Drug use generations and patterns of injection drug use: Birth cohort differences among people who inject drugs in Los Angeles and San Francisco, California

Drug Alcohol Depend. 2017 Jun 1:175:210-218. doi: 10.1016/j.drugalcdep.2017.04.001. Epub 2017 Apr 19.

Abstract

Objectives: A robust literature documents generational trends in drug use. We examined the implications of changing national drug use patterns on drug injection histories of diverse people who inject drugs (PWID).

Methods: Drug use histories were collected from 776 active PWID in 2011-13. Using descriptive statistics, we examine drug use initiation by year and birth cohort (BC) differences in drug first injected. A multivariate linear regression model of time to injection initiation ([TTII] (year of first injection minus year of first illicit drug use) was developed to explore BC differences.

Results: The first drug injected by BC changed in tandem with national drug use trends with heroin declining from 77% for the pre-1960's BC to 58% for the 1960's BC before increasing to 71% for the 1990's BC. Multivariate linear regression modeling found that shorter TTII was associated with the 1980's/1990's BC (-3.50 years; 95% Confidence Interval [CI]=-0.79, -6.21) as compared to the 1970's BC. Longer TTII was associated with being female (1.65 years; 95% CI=0.40, 2.90), African American (1.69 years; 95% CI=0.43, 2.95), any substance use treatment prior to injection (4.22 years; 95% CI=2.65, 5.79), and prior non-injection use of drug that was first injected (3.29 years; 95% CI=2.19, 4.40).

Conclusion: National drug trends appear to influence injection drug use patterns. The prescription opiate drug era is associated with shorter TTII. Culturally competent, demographically and generationally-targeted prevention strategies to combat transitions to drug injection are needed to prevent or shorten upstream increases in risky drug use practices on a national level.

Keywords: Birth cohorts; Heroin initiation; Illicit prescription opioid use; Injection drug use; Life course theory; Time to injection initiation.

MeSH terms

  • Adult
  • Age Factors*
  • Cohort Studies
  • Female
  • Heroin
  • Humans
  • Linear Models
  • Los Angeles / epidemiology
  • Male
  • Middle Aged
  • Multivariate Analysis
  • San Francisco / epidemiology
  • Substance Abuse, Intravenous / epidemiology*
  • Substance-Related Disorders / epidemiology*
  • Young Adult

Substances

  • Heroin