Insomnia Treatment and EMA (Ecological Momentary Assessment) Outcomes: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Insomnia Treatment and EMA (Ecological Momentary Assessment) Outcomes (NCT05908526), a randomized phase 2 study. The primary outcome is Change in Daytime Insomnia Symptoms Scale (DISS).

2. Clinical Question

The DISS assessment covers alert cognition, fatigue, sleepiness, negative mood, and positive mood. Participants were to complete the survey on a smartphone four times per day for approximately 16 days. The stated assessment points are baseline and the end of the study, before day 16. Higher scores indicate greater levels of the relevant construct, so the direction of a change needs to be interpreted separately for each domain. The registry record does not report the domain-specific results or an overall comparison between the treatment groups.

3. Trial Design

This is a completed phase 2 randomized, double-masked, parallel-group clinical trial sponsored by the University of Maryland, Baltimore. The registry lists an enrollment of 40. The study began on 2023-10-09, and primary completion was recorded on 2024-08-08. Those design and status details describe the trial’s conduct; they do not establish whether the intervention changed the outcomes.

The treatment arm description specifies an initial low-dose suvorexant period at 10mg by mouth at bedtime for two nights, followed by 20mg for a 14-day active treatment period. The comparator arm is described as placebo taken by mouth at bedtime for 16 nights. The record also lists baseline surveys, cognitive testing and ecological momentary assessments, along with Actiwatch monitoring. These measures provide context for the trial’s remote monitoring approach, but the registry record does not report adherence, completion, or device-use results.

The primary outcome is change in the DISS, assessed at baseline and at the end of the study before day 16. The stated score range is 0-100, with higher scores reflecting greater levels of a measured construct. Secondary outcomes include sleepiness, depression, anxiety, and several cognitive performance measures: vigilance lapses and median reaction time, Stroop accuracy and response time, and task-switching response time. The registry lists 11 outcome measures overall, but it does not report analyses for them.

The randomization ratio, sequence-generation method, concealment procedure, precise masking arrangements, and detailed eligibility criteria are not reported in the registry record. The record does not describe a statistical analysis plan or a participant-flow account. Consequently, the registered design can be described, but important details needed to assess implementation and analysis cannot be verified from this record.

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: The study participants that were confirmed eligible were randomized to drug or placebo in a 1:1 ratio by the IDS pharmacy.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Older adults with insomnia.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Change in Daytime Insomnia Symptoms Scale (DISS), measured over Baseline (start of study) and end of study (before day 16)..

The primary endpoint is change in the Daytime Insomnia Symptoms Scale (DISS), a self-report measure of daytime symptoms and functional impairment. Its five domains are alert cognition, fatigue, sleepiness, negative mood, and positive mood. Participants were to complete the survey on a smartphone four times per day for approximately 16 days. The registered comparison uses measurements at baseline and at the end of the study, before day 16.

The stated possible score range is 0-100, and higher scores indicate greater levels of the particular construct being measured. This matters because a higher score does not have one uniform interpretation across domains: for example, greater fatigue and greater positive mood describe different directions of experience. A change score therefore needs to be linked to its domain and scoring interpretation before it can be understood.

Repeated reports collected during daily life can capture symptoms as they vary across the day, rather than relying only on a single retrospective report. That is a general measurement rationale, not evidence that the registered assessment successfully captured every participant’s daily experience. The registry record does not report DISS scores, domain-specific treatment effects, variability, or missing assessments. It also does not explain whether the primary comparison was intended to combine the domains or analyze them separately. The primary endpoint is defined, but its observed result and its precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Several statistical ideas are useful for reading a clinical trial record, even when the outcome estimates are not reported. The following explanations are general. They do not describe an analysis method unless that method is explicitly stated in the registry record.

What does a mean represent?

For a continuous measure such as the DISS, a group mean is an average of participants’ scores. A mean can describe a group’s level at a particular assessment or a mean change between assessments, depending on the analysis. A comparison of means can summarize how groups differ on average, but it does not show how scores are distributed among individuals. In this trial, the registry identifies the primary outcome as change in DISS and identifies mean and standard deviation as the outcome summary type. It does not report the group means or standard deviations, nor does it explain the precise calculation of change used in an analysis.

Why is variability reported?

A standard deviation describes how dispersed individual measurements are around a group mean. It is not the same as the uncertainty in an estimated group mean or treatment difference. The standard deviation describes variation among observations; a confidence interval describes uncertainty around an estimate. A confidence interval is a range of values compatible with the data and the method used to calculate it. A narrow interval indicates greater precision than a wide interval, all else being equal. No confidence interval for the primary comparison is reported in the registry record, so its precision cannot be assessed from the record.

What would a treatment contrast tell a reader?

