Figure 1.

American Association of Poison Control Centers (AAPCC) codes, mapped into one of 92 International Classification of Diseases, Version 9 (ICD-9) based substance categories using a stepwise algorithm as shown above. The 10 most common categories of exposures in the emergency department (ED; table 1) were used for the analysis and are labeled ‘Common ED Substance Category’; the remainder are labeled ‘Other Substance Category.’