Smoking Cessation Intervention for Thoracic Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Smoking Cessation Intervention for Thoracic Patients (NCT00580398), a non-randomized phase 1, phase 2 study. The primary outcome is Determination of the Feasibility of a Cognitive Behavioral Smoking Cessation Intervention..

2. Clinical Question

The study therefore asks whether a pre-surgery and post-discharge cessation program could be delivered and assessed in this clinical setting, and whether participants could complete follow-up. It does not provide a randomized estimate of the program’s effect relative to usual care.

3. Trial Design

This was a completed pilot study sponsored by Massachusetts General Hospital. The registry lists Phase 1 and Phase 2, a parallel model, non-randomized allocation, and no masking. Enrollment was 49. The recorded start was 2008-01 and primary completion was 2012-04. The condition listed was lung cancer.

Participants were assigned to a control group receiving usual care or an intervention group receiving a smoking cessation program. Because allocation was non-randomized, assignment may have been related to participant characteristics, clinical circumstances, or other factors. The registry record does not report how allocation was determined. Without random assignment, measured differences between the groups cannot by themselves establish that the intervention caused any difference in an outcome.

The intervention combined behavioral counseling with varenicline. Counseling was directed at issues for thoracic cancer patients, and the program was intended to span the period before surgery through the post-discharge period. The registry describes a 12-week program and says 7 counseling sessions were offered, with flexibility in delivery. The description ends mid-sentence, so further details about that flexibility are not reported in the registry record. Control care included physician advice to quit smoking.

The primary endpoint was a count: the number completing the 12-week follow-up survey and thus the study. A secondary outcome was biochemically-validated 7-day Point Prevalence Tobacco Abstinence. The registry lists 2 outcome measures, but does not report the numerical result for either outcome. It lists 0 analyses. Details of the analysis plan, allocation process, masking procedures beyond none, and sample-size justification are not reported in the registry record.

This design is best understood as a feasibility-oriented pilot rather than a randomized comparative effectiveness trial. Its structure can describe implementation and follow-up, but the non-randomized groups do not support a clean causal comparison. The registry’s listed status is completed; that status does not, by itself, supply the missing endpoint results or analysis details.

4. Participant Flow and Accounting

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

Before assignment: A patient had to be willing to take varenicline in order to be eligible for the intervention group; if a patient who was otherwise eligible for the intervention group was taking nicotine replacement therapy or bupropion, he/she had to be willing switch to varenicline.

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 Determination of the Feasibility of a Cognitive Behavioral Smoking Cessation Intervention., measured over 12 weeks.

The primary endpoint measures how many participants completed the 12-week follow-up survey, which the registry treats as completion of the study. It is a count of participants, not a smoking-abstinence measure. The intended interpretation is therefore about whether participants could be followed through the planned assessment period, a practical component of evaluating whether a program can be delivered in a pilot setting.

Feasibility outcomes are useful because an intervention may be difficult to deliver, or participants may not complete follow-up, even when the intervention itself is clearly specified. A completion count can describe the amount of follow-up achieved. For a fuller assessment, researchers commonly consider the count alongside the number eligible, enrolled, and assessed at each stage, as well as reasons for non-completion. Those details are not reported in the registry record.

The registry description does not give the observed number who completed the survey. It also does not report a completion proportion, uncertainty interval, or comparison of completion between groups. No such values should be inferred from enrollment alone. The secondary outcome, biochemically-validated 7-day Point Prevalence Tobacco Abstinence, concerns smoking status over a stated short period and is distinct from the feasibility endpoint. Its result is not reported in the registry record.

Thus the endpoint definition clarifies what the primary outcome was intended to capture, but the posted information does not provide its observed value. Without that value and supporting follow-up details, the extent of feasibility achieved cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a participant count: those who completed the 12-week follow-up survey and thus the study. A count is a descriptive summary of how many people experienced or met a defined outcome. For this endpoint, the outcome is follow-up completion. The registry record does not report the observed count, so its numerical value and precision cannot be assessed. A count is more informative when its denominator and the handling of participants with unknown follow-up status are also clear; those details are not reported in the registry record.

The secondary outcome is a binary status, biochemically-validated 7-day Point Prevalence Tobacco Abstinence. In general, a binary outcome classifies each participant into one of two categories, such as meeting or not meeting a stated outcome definition. Counts in each category can be reported by group, and an analysis may compare those counts or corresponding proportions. The registry record does not give the abstinence counts or describe the statistical method used to analyze them. No group effect estimate can therefore be interpreted.

In general, an effect estimate describes the size and direction of a contrast between groups, while a confidence interval describes the range of values compatible with the data and analysis assumptions. A narrow interval indicates greater precision than a wide interval. A p-value addresses how compatible the observed data are with a specified null model; it does not measure the probability that the null hypothesis is true, and it does not indicate clinical importance. No effect estimates, confidence intervals, or p-values are reported in the registry record.

