A Mobile App Based Cognitive Dissonance Intervention for Smoking Cessation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Mobile App Based Cognitive Dissonance Intervention for Smoking Cessation (NCT05797155), a randomized na study. The primary outcome is Number of Participants With Cigarette Abstinence.

2. Clinical Question

The clinical question is whether the cognitive dissonance-based app, as described in the registry, is associated with a different count of participants meeting this short-window abstinence definition than the tips-only app. The endpoint is based on a self-reported answer to a single question: “In the past 7 days, have you smoked any cigarettes?” A response indicating no smoking is coded as abstinent; the other response is coded as not abstinent.

The question is limited to cigarette abstinence defined by that item and its follow-up time points. It is not a measure of every aspect of quitting, such as duration of abstinence beyond the past 7 days, use of other tobacco products, or changes in smoking frequency. Those outcomes are not specified as the primary measure in the registry record. The study description states a goal of testing the app’s efficacy, but no outcome estimate, comparison, or conclusion about efficacy is reported in the registry record.

3. Trial Design

The trial is listed as randomized, single-masked, and parallel-group. Random allocation is intended to create groups whose baseline characteristics are comparable on average, although it does not guarantee balance in any particular trial. A parallel-group design assigns participants to an intervention approach and follows the groups separately; the registry describes Support2Quit and a comparison app as the two approaches.

The Support2Quit group is described as receiving daily smoking cessation tips and completing activities designed to induce cognitive dissonance. The activities also involve creating and sharing videos related to them with an online group and providing support to other group members. The comparison group uses an app with smoking cessation tips but without the cognitive dissonance component. The masking field is listed as single, but the registry record does not identify which participants, staff, or assessors were masked, or how masking was implemented.

The listed enrollment is 437. The brief summary describes an aim to test the app with 500 adult smokers who express a desire to quit smoking. The registry record does not explain the relationship between the stated aim and the listed enrollment, so the difference should not be interpreted as evidence about recruitment, exclusions, or the final analysis population. The study status is completed. The listed start date is 2023-12-01 and the listed primary completion date is 2025-03-15. The phase is listed as NA.

The primary outcome is described at 1-month and 3-month follow-up. Although the record identifies the outcome measure and its coding, it does not present a single group comparison for those time points. It also does not report the allocation ratio, detailed analysis populations, or a statistical analysis plan. Randomization describes the intended assignment process; it does not by itself establish that outcomes were completely observed or that an estimated effect is unbiased under every possible pattern of missingness.

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:

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 Number of Participants With Cigarette Abstinence, measured over 1-month and 3-month follow-up.

The primary endpoint is the number of participants classified as abstinent from cigarettes at 1-month and 3-month follow-up. Classification is based on the answer to a single self-report item asking whether the participant smoked any cigarettes in the past 7 days. A report of no cigarette smoking is coded 1, meaning abstinent; otherwise the response is coded 0, meaning not abstinent.

This endpoint turns a reported behavior into a binary outcome that can be counted within each group. Such an outcome is useful for comparing the frequency of a defined status between randomized groups, provided the relevant group counts and analysis are reported. The past-7-day framing makes the definition specific and interpretable, but it does not establish continuous abstinence over the entire period since the intervention began. A participant could meet the endpoint’s definition without the measure describing their smoking behavior outside that 7-day window.

The endpoint is self-reported, and the registry record does not describe biochemical verification or another validation procedure. It also does not report how missing answers were handled, whether the endpoint was analyzed separately at each follow-up, or what statistical model was used. The record therefore defines what counts as abstinence but does not provide enough information to evaluate the precision or robustness of the outcome comparison.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical information in the registry record is incomplete for reconstructing the primary outcome analysis. It specifies random allocation, a parallel-group model, a single-masked design, a binary outcome definition, and two follow-up time points. It does not report the statistical model, the analysis population, the method for handling missing observations, or a primary comparison estimate. These omissions limit what can be said about how the posted outcome data were analyzed.

What does randomization contribute?

In general, randomization assigns participants to groups using a chance-based process. Its purpose is to reduce systematic differences between groups at the point of assignment, including differences in measured and unmeasured characteristics on average. Randomization does not ensure that every characteristic is balanced in a particular trial, and it does not address missing outcome data, deviations from assigned treatment, or measurement problems on its own. The registry record identifies the allocation as randomized but does not describe the sequence-generation procedure, concealment of assignments, or implementation details.

What does a binary endpoint represent?

The abstinence outcome is coded as 1 for a report of no cigarette smoking in the past 7 days and 0 otherwise. In general, this coding represents whether each participant meets a defined condition at an assessment. Group-level analysis might compare the number or proportion meeting that condition, or use a model for a binary response. Those approaches answer related but not identical statistical questions, and an appropriate choice depends on the design and analysis plan. The registry record does not state which approach was used or report a group comparison.

