Mortality and repeated poisoning after self-discharge during treatment for acute poisoning by substances of abuse: a prospective observational cohort study

Abstract

BackgroundThough substance use is a known risk factor for self-discharge, patients self-discharging during treatment for acute poisoning have not previously been described. We charted characteristics of patients self-discharging during treatment for acute poisoning by substances of abuse looking for associations between self-discharge, repeated poisoning, and death.MethodsAll patients 12 years and older treated for acute poisoning by substances of abuse at an emergency outpatient clinic in Oslo, Norway, were included consecutively from October 2011 through September 2012. We collected data on gender, age, main toxic agent, suicidal intention, homelessness, history of severe mental illness, and self-discharge. Information on deaths was retrieved from the National Cause of Death Register. We did a multiple logistic regression analysis to look for associations between self-discharge and repeated poisoning and a Cox regression analysis for associations between self-discharge and death.ResultsDuring one year, 1731 patients were treated for 2343 episodes of acute poisoning by substances of abuse. Two-hundred-and-sixty-six (15%) patients self-discharged during at least one poisoning episode. Self-discharging patients were older, median age 39 years vs 32 years (p < 0.001), more frequently homeless, 20/266 (8%) vs 63/1465 (4%) (p = 0.035), and the main toxic agent more frequently was an opioid, 82/266 (31%) vs 282/1465 (19%) (p < 0.001). Self-discharge was an independent risk factor for repeated poisoning. The adjusted odds ratio for two or more poisoning episodes during one year among self-dischargers was 3.0 (95% CI 2.2–4.1). The association was even stronger for three or more poisoning episodes, adjusted odds ratio 5.0 (3.3–7.5). In total, there were 34 deaths, 9/266 (3.4%) among self-discharging patients and 25/1465 (1.7%) among patients not self-discharging (p = 0.12). The adjusted hazard ratio for death among self-discharging patients was 1.6 (0.75–3.6).ConclusionsSelf-discharge was associated with frequent poisonings by substances of abuse. Short-term mortality was doubled among self-discharging patients, though this increase was not statistically significant. Still, the increased risk of repeated poisoning marks self-discharging patients as a vulnerable group who might benefit from targeted post-discharge follow-up measures.

Poisoning-related emergency department visits: the experience of a Saudi high-volume toxicology center

“…The larger mortality rate in the northeast Indian study is validated by an additional observational study that reported an overall mortality rate of 3.4% among self-discharging patients and 1.7% among patients, not self-discharging. 19 The low mortality rate in the current study may be due to the inclusion of all cases labeled as poisoning complaints in the system, regardless of whether they achieved a toxic dose or not.…”

Acute Poisoning Readmissions to an Emergency Department of a Tertiary Hospital: Evaluation through an Active Toxicovigilance Program

“…As mentioned in the methods and materials section, in the Bayesian analysis ( Table 4 ) we assume an OR value and a confidence interval established a priori based on previous studies: OR = 1.17 (0.78, 1.76) (psychiatric history) and OR = 2.06 (1.07, 3.97) (drug abuse intoxication), respectively [ 21 , 22 , 23 , 24 ].…”

“…The previous knowledge gained from the literature was considered for the calculation of the most likely interval to contain the OR. [ 21 , 22 , 23 , 24 ]. In this method, the researcher is asked to give prior values for both the OR and the 95% probability interval.…”

“…Acute poisoning cases (APC) are an important health problem [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ] constituting a notable proportion of emergency hospital admissions. Likewise, it has been observed that patients with APC have a high frequency of readmission [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 20 , 21 , 22 , 23 , 24 , 25 ]. In order to identify possible predictors of repeat APC, various studies were carried out to analyze admission patterns in patients with APC; nevertheless, 85% of them referred to voluntary poisonings.…”

Emergency medical services targeting opioid user disorder: An exploration of current out‐of‐hospital post‐overdose interventions

“…In a study by D'Onofrio et al, 3 the number of patients maintaining successful abstinence from opioids was doubled when buprenorphine was started in the ED compared with a referral for treatment. Once patients leave the hospital, if they have not started treatment, their chances decrease dramatically as they resume patterns of their prior life 57 …”