This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Mindfulness Versus Pharmacotherapy for Chronic Insomnia: A Pilot Study (NCT00515177), a randomized phase 2, phase 3 study. The primary outcome is Pittsburgh Sleep Quality Index (PSQI).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00515177 |
| Phase | Phase 2, Phase 3 |
| Condition | Chronic Insomnia, Primary Insomnia |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 30 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Minnesota |
| Results posted | Yes |
2. Clinical Question
Population
Adults with primary chronic insomnia were the intended population. The registry record describes an actual enrollment of 30 participants and identifies chronic insomnia and primary insomnia as the conditions studied. It does not report further eligibility details such as age limits, symptom duration requirements, or other clinical characteristics of the enrolled participants.
Intervention
The behavioral intervention was Mindfulness-Based Stress Reduction (MBSR). The registry describes 8-weeks of group instruction in mindfulness meditation techniques, followed by home practice and monitoring. The study rationale proposed that mindfulness training might reduce arousal and unhelpful cognitions associated with insomnia; that rationale is a hypothesis, not a reported trial finding.
Comparator
The comparison was a pharmacotherapy control using eszopiclone. The registry describes one 3 milligram pill nightly for 8 weeks, followed by use as needed at the same dosage for 3 months. The trial therefore compared a structured behavioral program and home practice with a medication regimen and subsequent as-needed use.
Primary question
The primary outcome was sleep quality measured with the Pittsburgh Sleep Quality Index (PSQI), assessed at 8 weeks and 5 months. The clinical question was whether the recorded sleep-quality scores differed between the MBSR and eszopiclone groups at those assessment times. The registry record does not report the scores or a statistical comparison, so it does not establish the direction, size, or precision of any difference.
3. Trial Design
The registry describes a randomized, single-masked, parallel-group pilot study, listed as Phase 2 and Phase 3. Its stated purpose was to establish feasibility and inform the design of a full-scale comparison of MBSR with prescribed sleep medication for chronic insomnia. The record lists 30 participants as the actual enrollment. The study status is completed, with a start date of 2007-08 and primary completion in 2009-06.
The two arms differed in the type and schedule of treatment. MBSR consisted of 8-weeks of group instruction followed by home practice and monitoring. The pharmacotherapy arm used eszopiclone nightly for 8 weeks and then as needed for 3 months. These are not simply two versions of the same intervention: one is a behavioral program with continuing practice, while the other is a medication regimen. Any comparison concerns these assigned strategies as described, not mindfulness or medication in isolation from their schedules and associated activities.
The registry's primary-outcome population description indicates 10 participants in the pharmacotherapy arm and 20 in the MBSR arm before the listed exclusions. It states that one person who refused the drug was excluded from the pharmacotherapy outcome population. In MBSR, one person who did not attend and one who attended fewer than 5 classes were excluded. The stated outcome populations are therefore 9 and 18, respectively. These exclusions mean that the primary-outcome population described in the record is not identical to the enrolled population.
Single masking is recorded, but who was masked and how masking was maintained are not reported in the registry record. The record also does not describe the randomization method or allocation concealment. The groups were monitored by telephone for side effects and adherence, and objective sleep assessment by actigraphy is mentioned in the study description. The primary outcome discussed in the record, however, is the self-reported PSQI.
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
| Stage | MBSR | Pharmacotherapy Control Arm |
|---|---|---|
| STARTED | 20 | 10 |
| COMPLETED | 18 | 9 |
| NOT COMPLETED | 2 | 1 |
Analysis population for the primary outcome, as defined in the registry: In the PCT arm, one person who refused to take the drug was excluded. 10-1=9 In the MBSR arm, one person who did not attend MBSR and one person who attended fewer than 5 classes were excluded. 20-2=18.
