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 Penguin Cold Caps in the Prevention of Hair Loss in Breast Cancer Patients (NCT03289364), a na na study. The primary outcome is Efficacy of PenguinTM Cold-caps for Prevention or Reduction of CIA.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03289364 |
| Phase | NA |
| Condition | Breast Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 12 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Providence Health & Services |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned patients with Stage I-III breast cancer receiving (neo)adjuvant chemotherapy. Its stated goal was to estimate cold-cap efficacy in patients receiving one of four common chemotherapy regimens. The registry lists 12 participants as enrolled. The efficacy description defines evaluable participants using chemotherapy dose received, but does not provide a posted count of evaluable participants or a more detailed population description.
Intervention
The intervention was Penguin Cold Caps, a device used for scalp cooling. The registry describes starting cold-cap therapy at least 50 minutes before chemotherapy infusion and continuing it for 4 hours after chemotherapy was completed. The study considered prevention or reduction of chemotherapy-induced alopecia, rather than a comparison of different cooling approaches.
Comparator
No separate control group is listed. The registry gives the allocation as NA and describes a single-group model, so it does not provide a like-for-like comparison between participants assigned to cold caps and participants assigned to another treatment or usual care. Any interpretation must therefore focus on the stated endpoint and the absence of posted efficacy results, not on a treatment contrast.
Primary question
The primary question was whether evaluable participants would have a Dean's alopecia scale score of 0-2 at the assessment 30 days post chemotherapy treatment. The registry defines this score range as less than 50% hair loss by standardized photography. Although this endpoint and its assessment time are specified, the registry record does not report the number who met the criterion or an estimated proportion.
3. Trial Design
This was a Phase 2 study listed with phase NA in the registry. It is described as a single-group study of Penguin Cold Caps in patients with Stage I-III breast cancer receiving (neo)adjuvant chemotherapy. The registry lists Providence Health & Services as sponsor, enrollment of 12, and a completed status. The recorded study start date is 2017-08-24, and the primary completion date is 2021-08-19. Completion status indicates the study is recorded as completed; it does not establish that efficacy results were posted.
The registry lists allocation as NA and masking as none. With no separate control group, the study does not provide a randomized comparison. The intervention description states that cooling began at least 50 minutes before chemotherapy infusion and continued for 4 hours after its completion. The goal was to estimate efficacy for preventing or reducing hair loss among patients receiving one of four common chemotherapy regimens.
The primary endpoint was assessed 30 days post chemotherapy treatment. The analysis description uses a modified intention-to-treat approach: participants receiving at least 75% of the prescribed chemotherapy dose would be considered evaluable, while those receiving less chemotherapy would be excluded to reduce confounding from chemotherapy dose. Participants withdrawing consent before efficacy assessment would be counted as treatment failures under the stated intention-to-treat principle.
The registry names exit interviews using the “Was It Worth It?” Questionnaire, EORTC QLQ-C30, and BR23 as secondary outcomes. It lists four outcome measures overall, but reports zero analyses. Detailed information on the chemotherapy regimens actually received, the number completing efficacy assessment, and the results of the primary or secondary outcomes is 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: Slow accrual and exhausted funding led to only 12 patients enrolled instead of the planned 20.
Overall Study
| Stage | Penguin Cold Caps |
|---|---|
| STARTED | 12 |
| COMPLETED | 10 |
| NOT COMPLETED | 2 |
Reasons for not completing this period:
| Reason | Penguin Cold Caps |
|---|---|
| Withdrawal by Subject | 2 |
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: Population analyzed reduced to 10 for publication due to two patients withdrawing before Cycle 1.
