(106 days)
Nix® Ultra Lice Treatment Kit is intended to kill and remove head lice and their eggs from adults and children two years of age or older.
The Nix® Ultra Lice Treatment Kit consists of two components: Nix® Ultra Lice Killing Solution and Nix® Ultra Lice Removal Comb. The kit also includes an Instructions for Use Leaflet.
Nix® Ultra Lice Killing Solution is a formulated device containing dimethicone and isoparaffin. The product kills lice and their eggs by physically coating the lice and clogging the spiracles through which they breathe and conduct water exchange; the solution also lubricates the hair to facilitate removal of dead lice and nits with the supplied comb. The Nix® Ultra Lice Treatment Kit is intended for over-the-counter use.
Here's an analysis of the acceptance criteria and study detailed in the provided document for the Nix® Ultra Lice Treatment Kit:
Acceptance Criteria and Reported Device Performance
The FDA 510(k) submission for the Nix® Ultra Lice Treatment Kit does not explicitly state pre-defined quantitative acceptance criteria in the typical sense (e.g., "The device must achieve X% sensitivity and Y% specificity"). Instead, it focuses on demonstrating substantial equivalence to a predicate device, the Clear™ Lice Egg Remover System (K981147).
The closest equivalent to "acceptance criteria" and "reported device performance" in this document is the demonstration of effectiveness against lice and nits and safety through in-vitro studies and a clinical study. The primary endpoints in the clinical study focused on "cure rates" (no infestation) at different time points.
Here's a table summarizing the relevant performance metrics from the studies:
| Acceptance Criteria (Implied) | Reported Device Performance (Nix® Ultra Lice Killing Solution) |
|---|---|
| In-vitro efficacy against Nits (lice eggs) | 97% Mortality Rate (vs. 24% for drug comparator, 10% for water control) |
| In-vitro efficacy against Adult Lice | 100% Mortality Rate (vs. 36.67% for drug comparator, 1% for water control) |
| In-vitro efficacy against Permethrin- and DDT-resistant lice | 100% Mortality Rate (vs. 43.3% for drug comparator, 1.7% for water control) |
| Clinical Cure Rate - Day 10 (all baseline infestations) | 92% - 96% of subjects free of infestation (depending on product in study) |
| Clinical Cure Rate - Day 7 (all baseline infestations) | 88% - 88.46% of subjects free of infestation (depending on product in study) |
| Clinical Cure Rate - Day 1 (all baseline infestations) | 92.31% - 96.15% of subjects free of infestation (depending on product in study) |
| Safety (Biocompatibility) | Not cytotoxic, non-irritating (human patch test), negligible irritation (rabbits), non-significantly/weakly sensitizing, mild corneal irritant. |
| Tolerability (Clinical Study) | Well tolerated (one mild, possibly related adverse event) |
| Post-marketing adverse events | 5 cases involving 13 patients out of 518,095 units sold (non-serious and temporary) |
Study Details
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Sample size used for the test set and the data provenance:
- In-vitro studies: The document details the subjects as "adult lice, nits, and lice genetically confirmed to be permethrin- and DDT-resistant (BR-HL strain)". The exact numerical sample size (e.g., number of lice or nits per test) is not provided, only the resulting mortality rates.
- Clinical Study (Ref# NUHL001-10/15): The tables show results for 25-26 subjects for "Reference" and 25-26 subjects for "Test" in the "All baseline infestations" category. For "Mild and Moderate Baseline Infestation," it's 19 subjects for "Reference" and 17-18 subjects for "Test". The specific country of origin is not explicitly stated, but the mention of a European marketer for post-marketing data suggests the clinical trial could have been conducted in Europe. The study is described as a "randomized, controlled, investigator- and assessor-blinded study," indicating it was a prospective clinical trial.
- Post-marketing adverse event data: This involved 518,095 units sold in Europe from June 2007 to December 2015, making it retrospective observational data.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- In-vitro studies: Not explicitly stated. The ground truth (live vs. dead lice/nits) would typically be assessed by laboratory technicians trained in entomology, potentially under the supervision of experts in parasitology. Specific qualification details are not provided.
- Clinical Study: The study involved an "investigator" to assess the baseline infestation and presumably monitor for cure or presence of lice. The document does not specify the number of investigators or their qualifications beyond the term "investigator." For Head Lice studies, these are often medical professionals or trained personnel experienced in examining scalps for lice and nits.
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Adjudication method for the test set:
- In-vitro studies: Not specified, but generally, clear criteria for "mortality" in entomological studies are pre-defined and applied consistently by trained observers.
- Clinical Study: Not explicitly described. Given it was an "investigator- and assessor-blinded study," it implies that at least two independent parties were involved in assessments, one of whom was blinded. However, the specific adjudication process (e.g., if there were discrepancies between assessors) is not detailed.
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If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
This is not an AI/imaging device. Therefore, an MRMC comparative effectiveness study involving human readers improving with AI assistance is not applicable to this device. The clinical study was a comparison of the Nix® Ultra product against a "Reference" product in terms of cure rates.
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If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
This is not an AI/algorithm-driven device. Therefore, a standalone algorithm-only performance study is not applicable. The "device" in this context is a physical lice treatment kit.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- In-vitro studies: Biological endpoint (mortality/viability of lice and nits) observed directly by trained personnel. This could be considered a form of direct biological observation, which is highly objective.
- Clinical Study: Clinical outcome (presence or absence of head lice infestation), assessed by an "investigator" based on visual examination, likely aided by comb-out procedures. This would implicitly involve a form of expert assessment or consensus if multiple investigators were involved, but the document doesn't detail this.
- Post-marketing adverse event data: Self-reported adverse events from users and classified by the marketer. This is outcomes data based on user experience.
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The sample size for the training set:
This device is a chemical and mechanical treatment for lice, not a machine learning model. Therefore, the concept of a "training set" for an algorithm is not applicable.
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How the ground truth for the training set was established:
As this is not a machine learning device, the concept of a "training set" and its associated ground truth establishment is not applicable.
§ 880.5960 Lice removal kit.
(a)
Identification. The lice removal kit is a comb or comb-like device intended to remove and/or kill lice and nits from head and body hair. It may or may not be battery operated.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 880.9.