Surveillance of prescription drug-related mortality using death certificate data

The prescription drugs or drug classes that are most frequently associated with death in the US might be identifiable from death certificate data.

To identify the drugs/drug classes associated with the greatest numbers of deaths in the US that might be considered as possible targets for prevention.

US vital statistics data were accessed in order to identify International Classification of Diseases (10th Revision) [ICD-10] codes indicating that prescription drugs had caused or contributed to death and diseases with significant drug-related mortality.

ICD-10 codes for primarily prescription drugs that were listed as the underlying cause or as 'total mentions' on death certificates and were implicated in >or=1000 deaths in any one year were selected. The annual number of deaths by ICD-10 code was obtained from the Division of Vital Statistics, National Center for Health Statistics. Codes for diseases with significant drug-related aetiologies and involvement in >or=1000 deaths in any one year were also identified and analysed separately.

For the selected ICD-10 codes, a total of 25 031 deaths were listed as having a prescription drug as the underlying cause in 2003, compared with 16 135 in 1999, a 55% increase. Total mentions of these codes increased from 46 523 in 1999 to 72 080 in 2003, also a 55% increase. Most codes involved 'poisonings' (overdose or the wrong substance given or taken in error that is accidental, intentional or with undetermined intent). Drugs associated with poisoning deaths had central nervous system effects. Among the codes associated with specified drug classes, poisonings and accidental poisonings involving narcotics, hallucinogens, psychoactive substances and opioids (other than opium and heroin) were associated with the largest numbers of deaths. Drug-related codes associated with the largest percentage increases in deaths between 1999 and 2003 included poisoning due to methadone (275%); poisoning by other and unspecified antidepressants (primarily selective serotonin reuptake inhibitors) [130%]; and poisoning by psychostimulants with potential for abuse (amfetamines and drugs for attention deficit hyperactivity disorder) [117%]. Anticoagulants were associated with the largest numbers of deaths with codes involving "adverse effects in therapeutic use". Among diseases with significant drug-related aetiologies, Clostridium difficile enterocolitis (associated primarily with antibacterials) had the largest percentage increase in total mentions, with a 203% rise between 1999 and 2003.

Deaths due to overdoses are the most prominent cause of drug-related mortality in death certificate data. Certain drugs and drug classes, especially the opioids (e.g. narcotics, methadone), psychoactive drugs (e.g. antidepressants, amfetamines), anticoagulants and antibacterials (which cause or contribute to C. difficile enterocolitis) are associated with large and increasing numbers of deaths and preventive strategies should be considered.