Evaluation of Learning-Theory-Based Smoking Cessation Strategies: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of Learning-Theory-Based Smoking Cessation Strategies (NCT01368653), a randomized na study. The primary outcome is 4-week Abstinence.

2. Clinical Question

The trial’s brief summary frames the central question as whether practicing progressively longer periods without smoking, alongside standard treatment, helped more smokers quit and stay quit than standard treatment alone. The endpoint specified for the primary outcome captures recent tobacco use at a particular follow-up: it records whether any tobacco use occurred in the 4th week of the quit attempt. It does not, by itself, describe smoking behavior throughout the full period since the target quit date or establish long-term abstinence.

A further question concerned the use of very low nicotine cigarettes after a lapse. That comparison was conditional on smoking in the last 7-days at a follow-up interview. The record describes participants from both initial treatment arms as potentially being assigned to very low nicotine cigarettes or advice and encouragement only. The reported information does not establish how many entered this conditional comparison or what their outcomes were.

3. Trial Design

The registry lists this as a randomized, parallel-group trial with no masking. Its status is completed. Enrollment is listed as 93, the start as 2012-06, and primary completion as 2013-07. Rutgers University is named as the sponsor, and the phase is listed as NA. These administrative details describe the registered study but do not provide a statistical result.

The main treatment arms were standard treatment and standard treatment plus practice quitting. Standard treatment consisted of a 6-week supply of 21-mg nicotine patches and 4 15-minute individual smoking cessation counseling sessions. In the experimental arm, practice quitting was added: participants practiced quitting 7 times before a target quit date, for 4-12 hours per day. The description ends after the words “and returning to”; the remaining details are not reported in the registry record.

The registry also describes very low nicotine cigarettes and advice and encouragement only as conditions for smokers from either initial treatment arm who had smoked in the last 7-days at a 4-week post-target-smoking-cessation-date follow-up interview. This is a conditional stage rather than an unconditional treatment assignment for everyone enrolled. The record’s descriptions of these conditions are incomplete, so details beyond their names and the stated eligibility condition are not available.

Random allocation means treatment assignment is intended to support comparisons that are less affected by systematic differences between groups at baseline. That general benefit depends on the actual allocation process and on how participants were handled after assignment; those details are not reported in the registry record. The no-masking designation indicates that the study is registered as unmasked. The record does not explain who knew the assignments or whether outcome assessment was conducted independently of treatment knowledge.

Although the record identifies the design and several outcomes, it does not report primary-outcome counts by group, an effect estimate, a confidence interval, or a test result. It also does not report the detailed analysis plan. As a result, the design can be described, but its comparative findings cannot be reconstructed from the registry information.

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: Randomization was in 2 phases; 1: participants who met inclusion/exclusion criteria were randomized to either standard treatment or standard treatment plus practice quitting; in phase 2, smokers who smoked between weeks 3 and 4 post-quit were randomly assigned to either receive advice only, or advice plus very low nicotine cigarettes.

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.

Population: The total number of participants in the sample was 93. The 40 participants randomly assigned to Very low nicotine cigarettes or Advice and encouragement only were a subset of the 93 participants randomly assigned to initial experimental conditions (Standard treatment or Standard treatment+practice quitting) if still smoking at 4-week follow-up.

6. Primary Endpoint

The registry lists the primary outcome as 4-week Abstinence, measured over 4 weeks.

The primary endpoint is titled 4-week Abstinence. It uses 7-day point prevalence abstinence at the 4-week post-quit follow-up: the measure captures whether participants used tobacco in the past 7 days, specifically whether any tobacco use occurred in the 4th week of the quit attempt. The outcome is expressed as a number of participants.

Point prevalence abstinence is a binary outcome at a defined assessment: each participant either meets the abstinence definition for that assessment or does not. This format can make a clinical question straightforward to state and can support a comparison of the number or proportion meeting the endpoint in each group. The registry’s stated parameter, however, is a number of participants, and it does not report the group-specific outcome counts or percentages. No comparative estimate can therefore be interpreted from the record.

The endpoint is useful for describing recent smoking status at a specified follow-up, but it has a limited time window. It does not alone show whether abstinence was continuous from the target quit date, whether a participant smoked earlier in the quit attempt, or whether abstinence persisted after the assessment. The registry separately names 10-week Abstinence and Prolonged Abstinence as secondary outcomes. Their names indicate that other aspects of abstinence were considered, but their definitions and results are not reported in the registry record.

