Implementation of Genomics in Substance Use Disorder Treatment: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Implementation of Genomics in Substance Use Disorder Treatment (NCT04768114), a randomized na study. The primary outcome is Change in Use of Smoking Cessation Pharmacotherapy in Past 30 Days.

2. Clinical Question

The registry describes a randomized, parallel-group comparison without masking. Its stated rationale is that genetics may relate to smoking behavior and smoking-related disease risk, and that including personalized factors in behavioral interventions may make them more engaging. The study summary frames the work as a pilot test of the risk communication tool and a demonstration of feasibility for a larger trial. That framing matters when interpreting the research question: the record presents an early evaluation of a personalized intervention, not a reported estimate of its effect on smoking cessation. The primary outcome concerns reported use of cessation medications or aids, rather than a direct measure of abstinence. The record lists questions about readiness to quit, perceived disease risk, perceived benefits and value of cessation treatments, self-efficacy, and intervention relevance as secondary outcomes.

3. Trial Design

The registry classifies the study as randomized, with a parallel-group model and no masking. It lists two interventions: Genetically-Informed RiskProfile, categorized as behavioral, and Brief Cessation Advice, categorized as other. The arm descriptions are blank in the registry record. Therefore, the labels identify the comparison groups, but the record does not report enough detail to describe the content, duration, or delivery of either arm beyond the study summary’s description of the personalized genetic risk communication tool.

The recorded enrollment is 148. The study status is completed; the recorded start date is 2021-03-19 and the primary completion date is 2022-12-07. The sponsor is Washington University School of Medicine, and the phase is listed as NA. The conditions include Tobacco Use Disorder, Smoking Cessation, and Tobacco Use Cessation.

The stated primary outcome is change in use of smoking cessation pharmacotherapy in the past 30 days. Assessment points are baseline, immediately prior to intervention receipt, 30-day follow-up, and 6-month follow-up. Participants were asked whether they had used any of several prescription medications or over-the-counter aids to help quit or cut back on smoking in the past 30 days. The listed response options include bupropion or Zyban, varenicline or Chantix, nicotine patch, nicotine gum or lozenge, and other aids.

The record describes the work as a pilot test intended to demonstrate feasibility for a larger trial. It does not report the randomization sequence, allocation concealment procedures, recruitment setting, or a sample-size justification. It also does not report the protocol details needed to determine how the intervention was delivered or how its components differed from brief advice.

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:

Analysis population for the primary outcome, as defined in the registry: Some participants did not complete assessments at prior to intervention, 30-day follow-up and 6 month follow-up so that is why the number of participants analyzed at these time points does not match the number of participants enrolled.

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 Change in Use of Smoking Cessation Pharmacotherapy in Past 30 Days, measured over Baseline, immediately prior to intervention receipt, 30-day follow-up, and 6-month follow-up.

The primary outcome is titled “Change in Use of Smoking Cessation Pharmacotherapy in Past 30 Days.” It is recorded as a count of participants and is assessed at baseline, immediately before intervention receipt, 30-day follow-up, and 6-month follow-up. The question asks whether participants used any of several prescription medications or over-the-counter aids to help quit or cut back on smoking during the preceding 30 days. Listed options include bupropion or Zyban, varenicline or Chantix, nicotine patch, nicotine gum or lozenge, and other aids.

Use of cessation medication is relevant to the stated study rationale because the summary describes low use of cessation treatments as an obstacle to quitting and presents behavioral engagement as a way to promote use of evidence-based medication. The outcome therefore concerns a treatment-use behavior, not smoking abstinence itself. It also does not directly measure whether a participant quit, reduced smoking, or continued smoking.

The outcome title refers to change, but the registry record does not report an analyzed contrast or explain how responses across the listed medication options were combined into the count. No primary outcome analysis is reported in the registry record. As a result, the assessment schedule and measurement question can be described, but the amount or direction of change cannot be determined from the posted results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does randomization contribute?