| Characteristic | Unit | Penguin Cold Caps |
|---|---|---|
| Participants analysed | 10 | |
| Age, Continuous | years | 49 (44 to 59) |
| Sex: Female, Male: Female | Participants | 10 |
| Sex: Female, Male: Male | Participants | 0 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 8 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 10 |
| Menopausal Status: Pre-Menopausal | Participants | 6 |
| Menopausal Status: Post-Menopausal | Participants | 2 |
| Menopausal Status: Unknown | Participants | 2 |
| Chemotherapy Setting: Adjuvant | Participants | 4 |
| Chemotherapy Setting: Neoadjuvant | Participants | 6 |
| Hair Thickness: Fine | Participants | 3 |
| Hair Thickness: Medium | Participants | 4 |
| Hair Thickness: Thick | Participants | 3 |
6. Primary Endpoint
The registry lists the primary outcome as Efficacy of PenguinTM Cold-caps for Prevention or Reduction of CIA, measured over 30 days post chemotherapy treatment.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is a participant count based on a binary criterion: whether an evaluable participant achieved a Dean's alopecia scale score of 0-2 at the assessment 30 days post chemotherapy treatment. The registry defines scores in this range as less than 50% hair loss by standardized photography. In the scale description, Grade 0 indicates no hair loss; Grade 1 indicates up to 25% hair loss; and Grade 2 indicates greater than 25% hair loss up to 50% hair loss. Grades 3 and 4 describe more extensive hair loss.
Using a prespecified score threshold turns a graded assessment into a clear endpoint that can be expressed as the count or proportion meeting the criterion. Standardized photography is identified as the assessment basis, but details about image review, assessor training, or masking are not reported in the registry record. The threshold represents prevention or reduction as operationalized by the study; it does not mean that participants had no hair loss, since scores through Grade 2 qualify.
The record specifies the endpoint and assessment time but does not report the observed count meeting the criterion, the number evaluable, or an estimated proportion. Consequently, the endpoint definition can be explained, but the study's observed efficacy on this measure cannot be described from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a single-group study with 12 participants enrolled and a defined primary hair-loss endpoint. It does not report a primary outcome analysis: the record lists zero analyses and provides no number of evaluable participants, no count meeting the Dean's alopecia scale threshold, and no estimated proportion. There is therefore no posted efficacy result to interpret for the primary question.
The endpoint is whether an evaluable participant had a score of 0-2 at the assessment 30 days post chemotherapy treatment. The record defines that threshold as less than 50% hair loss by standardized photography. Because the numerator and denominator are not reported, neither the frequency of meeting the criterion nor its precision can be assessed. A confidence interval, if reported, would describe the uncertainty around an estimated proportion; no such interval is reported in the registry record.
The single-group design also limits what an eventual proportion could establish. Without a separate comparison group, the registry cannot directly show how the observed hair-loss outcome differed from what would have occurred under another approach. A participant count or proportion would describe the study group under its treatment and assessment conditions, not a randomized treatment effect. The registry lists allocation as NA, masking as none, and the model as single group.
The modified intention-to-treat description adds important context for any future interpretation of efficacy results. Participants receiving at least 75% of prescribed chemotherapy dose were to be considered evaluable; participants receiving less were excluded to reduce confounding related to chemotherapy dose. Those withdrawing consent before efficacy assessment were to count as treatment failures. The record does not provide counts for these categories or report whether the analysis followed this plan.
Safety figures are reported separately from efficacy. For the Penguin Cold Caps group, the registry lists 10 participants at risk for serious adverse events and zero affected, and 10 at risk for other adverse events and 10 affected. These are descriptive counts, not a comparison with another group. The registry gives no serious adverse-event terms and does not name the other adverse events in the information recorded. The safety denominators differ from the enrollment count, and the reason is not reported in the registry record.
Overall, the record supports describing the trial design, endpoint definition, and recorded safety counts. It does not support a numerical conclusion about primary efficacy, the uncertainty around efficacy, or a causal comparison. Completed status should not be mistaken for the presence of posted outcome analyses.
9. Statistical Methods Explained
For a binary endpoint, each participant either meets the defined criterion or does not. In this study, the criterion is a Dean's alopecia scale score of 0-2 at the assessment 30 days post chemotherapy treatment. A summary could present the number meeting the criterion and the number evaluated, and could express those counts as a proportion. The registry record defines the endpoint but does not report the counts or proportion, so the result cannot be reconstructed.
