Pediatric Head Lice Study Product Comparison: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pediatric Head Lice Study Product Comparison (NCT02213055), a non-randomized phase 2 study. The primary outcome is Number of Participants Free of Live Head Lice and Free of Viable Eggs.

2. Clinical Question

3. Trial Design

This was a Phase 2, completed, parallel study of a pediatric head lice product comparison. The registry record lists an overall enrollment of 97 and gives the study dates as 2009-05 for the start and 2014-08 for primary completion. Hackensack Meridian Health is listed as the sponsor. The condition was head lice.

Allocation was non-randomized, and masking was none. The record describes families choosing between the investigational product and a standard treatment: parents who agreed to LiceMD could enter the experimental arm, while parents or guardians who declined it and chose standard treatment were asked to participate in the comparison arm. This design makes treatment assignment dependent on family choice rather than random allocation. Differences in family or participant characteristics could therefore accompany differences in treatment, whether measured or not. The registry record does not report an adjustment strategy to address such differences.

The parallel model means the treatment groups were followed as separate arms rather than participants crossing from one treatment to another. That description alone does not establish that the groups were comparable at baseline. The record identifies 58 evaluable subjects in the experimental arm for the primary outcome, but does not give the corresponding evaluable population for the standard-product arm.

The study objectives included evaluating efficacy and safety. The primary outcome description specifies freedom from live lice and viable eggs, with measurements on the day after first treatment and Day 14. The record lists one outcome measure and no analysis records. The protocol details, sample-size justification, eligibility criteria beyond the stated lice criterion, and any planned statistical analysis 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:

Analysis population for the primary outcome, as defined in the registry: There were 58 evaluable subjects in the experimental (LiceMD) arm of the study.

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: There were 58 evaluable subjects in the experimental (LiceMD) arm of the study.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants Free of Live Head Lice and Free of Viable Eggs, measured over Day after first treatment and Day 14 of study.

The primary endpoint counts participants who were free of live head lice and participants who were free of viable eggs. These are related but distinct outcomes: a child may meet one condition without meeting the other. The registry description says the determination of head lice effectiveness used two-week post-treatment data as the primary study outcome, and that measurements were calculated at Day 1, the day after first treatment, and Day 14. The timeframe therefore covers an early assessment as well as the later assessment.

Counting participants with an event is a binary-outcome approach: each participant is classified according to whether the specified condition was met. Reporting counts can make the outcome clinically interpretable, but a count alone does not convey the uncertainty around the result or establish how groups compare. The registry record does not provide the numbers free of live lice or free of viable eggs at either assessment, nor does it explain how missing or indeterminate observations were handled.

In general, measuring both live lice and viable eggs can represent different aspects of the study’s treatment objective. The endpoint wording does not establish that the two measures were combined into a single composite outcome; rather, it describes numbers free of each. The endpoint’s detailed operational definitions, assessment procedures, and rules for classifying participants are not reported in the registry record. Without those details and the observed counts, the endpoint can be described, but its results and precision cannot be evaluated.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods help translate observed participant outcomes into estimates that can be interpreted with appropriate uncertainty. The registry record describes a binary primary endpoint and gives assumptions for planning illustrations, but it contains no analysis records and no reported primary outcome estimates. The concepts below are general explanations, not a description of analyses documented for this study.

What does a binary endpoint capture?

For a binary endpoint, each participant is classified into a defined category, such as free of live lice or not free of live lice at an assessment. The number meeting the condition is a count of participants with the outcome. A count is most informative when its denominator is also clear: readers need to know how many participants were assessed and how many had missing or unusable measurements. The record gives 58 evaluable subjects in the experimental arm, but does not report the endpoint counts, the standard-arm evaluable population, or how missing observations were treated.

In general, a proportion can describe the frequency of an outcome within an arm, while a contrast can describe the difference or another relationship between arms. Such estimates should be accompanied by uncertainty measures. A confidence interval gives a range of values compatible with the data and the statistical method under its assumptions; it is not a guarantee that the true value lies in that particular interval. No confidence interval or comparative estimate is reported in the registry record.

Why does allocation matter?

Random allocation is used in general to reduce systematic differences between treatment groups at the point of assignment. This study is recorded as non-randomized. Families who accepted LiceMD entered the experimental arm, while those who declined the investigational product and chose standard treatment were asked to participate in the comparison arm. As a general matter, people selecting different treatments may also differ in characteristics related to outcomes. This creates a possibility of confounding: an observed difference could reflect treatment, group composition, or both.

Statistical adjustment can sometimes account for measured baseline differences, but it cannot automatically remove bias from unmeasured differences. The registry record does not report an adjustment method, a set of covariates, or baseline characteristics by arm. It is therefore not possible to determine whether or how the analysis addressed confounding. Even a well-specified adjusted model would require careful interpretation because non-random assignment remains a feature of the design.

What can the planning assumptions tell readers?

