Under-reporting of meth/amphetamine use in Australia following negative media coverage
Background: There is debate about the validity of prevalence estimates of use of illicit drugs that are socially stigmatised. While Australia experienced an 'ice epidemic', methamphetamine use in population surveys declined. We aimed to test if there was a change in self-reported lifetime prevalence of meth/amphetamine use by birth cohort and if the extent of under-reporting of use was associated with attitudinal ratings of meth/amphetamine use.
Methods: Observational study using seven waves of repeated cross-sectional nationally representative household surveys spanning 2001 to 2019.
Results: Meth/amphetamine reporting decreased in all age cohorts over successive survey years, suggesting under-reporting. Lifetime prevalence decreased from 6.1% (95% CI = 5.3–6.9) to 1.7% (95% CI = 1.2–2.2) in the 1951–1960 birth cohort (p < .001), from 13.0% (95% CI = 12.0–14.1) to 4.4% (95% CI = 3.7–5.2) in the 1961–1970 birth cohort (p < .001) and from 21.4% (95% CI = 19.9–22.9) to 11.2% (95% CI = 10.0–12.4) in the 1971–1980 birth cohort (p < .001).
The proportion of survey respondents who nominated meth/amphetamine as stereotypical of a 'drug problem' increased in all cohorts (all p<.001) and was associated with the degree of meth/amphetamine use under-reporting (b = 0.09, SE = 0.01, p < 0.001).
Conclusion: The prevalence of lifetime meth/amphetamine use in Australia may be up to four-fold higher than estimated in national household surveys. The level of under-reporting is strongly associated with increasing negative attitudes towards meth/amphetamine use.