How should uncertainty be described?

In general, an effect estimate describes the size and direction of a group contrast, while a confidence interval conveys uncertainty around that estimate under the chosen method. A significance test addresses compatibility of the data with a specified null hypothesis under model assumptions; a p-value is not a measure of the size or practical importance of an effect. Interpretation is stronger when estimates and intervals accompany a test result. The registry record does not report an effect estimate, confidence interval, or p-value for the primary outcome, so no assessment of statistical precision or evidence against a null hypothesis is possible from the primary result information.

Why do the follow-up times require care?

The primary measure is assessed at 1-month and 3-month follow-up. In general, observations at different times can be analyzed as separate endpoint comparisons or within a model that accounts for repeated measurements. Separate comparisons raise questions about which time point is primary and how multiple tests are handled. A repeated-measures approach requires assumptions about the relationship among observations and how missing assessments are treated. The registry record does not specify the analytic approach, the handling of the time points, or a hierarchy of testing.

What is the role of over-dispersion?

Over-dispersion is a general concern for count data when the observed variability exceeds what a chosen probability model expects. It can make standard errors too small if the model fails to account for extra variability. The primary outcome is described as a count of participants meeting a binary definition, but the registry record does not provide a model or a dispersion assessment. Whether over-dispersion is relevant depends on the actual analysis and data structure; it cannot be assumed from the endpoint label alone.

How should the planning illustration be understood?

The registry record describes planning illustrations based on an observed effect, using a two-sided significance level of 0.05, equal allocation between groups, and a normal approximation. The stated effect to detect is a fraction of the observed effect. These are planning assumptions, not evidence that the trial was designed using those assumptions. The record does not report the numerical planning results or the observed primary effect on which such an illustration would depend. Any sample-size figures associated with such an illustration are planning quantities, not observed power. They cannot substitute for a reported estimate and its uncertainty.

More broadly, a sample-size calculation describes the assumptions under which a future or planned study may achieve a target operating characteristic. It does not establish that an observed result is reliable, and it does not explain why a study enrolled the number listed in the registry. The record does not report the original sample-size justification, assumptions used in the trial’s design, or whether the planning illustration corresponds to the protocol.

10. Multiplicity, Missing Data and Analysis Populations

Multiplicity concerns arise when an analysis examines multiple outcomes, time points, or comparisons. In general, conducting multiple statistical tests can increase the chance of finding at least one apparently notable result even when no true difference exists. Researchers may address this through a prespecified primary comparison, an adjustment procedure, a testing hierarchy, or clear interpretation of exploratory analyses. The registry record identifies the primary measure at 1-month and 3-month follow-up, but does not report how those time points were treated in the analysis or whether multiplicity was addressed.

The record lists 4 outcome measures and 7 analyses. Those listings establish that more than one outcome or analysis is registered, but do not reveal the analysis plan, which results were confirmatory, or how conclusions were adjusted for multiple testing. A multiplicity method is not reported in the registry record. The primary outcome’s several time points are not reduced to a single comparison, so there is no single primary contrast available for interpretation.

Missing data are also important for a self-reported follow-up outcome. If participants do not provide an answer, the analysis must specify whether those observations are excluded, imputed, or classified using another rule. Different approaches can change the interpretation, particularly if the likelihood of missingness differs between groups or is related to smoking status. The registry record does not report the amount or pattern of missing outcome data, the missing-data method, or sensitivity analyses.

The analysis population is not reported in the registry record. It is therefore unclear whether the outcome analysis followed randomized assignment, included only participants who completed follow-up, or used another defined population. These distinctions matter because they specify which participants contribute to an estimate and what comparison that estimate represents. The registry record also does not report protocol deviations or adherence in a way that would clarify how participants were handled analytically.

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 safety listing records 0 serious adverse events, 0 other adverse events, and 0 deaths for the Support2Quit group, for which the listed number at risk is 292. It records 0 serious adverse events, 0 other adverse events, and 0 deaths for the comparison group, for which the listed number at risk is 145. These are the figures recorded for the groups; they do not establish that every possible event was detected or reported.

A zero count means that no events in the corresponding category appear in the registry listing. It does not show how safety events were solicited, whether reporting was complete for all participants, what observation period was used, or how an event was classified. The registry record does not report those details or list serious adverse event terms.

Safety counts should also be distinguished from the primary abstinence endpoint. The absence of recorded adverse events does not provide evidence about the smoking cessation outcome, and the abstinence outcome does not establish safety. The record does not provide a comparative safety analysis, an uncertainty estimate, or additional context for interpreting differences in exposure or follow-up between groups.