What does the endpoint threshold represent?
The scale records hair loss in ordered grades. The registry describes Grade 0 as no hair loss, Grade 1 as up to 25% hair loss, Grade 2 as greater than 25% hair loss up to 50% hair loss, Grade 3 as greater than 50% hair loss up to 75% hair loss, and Grade 4 as greater than 75% hair loss. The primary criterion groups Grades 0-2 together. Thus, the endpoint is not limited to complete prevention of hair loss: participants could qualify despite some hair loss, provided their score remained within the defined range. The registry identifies standardized photography but does not report further details about how scores were assigned.
How does the analysis population work?
The registry describes a modified intention-to-treat analysis. Participants receiving at least 75% of the prescribed chemotherapy dose were to be considered evaluable. Those receiving less chemotherapy were to be excluded, with the stated aim of minimizing confounding from chemotherapy dose. Participants withdrawing consent before the efficacy assessment were to count as treatment failures under the stated intention-to-treat principle. These rules define how certain participants should contribute to the efficacy analysis, but the record does not report how many participants fell into each category or whether the planned rules were applied in the final analysis.
This distinction matters because enrollment and analysis denominators need not be the same. The registry lists enrollment of 12, but does not report the number evaluable for efficacy. It also does not report the number assessed at the scheduled endpoint or the number with missing endpoint information. Without those details, readers cannot determine how much of the enrolled group contributes to a possible efficacy estimate.
What can a confidence interval tell a reader?
In general, a confidence interval expresses the statistical uncertainty around an estimate. For a binary endpoint, it can communicate how precisely a participant proportion is estimated, given the observed count and analysis population. Greater uncertainty is generally expected when information is limited, but the width of an interval depends on the data and the method used. No efficacy estimate or interval is reported in the registry record, so no conclusion about the precision of the primary outcome is available.
More broadly, a proportion from a single group is descriptive. It summarizes the outcomes observed in that group but does not, by itself, estimate a difference from a control condition. A randomized comparison is one way to support a causal contrast, but this registry entry describes a single-group study with allocation listed as NA. It therefore does not provide a like-for-like control comparison.
Why can over-dispersion matter?
As a general statistical concept, over-dispersion occurs when observed variability is greater than expected under a model's assumptions. It can make standard errors too small if the extra variability is ignored, leading to confidence intervals that are too narrow and tests that overstate precision. This concept is relevant to some count or clustered-data models, but the primary endpoint is specified as a participant count meeting a binary criterion. The registry record does not report a model, dispersion estimate, or statistical analysis results, so there is no basis to claim that over-dispersion was assessed or affected this analysis.
What do planning calculations mean?
In general, sample-size calculations describe how much information a proposed study might need to detect a specified effect under stated assumptions. They are planning illustrations, not observed power and not evidence that a study detected an effect. The record's sample-size description characterizes its illustrations as based on an observed effect and states general assumptions for those calculations. However, the registry record does not report an observed primary efficacy estimate or a primary analysis. The illustrations therefore cannot substitute for an outcome result or establish the precision of an unreported estimate.
The registry does not report the statistical test or model used for the primary endpoint, a confidence-interval method, an interim-analysis plan, or a detailed statistical analysis plan. These methods should not be inferred from the endpoint description. The stated analysis population and endpoint definition can be described, but the analysis actually performed and its numerical result are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry names secondary outcomes for the “Was It Worth It?” Questionnaire Exit Interview, EORTC QLQ-C30 Exit Interview, and BR23 Exit Interview. It lists four outcome measures overall but zero analyses. Numerical results for the primary endpoint and secondary outcomes are not reported in the registry record. A strategy for controlling multiplicity across outcomes or analyses is also not reported in the registry record.
