Trial Of NS2359 For The Treatment of Cocaine Dependence: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Trial Of NS2359 For The Treatment of Cocaine Dependence (NCT02798627), a randomized phase 2 study. The primary outcome is The Number of Participants Who Achieved Abstinence From Cocaine During the Last Three Weeks of the Trial.

2. Clinical Question

The study asks whether assignment to NS2359 rather than placebo was associated with a different number of participants meeting the registry’s abstinence definition. The outcome combines two sources of information: participants’ reports of use and urine benzoylecgonine results. Weekly use/no-use indicators were derived from the urine drug screens and Timeline Follow Back reports. The registry describes urine collection three times weekly and identifies the final three weeks as the primary outcome period.

This is a comparison of treatment groups, not a comparison of each participant with their own baseline. Randomization is intended to make the groups comparable on average, while masking is intended to limit influences on treatment delivery, outcome assessment, and reporting. The record identifies randomized allocation, triple masking, and a parallel design. It does not report the specific masking roles or details of how randomization was implemented.

The clinical question is narrow: the primary outcome concerns the number meeting the specified abstinence criterion during the stated treatment period. It does not, by itself, answer broader questions about longer-term abstinence, other patterns of cocaine use, or outcomes beyond those posted in the registry record.

3. Trial Design

The registry describes NCT02798627 as a completed Phase II, randomized, triple-masked, parallel-group trial comparing NS2359 with placebo. The University of Pennsylvania is listed as the sponsor. The recorded start was 2016-05 and the primary completion was 2020-03. The registry reports enrollment of 55 participants, with 27 assigned to NS2359 and 28 to placebo in the posted primary results.

Participants assigned to NS2359 began at 2 mg once daily; those with difficult adverse events at that dose could reduce to 1 mg once daily. The placebo group received matching pills, with the same stated option to reduce the daily dose. Both group descriptions include weekly cognitive behavioral relapse prevention psychotherapy from week 2 through week 9. Thus, the comparison concerns assignment to medication or matching placebo in the setting of the described psychotherapy, rather than medication in isolation.

The brief summary describes a proposed trial involving 100 participants, an eight-week trial, a one-week baseline, and a follow-up visit four weeks after the medication phase. The registry’s posted enrollment is 55. The registry record does not explain the difference between the proposed number and recorded enrollment, nor does it detail the follow-up results. The primary outcome timeframe is listed as 8 weeks, and the outcome description focuses on abstinence during the last three weeks of the trial.

The record lists one primary outcome and one posted secondary outcome. The primary outcome is the number achieving the abstinence definition. The secondary outcome is average weekly cocaine craving scores, assessed once per week in weeks 2 through 8. The registry record does not report further details about allocation concealment, adherence, treatment exposure, the handling of missing observations, or the original statistical design assumptions.

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: Participants had a screening telephone appointment to determine eligibility. If eligible, they were seen at the clinic for history, physical exam and urine drug screen. A positive urine drug screen for a cocaine metabolite (BE) was used as a stratifying variable in randomization.

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.

6. Primary Endpoint

The registry lists the primary outcome as The Number of Participants Who Achieved Abstinence From Cocaine During the Last Three Weeks of the Trial, measured over 8 weeks.

The primary endpoint counts participants who met the trial’s definition of cocaine abstinence during the last three weeks. To meet that definition, a participant had to report no cocaine use and have no cocaine-positive urine drug screens. The record says that urine benzoylecgonine levels were assessed through urine drug screens three times weekly and that self-reports came from the Time Line Follow Back. Those data were combined into weekly use/no-use indicators.

Combining reported use with urine results gives the endpoint more than one measurement source. Self-report captures participants’ accounts of use, while urine testing provides a biological measure within the testing schedule. Requiring both no reported use and no positive screens makes the endpoint a defined abstinence criterion rather than a measure of craving or the amount of use.

A count of participants meeting a binary criterion is readily interpretable as the number of people in each group who achieved the recorded outcome. The comparison can also be expressed as a difference in the proportions meeting that criterion. The posted results report 2 participants in the NS2359 group and 2 in the placebo group. These counts describe the observed trial groups; they do not establish that the groups were identical in all respects or that the treatment effects are known precisely.

