Reducing Suicidal Ideation Through Insomnia Treatment: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Reducing Suicidal Ideation Through Insomnia Treatment (NCT01689909), a randomized phase 4 study. The primary outcome is Scale for Suicide Ideation Index (SSI).

2. Clinical Question

The registry’s background describes earlier observations linking insomnia with suicidal ideation and explains that this trial was intended to test whether treating insomnia might reduce suicidality. That is the rationale for asking the question, not evidence that the proposed effect occurred. The primary endpoint is a scale score, not a count of suicide attempts or deaths. The posted result therefore addresses measured suicidal ideation over the treatment period, and should be interpreted at that level.

3. Trial Design

The registry identifies this as a Phase 4, randomized, quadruple-masked, parallel-group trial. The listed sponsor is Augusta University. The record gives a start date of 2012-12-06, a primary completion date of 2017-06, and a completed status. Enrollment is listed as 103. The posted primary outcome groups include 51 participants assigned to Zolpidem-CR and 52 assigned to placebo.

In a randomized trial, assignment is intended to create groups whose differences are not systematically determined by participant or clinician choice. Masking is intended to limit the influence of knowing the assigned treatment on trial conduct or assessment. The registry’s label “quadruple” indicates masking of four roles, but the identities of those roles are not reported in the registry record. The allocation ratio, randomization sequence, concealment procedures, and any stratification factors are also not reported in the registry record.

The parallel design means the two assigned groups were compared over the same general treatment period rather than participants crossing from one treatment to the other. The intervention descriptions specify nighttime tablets for 8 weeks: Zolpidem-CR at 6.25 or 12.5 mg, or placebo. The record does not state how a participant’s Zolpidem-CR dose was chosen, whether it could change during treatment, or what background care was allowed. Such protocol details are not reported in the registry record.

The primary outcome timeframe is over 8 weeks of treatment. The registry also names secondary outcomes concerning sleep beliefs, disturbing dreams and nightmares, hopelessness, depression, and insomnia severity. The posted outcome results do not, by themselves, describe the full analysis population, follow-up completeness, or the handling of participants who did not complete treatment. Those trial conduct details are not reported in the registry record. Accordingly, the design labels and posted group summaries describe the broad comparison, but do not fill in every operational or analytical detail.

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.

6. Primary Endpoint

The registry lists the primary outcome as Scale for Suicide Ideation Index (SSI), measured over Over 8 weeks of treatment.

The primary endpoint was the Scale for Suicide Ideation Index (SSI), reported as a least-squares mean in units on a scale over 8 weeks of treatment. The registry describes the SSI as a 19-item measure, with each item scored from 0 to 2 and a maximum total score of 38 points. Higher scores indicate worse suicidal ideation.

A scale can capture the degree or intensity of a measured experience rather than reducing it to whether an event occurred. Here, the endpoint therefore summarizes suicidal ideation as measured by the SSI; it is not itself a count of suicide attempts, suicide deaths, or other events. A group mean represents an average score, not the experience of every participant. The registry does not describe how the least-squares means were modeled, which covariates were included, or how measurements over the treatment period were combined. Those details are not reported in the registry record.

Using a defined scale makes it possible to compare the average measured ideation between the randomized groups. The direction of the scale matters: a lower score corresponds to less severe ideation according to the registry’s description. The posted means are 4.66 for Zolpidem-CR and 5.25 for placebo, while the accompanying mean difference is -0.59. Those summaries point numerically toward a lower average score in the Zolpidem-CR group, but the uncertainty around the comparison is substantial. A scale result should be read as evidence about this measured outcome during the stated timeframe, not as a direct answer about broader clinical outcomes or longer-term risk.

7. Results Posted in the Registry

• Zolpidem-CR: mean 4.66 versus 5.25 on control; difference -0.59 (95% CI -2.21 to 1.03), standardized effect d = -0.14; z-test p = 0.476.

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.

Dysfunctional Beliefs and Attitudes About Sleep

• 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:
  • Zolpidem-CR: mean 6.03 versus 6.07 on control; difference -0.04 (95% CI -0.51 to 0.43), standardized effect d = -0.03; z-test p = 0.869.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Zolpidem-CR and the control. The interval gives the range of effects that remain compatible with the data.