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.
| Characteristic | Unit | Randomized to MBSR | Randomized to PCT | Total |
|---|---|---|---|---|
| Participants analysed | 20 | 10 | 30 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 19 | 10 | 29 |
| Age, Categorical: >=65 years | Participants | 1 | 0 | 1 |
| Age Continuous | years | 47 (21 to 65) | 53.5 (29 to 59) | 51 (21 to 65) |
| Sex: Female, Male: Female | Participants | 15 | 7 | 22 |
| Sex: Female, Male: Male | Participants | 5 | 3 | 8 |
| Region of Enrollment: United States | participants | 20 | 10 | 30 |
6. Primary Endpoint
The registry lists the primary outcome as Pittsburgh Sleep Quality Index (PSQI), measured over 8 weeks and 5 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was the Pittsburgh Sleep Quality Index (PSQI), a self-reported measure of sleep quality. The registry describes it as a 19-item questionnaire with scores from 0 to 21, with higher scores indicating worse sleep quality. Scores greater than 5 indicate poor sleep according to the registry description. The stated assessment times were 8 weeks and 5 months.
A sleep-quality measure is relevant to this trial because the interventions were intended to address chronic insomnia, and the PSQI captures participants’ reported experience of sleep. Its self-report format also means that the score reflects participants’ responses rather than a direct physiological measurement. The study description separately mentions objective sleep assessment by actigraphy, but actigraphy is not identified as the primary endpoint in the registry record.
The registry lists the outcome as a mean with standard deviation, which describes a continuous measure: the mean represents the group’s average score, while the standard deviation describes how spread out individual scores are around that average. The record does not report PSQI means, standard deviations, group contrasts, confidence intervals, or p-values at either assessment time. It therefore gives the measure and interpretation rules but not the result needed to assess the observed sleep-quality comparison.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the PSQI as the primary outcome and specifies assessments at 8 weeks and 5 months. It does not report the values observed at those times or any statistical comparison between the groups. Consequently, the direction and magnitude of the sleep-quality results cannot be described from this record. There is no basis in the recorded results to say whether average PSQI scores were higher in one arm, whether any difference was statistically compatible with no difference, or how precise an estimated contrast might be.
This absence is important when interpreting the trial’s status. The study is marked completed, but completion does not itself show that outcome data were posted. The registry also reports zero analyses. That entry does not tell readers what analyses may have been conducted elsewhere; it means that a statistical analysis is not reported in the registry record. Neither the study rationale nor the intervention descriptions can substitute for measured results.
The registry describes the project as a pilot intended to assess feasibility and inform a later, full-scale trial. Pilot studies can provide useful information about procedures and recruitment, but conclusions about comparative outcomes require the outcome estimates and their uncertainty. Feasibility findings such as attendance, adherence, recruitment performance, or participant retention are not reported in the registry record as results. The listed exclusions do provide some information about who was omitted from the primary-outcome population, but not why the other outcome data may or may not be available.
The sample-size illustrations described for the statistical material are planning exercises rather than evidence of the trial’s observed precision. They are described as based on an observed effect and specified assumptions, but the record does not provide the primary-outcome estimate or numerical illustration values in the registry entries. They cannot be read as observed power or as a substitute for a confidence interval around a treatment contrast. In particular, no calculation based on the record can recover a result that was not reported.
The safety entries are separate from the efficacy question. The record lists no serious adverse events in either group, while it lists other adverse events in the pharmacotherapy arm and none in the MBSR arm. These counts describe entries in the registry, not comparative statistical tests; the record does not report tests or detailed event descriptions. The death entries are not populated, so deaths are not reported in the registry record.
The appropriate statistical conclusion is therefore limited: the registry describes a randomized pilot comparison and identifies its primary measure and assessment times, but does not report the primary outcome analysis. No treatment effect, uncertainty interval, or evidence of a between-group difference can be inferred from the design description alone.
9. Statistical Methods Explained
The registry identifies the PSQI as a continuous outcome analyzed as a mean with standard deviation. A continuous score can take a range of values rather than belonging only to categories such as present or absent. A group mean summarizes the average score, and the standard deviation conveys variation among participant scores. Neither quantity is a measure of uncertainty in the estimated mean by itself. A confidence interval, when reported, would describe a range of values compatible with the data and the statistical procedure used; no confidence interval is reported for this outcome in the registry record.
