The SleepWell Study - Chronotherapeutic Intervention to Improve Sleep Following ACS: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for The SleepWell Study - Chronotherapeutic Intervention to Improve Sleep Following ACS (NCT05299723), a randomized na study. The primary outcome is Percentage of Participants Who Complete 100% of the Outcome Assessments at Study Conclusion.

2. Clinical Question

The clinical question is principally about feasibility: whether a home-based light intervention and its associated assessments can be carried out among people following acute coronary syndrome. The registry also describes acceptability, appropriateness, and usability as primary aims. In Phase B, it additionally proposes assessing whether the intervention engages its proposed proximal target, sleep. Secondary outcomes named in the record concern insomnia severity, overall sleep quality, and the sleep-duration item of the Pittsburgh Sleep Quality Index. Results for those sleep measures are not reported in the registry record, so the posted completion counts cannot answer whether sleep changed or whether any change differed between groups.

3. Trial Design

The SleepWell Study is registered as a randomized, parallel-arm pilot with no masking. Its official title describes a pilot chronotherapeutic intervention following acute coronary syndrome. The registry lists the study status as completed, an enrollment of 19, a start date of 2022-04-18, and a primary completion date of 2024-02-27. Phase is listed as NA.

The study description separates the work into two phases. Phase A was planned as an open-label, single-arm feasibility study of home-based combined chronotherapy. The brief summary describes 5 post-ACS participants for this phase. The posted primary outcome results list 4 participants in the Phase A group. The intervention used a light visor for morning bright light therapy after waking and orange-colored glasses for blue light blocking at night. The Phase A arm description specifies 30 minutes of morning light and blue light blocking from 8:00 pm until going to sleep.

Phase B was planned as a parallel-arm randomized clinical trial with a 2:1 allocation to active CC or sleep hygiene education control. The brief summary describes 15 post-ACS participants for Phase B. The posted primary results list 8 participants in the active group and 5 in the control group. The active intervention continued the morning and evening light procedures over the 4-week intervention period and included sleep hygiene education. The control group received sleep hygiene education alone at the start of the 4-week monitoring period.

The registry describes feasibility, acceptability, appropriateness, and usability as primary aims in both phases. In Phase B, sleep is also identified as a proposed proximal target mechanism. The listed secondary outcomes concern the Insomnia Severity Index, the Pittsburgh Sleep Quality Index global score, and its sleep-duration item. Randomization is reported for the study overall, but a separate randomization method for Phase B, allocation concealment procedures, and operational details of masking are not reported in the registry 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.

Overall Study

Reasons for not completing this period:

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: Two patients from the Phase B CC intervention group withdrew from the study after randomization but before the start of study procedures.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants Who Complete 100% of the Outcome Assessments at Study Conclusion, measured over At end of 4-week intervention period.

The primary endpoint is the number of participants who complete all endpoint questionnaire assessments at the end of the 4-week intervention period. The registry title frames the outcome as the percentage who complete 100% of assessments, and its description says the total number completing all assessments will be documented and the proportion computed. The posted results, however, give participant counts for each group. Percentages are not reported in the registry record.

This endpoint is suited to a pilot whose stated aims include feasibility and usability. Completing the assessments is a practical indicator of whether participants can remain engaged with the study’s outcome-measurement process through its conclusion. It does not itself measure sleep quality, insomnia severity, or the effect of the light intervention on sleep. Nor does completion establish that the intervention was acceptable or usable; those concepts may require additional measures or participant feedback, which are not detailed in the posted primary outcome results.

The posted counts are 4 participants in Phase A, 7 in Phase B active CC, and 5 in Phase B sleep hygiene education control. The registry does not report inferential estimates or a comparison for this endpoint. In particular, there is no reported uncertainty interval or hypothesis test accompanying these counts. The counts therefore describe the recorded assessment completion in each group; they do not establish whether completion differed meaningfully between the randomized groups or how precisely any difference is estimated.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Clinical trial results can be presented as descriptive summaries or as estimates from a statistical comparison. A descriptive summary reports what was observed in the enrolled groups. An inferential comparison uses a specified method to estimate a difference or test a hypothesis, while accounting for sampling uncertainty and, where relevant, design features. These serve different purposes: counts can describe study conduct, but they do not by themselves estimate how confidently groups differ.

