Acetaminophen Toxicity: Trends in Hospitalization and Their Outcomes in United States from 2002-2011

1012

Introduction: Acetaminophen being one of the leading drug consumed, remains a major cause of overdose and overdose-related liver failure and death in the United States. We aimed to study the trends in acetaminophen toxicity-related hospitalization rate, inpatient mortality and acute liver failure among adults in the US over a period of decade from 2002-2011.

Methods: We queried the National Inpatient Sample (NIS) database from 2002 to 2011 to identify patients diagnosed with acetaminophen overdose using ICD-9-CM codes 965.4 and E 850.4 in any discharge diagnosis. Patients < 18 years of age and those with missing information on age, gender and inpatient mortality were excluded. We retrieved the complications pertaining to acetaminophen toxicity using additional ICD codes for hepatotoxicity. Analysis for trends of means and proportions was done via the Cuzick and Cochran-Armitage tests, respectively. P-values for significance were set a priori at 0.05 for testing any trend direction (two-sided) and at 0.025 for testing specific trend directions (one-sided).

Figure 1

Results: A total of 335512 admissions of acetaminophen toxicity were identified over the period of 10 years, with an increasing trend (0.084% in 2002 to 0.108% in 2011; p < 0.0001). Mean age of the cohort was 36.67±15.12 years with the majority being female (66.0%). The study population was otherwise relatively healthy with a mean Charlson Comorbidity Index (CCI) of 0.55±1.21 and a mean Length of Stay (LOS) of 3.23±4.25 days (median=2). All of the above variables exhibited increasing trends (p < 0.01), except for females who showed a decreasing trend (p < 0.0001). Whites and Native Americans had an increasing trend (p < 0.0001), whereas African-Americans (p=0.003), Hispanics and Asians/Pacific Islanders a decreasing trend (p < 0.0001). Suicidal intent was identified in overall 64.7%, with a decreasing trend. Toxicity-related complications as shown in the figure had an increasing trend (p < 0.0001). The most common complication overall was Acute Liver Failure (5.7%). Inpatient mortality comprised 1.5% of the cases and increased from 1.5% in 2002 to 1.9% in 2011.

Conclusion: During the study period, hospitalization and inpatient mortality rate from acetaminophen toxicity has increased. Acute liver failure was observed to be the most common complication during the hospitalization and its incidence has also increased from 2002 to 2011.