The record describes sample-size illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The intended effect is stated as a fraction of the observed effect. These are planning assumptions, not a report of the trial’s original design justification or proof that the study had adequate power. The sample-size justification for the trial is not reported in the registry record. No numerical sample-size illustration results are included in the available record.

In general, sample-size planning asks how many participants would be needed to detect a chosen effect under specified assumptions. Such a calculation depends on the selected effect size, outcome variability or event frequency, significance level, power target, allocation, and analysis method. Changing an assumed effect changes the planning result. A calculation based on an observed effect is especially dependent on that estimate and should not be treated as observed power. The planning illustrations described for this study do not replace an analysis of the outcomes actually observed.

Why consider over-dispersion and model choice?

General statistical methods must match the outcome and the way observations arise. A binary endpoint can be analyzed using methods for categorical outcomes, with the choice depending on the estimand, design, and assumptions. If observations are more variable than a model expects, over-dispersion can make standard errors too small and intervals too narrow. This concept is relevant when a model assumes a particular degree of variation, but the registry record does not describe a fitted model or report evidence of over-dispersion. It would be inappropriate to infer that a particular correction was used.

Repeated assessments also require clarity about whether observations from the same participant are analyzed separately or jointly. Measurements from one person can be related, so a method that treats them as independent may misstate uncertainty when that dependence is relevant. The record lists Day 1 and Day 14 assessments but does not report whether they were analyzed separately, jointly, or with a repeated-measures method. No method should be attributed to the investigators without a registry description.

What is missing for a reproducible interpretation?

A statistical analysis is easier to assess when the endpoint definition, analysis population, missing-data approach, model, contrast, and uncertainty measure are specified. Here the endpoint and its time points are described, but the actual counts and analysis are absent. The protocol, statistical analysis plan, handling of missing data, and approach to multiple outcomes or time points are not reported in the registry record. The record therefore supports a description of the intended measurement and design, not a reconstruction of the analysis.

General explanations of statistical concepts cannot fill those gaps. A result should be interpreted from the posted estimate and its uncertainty, alongside the design and assumptions. Since the record does not report the primary analysis, no numerical conclusion about comparative outcome frequency or precision is available.

10. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when a study assesses more than one outcome, time point, or statistical contrast. In general, carrying out multiple tests can increase the chance of finding an apparently unusual result by chance if each test is interpreted without accounting for the broader testing plan. Approaches to multiplicity depend on which outcomes and comparisons were prespecified and how conclusions are intended to be drawn.

The registry identifies one outcome measure, but its description includes freedom from live lice and freedom from viable eggs, assessed at Day 1 and Day 14. It does not report whether these were treated as separate endpoints, how they were prioritized, or whether any adjustment for multiple testing was planned or used. The multiplicity strategy is not reported in the registry record. The number of analyses listed is zero, so no analysis-level result or testing approach is available to assess.

Missing-data handling is also important because the primary endpoint is described for 58 evaluable subjects in the experimental arm, while overall enrollment was 97. The record does not explain why the evaluable population differs from overall enrollment, identify missing outcome counts, or state how missing measurements were classified or analyzed. The corresponding standard-product analysis population is not reported in the registry record. These gaps prevent assessment of whether the evaluable participants represent all enrolled participants for the endpoint.

Analysis populations such as all enrolled participants, treated participants, or participants with evaluable outcomes answer different questions. The registry record identifies an evaluable experimental-arm population but does not provide the analysis-population definitions or a full accounting by arm. No assumption about exclusions, attrition, or imputation should be made from the available information.

11. 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 0% reporting threshold.

Most frequent non-serious adverse event terms

The serious adverse event entries list LiceMD with 97 participants at risk and zero serious events. For other adverse events, LiceMD is listed with 97 participants at risk and one event. The standard head lice product group is listed with zero participants at risk and zero events in both categories. The record does not list serious adverse event terms.

These entries should be read with their denominators. A zero event count among participants recorded as at risk differs from a zero count where no participants are recorded as at risk. The standard-product entries therefore do not establish an absence of events in an observed comparison group. They provide no at-risk population for interpreting event frequency in that arm.

The record does not clarify how the 97 LiceMD participants at risk relate to the 58 evaluable experimental-arm subjects for the primary outcome. It also does not give descriptions or severity details for the one other adverse event, or explain the method used to collect adverse events. These are registry counts, not a complete comparative safety analysis. In general, event counts and denominators are needed to describe observed safety data, while differences in ascertainment and group composition can affect comparisons. The posted figures alone do not establish comparative risk.

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

The record documents a pediatric study intended to evaluate LiceMD efficacy and safety, with a primary endpoint based on participants free of live lice and participants free of viable eggs. It also records the assessment time points and describes how families entered the two treatment arms. Those details clarify the research question and the design, but they do not supply the outcome results needed to answer the comparative question.

