Prevalence of Lidocaine Ineffectiveness in Adults With and Without ADHD: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Prevalence of Lidocaine Ineffectiveness in Adults With and Without ADHD (NCT03676725), a na early/phase 1 study. The primary outcome is Number of Subjects With Lidocaine Ineffectiveness.

2. Clinical Question

These elements distinguish the scientific question from what the posted results can establish. The stated question concerns prevalence and possible variation by group, while the registered primary outcome is a count. A count can describe how many participants met an outcome definition, but interpreting prevalence also requires the relevant denominator and a clear account of which participants belong to each population group. Group-specific denominators and results are not reported in the registry record.

The protocol description says taste was rated before and after lidocaine on a scale from 0 (no taste) to 10 (very intense). For four before-and-after pairs, changes in intensity were calculated and combined as a weighted average; incorrectly identified tastes were excluded. A reduction in taste of at least 50% was considered effective. The record does not report how the study’s classifications were distributed among the population groups.

3. Trial Design

The registry describes an early phase 1 study with a single-group model, no masking, and allocation listed as not applicable. Enrollment is listed as 90, and the study status is completed. The registry gives a start date of 2019-08-14 and a primary completion date of 2020-03-01. PhenoSolve, LLC is listed as the sponsor.

All subjects received the lidocaine taste test. This is a within-participant assessment of taste before and after lidocaine, not a randomized comparison between a lidocaine group and a control group. The groups named in the study’s question—general population, males with ADHD, and females with ADHD with or without PMS—are intended comparison categories in the stated aim, but the registered model remains single-group. The record does not report the number of subjects in each category or how group membership was established.

The study is listed under ADHD and PMS. Its official title refers to assessing the frequency of lidocaine ineffectiveness in the general population versus males with ADHD and females with ADHD, with or without PMS. The brief summary likewise describes an assessment of prevalence. These statements establish the intended scope, but they do not give a detailed recruitment plan, eligibility criteria, or statistical comparison procedure; those details are not reported in the registry record.

The registered primary outcome is the number of subjects with lidocaine ineffectiveness. Its timeframe is a 30 minute visit added on to a regular clinic visit. The registry lists one outcome measure and three analyses, but the analysis details and primary outcome results are not reported in the registry record. The record also does not report a sample-size justification or explain how the enrollment target was selected. Planning illustrations based on an observed effect are not the study’s own design justification and should not be read as evidence about the study’s actual power.

Because the study is not a randomized comparison, differences between population categories, if reported elsewhere, would not by themselves establish that ADHD or PMS caused a difference in lidocaine response. Such comparisons would also depend on group composition, measurement, and analysis details that 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

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.

Only the first 6 of 7 groups are shown.

6. Primary Endpoint

The registry lists the primary outcome as Number of Subjects With Lidocaine Ineffectiveness, measured over 30 minute visit, added on to a regular clinic visit.

The primary outcome is the number of subjects with lidocaine ineffectiveness. The registry describes the taste test as a comparison of taste intensity before and after application of lidocaine gel. Subjects identified each taste and rated its intensity from 0 (no taste) to 10 (very intense). For each of four before-and-after pairs, the change in intensity was calculated, and a weighted average score was computed. Incorrectly identified tastes were excluded. A reduction in taste of at least 50% was considered lidocaine effective.

This endpoint is used to translate a change in taste intensity into a participant-level classification that can be counted. In general, a binary outcome reduces each participant’s measurement to a category, such as meeting or not meeting a defined criterion. A count can then describe the number of participants classified with the event of interest. It does not, on its own, describe the size of each participant’s taste change or the uncertainty around the group frequency.

The registry provides the effectiveness threshold but does not report the numerical count of participants with ineffectiveness. It also does not specify in the posted outcome description how missing measurements or other classification edge cases were handled. The endpoint result, its denominator by population group, and any uncertainty estimate are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

General statistical context. A clinical study’s statistical methods describe how observations are converted into estimates and how uncertainty is assessed. The registry record gives some details of the outcome measurement and study structure, but does not report the methods used for the three listed analyses. The general explanations below clarify relevant concepts; they are not claims about analyses performed in this study.

What does a participant count represent?

The registered primary outcome is a count of participants classified as having lidocaine ineffectiveness. In general, a count records how many people meet an outcome definition in a specified group. To interpret it as a frequency or prevalence, the count must be considered alongside the number of eligible participants in that group and the rules used to classify participants. A count alone does not convey how uncertain the underlying frequency may be.

The record describes a participant-level rule based on taste intensity changes. Taste was rated on a 0 (no taste) to 10 (very intense) scale before and after application of lidocaine. The change was calculated for four pairs, a weighted average score was computed, and incorrectly identified tastes were excluded. A reduction of at least 50% was considered effective. This definition connects the measured taste ratings to the outcome, but the numerical number classified with ineffectiveness is not reported in the registry record.

