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 Cleansing Device for the Treatment of Scalp and Hair Conditions (NCT05319444), a randomized na study. The primary outcome is Change in Adherent Scalp Flaking Scale (ASFS).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05319444 |
| Phase | NA |
| Condition | Dandruff, Seborrheic Dermatitis, Hair Loss |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 2 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Minnesota |
| Results posted | Yes |
2. Clinical Question
Population
The registry describes people with dandruff, seborrheic dermatitis, hair loss disease, and healthy scalps. The planned arm descriptions divide these groups by condition and by whether participants would receive one or three device treatments. The registry record reports enrollment of 2, but does not report which conditions or treatment groups those participants entered.
Intervention
The intervention was an off-brand Waterpik® device intended to massage and cleanse the scalp. The study objective was to evaluate scalp health after its use. Arm descriptions include one-treatment and three-treatment schedules, with one in-person follow-up described for each.
Comparator
The registry record identifies a randomized, parallel design and describes groups receiving different treatment schedules or having different scalp conditions. A single conventional control group or a specific head-to-head comparator is not reported in the registry record. The allocation procedure and the identity of the person or people masked are also not reported in the registry record.
Primary question
The planned primary question concerned change in the Adherent Scalp Flaking Scale (ASFS) at 4 weeks. The scale rates flaking in 8 defined scalp areas, with area scores from 0 to 10 and a total score from 0 to 80. The registry says this outcome was not collected or analyzed because the study was abandoned before the outcome data could be obtained. Therefore, the record does not answer whether scores changed or whether changes differed among groups.
3. Trial Design
The registry classifies the study as randomized, single-masked, and parallel, with phase listed as not applicable. It names the University of Minnesota as sponsor and lists dandruff, seborrheic dermatitis, and hair loss as conditions. The study objective was to evaluate scalp health after use of an investigational off-label scalp-massaging and cleansing device. The listed device intervention is an off-brand Waterpik®.
The arm descriptions cover participants with healthy scalps, dandruff, seborrheic dermatitis, or hair loss disease. For each condition with multiple described schedules, the record includes a one-treatment group and a three-treatment group; hair loss disease, dandruff, and seborrheic dermatitis each have both schedules, while healthy scalps also have both. These are descriptions of intended groups, not evidence that participants were enrolled in every group. The record reports enrollment of 2, and does not say how those participants were distributed among the described groups.
Each arm description includes one in-person follow-up. The planned primary outcome timeframe was 4 weeks. The registry status is terminated, and it states that the study was abandoned before primary outcome data could be obtained. The reason for termination, details of the randomization process, the masking arrangements, and any departures from the described treatment schedules are not reported in the registry record. A conventional untreated or placebo comparator is not identified in the registry record, so the intended statistical contrasts cannot be reconstructed from the arm labels alone.
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.
Only the first 6 of 8 groups are shown.
Overall Study
| Stage | Healthy Scalp and One Treatment | Healthy Scalp and Three Treatments | Dandruff and One Treatment | Dandruff and Three Treatments | Hair Loss Disease and One Treatment | Seborrheic Dermatitis With One Treatment |
|---|---|---|---|---|---|---|
| STARTED | 0 | 1 | 0 | 0 | 1 | 0 |
| COMPLETED | 0 | 0 | 0 | 0 | 0 | 0 |
| NOT COMPLETED | 0 | 1 | 0 | 0 | 1 | 0 |
Reasons for not completing this period:
| Reason | Healthy Scalp and One Treatment | Healthy Scalp and Three Treatments | Dandruff and One Treatment | Dandruff and Three Treatments | Hair Loss Disease and One Treatment | Seborrheic Dermatitis With One Treatment |
|---|---|---|---|---|---|---|
| Study abandoned | 0 | 1 | 0 | 0 | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: This outcome was not collected or analyzed because the study was abandoned before these outcome data could be obtained. Therefore, no data are available to report for these outcomes.
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: No participants enrolled in the six arms with zero participants
Only the first 6 of 9 groups are shown.
