This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Cigarillo Warnings Image Sorting Study (NCT05838378), a randomized na study. The primary outcome is Intention to Quit Smoking Cigarillos in the Next 30 Days at Weeks 2-4.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05838378 |
| Phase | NA |
| Condition | Smoking, Cigar |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 764 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Boston University |
| Results posted | Yes |
2. Clinical Question
Population
Young adult cigarillo users eligible for the online survey. The registry record describes recruitment and screening through a research company but does not report further eligibility details or participant characteristics.
Intervention
Repeated package image sorting while viewing pictorial cigarillo warnings. Participants were asked to sort cigarillo packages into flavor categories during the study’s 4-week period.
Comparator
Two text-only warning conditions: FDA text-only warnings and Surgeon General text-only warnings. All three conditions involved package image sorting; the warning format differed.
Primary question
How did quit intentions, measured at Weeks 2-4, compare across the three warning-format conditions? The registry record describes the intended outcome but does not report the scores, group comparisons, or estimates of between-group differences.
The study was designed to examine whether repeated exposure to different cigarillo warning formats during an image-sorting task was associated with participants’ intentions to quit smoking cigarillos. The primary measure combines responses about interest in quitting, perceived likelihood of quitting, and plans to quit in the next 30 days. The reported outcome is a mean score, with higher scores described as indicating greater quit intentions.
The experimental question is about warning format within this particular task and study population. It is not a comparison of cigarillo use with no use, nor a comparison of warnings with no warnings: each of the three conditions involved warnings. The registry record does not report outcome results, so it does not establish whether the groups had different mean quit-intention scores.
3. Trial Design
The registry record identifies this as a completed, randomized, parallel-group study with no masking. The listed enrollment is 764. Participants were assigned to one of three experimental conditions: package image sorting with pictorial warnings, FDA text-only warnings, or Surgeon General text-only warnings. The registry lists the condition as smoking, cigar and the sponsor as Boston University. The phase is listed as not applicable.
The study description says that participants would take part in an online survey and, for 4 weeks, sort a set of approximately 18 cigarillo packages into flavor categories selected by the research team. The record describes Qualtrics as the research company involved in programming the survey, recruiting and screening participants, and administering the survey. It also says that participants would be informed of the study purpose at the end and given links to information about cigarillo harms and cessation.
The registry lists a start date of 2025-01-14, a primary completion date of 2025-03-25, and a status of completed. These are record-level study details; they do not themselves establish how many participants completed each weekly survey or contributed to the primary outcome. The registry says the number contributing to the primary measure could fluctuate by study week, depending on survey completion.
The allocation ratio, details of the randomization procedure, and any procedures used to conceal assignment are not reported in the registry record. The record also does not report the planned sample-size justification, detailed analysis plan, or the number assigned to each warning condition. Although it lists 16 outcome measures, it lists zero analyses. Consequently, the design and intended measures can be described, but the posted record does not support a statistical comparison of the randomized groups.
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: 1020 potential participants began the baseline survey. Of those, 46 did not consent to participate in the study, and 193 did not complete the baseline questionnaire and were not randomized. 764 participants were enrolled and randomized in the study. 764 participants were included in the analysis. During the end of study de-briefing at the end of Week 4, 17 participants stated they did not want their data used, and thus were removed from the dataset.
