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 Deep Brain Stimulation Effects on Weight Change and Metabolic Rate (NCT01933113), a na na study. The primary outcome is Change in Metabolic Rate.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01933113 |
| Phase | NA |
| Condition | Obesity |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 3 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Allegheny Singer Research Institute (also known as Allegheny Health Network Research Institute) |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned people with severe obesity who had prior placement of a lateral hypothalamic area deep brain stimulation electrode under a previous study protocol. The registry record says those patients met the enrollment criteria for this study. It lists an enrollment of 3. Further participant characteristics are not reported in the registry record.
Intervention
The intervention was deep brain stimulation of the lateral hypothalamic area. The study description says testing was intended to determine optimal stimulation settings, with a single-arm description focused on settings for maximum resting metabolic rate. The specific settings and how they were selected are not reported in the registry record.
Comparator
There was no separate control or comparator group listed. The study is recorded as single-group, with allocation marked NA and masking listed as none. The intervention settings may have been varied during testing, but the details of those settings and any formal within-participant comparisons are not reported in the registry record.
Primary question
The primary outcome was titled “Change in Metabolic Rate.” The registry describes measuring metabolic rate and percentage change in the specified parameters during testing. In practical terms, the study sought to characterize metabolic-rate changes while assessing lateral hypothalamic area stimulation settings. The registry record does not report the measured values, an estimated effect, or a statistical test, so it does not establish the size or precision of any change.
3. Trial Design
This was a completed, single-group device study of deep brain stimulation of the lateral hypothalamic area in people with severe obesity. The registry lists enrollment as 3, allocation as NA, masking as none, and phase as NA. With no separate control group listed, the design does not support a direct randomized comparison between stimulation and a control intervention.
The study description says participants had prior placement of a lateral hypothalamic area electrode in accordance with a previous study protocol. The study’s stated goal was to determine optimal stimulation settings. Its single-arm description refers to stimulation for maximum resting metabolic rate. The record states that metabolic weight, temperature, and resting metabolic rate were measured at different settings during inpatient days 1-4, and that each subject had one week of testing. The detailed sequence of settings and measurement procedures is not reported in the registry record.
The study started in 2013-08 and had a primary completion date of 2015-07; its status is recorded as completed. The sponsor is Allegheny Singer Research Institute, also known as Allegheny Health Network Research Institute. The outcome is associated with testing at Pennington Biomedical Research Center. The record does not report a fuller account of recruitment, the number completing testing, or the duration of participation for each person.
These design features matter when interpreting any apparent change. In a single-group study, the observed outcome is not contrasted with a concurrently randomized control group. Variation over time, measurement conditions, and participant characteristics therefore cannot be separated from an intervention effect using a controlled between-group comparison. The registry record does not describe a different strategy for addressing those issues.
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 | Single arm |
|---|---|
| STARTED | 3 |
| COMPLETED | 2 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | Single arm |
|---|---|
| Fractured nonfunctioning lead. | 1 |
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 | Single arm |
|---|---|---|
| Participants analysed | 3 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 3 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 1 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 3 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 3 |
| BMI | Participants | 2 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Metabolic Rate, measured over One week of testing for each subject..
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Standard Deviation |
| Unit | percentage of increase in REM and SEE |
| Endpoint classification | not reduced to a single comparison |
The primary outcome is titled “Change in Metabolic Rate.” Its description says metabolic rate would be measured and percentage change in the specified parameters assessed. The listed unit is “percentage of increase in REM and SEE.” Those terms are not expanded in the registry record, so their intended definitions should not be inferred. Resting metabolic rate is mentioned in the intervention description as a measure taken at different settings and as the target for selecting settings.
Metabolic-rate measurements can serve as physiological indicators of energy expenditure. In general, measuring such an outcome can help characterize how a physiological measure varies during an intervention. That general rationale does not by itself establish that a measured change is caused by the intervention or that it corresponds to a change in body weight or health.