The registry classifies the allocation as randomized and the design as parallel. In general, randomization assigns participants to groups using a chance-based process. Its statistical purpose is to reduce systematic differences between groups at assignment, including differences that may not be measured. It does not guarantee that groups will be identical, ensure that follow-up data are complete, or by itself establish that an outcome difference is caused by the intervention. The registry record does not report how the random sequence was generated or whether allocation was concealed, so those procedures cannot be assessed.

A parallel-group design means that the comparison is between groups assigned to the respective interventions. The record lists Genetically-Informed RiskProfile and Brief Cessation Advice and states that masking was none. It does not provide arm descriptions. General methodological context: masking can reduce the influence of knowledge of assignment on some aspects of care, reporting, or assessment, depending on the outcome and study procedures. With no masking reported, the record does not establish that participants or study staff were unaware of group assignment. It does not report who, if anyone, could have been masked to outcomes or analyses.

What does the primary measure capture?

The outcome is a count of participants reporting use of smoking-cessation pharmacotherapy in the past 30 days. The wording asks about prescription medications or over-the-counter aids intended to help quit or cut back on smoking, with several named options and an “Other” response. Counts can provide an understandable summary of how many participants meet a stated definition. However, interpretation depends on the precise definition of a counted participant, including how multiple reported aids are handled and how missing answers are treated. Those details are not reported in the registry record.

The measure is collected at baseline, immediately prior to intervention receipt, 30-day follow-up, and 6-month follow-up. Repeated assessments can describe change over time, but a valid comparison needs a clearly defined summary or model that accounts for the repeated observations and the comparison between groups. General statistical methods for repeated data may use approaches that account for within-participant correlation, because observations from the same person are not generally independent. The registry record does not report an analysis method, so it is not possible to determine how repeated assessments would be combined or compared.

How should uncertainty and count data be considered?

General statistical explanation: an effect estimate describes the magnitude and direction of a contrast, and a confidence interval describes a range of values compatible with the data and the specified method. A narrow interval indicates greater precision than a wide interval, while both the estimate and interval are needed to understand the result. No primary estimate or confidence interval is reported in the registry record.

Counts of participants are discrete outcomes. Their statistical treatment depends on the definition of the count, the number of observations, the comparison of interest, and assumptions about how data were generated. For outcomes involving counts of events, over-dispersion means that variability is greater than a particular model expects; if present, it can make standard errors too small and intervals or tests misleading unless the method allows for that extra variability. This is general context only. The primary outcome is described as a count of participants, and the registry does not report an analysis model or a dispersion assessment.

What can the planning assumptions establish?

The record states assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation, with the effect to detect expressed as a fraction of an observed effect. It specifies that non-time-to-event illustrations are stated as participants per arm, while time-to-event illustrations use a total event count. These are planning assumptions, not a report of the trial’s original design rationale. The sample-size justification is not reported in the registry record.

General statistical explanation: a sample-size calculation uses a target effect and assumptions about variability, significance level, allocation, and desired power to illustrate the amount of information that might be needed for a future study. It is not an observed result and does not show that the current study had a particular probability of detecting an effect after the data were collected. Such illustrations should not be described as observed power. The registry record reports no primary outcome analyses, and the planning assumptions do not supply missing outcome estimates.

What analysis details remain unknown?

The registry record does not report a statistical analysis plan, the primary group contrast, adjustment for baseline values, covariate adjustment, handling of repeated measurements, model diagnostics, or a strategy for missing outcomes. It also does not report interim analyses. These details matter because different reasonable choices can lead to different estimates and uncertainty assessments, especially when participants have incomplete follow-up. Without the analysis methods and outcome results, statistical inference about the intervention comparison cannot be reconstructed from the record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and secondary outcomes concerning readiness to quit smoking, perceived disease risk, perceived benefits of cessation, perceived value of cessation treatments, self-efficacy of cessation, and personal relevance of the intervention. It records 8 outcome measures overall. The primary outcome itself is assessed at baseline, immediately before intervention receipt, 30-day follow-up, and 6-month follow-up. Multiple outcomes and assessment times create multiple opportunities to examine differences.