A treatment contrast expresses the difference between groups on an outcome, using a defined scale and analysis. Its meaning depends on the outcome’s scoring direction, the time point, and whether the contrast concerns final values, change from baseline, or another estimand. Here, the DISS has multiple domains and higher scores indicate more of the relevant construct. A valid interpretation would therefore require the domain and the comparison to be clear. The registry record does not report a treatment contrast or specify how the multiple DISS domains were handled in the primary analysis.

How should a p-value be read?

In general, a p-value measures how compatible the observed data are with a specified statistical model and null hypothesis. It does not measure the probability that the null hypothesis is true, and it does not indicate the size or clinical importance of an effect. A p-value also cannot replace an effect estimate and its confidence interval. No primary-outcome p-value is reported in the registry record, so there is no reported test result to interpret.

What is over-dispersion, and why can it matter?

As a general concept, over-dispersion occurs when observed variation is greater than a statistical model assumes. If a model understates variability, its uncertainty estimates can be too small and its tests can appear more conclusive than warranted. Appropriate handling depends on the outcome and model. The DISS is identified as a continuous measure summarized by a mean and standard deviation, but the registry record does not report a model, diagnostics, or a method for handling unusual variability. It is not possible to say whether over-dispersion was assessed or relevant to the analysis.

What do planning calculations mean?

A sample-size planning calculation asks how many participants per arm might be needed under specified assumptions to detect an effect with a chosen significance level and power. It is a design illustration, not a description of the observed trial result. The planning assumptions associated with the calculations use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is stated as a fraction of the observed effect. Such illustrations depend on their assumptions and should not be confused with the trial’s actual enrollment or an estimate of its achieved power. The registry record does not report the trial’s own sample-size justification. The illustrations are not observed power and do not establish that the trial could reliably detect a particular treatment effect.

The registry record does not report an analysis plan, model specification, adjustment covariates, handling of repeated measurements, or approach to missing outcome data. No recalculated treatment estimate can be presented without the underlying group results, and no sponsor analysis is available in the record for comparison. Statistical interpretation must therefore remain limited to the registered measures, design details, and adverse-event counts.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 11 outcome measures, including the primary DISS measure and secondary assessments of sleepiness, depression, anxiety, and cognitive performance. Multiple outcomes create a multiplicity question: when several hypotheses are tested, the chance of at least one apparently unusual result can increase if each test is judged separately without a prespecified strategy. General approaches include designating a primary outcome, defining a testing hierarchy, or adjusting inference across a family of comparisons. The registry record does not report a multiplicity strategy, a hierarchy among outcomes, or which secondary analyses were prespecified.

The primary outcome description covers five DISS domains and assessments at baseline and at the end of the study. The registry indicates that the primary outcome has several categories or time points and is not reduced to one comparison. It does not report whether domains were to be tested separately, combined, or interpreted with another rule. Thus the intended family of primary comparisons and the associated control of multiplicity are not reported in the registry record.

The record lists 0 analyses. It does not report a statistical analysis plan, analysis populations, or definitions such as intention-to-treat or per-protocol. The method for handling missing surveys, incomplete daily assessments, withdrawals, or missing cognitive tests is not reported in the registry record. Nor is the extent or pattern of missingness reported. These omissions prevent assessment of whether the analyzed participants and measurements represent the randomized groups, and whether missing data could affect the estimates. No conclusion about the conduct or quality of those analyses should be inferred from the absence of detail.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 3% reporting threshold.

The adverse-event summary lists the Treatment and Placebo groups separately. For each group, it records 20 participants at risk, 0 participants affected by serious adverse events, 0 affected by other adverse events, and 0 deaths. No serious-event terms are listed. These are the counts recorded in the registry, and they describe the safety summary rather than establishing that an event could not occur.

A zero count in a trial does not prove that the underlying risk is zero. The amount of information available depends on the number observed, the duration and completeness of follow-up, and how events were defined and collected. The registry record does not report the adverse-event definitions, the collection period, the ascertainment procedures, or whether all participants completed safety follow-up. The event counts should therefore be read as reported observations, not as a comprehensive estimate of risk.

The record does not provide event descriptions beyond the empty serious-event term list, or any analysis comparing safety between groups. It is not possible to infer from these counts whether there were symptoms not captured by the reported categories or whether the groups differed in risks not summarized in the record. The counts do not establish overall safety or support medical advice.

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

This trial record establishes that a randomized, double-masked, parallel phase 2 study compared suvorexant with placebo in older adults with insomnia. It describes a DISS primary outcome, multiple secondary measures, remote monitoring, and a completed study status. It also reports adverse-event counts for the two groups. These details help identify what the trial set out to measure and what the registry records about safety.