What would a group comparison describe?
A comparison of group means would address whether average PSQI scores differed between the assigned strategies at a specified assessment time. Because higher PSQI scores indicate worse sleep quality, the direction of a reported contrast would need to be interpreted using that scale direction. A difference in averages would not indicate that every participant experienced the same change, nor would it describe the range of individual responses. The registry provides no group means, standard deviations, mean contrast, or uncertainty interval, so none of those interpretations can be made for this trial from the record.
Why do assessment times matter?
The endpoint is specified at 8 weeks and 5 months. Those are distinct assessments, and a result at one time would not automatically describe the other. The treatments also have different schedules: the MBSR program includes group instruction followed by home practice, while the medication regimen changes from nightly use to as-needed use. A longitudinal analysis could account for repeated measurements within the same participant, but the registry does not state whether such a model was planned or used. It is not appropriate to assume a particular repeated-measures method or to treat the assessments as interchangeable.
What does randomization contribute?
In general, random assignment aims to make treatment groups comparable with respect to both measured and unmeasured characteristics at the start of a study. It supports a causal comparison of the assigned strategies when allocation, follow-up, and analysis are handled appropriately. Randomization does not guarantee that groups will be identical, especially in a pilot with limited enrollment. The record states that allocation was randomized, but the method of generating the sequence, concealment procedures, and details of implementation are not reported in the registry record.
The primary-outcome population description lists exclusions after assignment: a participant who refused medication, and two participants in MBSR who did not attend or attended fewer than 5 classes. Excluding participants based on post-assignment behavior can change the comparison from one based on assignment to one based on remaining participants. In general, an intention-to-treat analysis retains participants in their assigned groups regardless of adherence, while an adherence-based analysis focuses on participants meeting defined criteria. The registry does not identify the analysis population using either label or state the intended estimand. The stated outcome population should therefore be read as an explicit description of exclusions, not as proof of a particular standard analysis approach.
How should p-values and uncertainty be read?
In general, a p-value describes how unusual data at least as incompatible with a specified null hypothesis would be under the assumptions of a statistical model. It does not give the probability that a treatment works, and it does not measure the size or clinical importance of an effect. A confidence interval communicates uncertainty about an estimate and can help readers assess which effect sizes remain compatible with the data. Neither p-values nor confidence intervals for the PSQI comparison are reported in the registry record. Therefore statistical significance and precision cannot be evaluated.
What do the planning assumptions mean?
The record describes sample-size planning illustrations using a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It also says that the effect to detect is a stated fraction of the observed effect. These are assumptions for planning illustrations, not evidence that the trial was designed with those assumptions or that a particular effect was observed. The registry does not report its own sample-size justification. Sample-size illustrations are planning quantities, not observed power: they do not indicate the probability that the completed trial found a result, and they cannot replace the outcome estimate and its uncertainty. The numerical planning illustrations are not reported in the registry record.
The general notion of over-dispersion is relevant when count outcomes vary more than a statistical model assumes; in that setting, standard errors from a simple model may understate uncertainty. It is not a reported analysis issue for the primary PSQI endpoint, which is described as continuous, and no model diagnostics or over-dispersion assessment are reported. The registry lists no analyses, so the statistical model, covariate adjustments, assumptions checks, and handling of repeated measures are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome is measured at 8 weeks and 5 months, and the registry lists 6 outcome measures. It also names secondary measures of anxiety, depression, and health-related quality of life: the State-Trait Anxiety Inventory, the Center for Epidemiological Studies Depression Scale, and the Medical Outcome Study Short Form. Multiple outcomes and assessment times create more than one possible statistical comparison. In general, examining many comparisons without a prespecified strategy can increase the chance that at least one result appears notable by chance. The registry does not report a multiplicity adjustment, a testing hierarchy, or a prespecified primary time point for interpreting a single comparison.