| Characteristic | Unit | Healthy Scalp and One Treatment | Healthy Scalp and Three Treatments | Dandruff and One Treatment | Dandruff and Three Treatments | Hair Loss Disease and One Treatment | Seborrheic Dermatitis With One Treatment |
|---|---|---|---|---|---|---|---|
| Participants analysed | 0 | 1 | 0 | 0 | 1 | 0 | |
| Age, Categorical: <=18 years | Participants | — | 0 | — | — | 0 | — |
| Age, Categorical: Between 18 and 65 years | Participants | — | 1 | — | — | 1 | — |
| Age, Categorical: >=65 years | Participants | — | 0 | — | — | 0 | — |
| Sex: Female, Male: Female | Participants | — | 0 | — | — | 1 | — |
| Sex: Female, Male: Male | Participants | — | 1 | — | — | 0 | — |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | — | 0 | — | — | 0 | — |
| Race (NIH/OMB): Asian | Participants | — | 0 | — | — | 0 | — |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | — | 0 | — | — | 0 | — |
| Race (NIH/OMB): Black or African American | Participants | — | 0 | — | — | 0 | — |
| Race (NIH/OMB): White | Participants | — | 1 | — | — | 1 | — |
| Race (NIH/OMB): More than one race | Participants | — | 0 | — | — | 0 | — |
| Race (NIH/OMB): Unknown or Not Reported | Participants | — | 0 | — | — | 0 | — |
6. Primary Endpoint
The registry lists the primary outcome as Change in Adherent Scalp Flaking Scale (ASFS), measured over 4 weeks.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was change in the Adherent Scalp Flaking Scale (ASFS), assessed at 4 weeks. The scale describes the amount of dandruff flakes adhering to the scalp across 8 defined areas. Each area receives a score from 0 to 10, where 0 indicates no flakes and 10 indicates heavy flaking; the areas are combined into a total score ranging from 0 to 80.
As a general measurement principle, a scale focused on the symptom of interest can make that symptom more systematic to record than an informal impression. A defined scoring range also indicates how the measure is intended to represent differences in flaking. The registry description does not report whether the scale was validated, who performed ratings, or whether raters were masked.
The endpoint was intended to capture change over the stated follow-up period, rather than only a single score. But the registry says the primary outcome was not collected or analyzed because the study was abandoned before these data could be obtained. Consequently, there is no baseline-to-follow-up change estimate, group contrast, or measure of uncertainty to interpret. The planned scale and timeframe describe what the study sought to measure, not an observed treatment result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central statistical fact is that the planned primary outcome is unavailable. The registry says the study was abandoned before the ASFS data could be obtained, and records that the outcome was neither collected nor analyzed. Thus, no observed change in flaking, comparison between treatment schedules, effect estimate, confidence interval, or p-value is reported in the registry record. There is no primary-outcome result from which to judge the direction or precision of a difference.
The registry reports enrollment of 2, while its arm descriptions span several scalp conditions and treatment schedules. It does not report which groups those participants entered. The enrollment figure therefore cannot be used to infer the number assessed in any one group, the amount of follow-up completed, or the extent of treatment exposure. Nor does the randomized designation by itself establish that a usable randomized comparison was completed.
As a general statistical point, an estimate describes the observed contrast, while a confidence interval describes the range of values compatible with the data and analysis under the method used. Neither is available for the primary outcome in this record. A p-value would not remedy the absence of outcome data: without analyzed observations and a specified comparison, there is no reported test result to interpret. The same caution applies to the secondary outcomes, for which no analyses are listed.
The status and outcome statement are important when interpreting the sparse safety entries as well. Safety records list no adverse events in the listed groups, but most groups have no participants recorded as at risk, and the primary efficacy outcome was not collected. These entries do not establish that the device is safe or that it changes scalp flaking. They describe limited registry reporting in a terminated study with enrollment of 2.
The appropriate conclusion is therefore about the evidence available from this record, not about the device's clinical effect. The study planned to measure scalp flaking and other scalp-related outcomes, but the posted record contains no analyzed efficacy results. It cannot support an estimate of benefit, a comparison of one and three treatments, or an assessment of how reliably any effect might be reproduced.
9. Statistical Methods Explained
The registry identifies the design as randomized, single-masked, and parallel. These terms describe intended features of a study, but they do not specify all operational or statistical details. In a randomized study, assignment is intended to use a chance-based process; the method for generating or concealing assignments is not reported in the registry record. Single masking indicates that masking was planned for one party, but which party was masked and how masking was maintained are not reported in the registry record. A parallel design generally assigns participants to a group that remains their group during the study; the record does not provide further details about implementation.
What comparison was planned?
The arm descriptions combine scalp condition with treatment schedule. They include healthy scalp, dandruff, seborrheic dermatitis, and hair loss disease, alongside one-treatment or three-treatment schedules. The record does not specify a single primary contrast, such as a direct comparison of treatment schedules within a condition, or identify a conventional control group. It also does not report the planned statistical model or the handling of condition-specific comparisons. Without those details, the design labels and group descriptions are not enough to reconstruct the intended analysis.
What does the endpoint measure?
The primary measure was change in ASFS at 4 weeks. Its description defines area-level ratings and a total score, but does not give an analysis procedure for those scores. As a general statistical concept, an analysis of change could compare follow-up and baseline values within participants, and a treatment comparison could assess differences in those changes between groups. These are examples of possible approaches, not methods reported for this study. The registry states that the endpoint was not collected or analyzed, so no such calculation is available to interpret.
Why do analysis details matter?
