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 Transcranial Magnetic Stimulation for Treatment of Insomnia (NCT02196025), a na na study. The primary outcome is Pittsburgh Sleep Quality Index ( PSQI).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02196025 |
| Phase | NA |
| Condition | Insomnia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 23 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Florida |
| Results posted | Yes |
2. Clinical Question
Population
People with primary insomnia were the intended population. The registry describes the primary outcome population as participants who completed the Pittsburgh Sleep Quality Index at baseline through week 3. The record does not report further eligibility criteria or demographic characteristics.
Intervention
Participants received sequential bilateral bifrontal low frequency repetitive transcranial magnetic stimulation. The intervention description specifies daily stimulation on weekdays for three weeks. The record also describes keeping a sleep diary and completing sleep and mood questionnaires.
Comparator
There was no separate comparator group. The study is described as open label and single group, with allocation and masking listed as not applicable and none, respectively. The intended comparison was within participants, between baseline and the end of treatment.
Primary question
The primary question was whether Pittsburgh Sleep Quality Index scores changed between baseline and the end of three weeks of stimulation. The registry defines the score range from 0, described as good sleep, to 30, described as disrupted sleep. It does not report the observed change.
The investigators’ stated hypothesis was that low frequency stimulation might exert an inhibitory effect on a hyperexcitable cortical state in people with chronic insomnia. That is the rationale recorded for the study, not a result. The available record does not establish whether the proposed mechanism was measured or tested.
3. Trial Design
The registry describes an open-label, single-group device study of transcranial magnetic stimulation for insomnia. The sponsor was the University of Florida. The record lists an enrollment of 23 and a completed status. The recorded start was 2015-05, and the primary completion date was 2021-07-21. The phase is listed as not applicable.
Participants were to receive sequential bilateral bifrontal low frequency stimulation on weekdays for three weeks. There was no randomized allocation and no separate control arm. The stated primary comparison was a participant’s Pittsburgh Sleep Quality Index score at baseline versus the score at the end of treatment. Because the design is open label, participants and those assessing outcomes were not masked according to the registry.
The brief summary describes the investigators’ intention to compare change in insomnia scores in 20 patients, whereas the registry’s enrollment figure is 23. These figures describe different parts of the record: the planned number in the summary and the listed enrollment. The record does not explain the difference, so it should not be interpreted as the number who completed treatment or contributed to the primary outcome.
The intervention description also mentions the Insomnia Severity Index, Montgomery Asberg Depression Rating Scale, and a sleep diary. The listed secondary outcome is the Insomnia Severity Index. The record identifies two outcome measures, but does not provide numerical outcome results or analysis entries. Details such as the exact stimulation settings, eligibility criteria, and handling of participants who did not complete the scheduled assessments 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.
Before assignment: Participants were only included in the study if they met all of the inclusion and no exclusion criteria. Participants must have had a primary diagnosis of insomnia in order to qualify.
Overall Study
| Stage | Transcranial Magnetic Stimulation |
|---|---|
| STARTED | 23 |
| COMPLETED | 19 |
| NOT COMPLETED | 4 |
Analysis population for the primary outcome, as defined in the registry: All participants who completed the PSQI at baseline through week 3
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: 19 people were analyzed for the baseline measure
| Characteristic | Unit | Transcranial Magnetic Stimulation |
|---|---|---|
| Participants analysed | 19 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 19 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 12 |
| Sex: Female, Male: Male | Participants | 7 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 2 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 4 |
| Race (NIH/OMB): White | Participants | 12 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 |
| Region of Enrollment: United States | participants | 19 |
6. Primary Endpoint
The registry lists the primary outcome as Pittsburgh Sleep Quality Index ( PSQI), measured over three weeks.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | score on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change in the Pittsburgh Sleep Quality Index (PSQI) score from baseline to the end of three weeks of stimulation. The PSQI is a score on a scale; the registry describes a minimum of 0 as good sleep and a maximum of 30 as disrupted sleep. The stated endpoint is the change in that score, not simply the score at one time point. The record does not specify the direction or sign convention used to calculate change.
A questionnaire score can provide a standardized way to describe participants’ reported sleep quality. Comparing a participant’s score at two time points focuses on change during the study period and can account descriptively for each participant’s own baseline. However, without a control group, a change over time cannot by itself distinguish an intervention effect from other explanations, such as natural fluctuation or changes in participants’ circumstances.