The endpoint is limited to the stated abstinence window and measurement definition. It does not directly summarize use outside that period, nor does it convey the full pattern of weekly outcomes for each participant. The registry record does not report how incomplete urine testing or missing self-reports were handled.

7. Results Posted in the Registry

• NS2359: 7.4% (2/27) versus 7.1% (2/28) on control; risk difference 0.3 percentage points (95% CI -13.5 to 14.0), risk ratio 1.04 (0.16–6.85); unadjusted two-proportion z-test p = 0.970.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Average Weekly Cocaine Craving Scores NS2359 Group Versus the Placebo Group Comparator [ Time Frame: Once Per Week in Weeks 2 Through 8 ]

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • NS2359: mean 4.09 versus 3.89 on control; difference 0.20 (95% CI -0.80 to 1.20), standardized effect d = 0.11; z-test p = 0.695.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between NS2359 and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists one posted secondary outcome: average weekly cocaine craving scores, measured once per week in weeks 2 through 8. This outcome complements the primary abstinence endpoint by addressing craving rather than whether participants met the combined no-use and urine-screen criterion. The two outcomes therefore offer different views of the treatment groups and should not be treated as interchangeable measures.

Across the posted outcomes, the registry does not show a clear separation between the groups: the primary point estimate is close to zero, and the secondary mean-difference interval includes zero. This broad pattern is descriptive. The primary result remains the outcome identified as primary, while the secondary result does not strengthen or overturn it merely by measuring a related aspect of cocaine use.

Secondary outcomes are often interpreted with less weight than a prespecified primary outcome because they may be one of several opportunities to examine differences. Testing multiple outcomes can increase the chance of a seemingly notable result arising by chance unless the analysis plan accounts for multiplicity. The registry record does not report a multiplicity adjustment, a hierarchy of secondary hypotheses, or the full set of analyses considered. The posted secondary comparison should therefore be viewed as exploratory evidence rather than a confirmatory finding.

The registry record also does not report a sponsor inferential analysis for the craving comparison. Its posted summary statistics support a descriptive comparison, but they do not establish whether a particular inferential procedure was prespecified or how repeated weekly measurements were handled. A weekly average outcome can involve within-participant observations that are related to one another; the record does not provide enough detail to assess the underlying analysis model. The results should be interpreted within those limits and alongside the primary endpoint rather than as an independent confirmation.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Average Weekly Cocaine Craving Scores NS2359 Group Versus the Placebo Group Comparator [ Time Frame: Once Per Week in Weeks 2 Through 8 ]

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is binary at the participant level: each participant either met the recorded abstinence definition or did not. The registry reports the number meeting the criterion in each arm. A natural effect measure for this design is the risk difference, which subtracts the proportion with the outcome in one arm from the proportion in the other. Its units are absolute differences in outcome probability. A value close to zero indicates similar observed proportions, although uncertainty around the estimate remains important.

What does the confidence interval express?

A confidence interval describes the uncertainty around an estimated effect using a specified statistical procedure. In repeated use of the same procedure under its assumptions, intervals constructed in this way would cover the true effect at the stated rate. It is not a probability statement about the fixed effect in this particular trial. For the primary risk difference, the interval runs from -0.135 to 0.14. Because it spans zero and extends in both directions, the observed data are compatible with a range of possible differences, including no difference and differences favoring either group.

What does the chi-squared test assess?

The sponsor’s posted primary analysis is identified as chi-squared, with p = 0.97. In general, a chi-squared test for a categorical outcome compares observed group counts with the counts expected under a null hypothesis of no association between group and outcome. The test’s p-value summarizes how incompatible the observed data are with that null model, given the test assumptions. It does not measure the size of an effect, the probability that the null is true, or the practical importance of the result. The registry record does not report a test statistic, degrees of freedom, or further test details.

The unadjusted recalculation uses the posted summary statistics to express the group comparison as a risk difference and associated confidence interval. It is not an adjusted model and does not account for unreported covariates, repeated measurements, or missing observations. The registry’s reported primary analysis is also a chi-squared test, and the posted p-value is consistent with the recalculated comparison as recorded. The sponsor’s own analysis takes precedence when interpreting a discrepancy; the registry record identifies no discrepancy for this comparison.

