Insite: ‘Too early to tell’ if it works?

“I think it’s just too early to tell.”—Ontario health minister Deb Matthews on whether she opposes safe-injection sites, 11/02/2011

In the 1990s, Vancouver was Canada’s capital of drug-related crime and home to the fastest-growing AIDS epidemic in North America. Back then, drug users injecting were a common sight in the city’s Downtown Eastside. They were doing so against the backdrop of a changing HIV epidemic in Canada, with the concentration of the disease shifting from men who have sex with men to addicts sharing needles.

Thus, the city on Canada’s west coast was a fitting locale for Insite, the first safe-injection site on the continent. Allowing people to use pre-obtained drugs under medical supervision could potentially reduce the harms associated with this type of drug use—namely, the risk of overdose and infectious diseases such as HIV and hepatitis C.

Insite fell into the category of what health policy wonks call “harm reduction,” or policies and programs implemented to reduce the adverse health, social and economic consequences of illegal drugs (and other high-risk activities). International health organizations—such as the WHO and UNAIDS—believe in harm-reduction interventions, and endorse them as a key part of a global HIV-prevention strategy.

Since it opened its doors in September 2003, Insite has been the subject of rigorous scientific scrutiny. Evaluating the impact of Insite, after all, was the reason it was granted legal exemption to operate. Some 30 studies about the project have appeared in peer-reviewed journals, and last September, the Supreme Court made the unanimous decision to allow Insite to stay open.

Politicians across the country are pondering whether to set-up safe-injection sites in their own cities. But does the evidence support the decision to follow Vancouver’s lead?

Mortality reduction

Drug overdose is a major cause of mortality among people who inject opioids like heroin. An April 2011 article published in the Lancet looked at whether the opening of Insite was associated with a reduction in overdose mortality. The researchers reported a 35 per cent drop in overdose fatalities in the area around the facility, when comparing the two-year period before Insite opened in 2003, to the two years immediately after. (During the same five-year run, overdose deaths in other parts of the city also declined, but only by nine per cent.)

It’s important, however, to note that this was an observational trial (a population-based assessment) rather than a randomized trial, therefore—despite what the media reported—it does not prove causation.

But there are a few things to take into account: a randomized trial on access to safe injection was deemed unethical. Scientists could not limit the use of the safe-injection site to only those who agree to participate in research. So we will never see a randomized trial done on the site. As a Lancet editorial on the study noted, “for public health interventions for which randomised trials might be unfeasible, unethical, or otherwise unlikely to take place, findings from well-done implementation science are arguably the highest attainable standard of research that we might achieve.” Also, the research published in the Lancet controlled for other explanations of the drop.

One of the study’s authors, Dr. Thomas Kerr, explained to Science-ish that he and fellow researchers looked into heroin use and methadone provision over the same period to see if they declined and thus caused the reduction in overdose death. There had been no change in those measures. “It’s an observational study so you can’t prove anything,” he said, “but you can rule out the most obvious competing explanations.”

Less needle sharing

There is also good evidence that Insite reduces HIV transmission through needle sharing—a primary driver of the HIV epidemic around the world. (In Canada, injection drug exposure accounted for 17.7 per cent of new HIV infections, according to the most recent Public Health Agency of Canada data.) A cohort study, published in the American Journal of Infectious Diseases, looked at a group of Insite users between March and October of 2004. The researchers found that while syringe sharing was still widespread among a small group of Insite users, “rates of syringe sharing among this population are substantially lower than the rate observed previously in this community and it is noteworthy that exclusive (Insite) use was associated with reduced syringe sharing.”

As well, another cohort study, published in the Lancet, looked at injection-drug users around Insite between December 2003 and June 2004, and found that “use of the facility was independently associated with reduced syringe sharing after adjustment for relevant sociodemographic and drug-use characteristics.”

What about the costs…

There have been no controlled trials on cost, so the evidence here isn’t great. However, a researcher at St. Michael’s Hospital in Toronto has developed a model to simulate the project and determine its cost-effectiveness. He concluded that Vancouver’s safe-injection site is associated with cost savings—and improved health outcomes—largely because of evaded cases of HIV. (For criticism of the modelling, read here—though the critics also conclude that Insite is cost-effective.)

As for the impact on public order, there was concern that more drug dealers would cluster around Insite, and that the facility would encourage people to increase their drug use. Shortly after the facility was set-up, researchers looked at its impact on community well-being, measuring drug users injecting in public, publicly discarded syringes, and injection-related litter during the six weeks before and the 12 weeks after Insite opened. Their findings were published in the Canadian Medical Association Journal in 2004. In those weeks, Insite was independently associated with reductions on all those measures.

Bottom line

The evidence we have on Insite is as good as we are ever going to get in demonstrating that this type of program is helpful in managing the harms related to illicit drug use as well as the costs associated with treating related infections.

University of Ottawa professor Dr. Mark Tyndall and some of his colleagues are trying to get funding to support a systematic review of the studies on harm-reduction interventions, including supervised-injection sites. Summarizing the research is a worthwhile pursuit. But, as the Supreme Court recognized, we have sound scientific evidence to support the efficacy of the facility. Yet no more Insites have opened, which raises the question of how many systematic reviews and randomized-controlled trials will be needed to satiate politicians whose default is a tough-on-crime agenda—not prevention or harm reduction.

Consider this: Canada does not have a national harm-reduction policy, and the federal government has allocated 70 per cent of its $64 million in funding for the National Anti-Drug Strategy to law enforcement, according to this informal audit. Only 17 per cent is allocated to treatment, and four per cent to prevention.

“This policy,” Dr. Tyndell said, “has nothing to do with evidence and everything to do with ideology and the war on drugs.”

Hopefully, though, the evidence will win.

By Julia Belluz