A prespecified analysis plan helps clarify which comparison is primary, how outcomes are summarized, and how uncertainty is quantified. It can also define how missing observations, deviations from treatment schedules, and multiple outcomes are handled. The statistical analysis plan, model choice, covariate adjustment, and approach to missing data are not reported in the registry record. It is not possible to determine whether any analyses were planned beyond the outcome descriptions.
The record lists 3 outcome measures and identifies two secondary outcomes: change in erythema score and change in Patient Sensory Assessment of Scalp & Hair score. The number of analyses is listed as 0. No analysis results for these outcomes are reported. As a general concept, analyzing multiple outcomes or multiple comparisons can increase the chance of finding an apparently notable result by chance if no suitable approach is specified. The registry does not report a multiplicity strategy, and the absence of analyses means there is no set of reported tests to evaluate for that issue.
How should planning calculations be read?
The planning assumptions associated with the study describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of an observed effect. The stated assumptions characterize planning illustrations, not a completed analysis of this trial. The registry record does not report the trial's own sample-size justification, and the outcome data needed for an observed primary effect are unavailable. Any sample-size illustration should therefore not be read as observed power or as evidence that the trial was adequately sized. In general, power is a design-stage probability based on assumptions; it is not a measure of whether a completed study demonstrated an effect.
As a general statistical matter, confidence intervals communicate uncertainty around an estimate, while a p-value addresses compatibility between data and a specified null hypothesis under an analysis model. Neither substitutes for a clear design, a defined comparison, and observed outcome data. Here, no primary estimate, confidence interval, or p-value is reported in the registry record. The number of participants enrolled and the presence of a randomized design label cannot be used to reconstruct missing outcome analyses or determine their precision.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary outcome and two secondary outcomes, for 3 outcome measures in all. The secondary measures are change in erythema score and change in Patient Sensory Assessment of Scalp & Hair score. The primary endpoint was change in ASFS at 4 weeks. The registry records 0 analyses, and no results for the secondary outcomes are reported.
A multiplicity plan describes how statistical interpretation accounts for examining more than one outcome, comparison, or time point. As a general principle, without such a plan, a collection of tests may produce findings that appear notable by chance more often than a single prespecified test. The registry does not report a multiplicity adjustment, a hierarchy for testing outcomes, or which comparisons were intended to be confirmatory. Since no analyses are listed, there are no reported test results to assess under a multiplicity procedure.
The primary outcome record explicitly states that it was not collected or analyzed because the study was abandoned before those data could be obtained. The record does not explain whether secondary outcomes were collected, and it does not report their analysis populations or results. The reason for termination and any other missing-data details are not reported in the registry record.
Analysis populations, such as whether all randomized participants would have been included in a primary analysis, are not reported in the registry record. The record also does not describe a method for handling missing observations, incomplete follow-up, or participants who may not have completed the assigned schedule. These omissions prevent assessment of whether any planned analysis would preserve the randomized comparison. Most importantly, no efficacy estimate is available to evaluate for bias from missing outcome data.
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 |
|---|---|---|---|
| Healthy Scalp and Three Treatments | 0 | 1 | 0.0% |
| Hair Loss Disease and One Treatment | 0 | 1 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Healthy Scalp and One Treatment | 0 of 0 |
| Healthy Scalp and Three Treatments | 0 of 1 |
| Dandruff and One Treatment | 0 of 0 |
| Dandruff and Three Treatments | 0 of 0 |
| Hair Loss Disease and One Treatment | 0 of 1 |
| Seborrheic Dermatitis With One Treatment | 0 of 0 |
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 |
|---|---|
| Healthy Scalp and One Treatment | 0 of 0 |
| Healthy Scalp and Three Treatments | 0 of 1 |
| Dandruff and One Treatment | 0 of 0 |
| Dandruff and Three Treatments | 0 of 0 |
| Hair Loss Disease and One Treatment | 0 of 1 |
| Seborrheic Dermatitis With One Treatment | 0 of 0 |
The adverse-event entries list 8 groups. Two groups—Healthy Scalp and Three Treatments, and Hair Loss Disease and One Treatment—each have 1 participant recorded as at risk for adverse events. The other listed groups have 0 recorded as at risk. The entries report 0 serious adverse events, 0 other adverse events, and 0 deaths across the listed groups; no serious adverse-event terms are listed.
These figures should be read alongside the recorded exposure. A zero event count in a group with 0 participants at risk does not describe observed safety among exposed participants. The two groups with 1 participant at risk have no events recorded, but those entries represent very limited exposure. The registry reports overall enrollment of 2 and does not explain how the participants align with all the arm descriptions.