Why do denominators and group definitions matter?

In general, the same event count can imply different frequencies when group sizes differ. Comparisons also require clear definitions of the populations being compared and counts of participants in each group. The study’s stated question names the general population, males with ADHD, and females with ADHD with or without PMS. The registry does not report group-specific enrollment, outcome counts, or detailed group definitions. As a result, the planned population comparisons cannot be reconstructed from the posted results.

Group comparisons are also distinct from randomized treatment comparisons. A randomized design assigns participants to study conditions through a random process. This record instead lists a single-group model, no masking, and allocation not applicable; all subjects received the taste test. In general, differences between participant groups can be associated with factors other than the group label. A nonrandomized group contrast therefore does not, by itself, isolate a causal effect.

How should uncertainty be understood?

In general, a confidence interval expresses uncertainty around an estimate under the assumptions of a statistical model. It can show whether the data are compatible with a range of values, rather than implying that the estimate is exact. A confidence interval for a frequency or group contrast requires the relevant outcome data and a specified method. The registry record does not report primary outcome estimates or confidence intervals, so the precision of the intended population comparisons cannot be evaluated.

For binary outcomes, statistical methods may use models or interval procedures appropriate to counts and denominators. Sparse event counts can make estimates less stable, and different methods may behave differently when data are limited. These are general considerations, not descriptions of the analyses in this study: the registry lists three analyses but does not report their specifications, assumptions, or results.

What is over-dispersion?

In general, over-dispersion occurs when observed variation is greater than a statistical model expects. It is a concern in some count-data analyses, where the model’s assumed variability may be too small for the data. That can make uncertainty estimates overly narrow if not addressed. The registered primary outcome is described as a participant count, but the registry record does not report a count model, an over-dispersion assessment, or any analysis of this kind. It would therefore be inappropriate to claim that over-dispersion was present or handled in the study.

How do planning illustrations differ from study results?

General sample-size planning asks how many participants might be needed under chosen assumptions about an effect, significance level, allocation, and statistical model. The record describes a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. These are assumptions for an illustration, not a description of the registered single-group study design or evidence that the planned comparisons were performed as described.

Planning sample sizes are not observed power. In general, observed power calculated after a study is complete is not a substitute for reporting the estimate and its uncertainty. A planning calculation also cannot establish that the study was adequately powered when the underlying effect and design assumptions do not match the study question. The registry record does not report the numerical outputs of those illustrations or a sample-size justification for the trial itself.

Overall, the record supplies a measurement rule and basic design information, but not the statistical analysis details needed to evaluate the primary outcome. The three analyses are listed without methods or numerical findings. Any more specific account of modeling, adjustment, interval estimation, or handling of data would therefore be speculation rather than an explanation of reported methods.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure and three analyses. It does not report the identities of the analyses, whether they address separate population groups or alternative models, or whether any procedure was used to account for multiple analyses. Multiplicity refers, in general, to the increased chance of a misleading finding when many statistical questions are examined. Whether it is a concern depends on the analysis plan and how results are interpreted; those details are not reported in the registry record.

The record does not report a missing-data plan, the number of participants with incomplete taste-test measurements, or how such measurements were handled. The outcome description says incorrectly identified tastes were excluded, but it does not explain whether participants with excluded tastes could still receive a final classification or how incomplete before-and-after pairs were treated. Those details affect which observations contribute to an endpoint and how the analyzed population is defined.

The registry identifies all subjects as receiving the taste test but does not report an analysis-population definition, such as whether every enrolled subject was included in the primary analysis. In general, an analysis population specifies which participants and measurements contribute to an estimate. Without that definition and the primary outcome results, it is not possible to assess whether the reported analyses correspond to all enrolled subjects or a subset.

Accordingly, multiplicity handling, missing-data procedures, and analysis populations are not reported in the registry record. No conclusion should be drawn about the use or adequacy of particular methods.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

For the group labeled All Subjects, the registry lists 90 subjects at risk for serious adverse events and 0 affected. For other adverse events, it likewise lists 90 at risk and 0 affected. Deaths are listed as 0. These are the adverse-event counts recorded for this group; they are separate from the primary outcome of lidocaine ineffectiveness.

In general, an adverse-event count records events or participants according to the registry’s reporting conventions. A zero in the affected field means no affected participants are recorded in that field; it does not establish that no symptoms or events of any kind occurred. The record does not report definitions, collection procedures, follow-up beyond the stated visit, or details of how the adverse-event categories were assigned. Those details are not reported in the registry record.

The safety figures should therefore be read narrowly as posted counts, not as a comprehensive assessment of risk or proof that the intervention is free of adverse effects. They also cannot be used to infer the primary outcome result, which is not reported in the registry record.