The endpoint population is described as all participants who completed the PSQI at baseline through week 3. The registry does not report how many participants met that definition, their scores, the mean change, or the variability of the changes. Therefore, the endpoint’s magnitude and precision cannot be evaluated from the posted outcome information. The endpoint’s designation as primary identifies its planned role in the study; it does not imply that results were reported.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry establishes the intended design and primary outcome, but it does not provide the numerical result for that outcome. The primary endpoint is mean change in PSQI score between baseline and the end of three weeks of stimulation, with standard deviation as the stated measure of dispersion. No mean change, standard deviation, confidence interval, or statistical test result is reported in the registry record. The record lists zero analyses. Consequently, it is not possible to describe the observed direction or size of change, or how precisely it was estimated.
The study is open label and single group. Its baseline-to-end comparison is a within-participant description, not a comparison with an untreated or alternative-treatment group. In general, repeated measurements can show whether scores differ over time among those assessed, but a single-group design cannot separate an intervention-associated change from time trends, expectation, other concurrent changes, or measurement variation. This design limitation remains even if a numerical change is eventually reported.
The enrollment figure is 23, while the brief summary describes an intention to compare scores in 20 patients. Neither figure tells how many participants completed both PSQI assessments. The endpoint population is defined by completing the measure at baseline through week 3, but its size is not reported in the registry record. Without that count and the outcome summaries, the amount of missing outcome information and the precision of any estimate are unknown.
The safety information records no participants with serious adverse events among 23 at risk, two with other adverse events among 23 at risk, and no deaths. These are descriptive counts for the treatment group; the record does not list serious adverse event terms. Such figures do not resolve the efficacy question, and the small single-group experience should not be read as a comparison of safety against another treatment.
The record’s planning assumptions describe an illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two hypothetical arms, and a normal approximation. Those are assumptions for a planning exercise, not evidence that the trial itself used a two-arm design. Because the outcome effect is not reported in the registry record, the planning illustration cannot be independently related to a posted result. Sample-size planning values, where displayed, are not observed power or a substitute for an outcome estimate and its uncertainty.
Overall, the available registry information supports a description of what the investigators intended to measure and how the intervention was delivered. It does not support a conclusion about the amount of change in sleep-quality scores or the precision of that change.
9. Statistical Methods Explained
The primary outcome is continuous: it is a score rather than a count of events or a time until an event. The registry specifies a mean and standard deviation for the PSQI change. In general, a mean describes the center of a set of numeric observations, while a standard deviation describes how spread out the observations are around that center. These summaries would help readers understand the typical change and the variability among participants, but neither is reported for the primary outcome in the registry record.
The endpoint compares baseline with the end of treatment for participants who completed the PSQI at both time points. In general, an analysis of within-participant change first expresses each participant’s follow-up score relative to that participant’s baseline score, then summarizes those changes across participants. This approach preserves the paired nature of repeated measurements. It is different from treating baseline scores and follow-up scores as if they came from unrelated groups. The registry does not report the calculation convention for change, the specific statistical test, or any adjustment for other variables.
What would a confidence interval describe?
In general, a confidence interval gives a range of values compatible with the data and the statistical method, expressing uncertainty around an estimate. A narrow interval indicates greater precision than a wide interval, though the interval does not remove design limitations or guarantee that an estimate is unbiased. No confidence interval for PSQI change is reported in the registry record, so the precision of the primary estimate cannot be assessed.
What does the single-group comparison allow?
The stated baseline-to-end comparison can describe change among participants measured at both time points. In general, without a separate comparator, it does not estimate the difference between receiving stimulation and receiving no stimulation or another intervention. The pre-treatment score is a reference measurement, not a concurrent control group. As a result, changes over time and other influences cannot be disentangled from the intervention using the design alone.
How should the planning assumptions be read?
The registry describes a sample-size planning illustration based on the observed effect. It specifies a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect expressed as a stated fraction of the observed effect. Those assumptions describe the planning illustration; they do not establish that this single-group trial had two arms or used those assumptions for its own design. The record does not report the trial’s sample-size justification or its own statistical plan. The observed effect needed to interpret the illustration is also not reported with the outcome results.
