Increased mortality associated with dependence on legal drugs?

Mortality among subjects previously apprehended for driving under the influence of traffic-hazardous medicinal drugs

BACKGROUND

Most studies in the field of impaired driving have focused on the hazards represented by impaired drivers to the rest of society; there has been little follow-up of the drivers themselves. The aim of this study was to establish mortality rates among subjects previously apprehended for driving under the influence of traffic-hazardous medicinal drugs, alone or in combination with alcohol.

METHODS

A prospective cohort study of all drivers aged 20-49 years, apprehended in Norway in 1992-1996 and testing positive for traffic-hazardous medicinal drugs in blood, outcome variable: death.

STUDY POPULATION

805 drivers (598 males, 207 females). Mean follow-up period: 6.8 years. Information on deaths was collected from Statistics Norway.

RESULTS

During the follow-up period, 139 of the previously apprehended drivers died (110 males, 29 females). The calculated standardised mortality ratio (SMR) was 15.8 (95% CI: 13.0-19.0) for male and 20.0 (95% CI: 13.4-28.7) for female drivers.

CONCLUSIONS

Apprehension on suspicion of driving under the influence of drugs, combined with detection of traffic-hazardous medicinal drugs in the blood, seems to indicate an elevated risk of premature death in the age group 20-49 years. Secondary prevention of continued drug use could save lives in this drug user group.

Mortality in patients with substance abuse: a follow-up in Stockholm County, 1973-1984

A group of patients (N = 1630) hospitalized in Stockholm County with a diagnosis of substance abuse during 1971-1972 were followed through 1984 as regards mortality: 446 (296 males and 150 females) patients died. The excess mortality in the cohort was 5.3 (males 5.8, females 4.6) compared to the general population in Stockholm County. The highest mortality was found in opiate users, with an excess mortality of 18.3. Fifty-one percent of the causes of death belonged to ICD-8 chapter 17, injury and poisoning, and of these, 69% (155 patients) were definite or probable suicides. Since HIV entered the Stockholm drug addict population by the end of this follow-up, the excess mortality reported here can be even higher in the years to come. To follow and monitor the mortality among patients with substance abuse is an important aspect in the evaluation of programs for prevention and treatment.

Mortality of patients dependent on benzodiazepines

For patients dependent on benzodiazepines alone, or in combination with alcohol and/or other legal and illegal drugs, observed mortality rates were compared with the average population, and, in cases of isolated benzodiazepine dependence, also with a control group of non-dependent patients chosen to match each dependent not only in sex and date of birth, but also in pre-existing psychiatric illness besides dependence. For patients with an isolated benzodiazepine dependence, the mortality rate was increased, when compared with the average population, by a ratio of observed to expected numbers of deaths of about 3. However, this mortality rate did not differ from that of the control group (non-dependent patients with comparable psychiatric illnesses). For patients combining benzodiazepines with alcohol among other addictive drugs, and for patients combining benzodiazepines with illegal drugs among other addictive substances, the ratio of observed to excepted numbers of deaths was 6.2 resp. 21, thus corresponding well with other studies on mortality rates associated with alcoholism and dependence on illegal drugs. We conclude that our study does not give evidence of higher risk of early death correlated with dependence on benzodiazepines alone. However, it confirms the well-known fact of increased mortality rates in patients with psychiatric illnesses, especially with dependence on alcohol or illegal drugs.