For this trial, an interpretable treatment comparison would require the outcome data for each relevant group, plus a clear account of the analysis population and handling of unavailable assessments. Those details are not reported in the registry record. The endpoint definition is available, but the observed primary result is not.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies randomization, a parallel-group model, and no masking. These features describe how the study was organized, but they are not a complete statistical analysis plan. The allocation method, any stratification, the analysis population, the model used for the primary outcome, and the approach to missing observations are not reported in the registry record. The primary outcome is described as a participant count, and the result has not been reduced to one comparison.

What does randomization contribute?

As a general principle, randomization assigns participants to treatment groups by chance. It is used to reduce the risk that treatment groups differ systematically because of decisions made by participants or investigators. Randomization does not guarantee identical groups, especially in a study with limited enrollment, and it cannot correct for problems that arise after assignment, such as differential follow-up or analysis that excludes participants in a way related to their outcomes. The registry confirms a randomized design but does not report the allocation procedure or how assigned participants were included in analysis.

How should a binary endpoint be compared?

In general, a binary endpoint classifies each participant according to whether a defined event or status is present at assessment. For abstinence, the registry’s definition is whether any tobacco use occurred in the 4th week of the quit attempt. A treatment comparison could describe the number meeting the definition in each group and estimate a difference or another contrast. Such an estimate should be read with its uncertainty, commonly expressed through a confidence interval. The registry record does not report those primary-outcome counts or comparative statistics, so no effect estimate can be examined.

The endpoint is described as a number of participants. Counts alone are not enough to compare groups fairly when the numbers assessed differ; interpretation also requires the relevant denominators and a clear account of who was included. Although the adverse-event entries include at-risk counts, they are not primary abstinence data. No primary-outcome denominators or analysis population are reported in the registry record.

What does the record say about significance testing?

The record does not report a primary-outcome p-value or a confidence interval. A p-value, as a general concept, describes how compatible observed data are with a specified null hypothesis under the assumptions of a statistical test; it does not measure the size or clinical importance of an effect. A confidence interval gives information about uncertainty and a range of effect values compatible with the analysis. Neither can be interpreted for the primary endpoint because neither is reported. The registered count of analyses is 0, and the primary outcome was not reduced to a single comparison.

The record also does not describe whether the trial used an adjusted model, which covariates might have been included, or whether an intention-to-treat analysis was planned or performed. These terms refer to choices that can affect the estimand and interpretation. In general, an intention-to-treat approach analyzes participants according to their randomized assignment, while other approaches may use a different analysis population. The registry does not identify which approach applies.

What can sample-size planning tell readers?

The registry describes assumptions for a planning illustration based on the observed effect, rather than the trial’s own design. The assumptions include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. For time-to-event tables, the stated quantity is the total number of events using the Schoenfeld method; for other outcomes, it is participants per arm. These are planning assumptions, not observed trial findings. The record does not report the trial’s own sample-size justification, and planning illustrations must not be interpreted as observed power or as evidence that the trial was adequately powered.

More generally, a sample-size calculation depends on the target effect, variability or event rate, significance threshold, desired power, allocation, and analysis method. If the target effect is taken from an observed estimate, its uncertainty matters: an unstable observed estimate can make a planning illustration misleading. Because the primary outcome estimates are absent, readers cannot assess the observed effect or its precision from the registry record. The stated planning assumptions alone do not fill that gap.

Why is multiplicity relevant?

The registry lists secondary outcomes for 10-week Abstinence, confidence in quitting in the weeks leading up to the target quit date, and Prolonged Abstinence. Considering multiple outcomes or comparisons can increase the chance of a nominally unusual result arising by chance when many tests are conducted. A statistical plan may specify a primary comparison, a testing hierarchy, or an adjustment strategy. None of those details is reported in the registry record. Since the primary outcome itself is noted as having several categories or time points, a reader cannot infer a unique primary test from the available information.

Overall, the record gives enough detail to identify the design and the primary endpoint’s meaning, but not enough to reproduce or evaluate the main statistical analysis. The essential result components—group-specific abstinence data, a defined analysis population, an effect estimate, and its uncertainty—are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry names a primary endpoint, 4-week Abstinence, and also lists 10-week Abstinence, confidence in quitting in the weeks leading up to the target quit date, and Prolonged Abstinence as secondary outcomes. It notes that the primary outcome has several categories or time points and was not reduced to one comparison. No analysis is listed. The record does not describe a prespecified testing hierarchy, multiplicity adjustment, or which comparisons were intended to support confirmatory conclusions.