General statistical context: when many outcomes or contrasts are tested, the chance of at least one apparently unusual result can increase if each test is interpreted without considering the set of tests. Methods for addressing multiplicity can include defining a hierarchy of outcomes, adjusting inference, or treating secondary analyses as exploratory. The registry record does not report a multiplicity strategy. It also reports 0 analyses, so it provides no outcome test results to evaluate under any such strategy.

The record states that some participants did not complete assessments before intervention, at 30-day follow-up, and at 6-month follow-up, and that the numbers analyzed at those times do not match enrollment. It does not report how many participants completed each assessment, why assessments were missing, or whether missing values were excluded, imputed, or handled with a model-based approach. Those missing-data methods are not reported in the registry record.

The analysis population is also not reported in the registry record. In general, a study may define an analysis population using all randomized participants or a narrower set based on treatment receipt, protocol adherence, or outcome availability. The choice affects the interpretation of the comparison. No information in the record establishes which participants were included in an analysis, and no primary or secondary analysis is posted.

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.

Most frequent non-serious adverse event terms

The safety record reports serious adverse events separately for the two groups. For Genetically-Informed RiskProfile, 74 participants are listed as at risk, with 0 serious adverse events and 0 deaths. For Brief Cessation Advice, 74 participants are listed as at risk, with 0 serious adverse events and 0 deaths. The record lists 1 other adverse event in the Genetically-Informed RiskProfile group and 0 in the Brief Cessation Advice group.

These are reported counts, not a comparison adjusted for follow-up time or other factors. The record gives no serious adverse event terms, and the listed top serious-event terms are empty. It does not provide further detail about the one other adverse event, its timing, severity, or relationship to an intervention. The serious adverse event figures should therefore be read as the counts recorded in this registry entry, not as a complete characterization of safety.

General statistical context: zero recorded events does not establish that an event cannot occur, nor does it show that groups have identical safety profiles. Interpretation depends on the population observed, completeness and duration of safety monitoring, and how events were defined and collected. Those details are not reported in the registry record. The figures also do not provide information about the primary outcome of medication use.

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

The registry record establishes that a randomized, parallel-group study compared Genetically-Informed RiskProfile with Brief Cessation Advice and listed change in recent use of cessation pharmacotherapy as its primary outcome. It also records the scheduled assessments, the enrollment, and selected adverse event counts. These details describe the study question and its recorded conduct; they do not show whether the intervention changed medication use.

No primary or secondary analyses are reported. Consequently, the posted results do not provide a group difference, a measure of uncertainty, or evidence that would establish the direction or size of an effect. The absence of a reported analysis is not evidence that there was no effect, and it is not evidence that there was an effect. It means the comparative outcome question cannot be answered from the registry record.

The measured outcome is use of listed smoking cessation medications or aids during the preceding 30 days. It is not the same as quitting smoking, reducing cigarette use, or preventing smoking-related disease. The study summary explains the rationale for personalizing risk communication by using genetic information, but a rationale is not a result. The record does not report whether participants found the intervention personally relevant, changed their perceptions, or altered their readiness to quit.

The study is described as a pilot intended to demonstrate feasibility for a larger trial. The registry record does not report feasibility findings, the statistical plan, or the sample-size justification. It also notes incomplete assessments at several follow-up times without describing the missing-data approach. Those gaps limit what can be concluded about both the outcomes and their precision.

General interpretation: an estimate should be read alongside its uncertainty, outcome definition, analysis population, and the design that generated it. When those results are not reported, the responsible conclusion is limited to what the record documents. The adverse event counts describe the recorded events, but they do not answer the effectiveness question or establish comprehensive safety.

