Abstract
INTRODUCTION: In recent years gamma hydroxybutyrate (GHB) use appears to have increased. This study aimed to determine: (i) population rates of GHB-related death in Australia, 2001-2021; and (ii) whether there have been changes in the characteristics of GHB-related death in Australia over the period 2001-2023. METHODS: Retrospective study of all Australian cases in which GHB was a mechanism contributory to death retrieved from the National Coronial Information System (n = 217). Joinpoint regression models were used to analyse trends in overall rates. RESULTS: Death rates were stable between 2001 and 2015 ('stable period') (annual percent change [APC] = 3.7) but showed marked acceleration between 2016 and 2021 ('accelerated period') (APC = 44.4). Circumstances of death were: unintentional toxicity (81.6%), intentional toxicity (5.1%), self-harm (6.0%), traumatic injury (7.4%). Compared to the stable period, later cases were slightly older (34.2 vs. 30.7 years, p < 0.05), less likely to be employed (odds ratio [OR] 0.4), but more likely to have substance use problems (OR 3.9), a history of injecting drug use (OR 3.5), mental health problems (OR 3.6), and to have present in their blood at toxicological screening opioids (OR 3.2) and hypnosedatives (OR 3.7). The median blood GHB concentration was 170 mg/L, (range 0-3210), which did not change significantly. There were no differences in major organ pathology, but the proportion with aspiration pneumonia declined (OR 0.4). DISCUSSION AND CONCLUSIONS: GHB-related death rates increased from 2016, accompanied by changes in case characteristics. In recent years GHB use appears to have extended to a population more likely to have substance use problems and use other respiratory depressants.