Treatment With Mecamylamine in Smoking and Non-smoking Alcohol Dependent Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Treatment With Mecamylamine in Smoking and Non-smoking Alcohol Dependent Patients (NCT00342563), a randomized phase 2 study. The primary outcome is Percent Heavy Drinking Days During Active Treatment Phase.

2. Clinical Question

The trial’s stated purpose was to evaluate mecamylamine for reducing alcohol consumption in smoking and non-smoking alcohol-dependent patients. Its brief summary describes hypotheses that mecamylamine would produce a greater reduction in alcohol consumption than placebo, and that it could reduce both alcohol consumption and smoking among a subset of participants who smoked. Those statements describe the study’s aims, not findings established by the results.

The primary outcome is titled “Percent Heavy Drinking Days During Active Treatment Phase.” Its description says the data were calculated as the number of heavy drinking days averaged during 90 days of treatment. A heavy drinking day is defined as 5 drinks on one occasion for men and 4 for women. The registry lists the unit as days, so the title and unit do not use precisely the same wording. The posted means and their standard errors are reported by the four combinations of treatment and smoking status.

The comparisons are each anchored to the placebo-smoker group. They do not constitute a complete set of direct comparisons between all treatment and smoking subgroups. In particular, the record does not post a distinct analysis testing whether the mecamylamine effect differs between smokers and non-smokers. That question would require a direct treatment-by-smoking comparison or an interaction analysis, neither of which is reported in the registry record.

3. Trial Design

This was a randomized, triple-masked, parallel-group phase 2 study of mecamylamine and placebo in patients with alcoholism. Yale University is listed as the sponsor. The registry reports an enrollment of 136 and a completed study status. The recorded study start is 2004-05, and the primary completion date is 2015-07.

The posted primary outcome results are split into four groups: mecamylamine-smokers, mecamylamine-non-smokers, placebo-smokers, and placebo-non-smokers. Their reported sample sizes are 41, 27, 40, and 28, respectively. The randomization method, allocation ratio, and whether smoking status was itself a randomization stratum are not reported in the registry record. The record also does not explain how smoking status was defined or established.

Triple masking indicates that the record classifies the study as triple-masked, but it does not identify which roles were masked or describe how masking was maintained. The arm descriptions are blank, and details such as dose, treatment schedule, adherence procedures, and concomitant care are not reported in the registry record. The brief summary states the broad hypotheses, but does not provide a full protocol or a detailed account of the intervention.

The primary outcome timeframe is given as 12 weeks. Its description also refers to an average over 90 days of treatment. These are the registry’s stated timeframe and measurement description; further detail about when measurements were made or how the averaging was implemented is not reported in the registry record. Four outcome measures are listed, but there are no posted secondary outcome analyses. The record reports zero analyses, so the outcome summaries and comparisons should not be mistaken for a fully documented statistical analysis plan.

The design permits a descriptive look at the outcome in each treatment-and-smoking group and at comparisons with the placebo-smoker group. However, the posted results do not establish that every possible subgroup contrast was planned or tested. The registry record does not report the original sample-size justification, the planned primary statistical model, interim analyses, or an analysis population such as intention-to-treat.

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

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: One hundred and thirty six (136) individuals were randomized in this study with equal number of participants assigned to treatment (n=68) and placebo (n=68) groups. Randomization was stratified by gender and smoking status.

6. Primary Endpoint

The registry lists the primary outcome as Percent Heavy Drinking Days During Active Treatment Phase, measured over 12 weeks.

The primary endpoint is titled “Percent Heavy Drinking Days During Active Treatment Phase.” The registry describes the underlying measure as the number of heavy drinking days averaged during 90 days of treatment, with a heavy drinking day defined as 5 drinks on one occasion for men and 4 for women. The listed timeframe is 12 weeks, and the unit is days. The record does not clarify the difference between the title’s use of “Percent” and the unit and description’s use of days.

The posted group summaries are means with standard errors. A mean gives a group’s average value for the measured outcome; it does not describe every participant’s outcome or the distribution of individual values. The mean values are 16.75 for mecamylamine-smokers, 24.28 for mecamylamine-non-smokers, 20.51 for placebo-smokers, and 21.78 for placebo-non-smokers.

Heavy drinking days offer a way to summarize drinking patterns over the treatment period using the study’s stated threshold. The endpoint therefore addresses the study’s focus on alcohol consumption, but it is not by itself a complete account of drinking behavior, smoking, or other outcomes. The registry does not report the outcome’s measurement instrument, participant diary procedures, rules for missing days, or how incomplete observation periods were handled. Those details matter when interpreting a mean based on repeated behavior over time. The posted endpoint values describe the reported summaries; they do not by themselves show how individual participants changed from baseline or establish a causal treatment effect.