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

The record documents a trial designed to compare two app-based smoking cessation approaches: Support2Quit, which includes cognitive dissonance activities, and a tips-only comparison app. It defines the primary measure as the count of participants reporting no cigarette smoking in the past 7 days at 1-month and 3-month follow-up. This information clarifies the intervention contrast and what the registered endpoint represents.

It does not establish whether the intervention changed abstinence. The registry record does not report a single comparison for the primary measure, an estimated effect, or its precision. Without those results, the direction and size of any difference between groups cannot be described. The recorded enrollment is not a substitute for outcome data, and safety counts do not answer the efficacy question.

The endpoint also has a specific scope. It records self-reported cigarette abstinence over the past 7 days at the assessment, not continuous abstinence from the start of the study or a broader measure of tobacco use. It does not, by itself, establish whether an answer was independently verified. The registry record does not report validation procedures, missing-response handling, or the number of participants assessed at either follow-up.

More generally, a randomized design can support a comparison between assigned groups when the analysis and follow-up are adequately reported, but randomization alone does not resolve missing data, outcome measurement, or multiplicity. The record does not describe the analysis populations or statistical methods used for the primary endpoint. Conclusions should therefore remain limited to the fact that the trial was registered as randomized and completed, and that the endpoint was defined at the stated follow-up times. The primary outcome result and its statistical interpretation are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial raises several useful statistical questions because it compares app-based behavioral approaches while defining the main outcome as a binary, self-reported status at follow-up. The outcome definition is precise about the assessment question and the past-7-day window. That precision is helpful, but it does not make the measure equivalent to continuous abstinence or establish that self-report was validated.

The two follow-up assessments illustrate why timing and analysis plans matter. Results can vary by assessment time, and a clear report should identify the comparison that is primary and explain how additional time points are interpreted. The registry record does not report a single comparison across the stated follow-up times or an approach to multiplicity, so the registered endpoint cannot be reduced to one interpretable effect estimate.

The trial also shows why enrollment and outcome analysis are different quantities. The record lists enrollment as 437, while the brief summary describes an aim involving 500 adult smokers. Neither figure establishes how many participants contributed an outcome at each assessment. Without analysis denominators and missing-data information, the precision and representativeness of a follow-up comparison cannot be evaluated.

Finally, a completed status does not itself communicate the results of a trial. The record supplies design and endpoint information, but not the primary group comparison or uncertainty around it. For readers assessing clinical research, distinguishing a registered question from a reported answer is essential: a defined endpoint and randomized design are important, yet they do not replace transparent outcome estimates and analysis methods.

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 primary limitation for interpreting this record is that it does not report a single comparison for cigarette abstinence at 1-month and 3-month follow-up. No group effect estimate, confidence interval, or significance test is reported for that endpoint. The direction, magnitude, and precision of any difference therefore cannot be assessed from the registry record.

The endpoint depends on a single self-report question about smoking in the past 7 days. The record does not report verification procedures, the number of responses observed at each follow-up, or how missing answers were handled. It also does not describe whether the endpoint was assessed consistently across groups or how the analysis accounted for the two follow-up times.

Important design and analysis details are not reported in the registry record, including the allocation procedure, the party masked, the analysis populations, the statistical model, the multiplicity approach, and the original sample-size justification. The registry lists 4 outcome measures and 7 analyses, but that listing does not explain which analyses were confirmatory or how they were interpreted.

The enrollment listing of 437 and the brief summary’s stated aim involving 500 adult smokers are both recorded, but the registry does not explain their relationship. Neither should be treated as an outcome denominator. The listed serious adverse event, other adverse event, and death counts are 0 in both groups, but collection procedures and safety follow-up details are not reported. Together, these omissions constrain both efficacy and safety interpretation.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Mobile App Based Cognitive Dissonance Intervention for Smoking Cessation — NCT05797155.
• Registry record last updated 2025-11-24; status last verified 2025-11.
• Results first posted 2025-11-24.
• 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 record describes NCT05797155, “A Mobile App Based Cognitive Dissonance Intervention for Smoking Cessation,” sponsored by Oregon Research Behavioral Intervention Strategies, Inc. The study is listed as randomized, single-masked, parallel-group, and completed, with enrollment of 437. The phase is listed as NA.

The intervention is Support2Quit, with smoking cessation tips and cognitive dissonance activities, compared with a tips-only app. The primary measure counts participants reporting no cigarette smoking in the past 7 days at 1-month and 3-month follow-up. The study description states an aim involving 500 adult smokers who express a desire to quit smoking.

The registry record does not report a single primary outcome comparison, an effect estimate, or an uncertainty interval. It also does not report analysis populations, missing-data methods, or the statistical plan. The listed safety counts for serious adverse events, other adverse events, and deaths are 0 in each group.