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

The record documents a completed, single-group study in which all subjects received a lidocaine taste test. It describes how taste intensity was rated before and after lidocaine gel and states that a reduction of at least 50% was considered effective. It also reports enrollment of 90 and gives the study’s stated aim of assessing the frequency of ineffectiveness in population groups defined by ADHD and PMS.

However, the numerical primary outcome is not reported in the registry record. The posted results therefore do not establish how many subjects were classified as having lidocaine ineffectiveness, what fraction of any group that count represents, or whether the groups differed. The three listed analyses have no reported methods or results. No estimates or confidence intervals are reported for the primary question, so statistical precision cannot be assessed.

Even if group-specific findings were available, the registered single-group, nonrandomized design would limit causal interpretation. A comparison of participant categories is not the same as a randomized comparison, and differences could reflect characteristics of the groups or other factors. The registry record does not report enough information to assess such influences.

The adverse-event entries show 0 affected for serious adverse events and 0 affected for other adverse events among 90 listed as at risk in each category, with 0 deaths. These are the recorded counts and should not be generalized beyond the reporting information in the registry. They do not answer the primary question about taste-test classification.

In short, the record describes the intended question, measurement approach, and basic study structure, but does not provide the primary outcome findings needed to answer that question. The absence of a posted numerical result should not be interpreted as a favorable, unfavorable, or null finding.

13. Why This Trial Matters Statistically

This study is statistically notable because it combines a within-participant measurement procedure with a question framed as a comparison among population groups. The taste test measures each subject before and after lidocaine, then uses a threshold to classify effectiveness. That approach makes the definition of the score, the handling of incorrectly identified tastes, and the participant-level classification rule central to interpreting any count.

The distinction between measurement and comparison is important. A before-and-after assessment can describe change within a participant, while comparisons among the general population and ADHD/PMS categories require clear group definitions, denominators, and group-specific outcome results. The registry record describes the first part in some detail but does not report the data needed to evaluate the second part.

The record also illustrates why design labels matter. It lists a single-group model and allocation not applicable, even though the study aim names population categories for comparison. These categories do not constitute randomized treatment arms. In general, observational group contrasts can identify patterns in enrolled participants, but they do not automatically establish that group membership caused an outcome difference.

Finally, statistical interpretation depends on transparent reporting of estimates, uncertainty, and analysis choices. The registry lists three analyses but does not report their methods or findings, and the primary outcome count is absent. Without these elements, readers cannot judge the frequency of ineffectiveness, compare categories, or assess precision. The key statistical contribution of the record is therefore its description of the intended outcome and design, alongside a substantial gap in reported primary results.

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 primary limitation for interpreting this trial is that the registry record does not report the numerical result for its primary outcome. It also does not report the number of participants with ineffectiveness in each population category, the corresponding denominators, or uncertainty estimates. The stated prevalence question cannot be answered from the posted results alone.

The intended comparison groups are described broadly, but group-specific enrollment and detailed definitions are not reported in the registry record. The record does not explain how general-population participants were identified, how ADHD or PMS status was determined, or whether any other participant characteristics were considered. These omissions prevent assessment of how comparable the groups were.

The registered design is single-group, with no masking and allocation not applicable. All subjects received the lidocaine taste test. This structure does not provide randomized control groups for causal comparison. The record does not report analysis methods that might address differences among population categories.

The outcome description gives a taste-rating process and an effectiveness threshold, but does not report the final classification rules for incomplete measurements or other edge cases. Incorrectly identified tastes were excluded, while the handling of missing or unusable measurements is not reported. The three listed analyses are not described, and the analysis population and multiplicity procedures are not reported.

Finally, the adverse-event entries are counts without reported definitions or collection details. They should not be taken as a complete account of safety. These limitations concern what can be evaluated from the registry record; they do not establish that unreported procedures were absent from the conduct of the study.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Prevalence of Lidocaine Ineffectiveness in Adults With and Without ADHD — NCT03676725.
• Registry record last updated 2022-10-06; status last verified 2022-09.
• Results first posted 2021-07-14.
• 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

NCT03676725 is a completed early phase 1 study sponsored by PhenoSolve, LLC. The registry lists a single-group model, no masking, allocation not applicable, and enrollment of 90. All subjects received a lidocaine gel taste test.

The primary outcome is the number of subjects with lidocaine ineffectiveness, assessed during a 30 minute visit added on to a regular clinic visit. Taste intensity was rated before and after lidocaine, with a reduction of at least 50% considered effective. The study’s stated aim concerns the general population, males with ADHD, and females with ADHD with or without PMS.

The numerical primary outcome and group-specific findings are not reported in the registry record. Serious adverse events and other adverse events are each listed as 0 affected among 90 at risk; deaths are listed as 0. The registry lists three analyses but does not report their methods or results.