Self-reported drug use and mortality among a nationwide sample of Swedish conscripts - a 35-year follow-up

Abstract

Background: Drug users in clinical samples have elevated mortality compared with the general population, but little is known about mortality among users of drugs within the general population.

Aim: To determine whether self-reported use of illicit drugs and non-prescribed sedatives/hypnotics among young men in the general population is related to mortality.

Methods: A 35-year follow-up of 48024 Swedish men, born 1949-1951 and conscripted in 1969/1970, among whom drug use was reported by 8767 subjects. Cross-record linkage was effected between individual data from the Swedish conscription and other national registers. Deaths and causes of death/1000 person-years were calculated. Cox PH regression was used to estimate hazard ratios (HRs) for death with 95% confidence intervals (95% CIs). An HR was calculated for users of different dominant drugs at conscription compared with non-users by age interval, after adjusting for confounders and hospitalisation with a drug-related diagnosis.

Results: Drug users showed elevated mortality (HR 1.61, p<0.05) compared with non-users. After adjusting for risk factors, users of stimulants (HR 4.41, p<0.05), cannabis (HR 4.27, p<0.05), opioids (HR 2.83, p>0.05), hallucinogens (HR 3.88, p<0.05) and unspecified drugs (HR 4.62, p<0.05) at conscription with a drug-related diagnosis during follow-up showed an HR approaching the standard mortality ratios in clinical samples. Among other drug users (95.5%), only stimulant users showed statistically significantly increased mortality (HR 1.96, p<0.05).

Conclusions: In a life-time perspective, drug use among young men in the general population was a marker of premature death, even a long time after exposure.