The record does not report a statistical analysis plan, model specifications, covariate adjustments, or any completed analyses. It also does not report how missing observations were handled, whether participants were contacted after missed visits, or whether any imputation or sensitivity analyses were used. These omissions matter because missing outcomes can affect both the estimated group comparison and its uncertainty, particularly if the reasons for missingness differ between groups or relate to sleep outcomes.
The primary-outcome population description states that one participant who refused medication was excluded from the pharmacotherapy arm, and two participants who did not attend or attended fewer than 5 classes were excluded from MBSR. The record does not explain whether these participants had any outcome measurements, whether exclusions were decided before outcome data were reviewed, or whether all randomized participants were included in other analyses. The reported populations are thus informative about the stated endpoint population, but do not establish the handling of all missing data or the analysis population for every outcome.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Pharmacotherapy (Eszopiclone, 3mg) | 0 | 10 | 0.0% |
| MBSR | 0 | 20 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Pharmacotherapy (Eszopiclone, 3mg) | 7 of 10 |
| MBSR | 0 of 20 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Pharmacotherapy (Eszopiclone, 3mg) | MBSR |
|---|---|---|---|
| Taste disturbance | General disorders | 4 of 10 | 0 of 20 |
| Excessive sleepiness | Nervous system disorders | 3 of 10 | 0 of 20 |
| Headache | General disorders | 2 of 10 | 0 of 20 |
| Dizziness | Nervous system disorders | 2 of 10 | 0 of 20 |
| Reflux | Gastrointestinal disorders | 1 of 10 | 0 of 20 |
| Anxiety | Psychiatric disorders | 1 of 10 | 0 of 20 |
| Hypertension | Renal and urinary disorders | 1 of 10 | 0 of 20 |
| Strange dreams | Nervous system disorders | 1 of 10 | 0 of 20 |
The registry lists serious adverse events for 0 of 10 participants in the pharmacotherapy group and 0 of 20 participants in the MBSR group. It lists no serious adverse-event terms. These entries mean that no serious events are recorded in the registry for these groups; they do not establish that an event could not have occurred or that the treatments have no serious risks. With a pilot enrollment of 30, the counts provide limited information about uncommon events.
For other adverse events, the registry lists 7 of 10 participants in the pharmacotherapy group and 0 of 20 in the MBSR group. These are counts in the registry record, not a statistical comparison, and the record does not give event descriptions, severity categories for these entries, timing, or a formal analysis. The counts should not be interpreted as proving that the treatment groups differ in risk. The record’s death fields are not populated, so deaths are not reported in the registry record.
Safety counts and sleep-quality outcomes answer different questions. The absence of a recorded serious event is not evidence about the primary PSQI result, and the other adverse-event counts do not establish either efficacy or overall safety.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized pilot comparison of MBSR and eszopiclone was completed and identifies the PSQI as its primary sleep-quality measure. It describes measurements at 8 weeks and 5 months, and it explains the direction of the PSQI scale. These details allow readers to understand what outcome the trial intended to assess and how a reported score would be interpreted.
The record does not report the observed PSQI scores or an analysis comparing the groups. It therefore cannot show whether scores favored either strategy, how large any difference was, or how much uncertainty surrounded a comparison. A completed study without posted outcome estimates is not evidence of no difference. It is also not evidence that one intervention was better. Both claims would require results that are not reported in the registry record.
The study’s pilot purpose also limits the conclusions that can be drawn. A pilot can help assess whether study procedures are workable and can inform the design of a later trial. The record describes that intention, but does not report the feasibility results needed to judge recruitment, adherence, follow-up, or the acceptability of procedures. The sample-size assumptions described for planning illustrations should not be mistaken for observed power or evidence about the primary outcome.
The safety entries should be interpreted narrowly as registry counts. They report zero serious adverse events in both groups and different counts for other adverse events, but do not provide event details or a comparative statistical analysis. They do not answer the sleep-quality question, and they are not enough to establish a broad safety profile.
In short, the record describes the comparison and outcome framework, but leaves the central comparative result unresolved. Interpretation should stop at that boundary rather than filling in missing evidence from the study rationale, intervention descriptions, or the fact that the trial is marked completed.