As a general statistical principle, no observed events in a small or minimally exposed group cannot rule out uncommon harms or establish safety. Here, the registry record provides no detail about the duration or completeness of adverse-event surveillance, and the study was terminated. The entries are a report of events recorded in the registry, not evidence that adverse effects cannot occur.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, single-masked, parallel study was registered to evaluate a scalp-cleansing device, with planned groups representing different scalp conditions and treatment schedules. It also specifies a primary measure of scalp flaking and two secondary scalp-related measures. These details describe the study's objective and intended measurements.
They do not establish whether the device changed scalp flaking. The primary outcome was not collected or analyzed because the study was abandoned before those data could be obtained. The registry lists 0 analyses and reports no efficacy estimates. No conclusion about the direction, size, or precision of an effect can be drawn from a result that is not available.
Enrollment was 2, and the registry does not report the participants' group assignments. That enrollment figure cannot establish that the different conditions and treatment schedules were compared, nor can it show whether one-treatment and three-treatment schedules produced different results. The registry's randomized designation is not a substitute for completed follow-up and analyzed outcomes.
The safety entries report no events, but they also show very limited recorded exposure: only two listed groups have participants at risk, each with 1 participant. Such counts do not establish safety or exclude events that might occur with broader or longer exposure. The registry does not report further detail about safety monitoring.
As a general evidence principle, a study that ends before its outcome data are collected may document a research question without answering it. The record is useful for understanding the planned endpoint, design labels, and reasons that the posted outcome cannot be interpreted. It should not be treated as evidence that the device improves scalp health, has no effect, or is free of risk.
13. Why This Trial Matters Statistically
This study illustrates an important distinction between a registered research question and an answer supported by analyzed data. The record identifies a specific primary measure, a stated assessment timeframe, and groups defined by scalp condition and treatment schedule. Yet it also says that the study was abandoned before the primary outcome could be obtained. A clearly described endpoint does not produce an effect estimate when observations are unavailable.
The gap matters statistically because estimates require observed outcomes, and uncertainty requires both those outcomes and a defined analysis. With no reported primary analysis, there is no basis for judging the size or precision of a treatment contrast. A study's randomized label, endpoint definition, and treatment descriptions cannot supply the missing information.
The record also shows why enrollment and group-level safety counts need context. Enrollment of 2 does not tell readers how many participants were in any condition-specific group. The adverse-event entries show that most listed groups had no participants recorded as at risk. Without clear exposure and completed outcome data, zero event counts have limited interpretive reach.
As a general lesson for clinical research, transparent reporting of study status, outcome availability, analysis methods, and participant flow helps readers distinguish planned work from completed evidence. This record makes the key limitation explicit: the primary endpoint was not collected or analyzed. That clarity prevents planned measurements from being mistaken for results, even though it leaves the clinical question unanswered.
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 principal limitation is explicit: the study was abandoned before the primary outcome data could be obtained. The registry says ASFS was not collected or analyzed, leaving no primary efficacy result. The reason for abandonment is not reported in the registry record.
Enrollment was 2, but the record does not report how participants were distributed among the described groups, which conditions they had, or which treatment schedules they received. Although the design is labeled randomized, the randomization process, allocation concealment, and identity of the masked party are not reported in the registry record. A conventional control group and the planned comparisons are also not reported in the registry record.
The planned primary endpoint has a defined scale and timeframe, but the record does not report who rated the scale, whether raters were masked, or whether the scale was validated. It also does not report the statistical analysis plan, analysis population, approach to missing data, or multiplicity strategy. No analyses are listed for the primary or secondary outcomes.
Safety reporting is limited by the small enrollment and the sparse at-risk entries across the groups. The registry does not describe the completeness or duration of adverse-event monitoring. The study status is terminated, and the posted record does not establish whether follow-up or safety collection was completed for the participants who were recorded as at risk.
These limitations mean that the record can describe intended study features and the absence of reported outcome analyses, but cannot quantify an effect or establish the precision of an effect. The missing results should not be interpreted as evidence of no change.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Cleansing Device for the Treatment of Scalp and Hair Conditions — NCT05319444.
- Registry record last updated 2026-09-04; status last verified 2026-09.
- Results first posted 2026-09-04.
- 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 University of Minnesota sponsored this randomized, single-masked, parallel study of an off-brand Waterpik® device intended to massage and cleanse the scalp. The registry lists dandruff, seborrheic dermatitis, and hair loss among the conditions and describes groups with healthy scalps and with those conditions, receiving one or three treatments. Enrollment was 2, and the study status is terminated.
The planned primary outcome was change in Adherent Scalp Flaking Scale at 4 weeks. The registry says this outcome was not collected or analyzed because the study was abandoned before the data could be obtained. Two secondary outcomes are listed, but the registry reports 0 analyses. Safety entries list no adverse events or deaths, with only two groups recording 1 participant at risk each.
The record therefore describes a planned investigation but provides no analyzed efficacy result. The distribution of participants among groups, statistical analysis plan, and reason for termination are not reported in the registry record.