What the primary endpoint counts

The primary endpoint is based on participants completing all endpoint questionnaire assessments at study conclusion. A participant either met the stated completion criterion or did not, so the posted outcome is a count of participants meeting that criterion. The title describes a percentage, but the registry results give counts alongside group sizes. The record does not provide the percentages or an analysis of a percentage difference. No additional values should be inferred from the counts when interpreting the posted findings.

For a binary endpoint, a group count is one component of a proportion: the number meeting the criterion in relation to the number assessed or enrolled in the relevant analysis population. Interpretation also depends on how the denominator was defined and who was included. The primary outcome record supplies group sizes, but it does not explain an analysis population or give a participant-flow account. The exact handling of participants without endpoint data is not reported in the registry record.

Why a comparative estimate matters

In a randomized trial, an analysis may compare outcomes between assigned groups. A difference estimate conveys the direction and magnitude of the contrast on the chosen scale; a confidence interval communicates uncertainty around that estimate. A p-value, when used, describes how compatible the observed data are with a specified null hypothesis under the analysis assumptions. Neither a confidence interval nor a p-value is reported for the primary endpoint in this registry record. The listed analysis count is 0. As a result, the primary endpoint findings are descriptive rather than a reported statistical test of the Phase B comparison.

Even when a test is reported, statistical evidence and practical interpretation are not interchangeable. A small study may estimate effects imprecisely, and a result that is compatible with a range of effects should not be reduced to a binary claim of success or failure. Here, there is no posted inferential estimate to interpret, and the study’s stated aims include feasibility rather than only a comparative efficacy question.

Randomization and design

The registry describes a randomized, parallel design with no masking. Phase B is described as a randomized comparison of active CC and sleep hygiene education control, with a planned 2:1 allocation. Randomization is intended to make treatment assignment independent of participant characteristics on average, supporting a fair comparison when the trial is implemented and analyzed as planned. It does not guarantee that groups will be similar in every characteristic, particularly in a pilot with few participants. The sequence-generation method, concealment of allocation, and analysis procedures are not reported in the registry record, so those aspects cannot be evaluated from the posted information.

Phase A differs from Phase B because it is described as open-label and single-arm. It can contribute descriptive information about implementation and assessment completion, but without a concurrent comparison group it cannot separate intervention-related changes from other influences. The record identifies the overall masking status as none. Further details about whether outcome assessors were masked are not reported in the registry record.

Planning assumptions and observed results

The record describes a sample-size planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It specifies that the effect to detect is a stated fraction of the observed effect. Such an illustration is a planning exercise: it describes sample sizes under selected assumptions, not the probability that the completed trial detected an effect. Sample-size values and the underlying effect estimate are not included in the registry information available for this analysis. Therefore, there is no planning figure to interpret alongside the completion counts.

General statistical guidance is that planning calculations depend on the endpoint scale, the target effect, variability or event frequency, significance level, allocation, and the selected method. Departures between assumptions and the actual study can change precision. An illustration based on an observed effect also inherits uncertainty from that effect. In this study, no sample-size justification for the original design is reported in the registry record, and the planning illustration should not be read as observed power.

Binary outcomes and uncertainty

For a binary endpoint, the number of participants meeting a criterion may be modeled using methods for proportions or binary responses. The appropriate method depends on the design, the analysis question, and the amount of data. In small samples, standard approximations may be unreliable; exact or other small-sample methods may be considered in general. No method for a comparative analysis of this endpoint is reported in the registry record, so it would be inappropriate to attribute a particular model or test to the study.

Precision is especially relevant when reading counts from a pilot. A count can be exact as a record of observed participants while still offering limited information about the range of outcomes in a broader population. Confidence intervals are one way to express that uncertainty, but none are posted for the primary outcome. The descriptive counts should not be converted into claims about a treatment effect or the expected completion rate in other settings.