13. Why This Trial Matters Statistically
This trial matters statistically because it illustrates the difference between a detailed study description and an interpretable outcome analysis. The registry identifies randomization, the treatment strategies, the PSQI, and its assessment times. Those elements define the intended comparison. Without group estimates and their uncertainty, however, readers cannot quantify the result or judge how compatible it is with a range of possible effects.
The pilot designation also highlights a distinct purpose for small studies. A pilot may be intended to examine study procedures and inform a later trial rather than provide a definitive comparison of outcomes. That purpose should guide interpretation of any estimates: a small pilot can yield imprecise results, and an observed estimate may be unstable. In this case, the registry does not report outcome estimates or feasibility metrics, so even those limited forms of evidence are unavailable in the record.
The treatment schedules make clear why the statistical question needs to be specified at each assessment time. MBSR included group instruction and subsequent home practice; eszopiclone was prescribed nightly and then as needed. The PSQI was to be assessed at 8 weeks and 5 months. A valid analysis would need to state how outcomes across time were handled and what comparison was primary. Those methods are not reported in the registry record.
Finally, the stated exclusions show why population definitions matter. The outcome populations differ from the enrolled group, and exclusion after assignment can affect the interpretation of a randomized comparison. Clear reporting of who was analyzed, how missing measurements were addressed, and how multiple outcomes were handled would be important for evaluating the study statistically. The record does not provide those analysis details.
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.
The central limitation is that the registry record does not report the primary PSQI results or any statistical analyses. Without estimates, measures of spread, confidence intervals, or p-values, the comparative sleep-quality outcome cannot be interpreted. The record also lists several outcome measures and two primary assessment times, but does not report how multiplicity was addressed or which time-specific comparison was intended to carry the main inference.
The enrollment was 30, and the outcome population description indicates 10 participants in the pharmacotherapy arm and 20 in MBSR before exclusions. The described exclusions reduce those stated populations to 9 and 18, respectively. Such limited group sizes constrain how precisely a comparison could be estimated, although the actual precision cannot be assessed without results. The record does not report a sample-size justification for the trial itself.
The primary-outcome population description excludes participants based on medication refusal, nonattendance, or attendance at fewer than 5 classes. The registry does not explain the rationale for these exclusions beyond the listed behaviors, whether they were prespecified, or how these participants were handled in other analyses. This raises an analysis-population question because outcomes among participants who remain may not represent outcomes among everyone assigned.
Other limitations include the absence of reported information about the randomization procedure, allocation concealment, who was masked, missing-data methods, and statistical models. The registry mentions actigraphy in the study description but does not report its results. The safety entries lack detailed event descriptions and the death fields are not populated. These gaps limit assessment of both the outcome analysis and the completeness of the reported safety information.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Mindfulness Versus Pharmacotherapy for Chronic Insomnia: A Pilot Study — NCT00515177.
- Registry record last updated 2013-03-29; status last verified 2013-02.
- Results first posted 2013-03-29.
- 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.
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18. Record Summary
The registry record describes a completed randomized, single-masked, parallel-group pilot study of MBSR versus eszopiclone for primary chronic insomnia. Actual enrollment was 30. MBSR involved 8-weeks of group instruction followed by home practice; the pharmacotherapy regimen used eszopiclone nightly for 8 weeks followed by as-needed use for 3 months.
The primary outcome was PSQI sleep quality at 8 weeks and 5 months. Higher scores indicate worse sleep quality, and scores greater than 5 indicate poor sleep. The outcome population description lists 9 participants in the pharmacotherapy arm and 18 in MBSR after the stated exclusions. Primary outcome estimates and statistical analyses are not reported in the registry record.
The record lists zero serious adverse events in both groups, other adverse events in 7 of 10 pharmacotherapy participants and 0 of 20 MBSR participants, and no serious-event terms. It does not report deaths. The trial’s stated pilot purpose was to assess feasibility and inform the design of a full-scale comparison, but feasibility results are not reported in the registry record.