Week 1
| Stage | Pictorial Warnings | FDA Text-only Warnings | Surgeon General Text-only Warnings |
|---|---|---|---|
| STARTED | 251 | 256 | 257 |
| COMPLETED | 251 | 256 | 257 |
| NOT COMPLETED | 0 | 0 | 0 |
Week 2
| Stage | Pictorial Warnings | FDA Text-only Warnings | Surgeon General Text-only Warnings |
|---|---|---|---|
| STARTED | 251 | 256 | 257 |
| COMPLETED | 232 | 242 | 236 |
| NOT COMPLETED | 19 | 14 | 21 |
Reasons for not completing this period:
| Reason | Pictorial Warnings | FDA Text-only Warnings | Surgeon General Text-only Warnings |
|---|---|---|---|
| Did hot complete survey | 19 | 14 | 21 |
Week 3
| Stage | Pictorial Warnings | FDA Text-only Warnings | Surgeon General Text-only Warnings |
|---|---|---|---|
| STARTED | 251 | 256 | 257 |
| COMPLETED | 232 | 248 | 236 |
| NOT COMPLETED | 19 | 8 | 21 |
Reasons for not completing this period:
| Reason | Pictorial Warnings | FDA Text-only Warnings | Surgeon General Text-only Warnings |
|---|---|---|---|
| Did hot complete survey | 19 | 8 | 21 |
Week 4
| Stage | Pictorial Warnings | FDA Text-only Warnings | Surgeon General Text-only Warnings |
|---|---|---|---|
| STARTED | 251 | 256 | 257 |
| COMPLETED | 225 | 233 | 226 |
| NOT COMPLETED | 26 | 23 | 31 |
Reasons for not completing this period:
| Reason | Pictorial Warnings | FDA Text-only Warnings | Surgeon General Text-only Warnings |
|---|---|---|---|
| Did hot complete survey | 26 | 23 | 31 |
Analysis population for the primary outcome, as defined in the registry: The number of participants for each week reflects the number who completed the survey for that week out of the number randomized to specific arms and can fluctuate by study week.
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: Everyone who enrolled in the study, consented to participate, completed the baseline questionnaire, and was randomized to each condition.
| Characteristic | Unit | Pictorial Warnings | FDA Text-only Warnings | Surgeon General Text-only Warnings | Total |
|---|---|---|---|---|---|
| Participants analysed | 251 | 256 | 257 | 764 | |
| Age, Continuous | years | 29.1 (SD 4.0) | 29.3 (SD 4.2) | 29.6 (SD 4.2) | 29.3 (SD 4.1) |
| Sex/Gender, Customized: Woman | Participants | 137 | 154 | 133 | 424 |
| Sex/Gender, Customized: Man | Participants | 110 | 98 | 122 | 330 |
| Sex/Gender, Customized: Unknown | Participants | 4 | 4 | 2 | 10 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 4 | 2 | 1 | 7 |
| Race (NIH/OMB): Asian | Participants | 10 | 8 | 15 | 33 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 1 | 0 | 1 |
| Race (NIH/OMB): Black or African American | Participants | 86 | 104 | 81 | 271 |
| Race (NIH/OMB): White | Participants | 121 | 106 | 117 | 344 |
| Race (NIH/OMB): More than one race | Participants | 12 | 13 | 19 | 44 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 18 | 22 | 24 | 64 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 66 | 60 | 73 | 199 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 184 | 196 | 183 | 563 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 1 | 0 | 1 | 2 |
| Region of Enrollment: United States | participants | 251 | 256 | 257 | 764 |
| Intention to Quit Smoking Cigarillos in the Next 30 Days | scores on a scale | 2.36 (SD 1.15) | 2.36 (SD 1.09) | 2.32 (SD 1.17) | 2.35 (SD 1.13) |
6. Primary Endpoint
The registry lists the primary outcome as Intention to Quit Smoking Cigarillos in the Next 30 Days at Weeks 2-4, measured over Weeks 2-4.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the mean composite score for intention to quit smoking cigarillos in the next 30 days, assessed during Weeks 2-4. It combines responses to three survey items: interest in quitting, likelihood of quitting, and plans to quit. Each item uses a 5-point response scale ranging from 1, Not at all, to 5, Extremely. The items are averaged, producing a score that can range from 1 to 5; higher scores indicate greater stated intention to quit.
A composite measure can represent a broader construct through several related questions rather than relying on one response alone. In general, combining items may reduce reliance on any single item, but interpretation depends on how consistently the items measure the intended construct. The registry record describes the items and scoring approach, but does not report psychometric evidence or the results for any item or composite score.
Quit intention is an attitude or stated plan, not a direct measure of later smoking behavior. The study also lists secondary outcomes related to interest in cutting smoking and reported behaviors to reduce cigarillo smoking during Weeks 2, 3, and 4. Those measures address related but distinct questions. No primary endpoint mean, standard deviation, group contrast, or uncertainty interval is reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central statistical limitation is that the registry record contains no reported outcome analyses. It lists the primary endpoint and the overall enrollment, but does not give group-specific mean scores, standard deviations, participant counts contributing to each weekly score, or comparisons among the warning conditions. It therefore is not possible to describe the direction, size, or precision of any observed difference in quit intentions from the record.
