The characteristics associated with alcohol co-ingestion in patients visited to the emergency department with deliberate self-poisoning: Retrospective study

Objective: The aim of this study was to investigate the characteristics associated with alcohol co-ingestion by measuring blood alcohol concentration in patients visited to the emergency department with deliberate self-poisoning. Also, it was to evaluate the accuracy of self-reported alcohol ingestion. Methods: The initial assessment forms, medical records and laboratory tests of patients visited to the ED after DSP between March 2017 and June 2020 were retrospectively reviewed. Based on the patients’ BAC, two groups were formed: the non-alcohol group and the alcohol group. Results: This study included 286 patients (56.6%, n = 162) in the non-alcohol group and 43.4% (n = 124) in the alcohol group. In multivariate logistic analysis, alcohol coingestion was independently associated with no history of psychiatric admission (Odds Ratio = 6.222, 95% Confidence Interval = 1.148-33.716, P = 0.034), lactate (mg/dL) (Odds Ratio = 1.961, 95% Confidence Interval = 1.274-3.019, P = 0.002), and C-reactive protein level (mg/dL) (Odds Ratio = 0.003, 95% Confidence Interval = 0.000-0.897, P = 0.046). The receiver operating characteristics analysis of lactate value for the association with alcohol co-ingestion showed a cutoff value of 1.45, with 88.1% sensitivity, 71.6% specificity, and an area under the curve of 0.845. There was no statistically significant difference in emergency department disposition between the two groups. Using the 261 subjects who completed the self-report of alcohol co-ingestion, self-report resulted in 77.6% sensitivity and 76.6% specificity for the assessment of alcohol co-ingestion. The positive and negative predictive values for self-reporting were 72.6% and 81.0%, respectively. Conclusions: Alcohol co-ingestion was associated with no history of psychiatric ward admission, high lactate levels, and low C-reactive protein values in patients who visited the emergency department with deliberate self-poisoning. This study showed that self-reported alcohol co-ingestion was not a substitute for the blood alcohol concentration test.