Awareness Enhancement and Monitoring Device for Treatment of Trichotillomania: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Awareness Enhancement and Monitoring Device for Treatment of Trichotillomania (NCT01654523), a na phase 2 study. The primary outcome is Mean Change in Massachusetts General Hospital Hairpulling Scale Baseline to Post-treatment.

2. Clinical Question

In statistical terms, this is a within-group question: what change in the measured severity score was recorded over the treatment period among participants in the study? It is not, by design, a randomized estimate of how outcomes would differ between people receiving the device and otherwise comparable people not receiving it. A before-and-after change can describe participants’ score trajectories, but it does not by itself separate the intervention’s contribution from other influences on scores over time. The record identifies the intended measure and design, but not the numerical outcome needed to characterize the size or precision of the observed change.

3. Trial Design

This was a completed Phase 2 study sponsored by the University of Michigan. The registry record lists a start of 2005-01, primary completion in 2014-06, and enrollment of 33. The intervention was a device intended to enhance awareness and monitor hair-pulling behavior in the context of self-awareness training and general treatment for trichotillomania.

The design is described as an open trial with no randomization. The allocation entry is NA, masking is none, and the model is single group. These features mean the record does not describe random assignment to treatment conditions or blinded assessment. It also does not identify a parallel control group. The record does not report further design details such as recruitment procedures, treatment delivery, adherence monitoring, or the schedule of assessments beyond the stated baseline-to-post-treatment timeframe.

The primary outcome was a continuous measure: mean change in the Massachusetts General Hospital Hairpulling Scale from baseline to post-treatment, typically over 9 weeks. The scale’s total score ranges from 0 (none) to 28 (severe), and the listed change is calculated as baseline score minus score after treatment. The outcome description therefore specifies both the measure and the direction used to calculate change, but the registry record does not report the observed change, standard deviation, or other inferential results.

Enrollment is not necessarily the same as the number analyzed for an outcome. The number of participants included in the primary analysis, and the handling of participants without post-treatment scores, are not reported in the registry record. The safety figures list a different at-risk count; the record does not explain its relationship to enrollment. Details of the study’s statistical plan, including any prespecified analysis methods or sample-size justification, 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.

6. Primary Endpoint

The registry lists the primary outcome as Mean Change in Massachusetts General Hospital Hairpulling Scale Baseline to Post-treatment, measured over Baseline to post treatment; typically over 9 weeks.

The primary endpoint is mean change in the Massachusetts General Hospital Hairpulling Scale from baseline to post-treatment, typically over 9 weeks. The scale measures trichotillomania severity, with total scores ranging from 0 (none) to 28 (severe). The registry defines change as the baseline score minus the score after treatment. Under that convention, a positive change corresponds to a baseline score greater than the post-treatment score; a negative change corresponds to a post-treatment score greater than the baseline score.

A continuous score can describe severity across a range rather than reducing participants to a simple category. Reporting a mean change can summarize the average direction and magnitude of within-participant score changes, while a standard deviation describes how dispersed individual values are around that mean. Those are different kinds of information: the mean describes the group’s average change, and the standard deviation describes variation among observations.

The record names this endpoint but does not give the numerical mean change, its standard deviation, a confidence interval, or a p-value. It also does not report the number of participants contributing to the endpoint or detail how missing baseline or post-treatment scores were handled. Consequently, the measure and its intended interpretation can be described, but the observed outcome and its precision cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The endpoint is continuous because it is a numerical scale score, and the primary summary is a mean change. In general, a mean is calculated by combining observed values and dividing by the number of values included. Here, the relevant values would be participants’ baseline-to-post-treatment score changes. The registry defines each change as baseline score minus post-treatment score. The mean would summarize the average change in the analysis group, but it would not show whether every participant changed in the same direction or by a similar amount.

What does the standard deviation describe?

The standard deviation is a measure of spread among observed values. In this context, it would describe how much individual participants’ changes varied around the mean change. A small or large standard deviation cannot be inferred from the mean alone, and neither can be determined without the reported results. The outcome is described using a mean and standard deviation, but their numerical values are not reported in the registry record.

A standard deviation should not be confused with a standard error or a confidence interval. The standard deviation concerns variation among participants’ measurements. A standard error concerns the sampling uncertainty of an estimated statistic, and a confidence interval conveys uncertainty around an estimate under a particular method and assumptions. General statistical interpretation often considers the estimate together with its uncertainty, rather than treating a point estimate as exact. The registry record does not report a confidence interval or standard error for this endpoint.

What would a confidence interval add?

In general, a confidence interval gives a range of values compatible with the observed data under the specified statistical procedure. Its width reflects precision under that procedure: a wider interval indicates less precision than a narrower interval. It is not a range containing a fixed proportion of individual participant outcomes, nor does it remove limitations of the study design. For a single-group change, an interval could describe uncertainty about the average change, but it would not create a randomized comparison or account automatically for unmeasured influences on change. No interval is reported in the registry record.

How does the single-group design affect interpretation?

