Evaluation of NicCheck I Test Strips for the rapid detection of urine nicotine metabolites

Tobacco use adversely affects surgical outcomes, prompting guidelines for preoperative smoking cessation. Accurate assessment of smoking status is critical, yet self-reporting is often unreliable. Biochemical verification via nicotine metabolites, particularly cotinine, offers objective evaluation. While mass spectrometry provides high sensitivity, point-of-care (POC) tests offer rapid, accessible alternatives. This study assesses the performance of NicCheck I, a CLIA-waived urine test, by comparing its results to liquid chromatography-tandem mass spectrometry (LC-MS/MS) for detecting tobacco exposure in surgical patients.

Twenty-four frozen urine samples (12 cotinine-negative, 12 cotinine-positive) were analyzed using NicCheck I test strips and LC-MS/MS. Sample integrity, and pH were assessed using Siemens Multistix 10 SG reagent strips.

NicCheck I correctly identified all negative samples but detected nicotine metabolites in only 9 of 12 LC-MS/MS-confirmed positive samples. False negatives were associated with metabolite concentrations below the NicCheck I detection threshold (200 ng/mL) or urine pH outside the optimal range (4.5 - 8.5) consistent with manufacturer's package insert. LC-MS/MS demonstrated superior sensitivity.

NicCheck I test strips provide a practical and same-day rapid screening tool for nicotine exposure in clinical settings prior to surgery, but the test is less sensitive than LC-MS/MS. NicCheck I test strip performance may be affected by abnormal urine pH.