International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes used in this study
| Description | ICD-9-CM codes |
|---|---|
| Poisoning-related diagnoses | |
| Unintentional alcohol poisoning | E860 |
| Unintentional drug poisoning | E850–E858 |
| Illicit opioids (including opium and heroin) | E850.0 (965.00, 965.01)* |
| Prescription opioids (including methadone, and other opiates and related narcotics) | E850.1–E850.2 (965.02, 965.09)* |
| Non-opioid analgesics | E850.3–E850.9 (965.1–965.9)* |
| Sedatives/hypnotics (including barbiturates) | E851–E852, 967* |
| Tranquilisers (including benzodiazepines) | E853 (969.1–969.5)* |
| Antidepressants | E854.0, 969.0* |
| Other psychotropic agents | E854.1–E854.8 (969.6–969.9)* |
| Drugs acting on central and autonomic nervous system | E855 (966, 968, 971)* |
| Other drugs (antibiotics, other anti-infectives and all other drugs†) | E856–E858 (960–964, 972–979)* |
| Substance use disorder-related diagnoses | |
| Alcohol dependence syndrome | 303.0–303.9 |
| Drug dependence | 304.0–304.9 |
| Tobacco use disorder | 305.1 |
| Mood and anxiety disorder-related diagnoses | |
| Bipolar disorders | 296.0–296.1, 296.4–296.9 |
| Depressive disorders | 293.83, 296.2, 296.3, 300.4, 311 |
| Anxiety disorder | 293.84, 300.0–300.3, 300.5, 300.89, 300.9, 308, 309.81, 313 (minus 313.23, 313.81, 313.89, 313.9) |
*When external-cause-of-injury codes (E-codes) for poisoning by the specific type of drug were not available, these additional diagnosis codes were used to identify the drug type.
†‘All other drugs’ include hormones and synthetic substitutes; primarily systemic agents; agents affecting blood constituents, cardiovascular system, gastrointestinal system, smooth and skeletal muscles and respiratory system, skin and mucous membrane, and ophthalmological, otorhinolaryngological and dental drugs; water, mineral and uric acid metabolism drugs; and other specified/unspecified drugs.
Source: Commission on Professional and Hospital Activities.39 The International Classification of Diseases, Ninth Revision, Clinical Modification. Ann Arbor, Michigan, 1978.