All-cause mortality among individuals with disorders related to the use of methamphetamine: A comparative cohort study

Background: Understanding the mortality rate of methamphetamine users, especially in relation to other drug users, is a core component of any evaluation of methamphetamine-related harms. Although methamphetamine abuse has had a major impact on United States (US) drug policy and substance-abuse treatment utilization, large-scale cohort studies assessing methamphetamine-related mortality are lacking. Methods: The current study identified cohorts of individuals hospitalized in California from 1990 to 2005 with ICD-9 diagnoses of methamphetamine- (n=74,139), alcohol- (n=582,771), opioid- (n=67,104), cannabis- (n=46,548), or cocaine-related disorders (n=48,927), and these groups were followed for up to 16 years. Age-, sex-, and race-adjusted standardized mortality rates (SMRs) were generated. Results: The methamphetamine cohort had a higher SMR (4.67, 95% CI 4.53, 4.82) than did users of cocaine (2.96, 95% CI 2.87, 3.05), alcohol (3.83, 95% CI 3.81, 3.85), and cannabis (3.85, 95% CI 3.67, 4.03), but lower than opioid users (5.71, 95% CI 5.60, 5.81). Conclusions: Our study demonstrates that individuals with methamphetamine-use disorders have a higher mortality risk than those with diagnoses related to cannabis, cocaine, or alcohol, but lower mortality risk than persons with opioid-related disorders. Given the lack of long-term cohort studies of mortality risk among individuals with methamphetamine-related disorders, as well as among those with cocaine- or cannabis-related conditions, the current study provides important information for the assessment of the comparative drug-related burden associated with methamphetamine use.