13. Why This Trial Matters Statistically

This trial raises a statistical question about how a personalized risk communication approach might be evaluated alongside a brief advice comparator. The study summary connects the intervention rationale to individual genetic factors and to behavioral engagement around smoking cessation. That rationale makes the measurement choice important: the primary outcome concerns recent use of cessation pharmacotherapy, while other listed outcomes concern perceptions, readiness, self-efficacy, and intervention relevance.

Several features are relevant to evaluating a future or larger study. The registry records a randomized parallel-group design, repeated outcome assessments, and incomplete follow-up at some assessment times. General statistical planning must consider how to define the group contrast across repeated observations, how to retain information when follow-up is incomplete, and how to interpret multiple outcomes without overemphasizing isolated findings. The registry record does not report how these issues were addressed.

The record’s pilot framing is also important statistically. A pilot study may be intended to inform whether a larger evaluation is feasible, whereas a confirmatory comparison requires an explicit outcome analysis and sufficient information to estimate effects with useful precision. The registry record does not report feasibility results, a design justification, or outcome estimates. Its planning assumptions describe sample-size illustrations based on an observed effect, but those illustrations are not observed power and are not the trial’s own sample-size justification.

Most importantly, the record illustrates the distinction between registering a question and reporting evidence that answers it. Clear outcome definitions and assessment times are useful, but interpretation also requires the analysis population, method, estimate, and uncertainty. With no analyses reported, the central comparative result remains unavailable. The recorded design and outcome definitions can inform understanding of what was intended to be studied, but they cannot substitute for the results needed to assess the comparison.

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 registry record leaves important features of the intervention comparison undescribed. Although it names Genetically-Informed RiskProfile and Brief Cessation Advice, it does not include arm descriptions. The study summary characterizes the former as a personalized genetic risk communication tool, but details about content and delivery for either arm are not reported in the registry record. This restricts interpretation of what participants received and what the contrast represents.

The primary outcome wording refers to change in medication use, and the record gives four assessment points. However, it does not state how responses across the medication options were combined into the participant count or define the exact contrast used to represent change. The outcome is about use of cessation aids rather than smoking abstinence, so it cannot directly establish changes in smoking status.

Some participants did not complete assessments before intervention, at 30-day follow-up, and at 6-month follow-up. The registry notes that analyzed counts at those times do not match enrollment but does not report the counts, reasons for missingness, or handling method. The statistical analysis plan, analysis population, multiplicity strategy, interim analyses, and sample-size justification are also not reported in the registry record. No analyses are posted, leaving no effect estimates or uncertainty measures to interpret.

The safety record provides event counts but little additional context. Serious adverse event terms are not listed, and the record does not explain the other adverse event recorded in one group. Details about event definitions and monitoring are not reported. These limitations mean that the registry entry supports a description of the study design and recorded counts, but not a full assessment of comparative outcomes, precision, or safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Implementation of Genomics in Substance Use Disorder Treatment — NCT04768114.
• Registry record last updated 2024-01-03; status last verified 2023-12.
• Results first posted 2024-01-03.
• 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 NCT04768114, “Implementation of Genomics in Substance Use Disorder Treatment,” sponsored by Washington University School of Medicine. The official title is “Toward the Implementation of Genomics in Substance Use Disorder Treatment.” The study is listed as completed, randomized, parallel-group, and unmasked, with an enrollment of 148 and phase listed as NA. The recorded start date is 2021-03-19, and the primary completion date is 2022-12-07.

The two listed interventions are Genetically-Informed RiskProfile and Brief Cessation Advice. The primary outcome concerns change in use of smoking-cessation pharmacotherapy in the past 30 days, assessed at baseline, immediately prior to intervention receipt, 30-day follow-up, and 6-month follow-up. The record lists 8 outcome measures and 0 analyses. It reports 0 serious adverse events and 0 deaths in each group, with 1 other adverse event in the Genetically-Informed RiskProfile group and 0 in the Brief Cessation Advice group. Comparative outcome results are not reported in the registry record.