Multiplicity arises when several outcomes or statistical tests are considered: the more opportunities there are to identify a result as noteworthy, the more important it becomes to clarify which questions were primary and how the analyses were interpreted. The registry identifies a primary outcome, but does not report an adjustment method or a complete analysis plan. It is therefore not possible to assess how multiplicity was handled in any analysis.
The record does state an approach to some missing or excluded efficacy observations. Participants receiving at least 75% of prescribed chemotherapy dose were to be considered evaluable; those receiving less were to be excluded. Participants withdrawing consent before efficacy assessment were to count as treatment failures. This description does not provide the number of participants affected by each rule, nor does it report other missing-data procedures or sensitivity analyses. Whether the final analysis followed the stated approach is not reported in the registry record.
These gaps matter because the analysis population, missing outcomes, and handling of multiple questions can affect both the estimate and its interpretation. With no posted analyses, the reader cannot evaluate those issues empirically or determine whether the stated rules were implemented as planned.
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 |
|---|---|---|---|
| Penguin Cold Caps | 0 | 10 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Penguin Cold Caps | 0 of 10 |
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 |
|---|---|
| Penguin Cold Caps | 10 of 10 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Penguin Cold Caps |
|---|---|---|
| Nausea | Gastrointestinal disorders | 9 of 10 |
| Headache | Nervous system disorders | 2 of 10 |
| Vomiting | Gastrointestinal disorders | 2 of 10 |
| Head Sore | Skin and subcutaneous tissue disorders | 1 of 10 |
| Syncope | Nervous system disorders | 1 of 10 |
For the Penguin Cold Caps group, the registry lists 10 participants at risk for serious adverse events, with zero affected and zero deaths. It lists 10 participants at risk for other adverse events, with 10 affected. These are counts for the participants represented in the safety record; the registry lists 12 participants enrolled overall. The reason the safety denominators are 10 rather than the enrollment count is not reported in the registry record.
The record does not list serious adverse-event terms. It also does not name the other adverse events in the information recorded here, so the count cannot be interpreted by event type, severity, timing, or relationship to the intervention. The terms “serious” and “other” distinguish the registry's reporting categories; they should not be treated as interchangeable measures.
These counts are descriptive. Because the study is single-group and does not list a control arm, they do not establish whether the events were more or less frequent than under another condition. Zero recorded serious adverse events in the reported denominator does not establish that the risk is absent. The registry record does not report further detail that would support a comparative safety assessment.
12. What the Result Does, and Does Not, Mean
The record establishes that a completed single-group study evaluated Penguin Cold Caps in the setting of chemotherapy for Stage I-III breast cancer. It specifies the cooling schedule, a primary hair-loss threshold, and the intended assessment time. It also states an evaluability rule based on the proportion of prescribed chemotherapy dose received and describes how withdrawals before efficacy assessment were to be counted.
Those details explain what the study set out to measure, but they do not show the observed primary outcome. The registry record reports zero analyses and no count of participants meeting the Dean's alopecia scale criterion, no evaluable denominator, and no estimated proportion. It is therefore not possible to describe the frequency of meeting the endpoint or the precision of that estimate from this record.
The study design also affects the meaning of any eventual outcome proportion. A single-group result would describe participants in that group, but would not provide a randomized estimate of how outcomes differ from a control condition. The record lists allocation as NA, masking as none, and no separate control group. It cannot, on its own, separate outcomes associated with cooling from other influences, including the chemotherapy context.
The safety record reports zero serious adverse events among 10 participants at risk and 10 participants with other adverse events among 10 at risk. It does not provide event terms for those categories or a control-group comparison. These are limited descriptive data and should not be treated as a complete characterization of safety.
Accordingly, the registry supports a description of the study question and its planned endpoint, plus the safety counts it records. It does not support a conclusion that cold caps did or did not prevent hair loss, a comparative treatment claim, or a comprehensive account of benefit and harm. Those conclusions require posted outcome analyses and enough methodological detail to assess their reliability.
