Steps ICD-10 Codes
1. Include all deaths with an underlying COD for poisonings from controlled substances X41 X61 Y11 X42 X62 Y12
2. Include deaths with an underlying COD from poisonings due to unknown and other substances only if there is an associated controlled substance toxicology code X40 X43 X44 X60 X63 X64 Y10 Y13 Y14 and controlled substance toxicology codes
3. Include deaths with an underlying COD from poisonings due to unknown and other substances, where no controlled substance toxicology is specified, but a controlled substance use disorder code is present in contributing COD X40 X43 X44 X60 X63 X64 Y10 Y13 Y14 and controlled substance use disorder codes
4. Include deaths with an underlying COD from poisonings due to unknown and other substances, where no controlled substance toxicology is specified, no controlled substance use disorder code is present in contributing COD, but the only poisoning T code is T50.9 X40 X43 X44 X60 X63 X64 Y10 Y13 Y14 and T50.9
5. Include deaths with underlying COD of a controlled substance use disorder F11 F12 F13 F14 F15 F16 F19
6. Include deaths with underlying COD of selected controlled substances causing adverse events during therapeutic use Y45.0 Y47.0 Y47.1 Y47.5 Y47.8 Y47.9 Y49.6 Y49.7 Y49.8 Y49.9
7. Among deaths not yet included, add those records where there is controlled substance toxicity or controlled substance poisoning in the contributing COD fields, but no X85 in the underlying COD X85 and controlled substances poisoning and toxicology codes
Definitions  
Controlled substance toxicology codes T40.0 T40.1 T40.2 T40.3 T40.4 T40.6 T40.5 T42.4 T42.3 T43.6 T41.2 T40.7 T40.8 T40.9 T52.8
Controlled substance use disorder codes F11 F12 F13 F14 F15 F16 F19
Poisoning T codes T36 through T65
Controlled substance poisoning codes X41 X61 Y11 X42 X62 Y12
ICD-10: International Classification of Disease, 10th revision
COD: cause-of-death
Table 5: Proposed ICD-10-based definition of overdose mortality from controlled substances for vital statistics (Definition 8).