Disturbing Dreams and Nightmares Severity Index (DDNSI)

• 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:
  • Zolpidem-CR: mean 5.74 versus 6.44 on control; difference -0.70 (95% CI -2.68 to 1.28), standardized effect d = -0.14; z-test p = 0.488.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Zolpidem-CR and the control. The interval gives the range of effects that remain compatible with the data.

Beck Hopelessness Scale (BHS)

• 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:
  • Zolpidem-CR: mean 9.40 versus 9.63 on control; difference -0.23 (95% CI -1.84 to 1.38), standardized effect d = -0.06; z-test p = 0.779.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Zolpidem-CR and the control. The interval gives the range of effects that remain compatible with the data.

The registry names secondary measures covering sleep-related beliefs, disturbing dreams and nightmares, hopelessness, depression, and insomnia severity. Across the secondary endpoints with numerical comparisons shown, the pattern is broadly similar to the primary outcome: the point estimates favor lower scores in the Zolpidem-CR group, but the reported intervals include zero. The associated unadjusted p-values do not indicate a clear group separation in these posted comparisons.

This overall pattern is consistent with the primary result in the limited sense that the secondary summaries do not offer a clear, independent signal that resolves the primary endpoint’s uncertainty. Secondary outcomes can add context by examining related aspects of sleep and mood, but they do not replace the primary question or transform an uncertain primary comparison into a definitive one. Nor should the broad pattern be interpreted as evidence that all measured aspects changed together in a meaningful way.

Unadjusted secondary results carry less weight when many outcomes are examined. In general, testing multiple outcomes increases the chance that some results may appear noteworthy by chance, even when there is no underlying effect. Adjustment procedures or a prespecified hierarchy can address that issue, but the registry does not report whether one was used. The record also does not provide a complete statistical analysis plan or identify which secondary outcomes were confirmatory versus exploratory.

The registry lists secondary measures, but the reported summaries do not show every detail needed to assess their analysis or clinical interpretation. No outcome-specific thresholds for meaningful change, multiplicity strategy, or full analysis population are reported in the registry record. The secondary results are best treated as supporting context and interpreted cautiously alongside the primary estimate, rather than as separate conclusive tests.

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

• Dysfunctional Beliefs and Attitudes About Sleep
• Disturbing Dreams and Nightmares Severity Index (DDNSI)
• Beck Hopelessness Scale (BHS)
• Hamilton Rating Scale for Depression (HAM-D)
• Insomnia Severity Index (ISI)

9. Statistical Interpretation

10. Statistical Methods Explained

The registry reports the primary endpoint as a least-squares mean with standard error. These terms describe summaries of a continuous outcome. A mean is an average score. A least-squares mean is generally an adjusted or model-based average, but the particular model and any adjustments used are not reported in the registry record. A standard error describes uncertainty in an estimated mean; it is not the same as the spread of individual participants’ scores. The reported standard errors are 0.58 for Zolpidem-CR and 0.59 for placebo.

What does the group comparison express?

The comparison gives the mean difference for Zolpidem-CR relative to placebo as -0.59. The posted group means are 4.66 and 5.25, respectively. A negative difference indicates a lower mean score in the first-named treatment group than in the comparator group. Since higher SSI scores indicate worse suicidal ideation, the numerical direction is toward a lower score in the Zolpidem-CR group. Direction alone does not settle whether the contrast is distinguishable from chance variation or whether it is meaningful to participants.

The comparison interval runs from -2.212 to 1.032. A confidence interval is a range expressing the uncertainty around an estimate under the assumptions of the method used. In general, a narrower interval indicates greater precision, while a wider interval leaves a broader range of compatible values. Here the interval includes zero, the value corresponding to no difference between group means. It also includes values on either side of zero, so the estimate does not pin down the direction with confidence. The confidence level and the exact method for constructing this interval are not reported in the registry record.

How should the p-value be understood?

The comparison reports an unadjusted p-value of 0.476. In general, a p-value describes how unusual data at least as inconsistent with a specified no-difference model would be if that model and the analysis assumptions were true. It is not the probability that the no-difference model is true, and it is not a measure of the size or importance of an effect. “Unadjusted” means the reported value has not been adjusted for a stated set of multiple comparisons. The registry does not report the trial’s prespecified multiplicity procedure, if any.