13. Why This Trial Matters Statistically
This trial illustrates a basic distinction in clinical statistics: a clearly defined endpoint is not the same as a reported outcome. The registry specifies a binary success criterion based on the Dean's alopecia scale at 30 days post chemotherapy treatment. It also defines the population intended for the efficacy analysis. Yet it lists zero analyses and does not report the numerator, denominator, or estimated proportion for that endpoint. Without those elements, readers can understand the intended question but cannot assess the observed answer.
The study also shows why design information belongs alongside outcome interpretation. A single-group design can describe what happened among participants who received the intervention, but it does not supply a concurrent like-for-like control comparison. The registry lists allocation as NA and masking as none. These features shape the kinds of statistical conclusions the design can support, regardless of whether an endpoint is measured clearly.
Analysis-population rules are another important part of the statistical record. Here, evaluability depends on receiving at least 75% of prescribed chemotherapy dose, while withdrawals before efficacy assessment were to be counted as failures. Those rules can influence who contributes to the endpoint estimate. Since the counts and implementation are not reported, readers cannot judge their effect on the analysis.
Finally, the safety counts illustrate why denominators and event descriptions matter. The record reports safety denominators of 10, alongside overall enrollment of 12, but does not explain the difference. It also does not list serious event terms or identify the other events. Transparent reporting of outcomes, analysis populations, uncertainty, and event details is necessary for readers to assess what a clinical study can establish.
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.
A major limitation for statistical interpretation is the absence of posted efficacy analyses. Although the registry defines the primary endpoint and its timing, it does not report the number evaluable, the number meeting the endpoint, an estimated proportion, or its uncertainty. The reason analyses are absent is not reported in the registry record.
The single-group design provides no separate control group for a direct comparison. Allocation is listed as NA, masking as none, and the model as single group. Consequently, the record cannot support a randomized estimate of a difference between cooling and another approach. The registry does not report additional details that would permit a stronger causal interpretation.
The stated modified intention-to-treat rules may also affect how the efficacy population is defined. Participants receiving less than 75% of prescribed chemotherapy were to be excluded, while participants withdrawing consent before the efficacy assessment were to count as failures. The numbers in each category, any other missing endpoint data, and whether the stated rules were followed are not reported in the registry record.
There is limited detail about endpoint measurement. The registry identifies standardized photography and a Dean's alopecia scale threshold, but image-review procedures, assessor training, and assessment masking are not reported in the registry record. The actual chemotherapy regimens and the distribution of participants across them are also not reported in the registry record.
For safety, the record lists 10 participants at risk in each category despite enrollment of 12; the reason is not reported in the registry record. Serious-event terms are absent, and the other adverse events are not named. A detailed statistical analysis plan, the method for estimating uncertainty, and any multiplicity adjustment are not reported in the registry record. These omissions prevent a full assessment of the results and their precision.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Penguin Cold Caps in the Prevention of Hair Loss in Breast Cancer Patients — NCT03289364.
- Registry record last updated 2026-04-28; status last verified 2026-04.
- Results first posted 2026-04-28.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry describes a completed, single-group study of Penguin Cold Caps for preventing or reducing chemotherapy-induced alopecia in Stage I-III breast cancer. Providence Health & Services is listed as sponsor, enrollment is 12, and the recorded dates are 2017-08-24 for study start and 2021-08-19 for primary completion.
The primary endpoint is the count of evaluable participants scoring 0-2 on the Dean's alopecia scale at 30 days post chemotherapy treatment. The analysis description defines evaluability by receipt of at least 75% of prescribed chemotherapy dose and specifies how pre-assessment withdrawals were to be treated. The registry lists four outcome measures and zero analyses.
No primary efficacy estimate or secondary outcome analysis is reported in the registry record. Safety reporting lists zero serious adverse events among 10 at risk and other adverse events in 10 of 10 at risk; further event details are not reported. The record supports describing the design and intended measurement, but not estimating efficacy or comparing outcomes with a control group.