The record gives a timeframe of one week of testing for each subject and identifies standard deviation as the dispersion measure, with the outcome parameter marked as median. It does not report a numerical median, standard deviation, individual measurements, or a confidence interval. The measurement device, calculation formula for percentage change, reference condition, and timing of each measurement are not reported in the registry record. Without those details and the outcome values, the endpoint’s magnitude and precision cannot be evaluated from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a study intended to assess metabolic-rate changes during lateral hypothalamic area deep brain stimulation, but it does not report a numerical primary outcome result. There is no posted median change, standard deviation, confidence interval, or test result in the record. The number of analysis entries is listed as 0. Consequently, the registry information does not show the direction, size, or statistical precision of an observed metabolic-rate change.
The study’s enrollment is listed as 3. Even if outcome values were available, a result from a small single-group study would need to be interpreted as descriptive evidence from the participants measured, not as a controlled estimate of what would have happened without stimulation. There is no separate comparator group in the design information. The record also does not describe a prespecified statistical model or a method for accounting for repeated measurements across settings.
The primary outcome is identified as a median with standard deviation. In general, the median describes the middle of a set of observations and is less affected by extreme values than the mean. Standard deviation describes spread around the mean in the conventional formulation. Reporting these together can be less straightforward to interpret than a median accompanied by a measure of spread designed around the median. Here, no numerical values are posted, so even a descriptive assessment of central tendency and variability is not possible.
A statistical test or confidence interval would not, on its own, resolve the study’s design limitations. In general, a confidence interval conveys the uncertainty around an estimated effect under the statistical method used; a narrower interval indicates greater precision under that method. No interval or underlying estimate is reported in the registry record. A p-value is also not reported, and its absence cannot be interpreted as evidence for either a change or no change.
The study description states a goal of determining optimal stimulation settings, but no setting-specific results or method for selecting an optimum are reported. The record also does not say whether the measurements were analyzed individually, combined across settings, or compared with a baseline condition. Therefore, no conclusion about which setting produced a particular metabolic response can be drawn from the registry record.
Planning calculations based on an observed effect, where presented, are not observed power and do not substitute for outcome estimates. The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with effects specified as fractions of the observed effect. The registry record does not give the numerical observed effect or the actual calculation outputs. These assumptions describe an illustration for planning a future comparison, not a result of this single-group study.
9. Statistical Methods Explained
The registry record characterizes this as a single-group study, with allocation marked NA and no masking. These labels describe the recorded design; they do not establish that every feature of the conduct or analysis is fully documented. No randomized comparison is listed. General statistical interpretation of an intervention effect is stronger when the groups being compared are made comparable by design, because a concurrent control can help distinguish intervention-related change from other influences. That type of comparison is not available in the recorded design.
What does a single-group design allow?
In general, a single-group study can describe measurements made during or after an intervention and can explore variation across intervention conditions. If measures are repeated within a person, within-person comparisons may be informative, but their interpretation depends on the timing, order, stability of conditions, and analysis method. Those details are not reported in the registry record. The description says measurements were taken at different settings, but it does not specify a comparison procedure or model for those measurements. It is therefore not possible to determine how repeated observations were treated statistically.
How should the median and standard deviation be understood?
The primary outcome is labeled as a median with standard deviation. In general, a median is a measure of central location: after observations are ordered, it marks the central value. The standard deviation expresses spread around the mean and is commonly used when describing data in relation to that mean. These statistics answer related but different questions. A median may be useful when observations are skewed or include unusually high or low values, while the standard deviation is most directly interpretable alongside a mean under familiar distributional assumptions. The registry gives no values or additional explanation for this pairing, so it is not possible to assess the observed distribution or the appropriateness of the reported summary.
The record lists the outcome’s unit as percentage of increase in REM and SEE. In general, a percentage change requires a reference value and a rule for calculating the change. The baseline or reference condition and the calculation method are not reported in the registry record. REM and SEE are not expanded there. No interpretation should assume what those abbreviations mean or how the percentage was calculated.
What do uncertainty measures contribute?
In general, a confidence interval gives a range of values compatible with an estimate under the chosen statistical method and assumptions. It is useful for judging precision, but it is not a guarantee that the true effect lies within the interval, and it does not repair limitations in study design. No confidence interval or numerical estimate is reported for the primary outcome. A p-value, which in general quantifies how unusual data would be under a specified null model, is also absent. Without a stated model and result, statistical significance cannot be assessed.