Both the interval and p-value are consistent with considerable uncertainty about the group contrast. These are not independent pieces of proof: they summarize related information about the estimate and its uncertainty. The p-value should not be read in isolation as a verdict, and a result that does not meet a conventional threshold would not establish that the groups are identical.

What do the dispersion summaries tell us?

The primary endpoint lists standard error as its dispersion summary. This conveys uncertainty in the estimated mean, not the range or standard deviation of individual SSI scores. The comparison also includes a pooled standard deviation of 4.199 and marks it as approximate. In general, standard deviation describes variation among individual observations, while standard error describes precision of an estimated mean. They answer different questions. The approximate pooled standard deviation is useful for the accompanying standardized-effect and planning illustrations, but it should not be mistaken for a directly posted participant-level distribution.

The registry’s primary means are labeled least-squares means, while the comparison summary includes a mean difference, an interval, and an unadjusted p-value. The model specification, assumptions used for the sponsor’s analysis, and any covariate adjustments are not reported in the registry record. The accompanying comparison is therefore a compact summary, not a substitute for a full statistical report.

Why does the scale’s direction matter?

Interpretation begins with how the SSI is scored. Its maximum total is 38 points, and higher scores indicate worse suicidal ideation. A negative mean difference thus points toward lower scores in the Zolpidem-CR group. But the registry does not define a threshold for a clinically important score difference. Statistical evidence about a group mean and judgments about meaningful change are separate matters. No threshold or responder definition is reported in the registry record.

The outcome is continuous, and the analysis treats it as a score summarized by group means. A general advantage of a continuous measure is that it can retain gradations in scores. General limitations include sensitivity to the scale’s properties, score distribution, and missing observations. The registry does not report distributional checks, transformations, or sensitivity analyses for this endpoint. Those details are not reported in the registry record.

Randomization and masking are relevant to the credibility of a comparison, but they do not answer every analytical question. The record identifies randomized allocation and quadruple masking, yet does not specify how masking was maintained or whether it was assessed. It also does not give the analysis population or explain how deviations from assigned treatment were handled. These omissions limit how fully the estimate can be audited from the registry entry alone.

11. Confidence Intervals and Precision

The primary comparison is a mean difference of -0.59, with an interval from -2.212 to 1.032. The interval is wide enough to include zero and values on both sides of it. In practical terms, the posted estimate is not precise enough to distinguish a lower average SSI score in the Zolpidem-CR group from little or no group difference, or from a difference in the opposite direction. This uncertainty is central to interpreting the result.

A confidence interval is a range of values compatible with the observed estimate and the assumptions of the interval method. It helps show what the point estimate alone cannot: the range of uncertainty. The interval should not be treated as a list of equally likely effects, nor as proof that every value within it is equally plausible. The registry does not state the confidence level or the method used to form the interval, so those particulars are not reported in the registry record.

The posted means, 4.66 and 5.25, are point summaries for the groups. They do not display the distribution of scores or how much participants differed from one another. The standard errors, 0.58 and 0.59, describe uncertainty in the estimated means, while the comparison interval describes uncertainty in their difference. The approximate pooled standard deviation of 4.199 gives a separate summary of spread for the planning illustration.

Precision is not the same as whether a result is important. A more precise interval could still center on a small difference, and a point estimate alone cannot show whether any difference matters to participants. The registry does not report a clinically important difference for the SSI. The posted interval therefore supports a cautious conclusion: the mean-score contrast is uncertain, and the data presented do not establish a clear between-group difference.

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 table and curve are planning illustrations based on the observed effect, not a reconstruction of the trial’s original design. For this continuous outcome, the figures are participants per arm, not total events. The listed 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 the stated fraction of the observed effect.

The table shows separate assumptions for planning to detect 100%, 75%, or 50% of the observed effect. For planning for 100% of the observed effect, the table gives 796 participants per arm for 80% power and 1,065 participants per arm for 90% power. For planning for 75% of the observed effect, it gives 1,414 participants per arm for 80% power and 1,893 participants per arm for 90% power. For planning for 50% of the observed effect, it gives 3,181 participants per arm for 80% power and 4,259 participants per arm for 90% power.

In plain language, the 80% power column illustrates a planned study’s chance of detecting the specified effect under the stated assumptions if that effect were real. The 90% column reflects a higher target chance of detection for the same assumed effect. Smaller effects are harder to distinguish from random variation, so planning to detect a smaller effect requires more participants per arm in these illustrations. The table is not observed power. The original sample-size justification and design assumptions are not reported in the registry record, so these figures should not be read as the trial’s own target enrollment or as a retrospective judgment about its success.