7. Results Posted in the Registry

• Mecamylamine- Smokers: mean 16.75 versus 20.51 on control; difference -3.76 (95% CI -16.10 to 8.58), standardized effect d = -0.13; z-test p = 0.550.
• Mecamylamine- Non-Smoker: mean 24.28 versus 20.51 on control; difference 3.77 (95% CI -9.95 to 17.49), standardized effect d = 0.13; z-test p = 0.590.
• Placebo- Non-Smoker: mean 21.78 versus 20.51 on control; difference 1.27 (95% CI -12.17 to 14.71), standardized effect d = 0.05; z-test p = 0.853.

8. Statistical Interpretation

9. Statistical Methods Explained

The posted endpoint is continuous: it is summarized using means and standard errors. A continuous outcome can take a range of numerical values, unlike an outcome that is simply a count of participants in categories such as event or no event. A mean represents the average within a group. It can be useful for describing the typical level of an outcome, although it may not convey skewness, clustering, or the range of individual observations. The record does not report medians, distributions, or participant-level values for this endpoint.

The standard error (SE) describes the uncertainty in an estimated mean due to sampling variability under the assumptions of the statistical calculation. It is not the same as the spread of individual participant outcomes. The reported SEs are 4.33 for mecamylamine-smokers, 5.3 for mecamylamine-non-smokers, 4.57 for placebo-smokers, and 5.11 for placebo-non-smokers. The registry does not also report standard deviations for these groups. A standard deviation would describe variation among individual outcomes, whereas the SE pertains to uncertainty in the estimated mean.

The posted comparisons are mean differences against placebo-smokers. For the mecamylamine-smoker comparison, the reference mean is 20.51 and the other group mean is 16.75; the reported difference is -3.76. The mecamylamine-non-smoker comparison reports a difference of 3.77, and the placebo-non-smoker comparison reports a difference of 1.27. These estimates are presented as reported, without recalculating or adjusting them. The registry’s comparison records include pooled standard deviations and standardized effect estimates, but these are not needed to understand the mean differences. The reported analyses are not labeled as adjusted for other participant characteristics.

A confidence interval expresses a range of estimates compatible with the data under the method used to construct it. It conveys both the direction and precision of the estimated difference. The intervals for all three comparisons include zero, so they do not rule out no difference. They also cover values on both sides of zero, so they are compatible with differences favoring either group in the numerical direction of the outcome. Wider intervals indicate less precision than narrower ones, all else being equal. The confidence level is not reported in the registry record; the interval should therefore be interpreted without attaching an unreported confidence percentage.

A p-value describes how unusual data at least as discrepant from a specified null hypothesis would be under the assumptions of a statistical test. It is not the probability that the null hypothesis is true, nor does it measure the size or clinical importance of a difference. The posted p-values are 0.55, 0.59, and 0.853. They are identified as unadjusted, and the record does not report a multiplicity correction. A p-value alone cannot convey the range of plausible effect sizes, which is why it should be read alongside the difference estimate and interval.

Why does the reference group matter? Each comparison takes placebo-smokers as the reference. This gives a common anchor for the three reported contrasts, but it does not produce a direct treatment comparison within each smoking subgroup. A direct comparison of mecamylamine-smokers with placebo-smokers is reported. For non-smokers, the posted comparison is mecamylamine-non-smokers against placebo-smokers; the record also reports placebo-non-smokers against placebo-smokers. It does not report a direct mecamylamine-non-smoker versus placebo-non-smoker contrast. Comparisons across subgroups can reflect differences associated with smoking status as well as treatment, so they should not be treated as treatment-only contrasts within a subgroup.

What does over-dispersion mean in general? In general, over-dispersion occurs when observed variability is greater than a model assumes. It can make standard errors too small and intervals too narrow if the model does not account for the extra variability. It is most directly discussed for outcomes analyzed with probability or count models; the primary posted result is a mean and standard error for a continuous outcome. The registry does not report a model or dispersion assessment, so there is no basis to say whether over-dispersion was evaluated or affected the reported analysis.