No primary endpoint counts or statistical analysis are reported in the registry record. Consequently, the available information cannot show the observed frequency of either endpoint, quantify a difference between LiceMD and the standard product, or indicate how precise a comparison would be. The number of evaluable experimental-arm subjects is not an outcome result. Baseline findings about viable eggs and live lice likewise cannot substitute for post-treatment measurements.

The design also matters to what any comparison could mean. Treatment allocation was non-randomized and tied to parental agreement or treatment choice. In general, this leaves open the possibility that treatment groups differed in ways relevant to outcomes. The record does not report analyses that would help assess or adjust for such differences. Thus, even if a contrast were available, the design would require caution in interpreting it as a treatment effect.

The safety record reports zero serious events and one other event for LiceMD among 97 participants listed at risk. It does not provide an at-risk standard-product population, so the figures do not support a balanced safety comparison. They also do not resolve how the safety population relates to the primary-outcome population.

These limitations do not mean that a treatment was effective, ineffective, safe, or unsafe. They mean that the registry information does not contain the comparative outcome analysis needed to make those judgments. The responsible interpretation is limited to the study’s objectives, design, endpoint description, and recorded adverse-event entries. The effect, uncertainty, and robustness of the primary findings are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial illustrates why design information is essential when interpreting a treatment comparison. The study placed families in arms according to whether parents agreed to use the investigational product and whether they selected standard treatment. That non-randomized allocation creates a potential for differences between groups apart from treatment. Recognizing the assignment process is necessary before interpreting any comparative estimate.

The endpoint also shows why clear outcome definitions and results must be considered separately. Freedom from live lice and freedom from viable eggs are distinct measurements, and the record identifies assessments on the day after first treatment and Day 14. Yet without counts, denominators, and an analysis, the endpoint description cannot tell readers what happened after treatment or how precisely outcomes were estimated.

The record offers a further lesson about population accounting. It lists 97 enrolled participants and 58 evaluable experimental-arm subjects for the primary outcome, while the safety entries list 97 at risk in the LiceMD group. Without an explanation of how these populations relate, readers cannot assume that the same participants contributed to each analysis or determine why the endpoint population is smaller than the overall enrollment.

Finally, a safety comparison requires interpretable denominators in both groups. The standard-product group has zero recorded participants at risk, which cannot be read as a zero-event observation among a documented group. This distinction is basic but important: counts alone do not give a valid comparison when the populations behind them are unclear or absent.

Statistically, the record is useful for identifying the question and the sources of uncertainty, while leaving the central comparative result unresolved. That is a meaningful distinction between what a registry record documents and what readers might wish to infer from a study title or objective.

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 for interpretation is the absence of reported primary outcome counts and analysis. Although the registry describes the endpoint and time points, it does not state how many participants were free of live lice or viable eggs. It also provides no effect estimate, confidence interval, or statistical test. The primary comparative result is therefore not reported in the registry record.

The non-randomized design is an additional limitation specific to this study. Parents’ agreement or treatment choice determined which arm families were asked to join. This creates a possibility of selection differences between arms. Baseline characteristics by group and any strategy to address confounding are not reported in the registry record.

The outcome population information is incomplete. The record identifies 58 evaluable subjects in the experimental arm but does not give the standard-arm evaluable population or explain how participants became evaluable. The relation between this experimental endpoint population, total enrollment of 97, and the LiceMD safety population of 97 at risk is not explained. Missing observations, exclusions, and analysis-population definitions are not reported in the registry record.

The endpoint description includes two outcome concepts and multiple assessment times, but the record does not explain how they were prioritized or how multiplicity was addressed. Operational definitions and assessment procedures are also not reported. The specific standard product is unnamed, limiting description of the comparator treatment.

Safety interpretation is constrained by the absence of participants at risk in the standard-product entries and by limited detail for the one other LiceMD event. These limitations prevent a meaningful between-arm safety comparison from the posted figures. The registry record also does not report the protocol, detailed statistical plan, or trial sample-size justification.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Pediatric Head Lice Study Product Comparison — NCT02213055.
• Registry record last updated 2016-07-29; status last verified 2016-06.
• Results first posted 2016-07-29.
• 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.

18. Record Summary

The registry record describes a completed Phase 2, parallel, non-randomized study of LiceMD versus a standard head lice product in children. It lists an enrollment of 97, with Hackensack Meridian Health as sponsor and study dates of 2009-05 to 2014-08. Masking is listed as none.

The primary outcome concerns numbers of participants free of live head lice and free of viable eggs, assessed the day after first treatment and on Day 14. The record identifies 58 evaluable subjects in the experimental arm but does not report outcome counts or an analysis comparing arms. It also does not report the standard-arm evaluable population or the missing-data approach.

For safety, LiceMD is listed with 97 participants at risk for serious events and zero serious events, and 97 at risk for other events and one other event. The standard-product group has zero participants listed at risk. These entries do not permit a balanced safety comparison. Overall, the registry record documents the study question and design but does not report the primary comparative result.