The non-randomized allocation is important to statistical interpretation. In general, randomization helps make treatment assignment independent of participant characteristics, on average. With non-randomized allocation, differences in health, smoking history, readiness to quit, or other prognostic factors could be associated with group assignment and outcomes. These are examples of potential sources of confounding, not descriptions of what occurred in this trial. The registry does not report baseline characteristics, the allocation mechanism, or any covariate-adjustment plan. It is therefore not possible to assess group comparability or determine whether adjustment was used.

The parallel model indicates that the registry describes separate groups rather than a crossover structure. The record also lists no masking. In general, masking can reduce the influence of knowledge of treatment assignment on some assessments or behaviors. A biochemically validated abstinence outcome has an objective verification component, but the registry does not describe the validation procedure, assessors, or measurement schedule beyond the 7-day point-prevalence definition. The absence of masking and missing measurement details should be considered when evaluating potential sources of bias.

The registry lists 0 analyses. That does not establish that no analysis was conducted outside the registry; it means analyses are not listed in this record. The statistical analysis plan, model specifications, treatment of covariates, handling of multiple outcomes, and definition of analysis populations are not reported in the registry record. Statistical methods should not be inferred from the outcome names alone.

The sample-size assumptions describe a planning illustration based on an observed effect: two-sided significance level 0.05, equal allocation between arms, and a normal approximation. The effect to detect is framed as a stated fraction of the observed effect. In general, planning for a smaller target effect than an observed estimate requires a larger study, all else being equal. However, the registry does not report a sample-size justification for this pilot or specific planning results. The illustration is not observed power, and does not show how much power the completed study had.

In general, power is a design-stage probability of detecting a specified effect under stated assumptions if that effect is present. It is not a measure of whether an observed result is reliable, and calculating power after a study from its observed effect does not resolve uncertainty. Planning values are best read as hypothetical requirements under the assumptions used, not as evidence about the trial’s actual results.

For binary outcomes, the amount of information depends on the number of participants with and without the event and on the group sizes. Small event counts can yield imprecise estimates. In general, a confidence interval is especially useful in this setting because it conveys uncertainty around an estimate, rather than reducing interpretation to whether a threshold for statistical significance was crossed. The registry provides no interval for the abstinence outcome or primary endpoint.

For count outcomes, the interpretation depends on how the count is defined, the exposure or follow-up opportunity, and whether participants have comparable observation. The primary count refers to participants completing follow-up, but the registry does not provide the actual count, group-specific completion, or reasons for missing surveys. No model for a count outcome is listed, and none should be presumed. The endpoint can be described from its definition, but its statistical result cannot be reconstructed from the enrollment total.

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("Control", "Intervention")
n      <- c(17, 32)
events <- c(17, 32)
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  Control  17  17  100.0  80.5  100.0  81.6  100.0  81.5  99.9
ARM  Intervention  32  32  100.0  89.1  100.0  89.3  100.0  89.4  99.9

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 2 outcome measures: the primary feasibility endpoint and the secondary biochemically-validated 7-day Point Prevalence Tobacco Abstinence outcome. When a study examines multiple outcomes, there can be more opportunities for apparently notable findings to arise by chance. In general, a prespecified hierarchy or an adjustment for multiple comparisons can help clarify how such findings should be interpreted. The registry record does not report a multiplicity strategy, endpoint hierarchy beyond the primary and secondary labels, or whether any adjustment was planned.

The record lists 0 analyses and does not provide outcome results. The statistical analysis plan, analysis populations, and any rules for excluding participants are not reported in the registry record. It is also not reported how participants with missing follow-up surveys were handled, whether missingness was classified by reason, or whether sensitivity analyses were planned. These omissions matter because the primary endpoint is defined by follow-up completion, while missing outcome measurements can affect interpretation of the secondary abstinence outcome.

In general, missing data are not automatically equivalent to failure or success on an outcome. Their effect depends on why data are missing and how the analysis handles them. Assuming a missing participant had a particular outcome would require an explicit rule and justification. No such rule is reported in the registry record.

The registry does not describe an intention-to-treat population, a per-protocol population, or another analysis set. It also does not report baseline data or methods for handling differences between the non-randomized groups. Consequently, the available record does not support a full appraisal of multiplicity, missing-data assumptions, or population selection. These are unreported methods, not evidence that a particular approach was used.

12. 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 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: psychiatric instability (3.1%).

The serious adverse event figures are reported separately by group. In the control group, 0 of 17 participants at risk were listed as affected by a serious adverse event. In the intervention group, 1 of 32 participants at risk was listed as affected. The record lists 0 other adverse events in each group. These are descriptive counts, not estimates of a causal treatment effect.

Psychiatric Instability appears as the top serious adverse event term with 3.1%. The record does not provide further detail about the event, its timing, severity, relationship to an intervention, or how the term-level percentage was calculated. The listed group counts and the term entry should not be treated as a complete account of safety without those details.

Because allocation was non-randomized, a simple contrast between the groups would not isolate an intervention effect. The group sizes and event counts are small, and no comparative analysis or uncertainty interval is reported. The registry record does not report death counts. These figures describe what is listed in the registry; they do not establish that an intervention caused or prevented an adverse event, nor do they provide a complete safety profile.