Multiplicity matters because testing several outcomes, time points, or treatment contrasts can increase the chance that at least one result appears noteworthy by chance. As a general statistical approach, investigators may define a primary comparison in advance, adjust for multiple testing, or label additional analyses exploratory. The registry record does not state which approach was used. The available outcome names therefore do not establish how the analysis handled multiple possible tests.

Missing-data methods and analysis populations are also not reported in the registry record. It is not stated how participants without a follow-up assessment were classified, whether follow-up completeness differed by group, or whether analyses followed randomized assignment. These details are important for a binary abstinence endpoint because a missing assessment can affect the numerator, denominator, and meaning of the comparison. The registry gives no primary-outcome counts with which to examine this issue.

The record does not report an interim-analysis plan, stopping rules, or a statistical analysis plan. This does not establish that such procedures were absent; their details are not reported in the registry record. Consequently, readers cannot determine from this entry how missing observations, multiple outcomes, or multiple comparisons were addressed in the final analyses.

11. 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

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: tooth abscess (5.0%), upper gi tract disorder (5.0%), leg and back pain (5.0%), respiratory distress, diabetes, and dehydration (5.0%), bowel obstruction (2.2%).

The registry reports serious adverse event figures by group. Standard Treatment has 3 affected among 47 at risk; Standard Treatment+Practice Quitting has 4 affected among 46 at risk; Very Low Nicotine Cigarettes has 2 affected among 20 at risk; and Advice and Encouragement Only has 1 affected among 20 at risk. These are the recorded serious-event counts and corresponding at-risk counts. They should be read as safety reporting, not as evidence about the abstinence endpoint.

For other adverse events, the record lists 29 affected among 47 at risk for Standard Treatment, 22 among 46 for Standard Treatment+Practice Quitting, 10 among 20 for Very Low Nicotine Cigarettes, and 13 among 20 for Advice and Encouragement Only. The registry does not explain in this entry whether affected counts represent participants with at least one event or how repeated events were handled. The counts should not be interpreted as rates of treatment-caused harm without further definitions and analysis.

The serious-event terms listed include Tooth abscess, Upper GI tract disorder, Leg and back pain, Respiratory distress, diabetes, and dehydration at 5.0% each, and Bowel obstruction at 2.2% and Broken toe at 2.1%. The record does not provide enough detail to determine how these terms relate to individual groups or whether they were considered related to an intervention. Death counts are not reported in the registry record.

These figures do not establish that an intervention caused an event, and they do not support a safety comparison on their own. Definitions, attribution, timing, and analysis details are not reported in the registry record.

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

The record establishes that a randomized, unmasked, parallel-group trial evaluated smoking-cessation strategies and specified 4-week Abstinence as its primary outcome. It also documents the intervention descriptions, a conditional follow-up comparison involving very low nicotine cigarettes and advice and encouragement only, and several secondary outcomes. Those details explain what the trial was designed to examine.

They do not establish whether practice quitting changed abstinence compared with standard treatment. The registry record does not report the primary-outcome counts by group, an estimated treatment effect, a confidence interval, or a p-value. It is therefore not possible to say from this record whether the observed groups differed, how large any difference was, or how precisely it was estimated. The absence of a reported result is not evidence of no effect or of equal outcomes.

The endpoint itself has a specific scope: it records whether tobacco use occurred in the 4th week of the quit attempt, assessed at the 4-week post-quit follow-up. It does not by itself demonstrate continuous abstinence across the period since the target quit date or sustained abstinence beyond that follow-up. The record names 10-week Abstinence and Prolonged Abstinence as secondary outcomes, but their definitions and findings are not reported in the registry record.

The conditional cigarette comparison addresses a different stage of the study. It applies to smokers who had smoked in the last 7-days at the specified follow-up interview, rather than automatically applying to every participant. The record does not report how many participants were assigned at that stage or the relevant outcome results. No effectiveness conclusion about that comparison can be drawn from the available entry.