A within-group analysis compares measurements from the same participants at different times. This can describe change over time in the observed group. A randomized comparison instead uses groups assigned to different conditions to estimate a between-group contrast, subject to its design and analysis assumptions. Because this study is described as open, single group, and without randomization, the registry record does not support a randomized treatment-versus-control contrast. General sources of change over time can include factors unrelated to the intervention, and open assessment can leave outcomes more vulnerable to expectations or measurement influences. These are general methodological considerations, not documented events in this trial.

The outcome definition also matters. Since change is baseline minus post-treatment, reversing the subtraction would reverse the sign of every change value. Interpretation should therefore retain the registry’s stated convention. The score range from 0 (none) to 28 (severe) provides context for what the scale measures, but it does not tell how large a particular change is in clinical terms. The registry record does not report a threshold for interpreting change or a minimal important difference.

What can a p-value establish?

In general, a p-value describes how unusual data at least as incompatible with a specified null hypothesis would be if that hypothesis and the statistical model were true. It does not measure the probability that the null hypothesis is true, the probability that a result is due to chance, or the clinical importance of an effect. Its interpretation depends on the analysis, assumptions, and question being tested. A p-value is not reported in the registry record, and the statistical plan and tested hypothesis are not reported in the registry record. No conclusion about statistical significance can therefore be drawn from the registry information.

Statistical significance and practical importance are distinct. A small p-value, in general, does not establish that a change is important to participants, while a non-significant result does not prove there is no change. Assessment of magnitude and precision requires the estimate and its uncertainty; interpretation of importance also requires an appropriate clinical context. The registry record does not provide the outcome values or a clinical threshold with which to make those assessments.

Why do missing observations matter?

In general, participants may lack a post-treatment measurement for a range of reasons, and the analysis can be affected if the observed participants differ from those without measurements. The number included in the endpoint analysis and the method used to address missing data are important for understanding a before-and-after estimate. The registry record does not report the analysis population, the completeness of endpoint measurements, or a missing-data method. It is therefore not possible to determine how missing observations may have affected the reported analysis.

Finally, a sample-size calculation for planning is not an observed outcome and is not evidence that a study was adequately powered. The registry record does not report a trial-specific sample-size justification. A planned sample size, if described elsewhere, would depend on assumptions and would not substitute for the observed estimate, its variability, or an interval describing uncertainty. The reported enrollment alone does not establish the precision of the primary outcome estimate.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Awareness Enhancement and Monitoring Device")
n   <- c(19)
m   <- c(6.695)
sp  <- c(5.505)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Awareness Enhancement and Monitoring Device  19  6.695  5.505  4.042  9.348

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one primary outcome measure and one analysis. That description does not establish whether other outcomes or analyses were considered in the study, or whether the listed outcome was the only analysis conducted. A multiplicity adjustment, a prespecified hierarchy of hypotheses, and details of the statistical plan are not reported in the registry record. In general, testing multiple hypotheses can increase the chance of obtaining at least one apparently notable result, so the number and relationship of analyses matter when interpreting inferential results. No p-value is reported for the primary endpoint, and the available record does not permit assessment of any adjustment for multiple testing.

Missing-data information is also not reported. The registry record does not state how many enrolled participants had baseline and post-treatment scores, whether any measurements were missing, why measurements might be absent, or how missing values were handled. In general, a complete-case analysis uses participants with the measurements required for the analysis, while other approaches may use additional assumptions to account for missing outcomes. These methods can yield different estimates, and their suitability depends on the missingness process and analysis assumptions. No particular approach should be attributed to this study based on the registry record.

The primary analysis population is not reported in the registry record. Enrollment is listed as 33, but the outcome-analysis denominator is not stated. The safety summaries list 20 people at risk; the record does not specify how this group relates to enrolled participants or the primary endpoint population. The registry record also does not report whether participants were analyzed according to an intention-to-treat principle, a per-protocol definition, or another population rule. These omissions limit assessment of participant flow, representativeness of the analysis group, and the impact of incomplete data.

12. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry record lists the Treatment Arm with 20 people at risk for serious adverse events and 0 affected. It also lists 20 people at risk for other adverse events and 0 affected. These are the posted counts for the categories shown; they should not be interpreted as a complete description of all possible safety outcomes or as evidence beyond the registry’s recorded information.

The record does not explain why the at-risk count is 20 when enrollment is listed as 33, nor does it describe the timing or duration of safety observation. The deaths entry is null, so a death count is not reported in the registry record; null should not be read as a reported count of zero. No top serious adverse-event terms are listed. The record does not provide further detail about event definitions, collection procedures, severity grading, or attribution to the device.

In general, an adverse-event count depends on the participants observed, the period of observation, and the way events were collected and classified. A zero in a listed count means no affected participants are recorded for that category in the posted results; it does not by itself establish that no events occurred outside the recorded scope. The safety figures should therefore be read as registry summaries with limited accompanying detail.