General statistical practice distinguishes an unadjusted group comparison from a model-based analysis that accounts for baseline values, stratification, or other covariates. Adjustment may improve precision or address imbalances when properly planned, but the record does not report such an analysis for this endpoint. It also does not say whether the outcome was analyzed as a change from baseline, as a follow-up value, or through a repeated-measures model. The descriptions identify an average over treatment, but do not supply the analytic details needed to determine how the group means were estimated.

The comparison estimates are reported with a pooled standard deviation and standardized effect statistic in addition to the mean difference. Such standardized measures express a difference relative to a measure of variability and can aid comparisons across outcomes with different units. Their interpretation depends on the underlying calculation and assumptions. The results include a standardized estimate for each comparison, but these estimates do not replace the original-unit differences or their intervals. No conclusions about clinical importance can be drawn from standardization alone.

The posted results contain no analysis records beyond these summaries and comparisons. The original statistical plan, handling of repeated observations, treatment adherence criteria, missing-data method, and analysis population are not reported in the registry record. These limitations are relevant because a group mean can depend on which participants contribute data and how incomplete observations are treated. The statistical concepts above are general explanations; they do not imply that any particular model or procedure was used in this trial.

10. Confidence Intervals and Precision

The reported uncertainty intervals are wide relative to the point estimates and include zero in all three comparisons. For mecamylamine-smokers versus placebo-smokers, the mean difference is -3.76 and the interval runs from -16.1 to 8.579. For mecamylamine-non-smokers versus placebo-smokers, the difference is 3.77 and the interval runs from -9.946 to 17.49. For placebo-non-smokers versus placebo-smokers, the difference is 1.27 and the interval runs from -12.17 to 14.71.

An interval that includes zero does not establish that the groups have equal means. It indicates that the reported data and method do not distinguish a zero difference from values in either direction within the interval. The intervals permit a range of possible differences, so the point estimates alone should not be read as precise estimates of the group contrasts. The posted p-values—0.55, 0.59, and 0.853—are consistent with substantial uncertainty, but the intervals give more information about the range of estimates compatible with the data.

The confidence level for these intervals is not reported in the registry record. The standard errors for the group means are also reported, but they do not substitute for the uncertainty intervals around the mean differences. The sample sizes in the four groups are 41, 27, 40, and 28, respectively. Those group sizes and the reported uncertainty describe the precision of these summaries; they do not, by themselves, explain the original design rationale or establish whether the study was adequately powered for a prespecified effect.

Precision is not the same as validity or importance. An estimate can be precise but not answer the intended question if the comparison is not aligned with that question, and an imprecise estimate can remain compatible with effects in more than one direction. Here the comparisons use placebo-smokers as the reference, so the intervals do not directly quantify the treatment contrast among non-smokers. The registry’s reported differences and intervals should be interpreted within those limits.

11. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size table and curve are planning illustrations based on each observed comparison, not a record of the trial’s original design calculation. The listed figures are participants per arm, not total participants or total events. The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each row considers detecting the stated fraction of the observed effect. The trial’s own original sample-size assumptions are not reported in the registry record.

The 80% power column gives the estimated number of participants per arm for a design with an 80% chance of detecting the specified effect under the stated assumptions, if that effect is the true one and the model assumptions hold. The 90% power column gives the corresponding planning number for a 90% chance. These are design probabilities, not probabilities that the treatment works, and not probabilities that the observed result is correct. The calculations are planning illustrations, not observed power.

Rows for 100% of the observed effect use the observed estimate as the effect to detect; rows for 75% and 50% use smaller fractions. The table shows that planning for smaller effects requires more participants per arm. For example, the mecamylamine-smoker comparison lists 891 participants per arm for 80% power when planning for 100% of the observed effect, and 3,561 per arm when planning for 50% of that effect. Those figures depend on this particular observed estimate and the stated assumptions; they are not a recommendation or a reconstruction of the trial’s planned enrollment.

The curve should be read as a visual representation of the same relationship between assumed effect size and required sample size. It does not add evidence about the treatment effect, and its values inherit the uncertainty of the observed comparison used to generate the illustration. These figures concern two-arm planning contrasts; they do not account for additional requirements that might arise from subgroup analyses, multiple testing, missing observations, or a different statistical model. Those features of the trial’s original planning are not reported in the registry record.

12. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -3.760; pooled standard deviation σ = 28.313.
2. n = 2 × (1.96 + 0.842)² × 28.313² / -3.760² = 890.1, rounded up to 891 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -3.76                      # observed difference in means
sigma <- 28.3130421260305                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(342563)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 891 (80% power), 1,192 (90% power)
 75% of observed effect: n per arm = 1,583 (80% power), 2,119 (90% power)
 50% of observed effect: n per arm = 3,561 (80% power), 4,767 (90% power)
power.t.test: 891.1 
Simulated power at n = 891 per arm: 0.800 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

13. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when several outcomes, comparisons, subgroups, or time points are tested. The more analyses that are conducted, the greater the chance that at least one result may appear statistically notable by chance if each is interpreted without adjustment. The registry lists four outcome measures and posts three comparisons for the primary measure. The p-values are explicitly unadjusted. A multiplicity adjustment or hierarchy for testing is not reported in the registry record, and the posted comparisons should not be treated as if a correction had been applied.

The study’s stated hypotheses include alcohol consumption and, among participants who smoke, smoking. However, the posted outcome results identify the heavy-drinking endpoint, and no secondary analyses are posted. The record therefore does not show how many outcomes or contrasts were planned, which were designated primary before data collection, or whether the smoking hypothesis was tested using a prespecified method. The number of listed outcomes alone does not establish the number of analyses conducted under the full protocol.

Missing-data handling is not reported. The record does not state how participants with incomplete follow-up, missed assessments, or incomplete daily drinking information were handled, whether any imputation was used, or whether analyses included all randomized participants. It also does not describe withdrawals or outcome availability by group. Missing observations can affect estimates when their occurrence is related to treatment or participant outcomes; without a stated method and supporting details, the impact cannot be evaluated.

The analysis population is not reported in the registry record. It is therefore not possible to determine whether these summaries represent all randomized participants, participants who completed treatment, or another defined set. The record also does not report a prespecified statistical analysis plan, interim analyses, covariate adjustment, or a plan for subgroup and interaction testing. These absences do not prove that such methods were not used; they mean that the registry record does not document them. The unadjusted comparisons should consequently be interpreted as the posted results, without assuming additional control of multiplicity or missing-data effects.

14. 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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: chest tightness (3.6%), pneumonia (2.5%), suicidal ideation (2.4%), chest pain (2.4%), psychotic delusion (2.4%).

The registry reports serious adverse events and other adverse events separately for each of the four treatment-and-smoking groups. Serious adverse events were reported for 3 of 41 participants in the mecamylamine-smoker group, 0 of 27 in the mecamylamine-non-smoker group, 1 of 40 in the placebo-smoker group, and 1 of 28 in the placebo-non-smoker group. Deaths are listed as 0 in each group.

The record also lists other adverse events as affecting 41 of 41, 27 of 27, 40 of 40, and 28 of 28 participants, respectively. These are participant counts in the registry’s adverse-event categories; they do not convey the number of episodes or their severity, duration, or relationship to treatment. The record’s leading serious adverse event terms include Chest tightness (3.6%), Pneumonia (2.5%), Suicidal Ideation (2.4%), Chest pain (2.4%), and Psychotic Delusion (2.4%).

These figures describe what was posted, not comparative safety estimates. The registry record does not provide event-level details, exposure-adjusted rates, causal attribution, or a statistical comparison of adverse events between groups. The small group counts and the absence of these details limit what can be inferred from the raw counts. A listed event should not be assumed to have been caused by the study drug, and the absence of a listed event does not establish that a risk is absent.

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

The posted results describe mean heavy drinking days during active treatment in four groups defined by mecamylamine or placebo and smoking status. The group means are 16.75, 24.28, 20.51, and 21.78 for mecamylamine-smokers, mecamylamine-non-smokers, placebo-smokers, and placebo-non-smokers, respectively. Against placebo-smokers, the reported differences are -3.76, 3.77, and 1.27. Their intervals all include zero and extend in both directions.

These summaries do not establish that mecamylamine reduced or did not reduce heavy drinking. They also do not establish that the groups were equivalent. The uncertainty intervals allow a range of possible differences, and the record does not report a prespecified equivalence margin or a non-inferiority analysis. A non-small p-value is not proof of no effect, just as a point estimate in one direction does not prove an effect.

The comparisons do not answer every question raised by the study aims. In particular, the posted non-smoker treatment contrast is not a direct comparison of mecamylamine-non-smokers with placebo-non-smokers. The record does not post a treatment-by-smoking interaction analysis, so it cannot establish whether treatment effects differ by smoking status. Nor do the primary results report smoking outcomes, baseline-to-follow-up changes, or a full analysis of alcohol consumption beyond the stated endpoint.

The endpoint title refers to percent heavy drinking days, while its unit and description refer to days averaged during treatment. The registry does not resolve that wording difference. This matters for precise interpretation of the scale, so the values should be described according to the posted means and the stated unit rather than treated as a clearly defined percentage.

