Normalising methamphetamine

Reported in a soundbite during tonight's TV One News the italicised finding below.

The press release from which the soundbite arose:

Methamphetamine Use And Its Impact On Violence Laid Bare In World-first Study
Wednesday, 19 February 2020, 2:33 pm
Press Release: University of Otago
Almost a third of middle-aged New Zealanders have tried methamphetamine at least once, according to a new University of Otago, Christchurch study looking at the link between using the drug and violence in the general population.

"Almost a third" is 28%; "middle-aged" is 35 and  "New Zealanders" were 1,000 individuals born in Canterbury.

The other big market for meth is Australia. According to Flinders University in Adelaide:

In 2013, 7% of Australians reported that they had used methamphetamine in their lifetime, and 2% reported using in the past 12 months."

"In their lifetime" is a much larger window than by age 35 but read on.

Probably the most reliable NZ source for the prevalence of drug use is the Ministry of Health's  NZ Drug Survey which finds:

In 2015/16, 1.1 percent of adults (95% confidence interval, CI: 0.9–1.5) used amphetamines in the past year. This equates to about 34,000 New Zealanders.

1.1% is much lower than 2%, the Australian finding. Which calls into question the discrepancy between "middle-aged" and lifetime findings.

Back to the Christchurch Study press release:

"The findings show use of methamphetamine is common, as observed in the study’s cohort of middle-aged New Zealanders. According to Christchurch Health and Development data, methamphetamine is the third most common illicit drug after cannabis and ecstasy, Professor Boden says
...He cautions while methamphetamine use increases the risk of involvement in violence most people who used the drug did not engage in violence or experience violence in others.

I appreciate the study focuses on meth and associated violence and that is useful.

But what I heard - and subsequently read - was the message that methamphetamine usage is "common".

I've never used it. In my life I've used cannabis three times and wouldn't expect that to contribute to any claim about usage prevalence today.