In general, a sample-size calculation estimates how many observations a hypothetical design would require under stated assumptions. It is not a measure of the probability that a completed study found a true effect, and it does not replace an estimate and its uncertainty. Planning values are especially dependent on the assumed effect size. When that effect is not documented alongside an outcome result, readers cannot evaluate the assumptions against the trial’s observed data. The illustration’s equal-allocation assumption is also distinct from the actual registry design, which is single group.
Why do analysis details matter?
A complete statistical account would ordinarily make clear which participants were included, how repeated scores and missing assessments were handled, how the change was defined, and what method was used to estimate it. These details affect interpretation because analysis choices can determine which observations contribute and how uncertainty is quantified. The registry identifies an endpoint population based on completing the PSQI from baseline through week 3, but does not report the count in that population or the handling of incomplete observations. It also lists no analyses. It is therefore not possible to verify a calculation or assess whether the reported outcome, if one exists elsewhere, follows a prespecified analysis.
General statistical concepts can clarify what the record would need to show, but they cannot fill in absent results. No test statistic, p-value, adjusted estimate, or confidence interval for the primary endpoint is reported in the registry record. Accordingly, statistical significance and precision cannot be inferred from the design description, enrollment figure, or planning assumptions alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies PSQI change as the primary endpoint and lists the Insomnia Severity Index as a secondary outcome. The intervention description also mentions a depression rating scale and a sleep diary. The record lists two outcome measures, but it does not provide numerical results for either listed measure or an analysis entry. The planned role and analysis of the other mentioned measures are not reported in the registry record.
When a study assesses multiple outcomes or makes multiple statistical comparisons, the chance of at least one apparently notable result can increase. In general, a statistical plan may specify which outcomes are primary and how multiplicity will be handled. The registry record does not report a multiplicity adjustment or another approach to this issue. With no posted analysis results, the role of any adjustment cannot be evaluated.
The primary endpoint population includes participants who completed the PSQI at baseline through week 3. The number who completed both assessments is not reported in the registry record. Nor are reasons for noncompletion, missing-data methods, or sensitivity analyses reported. These omissions prevent assessment of whether participants with missing measurements differed from those with complete measurements, and how such missingness might affect the estimate.
The record does not state whether all enrolled participants were included in an analysis population, whether any participants were excluded, or how deviations from the planned intervention were handled. Those analysis-population details are not reported in the registry record. They should not be inferred from the enrollment figure or the endpoint definition.
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 |
|---|---|---|---|
| Transcranial Magnetic Stimulation | 0 | 23 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Transcranial Magnetic Stimulation | 0 of 23 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Transcranial Magnetic Stimulation | 2 of 23 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Transcranial Magnetic Stimulation |
|---|---|---|
| Slight right eye twinge | Eye disorders | 1 of 23 |
| Headache | Nervous system disorders | 1 of 23 |
| Pain at stimulation sight | Skin and subcutaneous tissue disorders | 1 of 23 |
The registry reports safety counts for the transcranial magnetic stimulation group. Among 23 participants at risk for serious adverse events, zero were reported as affected; among 23 at risk for other adverse events, two were reported as affected. Deaths are listed as zero. No serious adverse event terms are listed.
These are descriptive counts in a single treatment group. They do not compare risks with a control group, since there was no separate comparator. The record does not provide event descriptions for the two participants with other adverse events, their severity, timing, or whether events led to treatment changes. Such details are not reported in the registry record.
A zero count for serious adverse events in this group means that none were recorded as affecting participants in the registry’s reported safety data; it does not establish that serious events are impossible or that the intervention has no risk. In general, safety counts are interpreted in light of the number observed, the duration of observation, completeness of reporting, and the study design. The registry figures do not by themselves support a comparative safety conclusion.
12. What the Result Does, and Does Not, Mean
The registry record describes a completed, open-label, single-group study that intended to assess change in PSQI score from baseline to the end of three weeks of stimulation. It gives the intervention schedule, endpoint definition, enrollment figure, and descriptive safety counts. It does not report the primary outcome estimate, its standard deviation, a confidence interval, a p-value, or any analysis entry. The amount and precision of change in sleep-quality scores therefore cannot be determined from the posted results.