The design would ordinarily support comparisons among three randomized groups, provided the analysis accounted for the outcome’s measurement schedule and the participants contributing data. Random assignment is intended to make groups comparable, on average, at the point of assignment. It does not guarantee identical groups, and the strength of an inference depends on the actual data, analysis, and completeness of follow-up. Those details and results are not reported in the registry record.
The primary outcome is a mean on a bounded composite scale, with higher scores corresponding to greater stated intention to quit. Without the observed means and their variability, the registry record cannot indicate whether scores differed meaningfully across formats or whether any estimated differences were precise. A confidence interval, if reported, would describe the range of values reasonably compatible with the data and analysis under its assumptions. No confidence interval or other measure of uncertainty for the primary comparison is reported in the registry record.
The schedule also matters. The endpoint is described across Weeks 2-4, and the number of respondents may vary by week. A comparison using one week, an average across weeks, or a model using repeated weekly observations could answer different statistical questions. Which approach was used, how within-participant correlation was handled, and whether all weeks were analyzed together are not reported in the registry record. No analysis should be inferred from the endpoint description alone.
The record lists 16 outcome measures but zero analyses. It names secondary measures concerning interest in cutting smoking and reported behaviors to reduce cigarillo smoking. It does not report their results or how multiple outcomes and weeks were handled. The adverse-event fields show zeros for participants at risk and participants affected in each listed category. Because the record does not explain the ascertainment or reporting behind those entries, they should not be read as evidence that no adverse events occurred.
Any sample-size values used for planning are illustrations, not observed power and not a substitute for the trial’s own design rationale. The record describes planning illustrations based on an observed effect and equal allocation for a two-arm calculation, while this study has three conditions; the original sample-size justification is not reported in the registry record. In the absence of posted analyses and endpoint values, the statistical conclusion is limited to identifying the study question and the information that remains unavailable.
9. Statistical Methods Explained
The registry identifies a randomized, parallel-group study and describes a continuous primary outcome summarized as a mean with a standard deviation. These labels indicate the intended structure of the comparison, but they do not specify the statistical model used to analyze the data. The record lists no analyses, so the methods that generated any trial estimates are not reported in the registry record.
What does randomization contribute?
As general statistical context, randomization assigns participants to study conditions using a chance-based procedure. Its purpose is to reduce systematic differences between groups at assignment, including differences that investigators may not have measured. In a randomized comparison, analysis according to assigned condition can preserve the advantages of that assignment process. The record does not report whether analyses followed assignment, how randomization was carried out, or whether any participants were excluded from analyses.
The groups are parallel: each participant is assigned to one warning format rather than crossing through all conditions. This design can compare outcomes between assigned groups, but the analysis must still define which outcome occasion or occasions are being compared. The primary measure is described for Weeks 2-4. Whether the target contrast concerns each week separately, a combined score, or change over time is not reported in the registry record.
What do a mean and standard deviation describe?
As general statistical context, a mean describes the average value in a group. A standard deviation describes how spread out individual measurements are around that average. Together, they help convey both the group’s typical score and variation among participants. They do not by themselves show whether two groups differ convincingly: interpretation of a contrast also depends on the number of observations, the analysis method, and the uncertainty around the estimated difference. The registry lists mean and standard deviation as the outcome summary, but does not report their values for any group or week.
The composite is built by averaging three item responses on a 5-point scale. In general, a composite can be useful when several items are intended to measure a shared concept. The score’s meaning depends on the items, scoring rule, and quality of measurement. The record describes the three questions, their response anchors, and the resulting range, but does not report internal consistency, validation results, or how missing responses to individual items were treated.
Why is repeated measurement relevant?
As general statistical context, repeated measurements from one participant are usually related to one another. Treating each weekly response as if it came from a different independent person can understate uncertainty. An analysis that uses multiple weeks may need to account for this within-person dependence. Alternatively, a prespecified analysis might focus on one occasion or a summary across occasions. The registry record does not report which strategy was used, whether an analysis accounted for correlation across weeks, or how week-to-week changes were modeled.