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, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -0.590; pooled standard deviation σ = 4.199.
2. n = 2 × (1.96 + 0.842)² × 4.199² / -0.590² = 795.2, rounded up to 796 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 <- -0.59                      # observed difference in means
sigma <- 4.19922340769371                     # 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(1689909)
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 = 796 (80% power), 1,065 (90% power)
 75% of observed effect: n per arm = 1,414 (80% power), 1,893 (90% power)
 50% of observed effect: n per arm = 3,181 (80% power), 4,259 (90% power)
power.t.test: 796.2 
Simulated power at n = 796 per arm: 0.797 (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.

14. Multiplicity, Missing Data and Analysis Populations

The registry lists several secondary outcomes in addition to the SSI primary endpoint. When multiple outcomes are tested, the chance of at least one apparently unusual result can increase. Statistical methods can account for this by adjusting the testing procedure, defining a hierarchy, or clearly distinguishing confirmatory from exploratory analyses. Whether any such strategy was planned or used is not reported in the registry record. The posted secondary p-values are described as unadjusted, so they should not be treated as if they control the overall false-positive risk across outcomes.

The registry does not report a full statistical analysis plan, including the prespecified primary comparison, model specification, covariates, testing sequence, or handling of deviations from the planned analysis. It also does not state whether interim analyses were performed. These are not details that can be inferred from randomization, masking, or the reported outcome summaries; they are not reported in the registry record.

The record does not describe the analysis population, such as whether the primary result includes everyone randomized, only participants who completed treatment, or another group. It does not report how missing SSI measurements were handled, whether any imputation was used, or whether sensitivity analyses assessed alternative assumptions about missing data. Missing outcomes can affect estimates if their absence is related to treatment assignment or participant outcomes. The registry entry does not provide enough information to assess that possibility.

Likewise, baseline outcome scores and participant-level flow through the trial are not described in the posted results. Without those details, readers cannot assess baseline balance, completeness of follow-up, or how the reported means relate to changes from baseline. The appropriate conclusion is not that these methods were absent, but that they are not reported in the registry record. This reporting gap limits reproducibility and the ability to evaluate whether the statistical methods matched the trial’s original plan.

15. 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: pregnancy then miscarriage (2.0%).

The adverse-event summary lists serious adverse events in 1 participant in the Zolpidem-CR group, with 51 at risk, and in 0 participants in the placebo group, with 52 at risk. Deaths are listed as 0 in both groups. The registry also lists “pregnancy then miscarriage” among the top serious terms at 2.0%. The entry does not provide enough detail to determine the event’s relationship to treatment or the circumstances behind it, so no causal interpretation should be made from the term alone.

These figures describe the events recorded during the trial; they do not by themselves establish that one treatment caused an event or that the treatments have equivalent safety. With a small number of serious events, the summary offers limited information about how often rare harms might occur. The registry lists other adverse events affecting 31 participants in the Zolpidem-CR group and 37 in the placebo group. The event definitions, severity details, duration, and attribution procedures are not reported in the registry record. Safety interpretation should therefore remain descriptive and limited to the posted counts.

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

The posted primary result is a comparison of average SSI scores over 8 weeks of treatment. The mean was 4.66 with Zolpidem-CR and 5.25 with placebo; the reported mean difference was -0.59, with an interval from -2.212 to 1.032 and an unadjusted p-value of 0.476. The interval includes zero, so the posted comparison does not establish a clear difference between the groups in the measured outcome.

This does not prove that the groups were identical. An uncertain estimate can be compatible with a range of possible group differences, including no difference. The registry result also does not establish a clinically meaningful change because a threshold for meaningful SSI change is not reported in the registry record. A point estimate should not be converted into a claim of treatment success or failure without the broader evidence and design details.

The endpoint concerns suicidal ideation as measured by a scale. It is not a direct measure of suicide attempts, suicide deaths, or overall suicide risk. The registry background explains why the investigators considered insomnia treatment relevant, but that rationale is not itself a trial result. The posted primary comparison cannot establish whether treatment changes outcomes beyond the measured score and timeframe.