A change in scores within a group, if reported, would describe the participants’ observed scores over time. In general, it would not alone show that stimulation caused the change, because the design has no concurrent control group and is open label. The baseline measurement is useful as a reference, but it cannot account for all changes that might occur over the same period without treatment.
The registry’s stated hypothesis is a rationale, not evidence that a proposed mechanism occurred. Likewise, a completed status does not establish that every planned outcome was reported or that a particular result was found. The record does not report enough outcome information to characterize a treatment effect or its uncertainty.
The safety entries describe reported events among participants in the single group, not a comparison with another intervention. The absence of reported serious adverse events in the listed group should be read as a count in this record, not as proof of no risk. Overall, the information supports describing the study’s question and design, but not a conclusion that the intervention did or did not change insomnia-related outcomes.
13. Why This Trial Matters Statistically
This trial illustrates why a clear distinction between design, endpoint, and result matters. The registry specifies a clinically interpretable measurement, PSQI change over the treatment period, and identifies the population intended to contribute to it. Those details help define what the investigators sought to measure. But without the numerical change and a measure of its variability, readers cannot assess the size or precision of the observed outcome.
The single-group, open-label structure also makes the choice of comparison central to interpretation. A baseline measurement provides a within-participant reference, but it is not a randomized or concurrent control. In general, this means a change over time cannot be attributed to the intervention with the same confidence as a well-reported comparative estimate could support. Statistical methods cannot repair the absence of a comparator.
The record also distinguishes planning assumptions from the trial design. A planning illustration that assumes equal allocation between two arms is not evidence of a two-arm trial, and sample-size planning is not observed power. This is a useful reminder that numerical planning outputs depend on assumptions and should not be mistaken for trial findings.
Finally, the record demonstrates the value of reporting analysis populations, missing-data handling, outcome estimates, and uncertainty. The enrollment figure alone does not reveal how many participants contributed paired endpoint data. Without these elements, readers cannot independently evaluate the primary result, its precision, or the potential effects of missing measurements. Statistical transparency requires not only a named outcome and design, but also interpretable results and their limitations.
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 most direct limitation of the available record is that it contains no numerical primary outcome result or analysis entry. The mean change, its standard deviation, and any interval estimate or test result are not reported in the registry record. The primary outcome’s direction and magnitude therefore cannot be characterized.
The design is open label and single group, with no separate comparator. This limits what a baseline-to-end change can establish, even if outcome data are available elsewhere. The record also does not report details of masking beyond listing none, or whether outcome assessment procedures were otherwise standardized.
The listed enrollment is 23, while the brief summary describes an intention to study 20 patients. The registry does not explain the difference. It also does not report how many participants completed both baseline and week 3 PSQI assessments, whether all enrolled participants received the planned intervention, or why any participants may have discontinued. The primary endpoint population is defined by completion, but its size and missing-data handling are not reported.
Further details about eligibility criteria, participant characteristics, stimulation settings, and the statistical analysis plan are not reported in the registry record. The record does not describe how change was calculated, how the named secondary outcome was analyzed, or whether multiplicity was addressed. These gaps limit evaluation of reproducibility and of the applicability of any result that might be reported elsewhere.
Safety reporting is also limited to aggregate counts, with no serious event terms and no descriptions of the other adverse events. The single-group design supplies no comparative safety estimate. These limitations concern the information and design described in the registry, and should not be resolved by inference.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Transcranial Magnetic Stimulation for Treatment of Insomnia — NCT02196025.
- Registry record last updated 2024-08-06; status last verified 2024-07.
- Results first posted 2024-08-06.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry record describes NCT02196025, titled “Transcranial Magnetic Stimulation for Treatment of Insomnia,” as a completed, open-label, single-group device study sponsored by the University of Florida. The recorded start was 2015-05, primary completion was 2021-07-21, and enrollment was 23.
The intervention was sequential bilateral bifrontal low frequency transcranial magnetic stimulation on weekdays for three weeks. The primary endpoint was change in PSQI score from baseline to the end of treatment among participants completing the measure through week 3. The record lists the Insomnia Severity Index as a secondary outcome.
Numerical outcome results, statistical analyses, and details about missing-data handling are not reported in the registry record. Safety entries list zero participants with serious adverse events, two with other adverse events, and zero deaths among 23 at risk for each adverse-event category.