Annual and Seasonal Trends in Urine Drug Screening Positivity: A Four-Year Retrospective Study at a North Indian Tertiary Care Hospital.

Background Urine drug screening (UDS) using immunoassay-based panels is widely implemented in acute and intensive care settings for patients presenting with altered sensorium, unexplained agitation, or suspected intoxication. The diagnostic yield of UDS, however, varies considerably across regions and time periods, and data from North India remain limited. Immunoassays are subject to limitations such as cross-reactivity and false-positive results. Consequently, longitudinal, center-specific data are essential for contextualizing test utility and optimizing clinical decision-making. Aims and objectives This retrospective study evaluated annual and seasonal variation in UDS positivity and characterized the spectrum of substances detected over a consecutive four-year period at a North Indian tertiary care center. Methods A retrospective observational study was conducted at Max Super Speciality Hospital, Vaishali, a tertiary care center in the National Capital Region (NCR), India. All unique urine drug assay panels performed between January 2022 and December 2025 were analyzed (N = 323), irrespective of patient age, sex, or clinical indication. A panel was considered positive if at least one drug analyte was detected. Data were analyzed by year and season (winter: December-February; summer: March-May; monsoon: June-September; post-monsoon: October-November). Categorical variables were compared using the Chi-squared test, with p < 0.05 considered statistically significant. Results Overall, 42 of 323 panels (13.0%) were positive. Annual UDS positivity was 8.33% in 2022 and 7.63% in 2023, with higher rates of 23.64% in 2024 and 26.83% in 2025. The annual distribution differed significantly across the study years (p = 0.0005). Significant seasonal variation was observed (p = 7.7 × 10⁻⁶), with the highest positivity during the monsoon (27.14%) and summer (20.83%) and the lowest during winter (3.87%). Among 52 analyte-level detections, benzodiazepines accounted for 28 of 52 detections (53.8%), followed by tricyclic antidepressants (6/52, 11.5%) and cannabinoids (5/52, 9.6%). Conclusion UDS positivity varied significantly across study years and showed pronounced seasonal variation, with the highest yield during the monsoon. Benzodiazepines were the most frequently detected drug class. Given the limitations of immunoassays, UDS results should be interpreted within the clinical context, and confirmatory testing should be considered when results would materially affect diagnosis or management. Future multicenter prospective studies incorporating clinical indications and definitive toxicological testing are needed to validate these findings.