How should the secondary outcome be understood?

The secondary outcome is a continuous score, reported as a group mean with a standard error. The posted mean difference is 0.2, with a 95% confidence interval from -0.801 to 1.201. A mean difference expresses the separation between group averages on the score scale. Its interval describes uncertainty in that estimated separation. The standard error describes uncertainty in an estimated mean; it is not the same as the spread of individual participant scores. The registry does not report the score’s full distribution or a sponsor-reported inferential analysis for this outcome.

For both outcomes, interpretation depends on the design and measurement details. Randomized allocation supports a treatment-group comparison, but randomization does not eliminate uncertainty in a small trial. Masking can reduce some sources of bias, yet the registry record does not describe the masking roles or whether masking was maintained. The record also does not state how outcomes were handled for participants with incomplete follow-up, whether the analysis followed assigned treatment regardless of adherence, or whether any covariate adjustment was planned.

General statistical interpretation should separate three questions: the estimated effect, the uncertainty around it, and the assumptions behind the analysis. The risk difference estimates the observed absolute contrast; the confidence interval indicates substantial uncertainty; and the chi-squared result is a test of a null comparison. None alone provides a complete account of clinical relevance, safety, or longer-term outcomes.

11. Confidence Intervals and Precision

The primary risk-difference estimate is 0.003, with a 95% confidence interval from -0.135 to 0.14. The estimate lies close to zero, while the interval includes zero and extends to effects in either direction. The interval’s breadth means the observed data do not pin down the magnitude of the group difference with high precision. The low number of participants meeting the primary criterion is relevant context for interpreting that uncertainty.

A confidence interval is an estimate-centered range produced by a statistical method. It reflects sampling uncertainty under the method’s assumptions; it does not account automatically for possible bias, missing data, or errors in outcome classification. The registry record does not report the missing-data rules or enough detail to assess whether every randomized participant contributed complete primary outcome data.

The secondary mean-difference estimate is 0.2, with a 95% confidence interval from -0.801 to 1.201. This interval also spans zero and permits values on either side of the point estimate. It should be read in the units of the craving score, not as a difference in abstinence. The record reports standard errors for the group means, but does not describe the score’s distribution or provide a sponsor-reported comparison analysis.

Precision is distinct from statistical significance. A test result alone cannot show whether an effect estimate is narrow enough to be useful, and a confidence interval does not establish that all included values are equally plausible. Interpretation should focus on the estimates and their ranges, alongside the outcome definitions and limitations of the record.

12. 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 planning estimates are participants per arm, not total participants, because the outcomes are not time-to-event outcomes. The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set to the stated fraction of the observed effect. The registry record does not report the trial’s original sample-size assumptions or justification.

The 80% power column gives the number of participants per arm in the planning illustration for a design with an 80% chance of detecting the specified effect under the stated assumptions, if that effect and the model assumptions were correct. The 90% power column describes the corresponding planning target with a 90% chance. These are design targets, not guarantees that a future study will produce a statistically significant result.

Rows planning for 100%, 75%, and 50% of the observed effect illustrate how the required sample size changes as the target effect becomes smaller. Smaller effects need more participants to distinguish them from random variation with the same significance level and power target. For the primary outcome, the planning figures are extremely large relative to the 55 participants enrolled, reflecting how little information the observed risk difference provides for planning around a very small effect. The estimates are illustrative and depend strongly on the observed effect used as their starting point.

The sample-size curve expresses the same general relationship between a chosen effect and the corresponding planning requirement; it is not an additional observed trial result. These calculations are not observed power. Observed power is not a useful substitute for interpreting the estimated effect and its confidence interval after a study has been completed.

13. 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, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.071; treatment proportion p₁ = 0.074; average p̄ = 0.073.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.3673 = 0.7199.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.3673 = 0.3091.
4. n = (0.7199 + 0.3091)² / (0.0026)² = 151,305.6, rounded up to 151,306 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
p0 <- 0.0714285714285714                          # control proportion
p1 <- 0.0740740740740741                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^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 (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(2798627)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 151,306 (80% power), 202,555 (90% power)
 75% of observed effect: n per arm = 267,862 (80% power), 358,591 (90% power)
 50% of observed effect: n per arm = 600,152 (80% power), 803,433 (90% power)
power.prop.test: 151305.6 
Simulated power at n = 151,306 per arm: 0.797 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-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.