The registry lists three secondary outcomes: the difference in Insomnia Severity Index total score, the difference in Pittsburgh Sleep Quality Index global score, and the difference in the Pittsburgh Sleep Quality Index sleep-duration item. It also lists 12 outcome measures overall. The results for the secondary sleep endpoints and their analysis methods are not reported in the registry record. Therefore, no interpretation of their direction, size, or precision is possible from the posted results.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Phase A - Open Label Single-arm", "Phase B - Active CC Treatment", "Phase B - Sleep Hygiene Education Control Group")
n      <- c(4, 8, 5)
events <- c(4, 7, 5)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Phase A - Open Label Single-arm  4  4  100.0  39.8  100.0  51.0  100.0  47.8  99.5
ARM  Phase B - Active CC Treatment  8  7  87.5  47.3  99.7  52.9  97.8  51.8  97.2
ARM  Phase B - Sleep Hygiene Education Control Group  5  5  100.0  47.8  100.0  56.6  100.0  54.1  99.6

11. Multiplicity, Missing Data and Analysis Populations

The registry lists three secondary sleep outcomes: the Insomnia Severity Index total score, the Pittsburgh Sleep Quality Index global score, and the sleep-duration item of that index. It lists 12 outcome measures overall. Considering multiple outcomes can raise a multiplicity issue: when many hypotheses are tested, the chance of at least one apparently notable finding can increase. General approaches include prespecifying a primary comparison, adjusting for multiple testing, or treating secondary results as exploratory. The statistical plan for multiplicity, including whether any adjustment was intended, is not reported in the registry record.

The primary outcome description says the proportion of participants completing all endpoint questionnaire assessments would be computed, but the posted primary results provide counts. A missing-data strategy for incomplete assessments is not reported in the registry record. The reasons for missing or uncompleted questionnaires, the timing of missingness, and whether participants were included according to randomization assignment are also not reported. Without this information, it is not possible to assess whether missing outcomes might affect interpretation.

An analysis population, such as an intention-to-treat or per-protocol population, is not reported in the registry record. The analysis count is 0, and no model or hypothesis test is posted for the primary outcome. No interim analysis plan, outcome hierarchy, or prespecified handling of the secondary analyses is reported in the registry record. These omissions limit assessment of how the posted results relate to the original analysis plan and how selective reporting may have been addressed.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports serious adverse events for 4 participants in Phase A, 8 in Phase B active CC, and 5 in the Phase B sleep hygiene education control group. The number of serious adverse events affected is recorded as 0 in each group. Deaths are also recorded as 0 in each group.

For other, non-serious adverse events, the record reports 0 affected participants in Phase A, 2 in the Phase B active CC group, and 0 in the Phase B control group. These are participant counts, not event rates adjusted for time at risk. The registry does not identify terms for serious adverse events; the serious-event terms list is empty. Further descriptions of the other events, their severity, timing, or relationship to the intervention are not reported in the registry record.

Zero recorded serious events in these small groups means that none are listed in the posted safety results; it does not establish that serious events are impossible or that risk is absent. Adverse-event summaries are also affected by the size and duration of observation. The record does not supply enough detail to compare safety statistically or to determine whether the two other events in the active group were related to the intervention. These figures describe the registry safety reporting and should not be interpreted as a general safety conclusion.

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

The posted results establish that the registry records completion of all endpoint questionnaire assessments for 4 participants in Phase A, 7 in Phase B active CC, and 5 in Phase B sleep hygiene education control. This is a narrow but relevant feasibility finding because the primary endpoint concerns completion of outcome assessments at the end of the intervention period.

The counts do not show whether the combined light intervention improved sleep. The registry names sleep as a proposed proximal target in Phase B and lists secondary measures of insomnia severity, sleep quality, and sleep duration, but their results are not reported in the registry record. The completion endpoint is not a sleep outcome, and completing questionnaires cannot be treated as evidence that symptoms changed.

The counts also do not establish a difference between the active and control groups. No comparative estimate, confidence interval, or p-value is reported for the primary endpoint, and the listed analysis count is 0. The registry record does not describe a statistical analysis plan or the population included in an analysis. The observed counts therefore should not be interpreted as proof that one group had better completion or as evidence about the causal effect of CC.

This pilot was designed to examine feasibility, acceptability, appropriateness, and usability. The posted outcome provides information about assessment completion, but does not by itself answer all those implementation questions. Details on participant views, adherence to the light procedures, and the reasons for any incomplete assessments are not reported in the registry record.

The evidence is bounded by the specific study groups and reporting available. The registry lists an enrollment of 19, while the reported primary outcome groups total 4, 8, and 5 participants; the relation between enrollment and these outcome counts is not explained. The findings are therefore best read as a descriptive account of completion in a small pilot, not as a definitive estimate of intervention efficacy, generalizability, or safety.