The registry lists 0 analysis entries. This does not provide a statistical analysis plan. The selected model, treatment of repeated measurements, handling of missing observations, and procedures for comparing settings are not reported in the registry record. Nor does the record report whether analyses were adjusted for any covariates. These omissions prevent an independent appraisal of the analysis choices and their assumptions.
How do planning calculations differ from trial results?
General sample-size calculations estimate the amount of information a future study may need under assumptions about an effect, variability, significance level, allocation, and statistical method. The stated planning illustration uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes effects as a fraction of the observed effect. For time-to-event calculations, the stated convention is total events; for other calculations, the convention is participants per arm. These are planning assumptions, not observed findings from this single-group study. A planning calculation is not observed power, and it cannot establish whether the primary endpoint changed.
The planning illustration is described as based on the observed effect, but the registry record does not report a numerical primary result or numerical planning outputs. It is therefore not possible to judge the size of the effect used, whether the assumptions are suitable, or the resulting precision. More generally, planning values should be understood conditionally: changing assumptions about effect size or variability can change the amount of information needed. No alternative assumptions or sensitivity analyses are reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies one primary outcome measure, titled “Change in Metabolic Rate,” and lists 0 analysis entries. It does not report a multiplicity adjustment or explain whether additional outcomes or comparisons were analyzed. The intervention description refers to measurements at different settings, but the record does not say how many setting comparisons were planned or whether any formal comparisons were made.
In general, testing multiple hypotheses can increase the chance of obtaining an apparently notable result by chance if no adjustment or prespecified testing strategy is used. An adjustment is not necessarily required for every analysis; the relevant issue is whether the analysis plan identifies the questions and controls interpretation appropriately. The registry record does not report such a plan, so the approach to multiplicity is not reported in the registry record.
Missing-data methods are also not described. The record does not report whether all scheduled measurements were obtained, how unavailable measurements were handled, or whether any participants were excluded from an analysis. The enrollment entry is 3, but the number contributing to the primary outcome analysis is not reported in the registry record. No analysis population is defined, such as a population based on enrollment or completion of testing.
These are reporting gaps, not evidence that data were missing or that a particular method was used. Without analysis-population definitions, missing-data handling, and a statistical plan, the completeness and reproducibility of the outcome analysis cannot be assessed from the registry record.
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 |
|---|---|---|---|
| Single arm | 0 | 3 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Single arm | 0 of 3 |
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 |
|---|---|
| Single arm | 0 of 3 |
The registry safety fields list 3 people at risk for serious adverse events and 0 affected. For other adverse events, the fields also list 3 at risk and 0 affected. Deaths are listed as 0, and no serious adverse-event terms are listed.
These figures describe what is entered in the registry safety fields; they should not be read as proof that no adverse experiences of any kind occurred. The record does not provide event-level detail, a definition of the observation period, or information about how events were collected and classified. It also does not report the severity or timing of other non-serious events beyond the listed count of affected participants.
Zero affected in a small study is a limited observation, not evidence that the intervention has no safety risks. The safety figures do not establish how often an event might occur in a larger or different population. They should be interpreted alongside the study’s small enrollment and the incomplete event-detail reporting, without treating the counts as a comprehensive safety profile.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed single-group study was conducted to assess lateral hypothalamic area deep brain stimulation and metabolic-rate measurements in people with severe obesity. It lists an enrollment of 3 and describes testing at different stimulation settings, including a goal of identifying settings for maximum resting metabolic rate. It also identifies a primary outcome and its intended summary format.
The record does not report the primary outcome values, a comparison across settings, or an inferential analysis. Thus, it does not show how much metabolic rate changed, whether it increased or decreased, how variable the measurements were, or how precisely any change was estimated. The absence of a reported result is not evidence that there was no change. It means the registry record does not provide the information needed to judge the result.