14. Analyses Reported by the Sponsor

The registry reports a chi-squared primary analysis with p = 0.97. The unadjusted recalculation from the posted counts gives a risk difference of 0.003 and a 95% confidence interval from -0.135 to 0.14. The registry record identifies no discrepancy between the reported primary result and the recalculated comparison.

The recalculation is a simple, unadjusted comparison based on the posted group summaries. It is useful for expressing the absolute difference and its uncertainty, but it does not replace the sponsor’s analysis or establish what other methods may have been used outside the registry record. The sponsor’s own analysis takes precedence if a discrepancy is present. Here, the reported p-value and the recalculated estimate both indicate that the observed group comparison is close to zero, while the confidence interval shows substantial uncertainty.

The registry does not report a sponsor analysis for the posted secondary craving comparison. The secondary mean difference and its interval are therefore descriptive recalculations from the posted group statistics, rather than a reported sponsor inferential result. Neither the primary nor the secondary figures reveal details absent from the record, such as an adjusted analysis or missing-data method.

15. Multiplicity, Missing Data and Analysis Populations

The registry record lists one primary outcome and one secondary outcome, but does not report whether the investigators adjusted for multiple comparisons. When several outcomes or analyses are examined, the chance of finding an apparently unusual result can increase. General statistical practice may address this through a prespecified testing hierarchy or an adjustment to the testing procedure; the record does not state whether either approach was used. The secondary result should consequently receive less confirmatory weight than the primary outcome.

The registry record does not report the analysis population, such as whether all randomized participants were included according to their assigned group, or how participants who discontinued treatment were handled. It also does not report how missing urine screens, self-reports, or craving scores were treated. These details matter because excluding incomplete observations or making assumptions about missing outcomes can affect group estimates. No particular missing-data approach can be inferred from the posted counts.

The record does not report whether the primary analysis was adjusted for baseline measures or other covariates, whether any subgroup analyses were planned, or how protocol deviations were treated. It gives a chi-squared method for the primary comparison but no further test specifications. For the secondary outcome, no sponsor-reported inferential analysis is listed, and details about handling repeated weekly scores are not reported in the registry record.

These omissions do not establish that the trial lacked a statistical plan or that particular analyses were not conducted. They mean only that those methods are not documented in the registry record. Without that information, readers cannot fully assess prespecification, the handling of incomplete data, or whether the posted results represent the intended analysis population and procedures.

16. 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 5% reporting threshold.

Most frequent non-serious adverse event terms

The posted serious adverse event figures show 0 serious adverse events among 27 participants at risk in the NS2359 group and 0 among 28 participants at risk in the placebo group. The registry also lists 0 deaths in each group. These figures describe the serious-event and death counts recorded for the participants at risk in each arm; they do not establish that no other adverse events occurred.

For other adverse events, the registry lists 11 affected participants among 27 at risk in the NS2359 group and 1 among 28 at risk in the placebo group. These are counts of participants with an event, not necessarily counts of all event episodes. The registry record does not provide event terms, severity breakdowns, timing, or a fuller account of how events were collected. No top serious adverse event terms are listed.

Safety counts should be interpreted descriptively, especially in a trial with 55 participants enrolled. Zero recorded serious events in both groups does not rule out uncommon harms, and the difference in other affected participants does not by itself explain causation, event type, or clinical significance. These figures are not a substitute for a complete safety analysis.

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

The posted results describe a small randomized comparison in which 2 participants in each group met the primary abstinence criterion. The estimated risk difference is 0.003, and its 95% confidence interval ranges from -0.135 to 0.14. The sponsor-reported chi-squared p-value is 0.97. Taken together, these statistics indicate that the observed primary comparison is close to zero but imprecise. They do not establish equivalence, prove no effect, or quantify effects outside the confidence interval’s assumptions.

The primary endpoint captures abstinence during a specific period using both self-report and urine screening. It does not describe every aspect of cocaine use, craving, treatment adherence, or outcomes after the recorded period. The posted secondary craving comparison addresses a distinct outcome and likewise has uncertainty. Neither result can be generalized automatically to other populations, treatment schedules, or durations.

