outcome estimate, particularly because the primary outcome group denominators and results are not reported.

Finally, the adverse-event entries provide counts but not event definitions, surveillance methods, follow-up duration, or detailed event descriptions. Zero recorded events should therefore be interpreted narrowly. These limitations do not establish that the trial was poorly conducted; they identify what cannot be evaluated from the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: E-Visit for COPD and Smoking Cessation — NCT04155073.
• Registry record last updated 2024-02-21; status last verified 2023-07.
• Results first posted 2024-02-21.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry describes a completed, randomized, parallel pilot trial with no masking, comparing an electronic visit for smoking cessation and early COPD detection with treatment as usual. Enrollment is recorded as 125, and the phase is listed as not applicable.

The primary outcome is evidence-based cessation treatment utilization, measured as a participant count over baseline through Month 3. Participants were queried about smoking cessation medication use since the last assessment. The registry notes multiple categories or time points and does not reduce the outcome to one comparison. No analyses or primary outcome results are reported in the registry record.

Acceptability and feasibility is listed as a secondary outcome, without a reported result. Safety entries list zero serious adverse events, zero other adverse events, and zero deaths in each group. The stated objective was to provide effect-size estimates for a larger randomized trial.