The study is not a randomized comparison and lists no separate control group. Even if a change had been reported, a single-group observation would not by itself establish that stimulation caused the change. Other influences and the measurement conditions could contribute; the registry record does not describe a design or analysis that separates those possibilities.
The study’s stated purpose of determining optimal settings should also be distinguished from evidence that a setting was identified. Setting-specific results and the selection method are not reported. The record therefore cannot support a conclusion about which setting was optimal or whether any setting produced a clinically meaningful change.
Finally, metabolic-rate measurements are physiological outcomes. In general, a change in such a measure is not automatically equivalent to a change in body weight or to a patient-important benefit. The registry record does not report those outcomes or establish a relationship between them. The appropriate interpretation is limited to the study objective and the available design information, not a claim about treatment benefit or lack of benefit.
13. Why This Trial Matters Statistically
This trial is statistically notable because it asks a physiological question in a highly specialized setting while using a single-group design and a small enrollment. The record lists 3 participants and describes measurements across different stimulation settings. Such data may be relevant to characterizing an early research question, but the strength of any conclusion depends on complete reporting of measurements, comparisons, and uncertainty. The numerical primary result and analysis are not reported in the registry record.
The distinction between a study objective and an estimated result is especially important. A goal of finding settings associated with maximum resting metabolic rate is not itself evidence that a maximum was observed, that settings differed, or that the difference was precise. Those questions require setting-specific data and a transparent method for comparing them, neither of which is reported.
More broadly, this record illustrates why statistical interpretation depends on both design and reporting. A single-group study cannot provide the same controlled contrast as a randomized comparison. A median and standard deviation label does not reveal the distribution or the size of an effect when no values are posted. Likewise, a planning calculation cannot replace observed outcome estimates. Each piece of information serves a different purpose, and none can stand in for the missing primary result.
The study remains informative as a record of the question, intervention, and intended measurement approach. Its statistical contribution cannot be judged from the registry entry alone because effect estimates, uncertainty, analysis methods, and setting comparisons are absent. That limitation is not a verdict on the study’s conduct; it describes what the registry record allows readers to evaluate.
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 consequential limitation for interpretation is the absence of a numerical primary outcome result. The registry names the endpoint and its summary format but does not report the estimate, variability, or uncertainty. The number of analysis entries is listed as 0. This prevents assessment of the magnitude, direction, and precision of the measured change.
The design is recorded as single-group, with no separate comparator. The record describes measurements at different settings but does not give the settings, their order, or a formal comparison method. Without those details, it is not possible to determine how setting-related variation was distinguished from time or measurement effects. The allocation and masking fields are recorded as NA and none, respectively.
The registry does not define the analysis population or state how missing measurements were handled. It lists an enrollment of 3, but does not report the number with complete primary outcome data. The primary endpoint’s listed unit includes REM and SEE, but those abbreviations and the percentage-change calculation are not explained. Measurement timing and the reference condition for the change are also not described in the record.
Generalizability is constrained by the small enrollment and the specific eligibility context of prior lateral hypothalamic area electrode placement. Further participant characteristics are not reported. The record does not supply enough analysis detail to evaluate the effect of individual observations, the handling of repeated measures, or the role of potential confounding. These limitations mean that the registry entry supports a description of the study’s purpose and design, but not an appraisal of an estimated treatment effect.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Deep Brain Stimulation Effects on Weight Change and Metabolic Rate — NCT01933113.
- Registry record last updated 2025-10-27; status last verified 2018-12.
- Results first posted 2019-01-08.
- 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
NCT01933113 is a completed, single-group device study of deep brain stimulation of the lateral hypothalamic area for severe obesity. The registry lists enrollment of 3, no masking, allocation marked NA, and phase marked NA. The study started in 2013-08, with primary completion in 2015-07. Its stated goal was to determine optimal stimulation settings in people with prior placement of a lateral hypothalamic area electrode.
The primary outcome is “Change in Metabolic Rate,” with a timeframe of one week of testing for each subject. The registry describes testing at different settings and labels the summary parameter as median with standard deviation. It does not report numerical outcome results or analysis entries. Safety fields list 0 affected by serious adverse events, 0 affected by other adverse events, and 0 deaths among the listed group.