The INTOXICATE study: Methodology, experience and preliminary results of a prospective cohort study

Abstract

Background No practice-based, multicenter database of poisoned patients admitted to intensive care units (ICUs) exists. The INTOXICATE study, endorsed by the ESICM and EAPCCT, aimed to collect detailed data on such patients. We hypothesized that the proportion of ICU intoxicated patients requiring genuine intensive care would be greater than previously reported. Methods Ethical approval was obtained for this multicenter, prospective study, and data-sharing contracts were signed. An electronic case report form was used to collect patient demographics, exposure, clinical features, investigations, treatment, and in-hospital mortality. The primary outcome was the proportion of patients who received mechanical ventilation and/or vasopressors in the first 24 h after ICU admission, and/or who died in the hospital. A one-proportion z test was used to test the difference in outcome in this study compared with the proportion of 6.5% previously observed in a large study. Results Seventy-eight ICUs, mainly from Europe, but also from Australia and the Eastern Mediterranean, participated. The median time to sign a data sharing agreement between a unit and the coordinating center was 17 months. A total of 2,275 patients were enrolled between November 2020 and June 2023. The median patient age was 41 years, 72% of whom were exposed to human drugs; neurological symptoms were the most common clinical feature (83% of admissions), and the ICU mortality rate was 3.7%. The observed proportion of patients with the primary outcome (requiring ICU treatment) was 40% versus 6.5% as previously mentioned (p-value < 0.001). Conclusions This study collected high-quality detailed clinical data from a large cohort of acutely intoxicated ICU patients. The proportion of intoxicated patients admitted to the ICU and requiring ICU treatment was much greater than previously mentioned. The challenges identified during the study setup and data collection will enable modifications of these processes for future data collection studies. Trial registration OSF registration ID: osf.io/7e5uy