Understanding research methods, limitations, and applications of drug data collected by the National Forensic Laboratory Information System ( NFLIS‐Drug )
Open accessAbstract
The National Forensic Laboratory Information System (NFLIS) is a drug surveillance program of the US Drug Enforcement Administration that systematically collects data on drugs that are seized by law enforcement and submitted to and analyzed by the Nation's forensic laboratories (NFLIS‐Drug). NFLIS‐Drug data are increasingly used in predictive modeling and drug surveillance to examine drug availability patterns. Given the complexity of the data and data collection, there are some common methodological pitfalls that we highlight with the aim of helping researchers avoid these concerns. The analysis done for this Technical Note is based on a review of the scientific literature that includes 428 unique, refereed article citations in 182 distinct journals published between January 1, 2005, and April 30, 2021. Each article was analyzed according to how NFLIS‐Drug data were mentioned and whether NFLIS‐Drug data were included. A sample of 37 articles was studied in‐depth, and data issues were summarized. Using examples from the literature, this Technical Note highlights eight broad concerns that have important implications for the proper applications, interpretations, and limitations of NFLIS‐Drug data with suggestions for improving research methods and accurate reporting of forensic drug data. NFLIS‐Drug data are timely and provide key information to inform drug use trends across the United States; however, our present analysis shows that NFLIS‐Drug data are misunderstood and represented in the literature. In addition to highlighting these issues, DEA has created several resources to assist NFLIS data users and researchers, which are summarized in the discussion.
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Although NFLIS and NPS Discovery data are widely used as proxies for the US illicit drug supply, they do not fully capture the true prevalence or distribution of nitazene analogs nationwide.
“although NFLIS and NPS Discovery data are widely used as proxies for the US illicit drug supply, they do not fully capture the true prevalence or distribution of nitazene analogs nationwide [26].”
From Temporal and geographical patterns of nitazene detections in drug samples and biospecimens in the United States, 2019–2024 (2026) · cites this paper as [26]
The Abstract says NFLIS-Drug is increasingly used to examine drug availability, and §3.2 explains why its reports cannot fully represent the drug supply: not all seized drugs are submitted or tested, and some laboratories cannot detect newer synthetic substances. The paper does not address NPS Discovery or specifically assess the nationwide prevalence or distribution of nitazene analogs. (LLM, conf=0.87)
Experimental — accuracy not yet measuredThe 'co-reported drugs' field in NFLIS does not reliably capture true polysubstance involvement because it reflects substances identified within the same submission but not necessarily within the same mixture.
“In contrast, the ‘co‐reported drugs’ field in NFLIS reflects substances identified within the same submission, but not necessarily within the same mixture and, therefore, does not reliably capture true polysubstance involvement [26].”
From Temporal and geographical patterns of nitazene detections in drug samples and biospecimens in the United States, 2019–2024 (2026) · cites this paper as [26]
Although NFLIS co-reports other substances in the same seizure, it does not specify whether they were physically mixed, a limitation that precludes valid inference about true polysubstance patterns.
“Although NFLIS ‘co‐reports’ other substances in the same seizure, it does not specify whether they were physically mixed, a well‐recognized limitation that precludes valid inference about true polysubstance patterns [26].”
From Temporal and geographical patterns of nitazene detections in drug samples and biospecimens in the United States, 2019–2024 (2026) · cites this paper as [26]
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- Authors
- Pitts, W. J., Heller, D., Smiley‐McDonald, H., Weimer, B., Grabenauer, M., Bollinger, K., Ropero‐Miller, J., & Pressley, D.
- Affiliations
- RTI International (US)
- RTI International Research Triangle Park North Carolina USA
- Drug Enforcement Administration (US)
- Corresponding author
- Pressley, DeMia
- ORCID
- Venue
- Journal of Forensic Sciences
- Publisher
- Wiley
- Published
- 2023-05-26
- Volume
- 68
- Issue
- 4
- Pages
- 1335-1342
- ISSN
- 0022-1198 (ISSN-L)
- 1556-4029
- OpenAlex
- W4378418055
- Cited by
- 26
- References
- 23
- Citations by year
- 2026: 8 · 2025: 4 · 2024: 8 · 2023: 4 · 2022: 2
- FWCI
- 0.93
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Journal of Forensic Sciences (publishedVersion)
- PubMed (publishedVersion)
- Funders
- United States Drug Enforcement Administration (15DDHQ18D00000018)
- Topics
- Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Toxicology › Forensic Toxicology and Drug Analysis
- Health Sciences › Medicine › Epidemiology › Substance Abuse Treatment and Outcomes
- Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Opioid Use Disorder Treatment
- Keywords
- pharmacovigilance, seized drugs, drug availability, drug use trends, data limitations, methodological pitfalls, predictive modeling
- MeSH terms
- Clinical Laboratory Information Systems, Pharmaceutical Preparations, Forensic Medicine, Humans, United States, Substance-Related Disorders, Law Enforcement
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