Overall, the registry provides group summaries and unadjusted comparisons with substantial uncertainty. It does not report enough of the analysis plan, missing-data procedures, or population definition to determine how robust the findings are to those choices. The results are best understood as limited descriptive evidence from the posted record, not as a standalone determination of efficacy, lack of efficacy, or comparative safety.

16. Why This Trial Matters Statistically

This trial illustrates how a randomized study can produce several distinct subgroup summaries without necessarily providing the contrast needed to answer every subgroup question. The outcome is shown for smokers and non-smokers in both treatment groups, but the reported comparisons use placebo-smokers as a shared reference. The result for mecamylamine-non-smokers is therefore not the direct treatment comparison within non-smokers. Recognizing the reference group is essential before interpreting a difference as a treatment effect.

It also demonstrates why point estimates, intervals, and p-values should be considered together. The three mean differences have intervals that include zero and cover values in both directions. The p-values alone cannot show the range of effects compatible with the data, while the point estimates alone can overstate certainty. In this record, the intervals make the imprecision visible and discourage treating a nonsignificant result as proof of equivalence.

The endpoint wording presents another practical statistical issue: its title says “Percent Heavy Drinking Days,” while its listed unit is days and its description refers to an average number of heavy drinking days. Clear alignment of an outcome’s name, unit, and calculation is important for interpreting both the magnitude and meaning of a result. The registry does not explain the difference, so readers must preserve that ambiguity rather than silently resolve it.

Finally, the posted comparison-based sample-size illustrations show how planning needs depend on the effect a study aims to detect. Smaller assumed effects call for more participants under the stated assumptions. These retrospective illustrations are not evidence of the original design rationale or of the study’s achieved power. Together, these points show why a statistical reading must distinguish descriptive summaries, targeted contrasts, uncertainty, and design planning rather than treating them as interchangeable evidence.

17. Limitations

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

The registry record does not report the original sample-size justification, the planned analysis model, or the confidence level for the posted intervals. It also does not state whether the analysis adjusted for baseline outcome values or other covariates, whether repeated observations were modeled, or which analysis population was used. These omissions make it difficult to assess whether the reported comparisons match the original design and analysis plan.

There is a mismatch in the endpoint’s wording: the title refers to percent heavy drinking days, while the unit is days and the description refers to the average number of heavy drinking days. The record does not clarify the measurement scale or how the average was constructed from observations over 90 days. It does not report baseline values, individual outcome distributions, adherence, the measurement instrument, or the handling of missing daily information.

The comparisons use placebo-smokers as the reference for all three estimates. Consequently, the posted results do not directly provide both treatment-versus-placebo contrasts within smoking strata, and no interaction analysis is reported. The record does not document whether subgroup analyses were planned in advance. The p-values are unadjusted, while a strategy for multiplicity is not reported.

The registry reports adverse event counts and selected serious-event terms but does not provide event-level descriptions, causal assessments, or comparative statistical analyses. More generally, the arm descriptions are blank and details about dose, treatment schedule, allocation procedures, and the masking process are not reported in the registry record. These limitations concern what the registry documents; they should not be read as proof that the full study records contain no further information.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: Treatment With Mecamylamine in Smoking and Non-smoking Alcohol Dependent Patients — NCT00342563.
• Registry record last updated 2019-06-04; status last verified 2019-05.
• Results first posted 2017-05-17.
• 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.

21. Record Summary

NCT00342563 is a completed, randomized, triple-masked, parallel-group phase 2 study sponsored by Yale University. It enrolled 136 patients with alcoholism and compared mecamylamine with placebo, with posted results separated by smoking status. The recorded study start is 2004-05 and the primary completion date is 2015-07.

The primary outcome is titled “Percent Heavy Drinking Days During Active Treatment Phase,” with a listed timeframe of 12 weeks and a unit of days. Its description defines a heavy drinking day as 5 drinks on one occasion for men and 4 for women, averaged during 90 days of treatment. The registry posts means, standard errors, and three unadjusted comparisons against placebo-smokers. All three comparison intervals include zero.

The record lists four outcome measures but no posted secondary analyses. The original sample-size rationale, analysis population, missing-data method, multiplicity plan, and statistical analysis plan are not reported in the registry record. Adverse-event counts are posted by group, including serious events and deaths. The results support cautious interpretation of descriptive group averages and uncertain comparisons, rather than a definitive conclusion about treatment effects.