14. Why This Trial Matters Statistically

Clinical interventions are evaluated not only by whether they might change a health outcome, but also by whether the intervention and its measurement procedures can be carried out. This study addresses a practical question after acute coronary syndrome: whether participants can engage with a home-based schedule combining morning bright light therapy and evening blue light blocking, while completing endpoint questionnaires at the end of the intervention period.

That emphasis makes the study statistically distinct from a definitive effectiveness trial. Feasibility outcomes help describe implementation and can inform later study planning, while efficacy questions require outcome-specific estimates and a design capable of supporting comparative conclusions. The registry identifies the study as a pilot and lists completion as the primary endpoint. It also names acceptability, appropriateness, and usability among its aims, alongside the proposed sleep mechanism in Phase B.

The two-phase structure provides distinct kinds of information. The open-label single-arm phase can provide descriptive implementation experience. The randomized Phase B design introduces a control group and can, in principle, support a comparative evaluation. However, the posted record gives completion counts without an inferential comparison, and it does not report results for the named sleep outcomes. Recognizing that distinction prevents a feasibility result from being mistaken for evidence of a sleep effect.

The study also illustrates why transparent outcome reporting matters. The primary outcome title refers to a percentage, while the results display counts; the relationship between the listed enrollment and the outcome-group counts is not explained. The statistical analysis plan, missing-data handling, and analysis population are not reported in the registry record. These details are important for evaluating precision and understanding exactly which participants and measurements inform a result.

For biostatisticians and clinical researchers, the key lesson is to match interpretation to the estimand and the posted analysis. Completion counts can be informative for study conduct, but they cannot answer a different question about sleep change. Clear reporting of denominators, participant flow, missingness, and prespecified analyses would strengthen the interpretation of future pilot and randomized studies.

15. 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 does not report an inferential analysis of the primary completion endpoint. The results consist of participant counts, with no confidence interval, p-value, or comparative estimate. The record also does not report results for the named secondary measures of insomnia severity, global sleep quality, or sleep duration. As a result, the posted information supports only a limited descriptive interpretation.

The relationship between the registry enrollment of 19 and the primary outcome group counts of 4, 8, and 5 is not explained. The record does not provide a detailed participant-flow account, reasons for any difference between enrollment and outcome groups, or a definition of the analysis population. Missing-data procedures and reasons for incomplete questionnaire assessments are not reported in the registry record.

Important design and analysis details are absent. The record does not describe the randomization sequence method, allocation concealment, an analysis plan, or how multiplicity across outcomes would be handled. It lists no statistical analyses for the posted primary results. The overall masking status is none, but whether particular assessment procedures involved masked assessors is not reported.

The study is a pilot with relatively few participants in the posted outcome groups, so the descriptive counts have limited reach beyond those groups. Phase A is single-arm and open-label, and cannot provide a concurrent comparison. Phase B includes a randomized control group, but the absence of a reported comparison and sleep outcome results prevents assessment of intervention effects from the registry record. The safety reporting is also brief: two other adverse events are recorded in the active group, without terms or further context, and no serious-event terms are listed.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: The SleepWell Study - Chronotherapeutic Intervention to Improve Sleep Following ACS — NCT05299723.
• Registry record last updated 2025-01-07; status last verified 2024-12.
• Results first posted 2025-01-07.
• 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.

19. Record Summary

NCT05299723 is the completed SleepWell Study, a randomized, parallel-arm pilot with no masking, sponsored by Columbia University. The registry lists an enrollment of 19, a start date of 2022-04-18, and a primary completion date of 2024-02-27. The study concerns sleep disturbance and insomnia following acute coronary syndrome.

The intervention combined morning bright light therapy and evening blue light blocking. Phase A was an open-label single-arm phase; Phase B compared active CC with sleep hygiene education control. The primary endpoint concerned completion of all endpoint questionnaire assessments at the end of the 4-week intervention period.

Posted completion counts are 4 in Phase A, 7 in Phase B active CC, and 5 in Phase B control. The registry reports 0 serious adverse events and 0 deaths in each group; it records 2 participants with other adverse events in the active group and 0 in the other groups. Comparative analyses and results for the listed secondary sleep outcomes are not reported in the registry record.