The same caution applies to broader claims about insomnia or depression. The trial’s registry title and listed conditions identify the subject area, but the primary result is not a complete assessment of every symptom, longer-term outcome, or potential harm. The registry does not report follow-up beyond the stated treatment period or a full statistical analysis plan. The result should be understood as a limited and uncertain group comparison, not medical advice or a guarantee about an individual’s response.

In short, the posted data show a numerically lower average SSI score in the Zolpidem-CR group, but the interval is compatible with no group difference and with effects in either direction. That is the extent of the statistical conclusion supported by this result. It neither confirms a benefit nor demonstrates the absence of an effect.

17. Why This Trial Matters Statistically

This trial is statistically relevant because it tests a clinical question that joins sleep symptoms with a measure of suicidal ideation, while using a randomized, quadruple-masked, parallel-group design. Those design features are important to the interpretation of a treatment comparison: randomization aims to limit systematic differences in assignment, and masking aims to reduce influence from knowing the assigned group. The registry’s design labels offer useful context, although important implementation details are not reported in the registry record.

The trial also illustrates why effect estimates should be read together with their uncertainty. The primary group means differ numerically, but the comparison interval spans zero and the unadjusted p-value is 0.476. Looking only at the means could overstate the evidence for a difference; looking only at the p-value could obscure the range of estimates compatible with the data. The interval makes the imprecision visible.

Another statistical lesson is the distinction between a measured scale and a broader clinical outcome. The SSI captures suicidal ideation as a score, but does not directly answer questions about attempts or deaths. A result on one scale can inform a focused research question without settling the larger clinical question that motivated it.

Finally, the registry record demonstrates the value of reporting analysis plans, missing-data handling, participant flow, and multiplicity procedures alongside results. Without these details, readers can describe the posted comparison but have less basis for judging its reproducibility and robustness. The case is a reminder that a result is not just a point estimate: design, measurement, uncertainty, and transparent reporting all shape what can responsibly be concluded.

18. 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 entry leaves several trial-specific details unclear. It does not report the eligibility criteria in full, baseline characteristics, baseline SSI scores, participant flow, or whether all randomized participants contributed to the primary analysis. These omissions make it difficult to judge the comparability of participants at baseline or the completeness of outcome follow-up from the posted summary alone.

The outcome is reported as a least-squares mean, but the model, covariates, assumptions, and treatment of repeated measurements are not described. The registry also does not give the confidence level or construction method for the comparison interval. The posted summaries therefore do not permit an independent reconstruction of the sponsor’s full analysis. Details on handling missing measurements and sensitivity analyses are also not reported in the registry record.

The registry names multiple secondary outcomes, but does not describe a multiplicity strategy or identify which analyses were prespecified as confirmatory. This matters because a collection of unadjusted comparisons can produce results that look more informative than they are when considered one at a time. The record does not report a clinically meaningful threshold for the SSI, so statistical differences cannot be directly mapped to a stated importance threshold.

The primary timeframe is over 8 weeks of treatment. Longer-term outcome results are not reported in the registry record. The SSI is a scale of suicidal ideation, not a direct record of suicide attempts or deaths; the primary result should not be generalized to those outcomes. Finally, the posted safety figures are descriptive and do not provide detailed event narratives, attribution, or uncertainty estimates. These limitations do not erase the reported results, but they narrow the claims that can be made from this registry record.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Reducing Suicidal Ideation Through Insomnia Treatment — NCT01689909.
• Registry record last updated 2022-02-16; status last verified 2022-02.
• Results first posted 2018-06-20.
• 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.

22. Record Summary

This completed Phase 4 trial, sponsored by Augusta University, is listed as randomized, quadruple-masked, and parallel-group, with enrollment of 103. It compared nighttime Zolpidem-CR, at 6.25 or 12.5 mg, with placebo over 8 weeks. The primary endpoint was the Scale for Suicide Ideation Index, for which higher scores indicate worse suicidal ideation.

The posted primary means were 4.66 for Zolpidem-CR and 5.25 for placebo. The mean difference was -0.59, with an interval from -2.212 to 1.032 and an unadjusted p-value of 0.476. The interval includes zero, so the posted summary does not establish a clear difference in average SSI score. The registry record does not report key analysis details, including the missing-data approach, analysis population, and multiplicity procedure. The result is best read as an uncertain comparison of the measured scale outcome over the stated treatment period, not as a conclusion about suicide risk or longer-term outcomes.