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

The record establishes that this was a completed Phase 2, open, single-group study of an awareness enhancement and monitoring device for trichotillomania. It identifies the primary outcome as mean change in the Massachusetts General Hospital Hairpulling Scale from baseline to post-treatment, typically over 9 weeks, using baseline minus post-treatment as the change definition. It also lists enrollment of 33 and provides limited adverse-event counts for the Treatment Arm.

The record does not report the numerical primary outcome. The mean change, standard deviation, confidence interval, and p-value are not reported in the registry record. As a result, the direction and magnitude of the average score change, variation among participants, and statistical precision cannot be assessed from the recorded information. The scale range and change convention explain how an outcome would be read, but they do not reveal what outcome was observed.

The study design also defines what the result could mean. A single-group before-and-after study can describe change in its participants over time. Without a randomized comparator, it cannot isolate the intervention’s effect from other potential influences on change. This is a general limitation of the design, not evidence that any particular alternative explanation occurred in this study.

The safety summary records 0 participants affected in the serious adverse-event category and 0 in the other adverse-event category, each among 20 at risk. The record does not report a death count, and it does not explain the safety denominator or observation period. These figures should be interpreted within that limited reporting context.

Overall, the registry record supports a description of the study’s purpose, design, endpoint, and posted safety counts. It does not support a conclusion about the size or precision of the primary outcome, a causal treatment comparison, or a broader safety profile. Those distinctions keep the interpretation aligned with what the registry record actually documents.

14. Why This Trial Matters Statistically

This study raises several useful statistical questions because its stated endpoint is a continuous change score in a single-group, open design. The scale provides a structured way to measure severity, and the baseline-to-post-treatment definition makes clear how a change value is oriented. For readers, retaining that sign convention is essential: baseline minus post-treatment is not interchangeable with post-treatment minus baseline.

The design also illustrates the distinction between describing change and estimating a causal contrast. A within-group mean change answers a descriptive question about the participants observed. A randomized comparison is designed to support a different question about outcomes under alternative treatment assignments. Since randomization and a comparator are not described in this trial, those questions should not be conflated.

Reporting an estimate together with its variability and uncertainty is important for continuous outcomes. A mean alone would not describe how consistently participants changed, while a standard deviation alone would not identify the average direction or size. A confidence interval would add information about precision under its method and assumptions. The registry record names the endpoint and its dispersion measure, but does not report their values, which makes this a clear example of how a defined outcome is not the same as an interpretable numerical result.

The record also illustrates why enrollment and analysis denominators should be distinguished. Enrollment is 33, while the adverse-event summaries list 20 people at risk. The record does not report the primary endpoint analysis count or explain the safety count. Without those details, readers cannot determine how the analyzed participants relate to all enrolled participants.

These points matter for statistical reading without implying a judgment about the device. The design, outcome definition, analysis population, uncertainty, and completeness of reporting all shape what can be concluded. Here, the stated question is identifiable, but the missing numerical endpoint results prevent evaluation of the observed change.

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 main limitation for interpreting the primary outcome from the registry record is that its numerical result is not reported. The mean change and standard deviation are not reported in the registry record, and neither are a confidence interval or p-value. The direction, size, variability, and precision of the observed endpoint therefore cannot be assessed.

The design is open, single group, and without randomization. No concurrent comparator is described. A within-group baseline-to-post-treatment change cannot, by itself, distinguish an intervention-associated change from other influences over time. The record does not report whether outcome assessment was independent or whether any steps were taken to reduce assessment or expectation effects.

Enrollment is listed as 33, but the number analyzed for the primary endpoint and the handling of missing measurements are not reported in the registry record. This prevents assessment of participant flow and the relationship between enrollment and the endpoint estimate. The safety summaries list 20 people at risk, with no explanation of how that group relates to enrollment or outcome analysis. The observation period for safety reporting and a death count are not reported in the registry record.

Additional details that would aid interpretation are not reported in the registry record, including the statistical analysis plan, a trial-specific sample-size justification, eligibility criteria, participant characteristics, treatment delivery details, adherence, and a clinical threshold for meaningful scale change. These are limits on the available registry description; they should not be taken as evidence that a particular procedure was or was not used. The endpoint and broad design can be identified, but substantial information needed to assess the result is absent.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Awareness Enhancement and Monitoring Device for Treatment of Trichotillomania — NCT01654523.
• Registry record last updated 2016-07-22; status last verified 2016-06.
• Results first posted 2016-07-22.
• 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

This completed Phase 2 study, sponsored by the University of Michigan, investigated an awareness enhancement and monitoring device for trichotillomania. The registry record lists enrollment of 33, a start of 2005-01, and primary completion in 2014-06. The design is open, single group, and without randomization or masking.

The primary endpoint was mean change in the Massachusetts General Hospital Hairpulling Scale from baseline to post-treatment, typically over 9 weeks. The scale ranges from 0 (none) to 28 (severe), and change is defined as baseline score minus post-treatment score. The numerical endpoint result and its uncertainty are not reported in the registry record.

Safety summaries list 20 people at risk and 0 affected for serious adverse events, and 20 at risk and 0 affected for other adverse events. The death count and the relationship between the safety denominator and enrollment are not reported in the registry record.