The record does not report the primary outcome results. Without group estimates, a treatment contrast, or a confidence interval, it is not possible to characterize the size, direction, or precision of a DISS difference. The stated hypothesis that suvorexant would improve sleep and daytime symptoms remains a hypothesis in the absence of reported outcome estimates. A completed study status is not a substitute for results.

The DISS assesses several distinct daytime domains, and a change in one domain need not imply a change in another. The registry record does not specify how those domains were combined or report domain-level findings. Secondary outcomes are listed, but their results are not reported either. It is therefore not possible to determine whether the measured outcomes moved together, diverged, or showed no clear group separation.

The safety counts record no serious or other adverse events and no deaths in either group, with 20 at risk in each group. Such observations are limited by the information reported about event collection and follow-up, which is not detailed in the registry. They should not be interpreted as proof of no risk.

In statistical terms, the registry record permits a description of the question, design, registered measures, and recorded safety counts. It does not permit a quantitative estimate of the primary effect, an evaluation of its uncertainty, or a conclusion about whether any outcome differed between groups. Those limits apply to interpretation of this record and do not establish what an unreported analysis might have found.

13. Why This Trial Matters Statistically

This trial is statistically notable for measuring daytime symptoms repeatedly in daily life while also including cognitive tests and device-based monitoring. The DISS was to be completed on a smartphone four times per day for approximately 16 days. Repeated self-reports can, as a general measurement approach, provide information about within-day variation that a single assessment may not capture. Such a design also makes complete and consistent reporting important: missing assessments can affect which experiences are represented in an analysis. The registry record does not report completion or missingness.

The endpoint includes five domains rather than one simple symptom measure. That breadth can be informative, but it raises analysis and interpretation questions: whether domains are analyzed separately, how multiple comparisons are handled, and how score direction is interpreted. The record does not report a statistical plan or primary results that answer those questions. This makes the distinction between a clearly described measurement strategy and a fully interpretable effect estimate especially important.

The study also lists secondary measures of sleepiness, depression, anxiety, and performance on several cognitive tasks. Their inclusion reflects a range of outcomes, but without reported analyses it is not possible to judge which were informative or how uncertain their estimates were. The serious and other adverse-event counts are recorded as zero for both groups, but limited safety details constrain interpretation.

For readers assessing trial evidence, a registry entry is most useful when outcome definitions are accompanied by group-level results, effect estimates, uncertainty, analysis methods, and missing-data information. In this record, the study question and design are identifiable, while the numerical outcome evidence needed to assess treatment effects is not reported.

14. Limitations

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

A central limitation for interpreting this trial record is the absence of reported outcome estimates. The registry identifies the primary DISS endpoint and its assessment schedule but does not report group means, standard deviations, treatment contrasts, confidence intervals, or p-values. It lists 0 analyses. The status is completed, but the record does not provide the numerical findings needed to evaluate changes or differences between groups.

The primary measure covers five domains, yet the record does not explain whether the domains were to be combined or examined separately. It also does not reduce the several categories or time points to one comparison. Without a stated analysis approach, readers cannot determine what estimand would answer the primary question or how multiplicity was addressed. The statistical plan, sample-size justification, and analysis populations are not reported in the registry record.

The assessment schedule involves frequent smartphone surveys, cognitive testing, and Actiwatch monitoring. The registry record does not report participant adherence, completeness of repeated assessments, device data availability, or methods for handling missing measurements. These details matter because incomplete measurement can influence which observations contribute to an analysis. Eligibility criteria beyond the broad description of older adults with insomnia, randomization procedures, and masking implementation are also not reported in the registry record.

Safety interpretation is limited by the lack of detail about event definitions, collection methods, and follow-up period. The recorded zero counts are observations, not proof of zero underlying risk. The record also does not report detailed outcomes for the listed secondary measures. These are limitations of what can be learned from the registry record; they should not be mistaken for evidence that the unreported procedures or results had any particular form.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Insomnia Treatment and EMA (Ecological Momentary Assessment) Outcomes — NCT05908526.
• Registry record last updated 2025-10-30; status last verified 2025-09.
• Results first posted 2025-10-30.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry describes a completed, randomized, double-masked, parallel phase 2 trial sponsored by the University of Maryland, Baltimore, comparing suvorexant with placebo in older adults with insomnia. Enrollment is listed as 40. The primary outcome is change in the DISS, a measure of daytime symptoms and functional impairment across alert cognition, fatigue, sleepiness, negative mood, and positive mood. The study also lists secondary sleepiness, mood, anxiety, and cognitive performance outcomes, as well as smartphone assessments and Actiwatch monitoring.

The record does not report analyses or numerical results for the primary or secondary outcomes. Its adverse-event summary lists 0 serious adverse events, 0 other adverse events, and 0 deaths in each group, with 20 at risk in each group. These counts do not establish absence of risk. The study question and registered design are clear, but treatment-effect estimates and their precision are not reported in the registry record.