The serious adverse event and other event counts are descriptive safety information. They do not answer the primary abstinence question, and without further information they do not establish that events were caused by an intervention. Overall, the record supports a description of the study’s questions and registered design, but not a judgment about comparative efficacy, precision, or causal safety effects.

13. Why This Trial Matters Statistically

This trial raises a statistical question about how to evaluate an intervention whose intended effect is behavioral practice added to standard smoking-cessation treatment. The randomized design is relevant because it can support a comparison between groups, while the binary abstinence endpoint gives a defined way to classify smoking status at a particular follow-up. The registry also identifies a separate, conditional comparison after smoking during the quit attempt. Keeping these questions distinct is important: they involve different eligibility conditions and should not be treated as one undifferentiated comparison.

The endpoint illustrates why outcome definition matters. 4-week Abstinence is based on tobacco use in the past 7 days at the 4-week post-quit follow-up. That definition is interpretable, but it does not capture every possible meaning of quitting, such as uninterrupted abstinence throughout the attempt or maintenance over a longer period. The listed secondary outcomes indicate that the investigators also considered other dimensions, though their definitions and results are not reported in the registry record.

The record also shows why trial registration and results reporting serve different purposes. Design information can identify the intended question, intervention, and endpoint. Statistical interpretation requires the observed data and analysis details as well. Without group-specific primary-outcome results, an effect estimate, and its uncertainty, the existence of randomization cannot be translated into a conclusion about the treatment comparison.

For biostatisticians and clinical researchers, the key lesson is to separate design quality from evidential completeness. A well-defined endpoint and randomized structure are important, but readers also need transparent reporting of outcomes, analysis populations, missing-data handling, and multiplicity decisions. Those details are not reported in the registry record, leaving the comparative findings unavailable for assessment.

14. Limitations

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

The main limitation for interpreting this trial entry is that the primary-outcome result is not reported. The record does not give group-specific abstinence counts, a treatment-effect estimate, a confidence interval, or a test result. The primary outcome is also noted as having several categories or time points and not being reduced to one comparison, while the number of analyses listed is 0. This prevents reconstruction of a single primary contrast.

Important participant and analysis details are not reported in the registry record. The enrollment figure is listed, but eligibility criteria beyond smokers with nicotine dependence, baseline characteristics, follow-up completeness, the analysis population, and missing-data handling are not described in the information available. The allocation method and statistical model are also not reported, so it is not possible to assess those choices or reproduce an analysis.

The intervention descriptions are incomplete. The practice-quitting description ends after “and returning to,” and the descriptions for very low nicotine cigarettes and advice and encouragement only are truncated. The registry gives the conditional eligibility rule for the latter-stage comparison, but not the number assigned to each condition or its outcome findings. These gaps limit understanding of intervention delivery and the scope of that comparison.

The record names secondary outcomes but does not give their definitions or results. It also does not report how multiple outcomes and comparisons were handled, whether interim analyses were planned, or the trial’s own sample-size justification. The planning assumptions described in the registry are an illustration based on the observed effect, not documentation of the original design justification. Finally, no masking was reported, and the entry does not explain the extent to which treatment knowledge could have influenced assessment. These limitations restrict both statistical interpretation and evaluation of the study’s conduct.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Evaluation of Learning-Theory-Based Smoking Cessation Strategies — NCT01368653.
• Registry record last updated 2022-04-27; status last verified 2022-03.
• Results first posted 2014-11-18.
• 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

NCT01368653, Evaluation of Learning-Theory-Based Smoking Cessation Strategies, is listed as a completed randomized, unmasked, parallel-group trial sponsored by Rutgers University. Enrollment is 93; the start is recorded as 2012-06 and primary completion as 2013-07. The condition is nicotine dependence, and the phase is listed as NA.

The main comparison was standard treatment, consisting of a 6-week supply of 21-mg nicotine patches and 4 15-minute individual smoking cessation counseling sessions, versus the same standard treatment plus practice quitting. The primary outcome was 4-week Abstinence, defined as 7-day point prevalence abstinence at the 4-week post-quit follow-up. A conditional comparison of very low nicotine cigarettes with advice and encouragement only is also described for smokers who had smoked in the last 7-days at a follow-up interview.

The registry names 10-week Abstinence, confidence in quitting, and Prolonged Abstinence as secondary outcomes. It reports adverse-event counts but does not report primary-outcome results, effect estimates, or analysis details. The comparative efficacy findings therefore cannot be assessed from the registry record.