Drug-related Causes the Primary Reasons for Death among People with Injection Drug Use who are Seropositive for HCV

To determine whether hepatitis C virus (HCV) is a major cause of mortality among people who use injection drugs, this observational cohort study included 523 HCV seropositive patients admitted to residential substance use treatment in Norway followed using the national mortality register.

• Of the 523 HCV seropositive people with injection drug use, 63% were HCV RNA+ (i.e., had chronic infection).
• At the end of follow-up (mean 33 years), 42% died.
• The mortality rate for HCV RNA+ people was 1.75 per 100 person-years, versus 2.05 in HCV- people (i.e., presumed to have spontaneous clearance)(P=0.25).
• Opioid overdose was the most frequent cause of death, followed by violent death and suicide.
• Twelve patients (7.5%) died of liver disease; 10 were HCV RNA+ and the remaining 2 had chronic hepatitis B.
• Restricting analyses to those ≥50 years of age, the liver-related mortality rate was 0.94 per 100 person-years among HCV RNA+ people, and was 0 (no deaths) among those who were HCV RNA-.

Comments:

This study confirms high mortality rates for people who use injection drugs and reinforces that drug-related causes remain the primary risks for death in this population. Thus, some patients with HCV may not benefit from HCV treatment because of competing causes of death. However, among people with injection drug use who survive beyond age 50, liver-related mortality emerges as a cause of premature death, confirming prior modeling studies. The study’s main finding should be cautiously interpreted given that there was some potential for misclassification bias (cases of unidentified reinfection or clearance through treatment).

Judith Tsui, MD, MPH

Reference:

Kielland KB, Skaug K, Amundsen EJ, Dalgard O. All-cause and liver-related mortality in hepatitis C infected drug users followed for 33 years: A controlled study. J Hepatol. 2013;58(1):31–37.