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Good data, the devil and the details

1 Nov 2018
Rob Zorn
This article was published 6 years ago. Content may no longer be relevant.

At some stage before the next election, New Zealanders will take part in a referendum about cannabis legalisation or decriminalisation. While it’s hard to predict what the outcome will be – we don’t even know yet what the question will be and that will be important – it does seem like some steps towards strictly regulating cannabis are inevitable. Worldwide trends have become too numerous and compelling to ignore. Rob Zorn digs deep.

Those favouring legalisation and regulation claim to have a lot of evidence and want change because they believe it will reduce drug harm by taking control and supply out of the hands of criminals and gangs, ensuring products sold are safe and informatively packaged, providing a point of contact where help with addiction and misuse can be offered, removing criminal convictions for curious young people and moderate users and raising tax revenue that could be spent on education and treatment.

The problem is, if we did legalise, how would we know whether all these great things were actually happening? How would we know important things like how people are changing their drug-taking behaviour and where they are buying their cannabis from? And, in a wider context, how will a legalised and regulated market affect the economy?

Other countries and American states have realised the importance of capturing really good data so they can monitor health and economic trends after legalisation. A number have put monitoring systems and trend analysis mechanisms in place that may or may not be working well but that at least we could learn from.

We’ll look at a few shortly, but the point right now is that, no matter how good the data collection after a law change, its usefulness is diminished if there’s little or no baseline data prior to the law change to compare it to. It’s a problem many other countries and states that have legalised are finding they’re up against.

With them and for us, of course, the problem is that fear of prosecution or other repercussions mean a lot of people won’t tell all about their drug use when surveyed. Secondly, the monitoring we have been doing so far in New Zealand wasn’t really set up with eventual legalisation or decriminalisation in mind. It’s a bit half-pie, infrequent and inconsistent.

The annual New Zealand Health Survey, for example, only looks at prevalence data (last year use) for cannabis and methamphetamine. This doesn’t really give us much of an idea about how frequently, heavily or harmfully people are using – and it tells us nothing about any other drug use. Every few years, the survey will include some additional indicators about harmful use, method of  use and help-seeking behaviours, but it completely ignores things like problems with the law, mental health issues or injury.

What we need is a comprehensive package of drug indicators to monitor things like patterns of consumption, harmful use, negative life impacts, criminal justice-related statistics, attempts to cut down or stop and whether treatment demands are being met. We need that regularly for all drugs, whether legal – alcohol, tobacco and potentially cannabis – or illegal, such as ecstasy, methamphetamine, synthetics or opioids, and we need it now.

Canada has set up baseline collection and more

Canada – a country we should watch because its legalisation process has many features that are likely to be emulated here – has put in place the centralised Cannabis Stats Hub database. This uses crime reporting surveys, tobacco, alcohol and drug surveys, mental health surveys and gross domestic product records to provide up-to-date statistics on the health, justice and economic implications of legalised cannabis use that governments and other agencies can use to detect trends and problems, then deal with them.

The site invites Canadian consumers to submit information about their last purchase to help the hub monitor price estimates. This would be easily emulated here in New Zealand where data from the same sorts of local surveys used in Canada is combined with frequently updated data from consumers.

In fact, we could go a step further and hold yearly, well publicised, funded surveys where people using drugs could answer all sorts of nitty-gritty questions about what they’re using and how much, where they’re getting their drugs and what implications drug use is having in their lives. Online surveys are good for protecting anonymity, they’re cheap to run and the data they produce is easy to crunch. Even if we don’t change our drug laws, we’d still have useful health and economic data the government and agencies could use to target drug-related interventions and spending.

Back in 2016, with legalisation already looming, the Canadian Centre on Substance Use and Addiction embarked on a research agenda to provide evidence-based advice and analysis on the health impacts of cannabis. Among its first steps was identifying data sources and research opportunities. They found that certain questions and considerations – what they termed “cross-cutting issues” – arose consistently.

The first of these was the inconsistencies in the methodologies, measured outcomes and contexts of existing studies on cannabis harms, which made it difficult to draw meaningful conclusions. The second was the obvious fact that it takes a long time to determine the long-term impacts particularly around “causality and the permanence of observed effects”. Third was the identification of gaps in sources of data and that input into what should be collected was essential from all stakeholders. Special mention was made of the need to capture data from the emerging cannabis industry and from stakeholders such as young people and their families.

Washington State measures cost-benefit of legalisation

When voters in the US state of Washington passed Initiative 502 (I-502) in 2012, part of this legislation legalising adult use of cannabis included a direction to the Washington State Institute for Public Policy (WSIPP) to conduct benefit-cost evaluations examining outcomes related to public health, public safety, substances use, criminal justice, economic impacts and administrative costs and revenues. WSIPP was required to produce reports on these outcomes in 2015, 2017, 2022 and 2032.

The WSIPP study also drills down to examine effects of the law change on things like traffic safety, education and school disciplinary actions and workplace safety and productivity.

The 2015 report dealt with the research agenda, and the second report (2017) was concerned mainly with “cannabis abuse treatment admissions” and compared Washington to non-legalising states and with how local differences in the amount of legal sales affected amounts used, treatment admissions and drug-related criminal convictions.

We could pause to point out the second report finds that treatment admissions were not affected by I-502 enactment and that amount of sales had virtually no effect upon the research outcomes generally. But the important thing to note, and perhaps to copy, is the long-term focus of the Washington research agenda – the requirement to report and update data over decades as the full effects of I-502 implementation are better understood.

There are other studies comparing legalising and non-legalising American states that we could learn from. For example, “In the weeds: a baseline view of cannabis use among legalizing states and their neighbours”, published in Addiction in 2016, compared recreational versus medical use in two states that had legalised (Washington and Colorado) with two states that had not at the time (New Mexico and Oregon).

Anticipating legalisation, recruitment for the study began in 2013 and eventually ended up with a knowledge panel consisting of some 50,000 members that was regularly refreshed with new members. The study report covers the responses of 2,100 of these participants over several months (using internet-based surveys and three-minute phone calls) and looks closely at how patterns of use changed with legalisation for both recreational and medicinal users, where they were sourcing their cannabis and whether that changed and things like how much cannabis use in both populations was being combined with alcohol use.

The study found that only a small percent of cannabis users regularly combined their use with alcohol (12 percent) – “an issue of particular concern for those opposed to legalisation”. However, the finding that one in five recreational users combined the two substances – and very few medicinal users did – meant public health campaigns to discourage simultaneous use could be better targeted.

Future WSIPP reports will look more closely at the economic impacts of a legal cannabis market, and efforts are being made to standardise data reporting and make it consistent so that comparators make more sense and a more reliable understanding of the economic impacts can be gained. One of the issues to be looked at, for example, will be how to better target and spend the money and resources now being used for enforcement and justice approaches.

These are exactly the sorts of things we need to know if we’re considering legalisation or decriminalisation, and it would seem sensible to be organising consistent, comprehensive and both short-term and long-term studies now so we can know how best to target interventions and resources to minimise harm across the spectrum when we legalise or decriminalise cannabis along with other drugs.

Of course, decriminalising all drug use would really help data gathering because it would remove a lot of barriers to how people share information about their activities that are currently illegal.

It will take some time before all New Zealanders accept that change is OK, but perhaps an even greater tragedy would be if we listened to the short-sighted views of any who oppose setting up good data gathering now because they believe all drugs should be illegal forever. Such a view may be doomed in the long run, but it could still do a lot of harm and leave us poorly prepared for when legalisation or decriminalisation happens here. 


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