The number of survey completers can change across the scheduled weeks, according to the registry description. This makes the analysis population and missing-data approach important. As general statistical context, a complete-case analysis uses only participants with the required observations, whereas other methods may use partial data under explicit assumptions. Each approach has limitations. The registry does not report the number of participants with primary outcome data at each week, reasons for missing data, or the method used to address missingness.
What would an uncertainty interval add?
As general statistical context, a confidence interval communicates uncertainty around an estimated quantity, such as a mean difference between warning conditions. A narrower interval indicates greater precision under the chosen model and assumptions; a wider interval indicates less precision. An interval that includes values representing little or no difference would not support the same interpretation as an interval concentrated away from those values. This is a general explanation, not a description of a result from this study: no primary effect estimate or confidence interval is reported in the registry record.
A p-value, when reported, summarizes how compatible the observed data are with a specified null hypothesis under the analysis assumptions. It is not the probability that the null hypothesis is true, nor a measure of the size or practical importance of an effect. The registry lists zero analyses and does not report a p-value for the primary endpoint. It is therefore not possible to characterize statistical significance from the posted record.
How should planning calculations be read?
As general statistical context, sample-size planning uses assumptions about the target effect, variability, significance level, allocation, and analysis method to illustrate the amount of information a study might need. Such calculations are prospective planning tools, not evidence about the results obtained. The registry’s description characterizes its planning illustrations as based on the observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; it says that the effect to detect is a stated fraction of the observed effect. These illustrations are not the trial’s own design justification. The record does not report that justification, and such planning values should not be described as observed power.
10. Multiplicity, Missing Data and Analysis Populations
The study lists 16 outcome measures. The primary endpoint is assessed across Weeks 2-4, and several secondary outcomes also refer to specific weeks. Considering multiple outcomes or occasions can increase the chance of finding an apparently unusual result by chance if many comparisons are conducted. As general statistical context, investigators may address this by identifying a primary comparison in advance, adjusting inference for multiple tests, or clearly treating secondary analyses as exploratory. The registry record does not report whether or how multiplicity was addressed.
The record names the primary measure and describes several secondary measures, but lists zero analyses. It does not report which contrasts among the three warning conditions were planned, whether pairwise comparisons were intended, or whether a hierarchy of outcomes or time points was specified. The analysis plan and any adjustment for multiple comparisons are not reported in the registry record. In the absence of results and a stated analysis approach, no claim about multiplicity-adjusted evidence can be made.
Missing data are also relevant because the registry says the number of participants contributing to the primary outcome could fluctuate by week. Counts completing each survey, reasons for noncompletion, and the handling of missing weekly responses are not reported in the registry record. The analysis population is likewise not reported: it is unknown whether the intended analyses included all randomized participants, only participants with outcome data, or another defined group.
As general statistical context, missingness can affect both precision and the validity of comparisons, especially if the likelihood of completing a survey is related to participants’ responses or assigned condition. The assumptions and methods used to address missing observations therefore matter. No imputation method, sensitivity analysis, or missing-data assumption is reported in the registry record.
11. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized study was conducted to compare three cigarillo warning formats during a repeated image-sorting task. It describes the primary construct as participants’ intention to quit smoking cigarillos in the next 30 days, measured with a three-item composite during Weeks 2-4. It also records an enrollment of 764 and a completed status.
Those design details do not establish what the study found. Group means, standard deviations, participant counts at each measurement occasion, treatment contrasts, confidence intervals, and p-values are not reported in the registry record. Without those results, the direction and size of any difference between pictorial and text-only formats cannot be determined, nor can the precision of a comparison be assessed. The record does not support a conclusion that one format produced higher or lower quit intentions.
Even if outcome estimates were available, a stated intention to quit is not the same as quitting or reducing cigarillo smoking. The primary score captures responses about interest, likelihood, and plans. The record lists secondary measures concerning interest in cutting smoking and self-reported behaviors to reduce smoking, but their results are not reported. The registry therefore cannot establish effects on subsequent behavior from the information available.