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

The registry record establishes that a pilot smoking cessation study for patients with lung cancer undergoing surgery was completed, with 49 participants enrolled. It defines a feasibility-focused primary endpoint: completion of a 12-week follow-up survey. It also identifies smoking abstinence as a secondary outcome and reports limited serious adverse event counts.

Those details do not establish whether the primary feasibility objective was met. The observed follow-up completion count is not reported in the registry record. The secondary abstinence result is also not reported, so the posted information does not show the number of participants who achieved the outcome or how groups compared on it.

The non-randomized design further limits causal interpretation. Any difference between control and intervention participants could reflect underlying differences between the groups, as well as any effect associated with the intervention. The registry does not describe an adjustment strategy or give the baseline information needed to assess such differences. A descriptive comparison should therefore not be read as proof that the program caused an outcome.

The listed serious adverse event counts provide a limited description, not a comprehensive assessment. One affected participant is listed in the intervention group and none in control; the registry does not report a statistical comparison, full event narratives, or death counts. The term Psychiatric Instability is listed at 3.1%, but the registry does not provide further context for that entry.

In general, a pilot study can inform questions about implementation, recruitment, follow-up, and the design of later research. It does not necessarily provide a precise estimate of an intervention effect. Here, the registry identifies the feasibility question but omits its outcome value, while also omitting the abstinence result and analysis details. Conclusions about the intervention’s efficacy or the success of follow-up cannot be drawn from the registry record alone.

14. Why This Trial Matters Statistically

This study raises a practical statistical question: can smoking cessation support be delivered around lung surgery and can participants be followed through the planned assessment? The choice of follow-up completion as the primary endpoint fits a feasibility-oriented pilot. It recognizes that implementation and retention are necessary considerations before outcome comparisons can be interpreted reliably.

It also illustrates why endpoint definitions and endpoint results are different pieces of information. The registry clearly describes the primary outcome as a count of people completing the 12-week survey, but does not report that count. Without the observed value and information about the participants whose follow-up status is unknown, the feasibility question remains unanswered in the posted results.

The design highlights the distinction between describing groups and estimating causal effects. A parallel, non-randomized comparison may be useful for describing the study’s organization, but allocation can be related to factors that also influence smoking outcomes. Statistical adjustment can sometimes address measured differences, but no adjustment method or baseline data are reported in the registry record. Unmeasured differences may remain even when measured factors are considered.

The record also demonstrates the importance of reporting analysis methods alongside outcome definitions. The number of listed outcome measures is known, but the registry does not report a multiplicity approach, missing-data method, analysis population, or inferential results. Without these elements, readers cannot evaluate the precision or robustness of an outcome estimate.

Finally, planning illustrations should be kept separate from observed evidence. The stated assumptions concern hypothetical sample-size planning based on an observed effect; they are not observed power and do not replace results from the completed study. That distinction is especially relevant for a pilot, where the purpose and scale may be different from a definitive comparison. The registry record does not provide a study-specific sample-size justification.

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 registry record does not report the observed primary outcome, despite describing it as the number completing the 12-week follow-up survey. It also does not report the secondary abstinence result. This prevents assessment of the stated feasibility aim and prevents interpretation of the smoking outcome from the posted information.

Allocation was non-randomized and the record does not explain how participants entered the control or intervention group. Baseline characteristics and statistical adjustment methods are not reported in the registry record. This makes it impossible to judge whether the groups were comparable or how confounding was addressed. The lack of masking is recorded, but the registry does not describe outcome assessment procedures in enough detail to evaluate their implementation.

The intervention description is incomplete at its final sentence. Although the record identifies a 12-week cognitive-behavioral program, varenicline, counseling, and 7 offered sessions, details about the stated flexibility are not fully reported. The registry also does not provide fuller information about adherence, treatment exposure, or reasons participants may not have completed follow-up.

Analyses are not listed, and the analysis plan, missing-data handling, multiplicity strategy, analysis populations, and uncertainty estimates are not reported. The adverse event information is limited to group counts and a listed top serious event term; event narratives, timing, attribution, and death counts are not reported in the registry record. Together, these limitations restrict both outcome interpretation and appraisal of the study’s methods.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Smoking Cessation Intervention for Thoracic Patients — NCT00580398.
• Registry record last updated 2018-10-12; status last verified 2018-09.
• Results first posted 2014-11-21.
• 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.

19. Record Summary

The registry describes NCT00580398, titled “Smoking Cessation Intervention for Thoracic Patients,” as a completed Phase 1 and Phase 2, parallel, non-randomized study with no masking. Massachusetts General Hospital is listed as sponsor. Enrollment was 49, with a recorded start of 2008-01 and primary completion of 2012-04.

The intervention combined smoking cessation counseling with varenicline; usual care in the control group included physician advice to quit smoking. The primary endpoint was the number completing the 12-week follow-up survey. The secondary outcome was biochemically-validated 7-day Point Prevalence Tobacco Abstinence.

The registry does not report the primary endpoint result, the secondary outcome result, or listed analyses. Serious adverse event counts were 0 among 17 control participants at risk and 1 among 32 intervention participants at risk. Other adverse events were listed as 0 in both groups. The record does not report death counts or a comparative safety analysis.