We have the worst rate of methamphetamine usage in the country. – West Australian Labor leader Mark McGowan, quoted in The West Australian, February 6, 2017.

The illicit drug methamphetamine, commonly known as “speed”, “crystal meth” and “ice”, continues to make headlines in Australia as communities grapple with its destructive effects.

In a news report outlining the Liberal and Labor party’s strategies for tackling drug-related crime in Western Australia, state Labor leader Mark McGowan was quoted as saying “we have the worst rate of methamphetamine usage in the country”.

Is that right?

Checking the source

When asked for sources to support his statement, a spokesperson for Mark McGowan referred The Conversation to the 2013 National Drug Strategy Household Survey, particularly page 11 of the report, which says:

Meth/amphetamine use was higher in Western Australia (3.8%) than any other jurisdiction.

The spokesperson also referred The Conversation to the state government’s Western Australian Meth Strategy 2016 report, which states on page seven that meth use in Western Australia is higher than the national average.

And the spokesperson cited Western Australia’s Police Commissioner Karl O'Callaghan, who was reported as saying the state continues to have the highest methamphetamine use per capita in Australia.

You can read the full response from McGowan’s office here.

Does Western Australia have the highest rate of methamphetamine use?

Yes. The latest available Australian data, published in the 2013 National Drug Strategy Household Survey, show that 3.8% of the West Australian population had used methamphetamine in the 12 months prior to the survey. That’s nearly double the Australian average of 2.1%.

This isn’t a recent phenomenon. The rate of methamphetamine use in Western Australia has been higher than the rest of the nation since at least the 1990s.

The Conversation , CC BY-ND

The Conversation , CC BY-SA

The rate of methamphetamine use across Australia has been declining since 1998 – including in Western Australia. But over that time, the rate of use in the state has remained consistently higher than the Australian average.

The rate of use of many other drugs, including binge drinking, cannabis and pharmaceuticals for non-medical purposes, is also higher in Western Australia than the Australian average.

How do we know?

The data in the charts above come from the National Drug Strategy Household Survey. It’s a reliable data set that’s been collected every three years since the 1990s.

It’s the only population level data we have that shows drug use trends. That means it collects data from the general population, including people who don’t use drugs at all, not just among specific groups of people who use drugs.

It’s not perfect; no dataset is. The survey has been criticised because it’s likely to underestimate drug use. But it is likely to underestimate usage of all drug types in all locations and relatively consistently over time, so it can give us a good sense of trends over time and differences between states.

All the other reliable data available is collected among people in treatment, people in the justice system, or populations of people who regularly use drugs. The rates of use among these groups is much higher than the general population, so the data doesn’t reflect drug use in the general community.

The 2016 National Drug Strategy Household Survey is due to be released shortly. In general, drug use shows relatively small increases and decreases over time (typically less than half to one percentage point change between years), so it’s unlikely that the 2016 data will buck the long term trend too much.

People are using more potent forms of methamphetamine

Although the rate of methamphetamine use across Australia has stabilised at 2.1% of the population between 2010 and 2013, we have seen a major shift in the type of methamphetamine people are using. Western Australia has seen the same shift as the rest of the country.

In 2010, most people who used methamphetamine preferred to use the less potent powder form, known as “speed”. But by 2013 around half the people surveyed preferred to use the stronger crystal form, known as “ice”. Speed and ice have the same chemical makeup, but ice is a lot stronger.

Changes in methamphetamine use among Australian users aged 14 or older, 2007 to 2013

The majority of people who use methamphetamine use a small amount, very occasionally, for a short period in their life, and never experience any major problems with it. Around 70% of people who used a methamphetamine in the last year used it fewer than 12 times, and many of those used it only once or twice.

But for the small percentage who do experience problems, it is a drug that can cause significant harm.

Even though there hasn’t been a significant increase in the number of people using methamphetamine, the shift to the stronger form means that the risks – which include drug dependence, overdose, aggression and mental health problems – are amplified. As a result, we have seen a big increase in people who use methamphetamine regularly coming to hospital, needing an ambulance, seeking drug treatment and being arrested.

Verdict

Mark McGowan’s statement is correct. Western Australia has the highest rate of methamphetamine use in Australia – and has since records of the use of this drug began. Western Australia has a higher rate of other drug use as well. – Nicole Lee

Review

This is appears to be a fair representation of the available population data. As the author notes, no data set is perfect. When you look at groups of people who regularly use drugs, the jurisdictional trends differ from general population trends.

In addition we’d note the heading would more accurately read “It’s true – Western Australia has the nation’s highest rate of methamphetamine use according to available population data”. – Courtney Breen and Amanda Roxburgh

Have you ever seen a “fact” worth checking? The Conversation’s FactCheck asks academic experts to test claims and see how true they are. We then ask a second academic to review an anonymous copy of the article. You can request a check at checkit@theconversation.edu.au. Please include the statement you would like us to check, the date it was made, and a link if possible.