General statistical interpretation also distinguishes a difference in average scores from its practical meaning. A precise estimate can still represent a small difference, and an imprecise estimate can leave a wide range of possibilities. In this case, neither the estimates nor their uncertainty are reported. The appropriate interpretation is that the registry describes the question and study structure but does not provide the results needed to judge the comparisons.
The record’s zero entries for adverse-event fields should also be interpreted cautiously. They are registry entries, not a detailed account of how events were collected or assessed. The record does not provide enough information to infer that there were no adverse events.
12. Why This Trial Matters Statistically
This study raises a useful statistical distinction between a randomized design and a reported randomized comparison. Random assignment can support causal interpretation when the study is implemented and analyzed appropriately, but the design label alone does not supply an effect estimate. For this study, the registry describes three warning-format conditions and a repeated measure of quit intentions, yet does not report the analyses or the primary outcome values.
The repeated schedule adds an important design question. Scores collected at multiple weeks from the same participant are not necessarily independent. An analysis needs to define whether it estimates a condition difference at a particular week, an average over weeks, or a pattern over time, and how it accounts for correlation among observations. The registry does not report that analytic choice. The potential for differing numbers of completed surveys by week further connects the estimand, analysis population, and missing-data assumptions.
The endpoint also illustrates why outcome type matters. The primary measure is a composite of stated intentions, not an observed count of quit attempts or a direct measure of smoking behavior. Statistical findings about the composite, if reported, would need to be interpreted as findings about that measured construct. The record lists additional behavioral outcomes, but does not report their analyses.
Finally, the record lists 16 outcome measures but zero analyses. For readers assessing evidence, registration details can clarify what investigators intended to study, while posted results are needed to evaluate estimates and uncertainty. Here, the design description is informative, but it cannot substitute for those results. The gap underscores the importance of reporting outcome summaries, analysis populations, and methods for handling repeated observations and missing data.
13. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The most consequential limitation for statistical interpretation is the absence of posted outcome results. The registry record does not report primary outcome means or standard deviations, the number of participants contributing data at each week, or any comparison among the three conditions. It therefore does not permit assessment of effect size, direction, or precision.
The record describes changes in the number of participants completing surveys across weeks as possible, but does not report actual completion counts, reasons for missing responses, or how missing data were handled. This prevents assessment of whether the available observations represent all randomized participants or whether attrition differed across conditions. The analysis population and missing-data assumptions are not reported in the registry record.
The primary endpoint is a self-reported composite of quit intentions. The registry describes its items and scoring, but does not report evidence about reliability or validity in this study. Nor does it provide a behavioral endpoint result that could show whether stated intentions corresponded with later behavior. The listed secondary behavioral measures have no reported analyses in the record.
Important design and analysis details are also not reported in the registry record, including the randomization procedure, allocation ratio, sample-size justification, planned contrasts, handling of repeated measurements, and any approach to multiplicity. The record identifies a completed randomized study, but those details are needed to evaluate how well the analysis followed the design and how uncertainty should be interpreted.
The registry’s zero entries in adverse-event fields lack accompanying information about event collection and reporting. They cannot be used to establish that no events occurred. These limitations concern what can be concluded from the registry record; they are not claims about the full study materials or data.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Cigarillo Warnings Image Sorting Study — NCT05838378.
- Registry record last updated 2026-04-08; status last verified 2026-03.
- Results first posted 2026-04-08.
- 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.
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17. Record Summary
The registry identifies NCT05838378 as the Cigarillo Warnings Image Sorting Study, an online randomized parallel-group study with no masking. It lists Boston University as sponsor, an enrollment of 764, and a completed status. The listed study dates are 2025-01-14 for start and 2025-03-25 for primary completion.
Participants were assigned to package image sorting with pictorial warnings, FDA text-only warnings, or Surgeon General text-only warnings. The primary outcome is a three-item mean composite of intention to quit smoking cigarillos in the next 30 days, measured during Weeks 2-4. The record lists 16 outcome measures and zero analyses.
Primary outcome estimates, group comparisons, uncertainty intervals, analysis methods, and participant counts by week are not reported in the registry record. The posted information describes the study question and intended measurement, but does not provide results from which to assess differences among the warning conditions.