Speed and smoking kill: A time-varying survival analysis linking methamphetamine use, cigarette smoking, and...

Sexual minority men (SMM) in the US experience high rates of methamphetamine use and are disproportionately affected by HIV. Unlike prior studies among treatment-seeking populations, this study examined associations between methamphetamine use, smoking, and mortality in a community-based cohort of SMM, half of whom have HIV. Using time-varying survival models, we assessed how dynamic patterns of substance use impact mortality risk over time.

This longitudinal cohort study followed N = 541 SMM in Los Angeles from two community-based sites (2014-2023). Substance use and health outcomes data were collected biannually through behavioral surveys and clinical evaluations. Deaths were defined using the Los Angeles Medical Examiner Database or direct reports from participants' family or friends. We used Cox proportional hazards regression with time-varying covariates to assess the association between methamphetamine use, cigarette smoking, and mortality risk.

There were N = 19 observed deaths in our cohort. Daily methamphetamine use (aHR=4.45, 95 % CI 1.33-14.9), weekly methamphetamine use (aHR=3.32, 95 % CI 1.09-10.1) and smoking more than ½ pack of cigarettes per day (aHR=3.28, 95 % CI 1.07-10.0) were significantly and independently associated with increased risk of mortality, after adjusting for confounders.

Findings confirm that consistent methamphetamine use and cigarette smoking above a threshold frequency of use significantly increase mortality risk among otherwise healthy SMM. Comprehensive interventions including behavioral therapies and risk screening are warranted to mitigate early mortality and improve health outcomes among SMM.