Randomized allocation and triple masking are design features recorded by the registry, but the record does not provide details about implementation or maintenance of masking. It also does not report analysis populations, missing-data procedures, or the original sample-size justification. These gaps constrain conclusions about possible sources of bias and the robustness of the posted estimates.

The safety record lists no serious adverse events or deaths in either group, alongside different counts of participants affected by other adverse events. With the available details, those counts are descriptive and cannot characterize event types or uncommon risks. Overall, the registry results support a cautious account of what was observed in this trial, not a medical recommendation or a definitive conclusion about treatment effects.

18. Why This Trial Matters Statistically

This trial illustrates why an estimated effect and its precision should be read together. The primary risk difference is close to zero, but the confidence interval is broad and includes both negative and positive values. A near-zero point estimate alone could be mistaken for evidence of no difference; the interval makes clear that the posted data do not tightly determine the effect’s direction or magnitude.

The endpoint also shows how outcome definition shapes interpretation. Abstinence was based on both participant reports and urine drug screens, with the results combined into weekly indicators. That operational definition makes the target outcome explicit, while leaving unanswered questions about incomplete measurements and the rules used for missing data.

The registry identifies a sponsor-reported chi-squared analysis and a secondary craving outcome, but does not document multiplicity procedures, the analysis population, or the original sample-size rationale. These are not merely technical details: they help readers evaluate whether analyses were prespecified, how uncertainty was handled, and how much weight to give secondary comparisons.

Finally, the planning illustrations highlight the connection between the size of an effect, the number of participants required, and desired power. They use the observed effect and stated planning assumptions, not the trial’s original design assumptions. Treating those figures as planning examples rather than retrospective evidence avoids confusing a completed trial’s uncertainty with the probability that its result was significant.

19. 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 reports 55 participants enrolled, despite the brief summary describing a proposed study of 100 participants. It does not explain this difference. The actual posted group sizes are 27 and 28, and only 2 participants in each group met the primary abstinence criterion. The resulting primary estimate is imprecise, so the observed comparison cannot support a narrow conclusion about the size of a difference.

The primary outcome description has a timing detail that is not fully clear: the narrative identifies the last three weeks, while its parenthetical time frame lists weeks 6,7.8. The record also identifies an 8-week timeframe. The registry record does not clarify that notation. The outcome combines urine testing and self-report, but does not describe how discordant results, missed urine screens, or incomplete reports were handled.

The brief summary describes one follow-up visit four weeks after the medication phase, but follow-up results are not included in the posted outcome data. The record does not report the number completing follow-up, adherence, treatment discontinuations, or the analysis population. It also does not report allocation concealment, masking roles, baseline characteristics, the original sample-size justification, interim analyses, or a detailed statistical plan.

The secondary outcome is listed as an average weekly craving score, but the registry does not give details about the score distribution or the handling of repeated weekly measurements. No sponsor inferential analysis is reported for that endpoint, and no multiplicity procedure is described. Safety reporting includes event counts but not event terms or a fuller clinical characterization. These limitations concern what is documented in the registry record and do not establish what may have been available elsewhere.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Trial Of NS2359 For The Treatment of Cocaine Dependence — NCT02798627.
• Registry record last updated 2021-05-24; status last verified 2021-05.
• Results first posted 2021-05-24.
• 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.

23. Record Summary

NCT02798627 is recorded as a completed Phase II randomized, triple-masked, parallel-group trial sponsored by the University of Pennsylvania. The registry reports 55 participants enrolled, with 27 assigned to NS2359 and 28 to placebo. The primary outcome counts participants who achieved abstinence during the last three weeks, using self-reports and urine drug screens.

The posted primary counts are 2 participants in each group. The unadjusted risk difference is 0.003, with a 95% confidence interval from -0.135 to 0.14; the reported chi-squared p-value is 0.97. The secondary outcome concerns weekly cocaine craving scores. The record lists no serious adverse events or deaths in either group and reports other adverse events in 11 NS2359 participants and 1 placebo participant.

The record does not report the original sample-size assumptions, analysis population, missing-data approach, or multiplicity procedures. Those absences limit interpretation of the methods and the certainty that can be attached to the posted estimates.