The cost-effectiveness of Vancouver's supervised injection facility

Abstract

Supervised injection sites offer a safe and hygienic environment for people to inject their previously obtained illicit drugs under supervision.1,2 Observational studies from the facility in Vancouver, British Columbia, have demonstrated positive effects: a decrease in needle sharing and reuse of syringes, fewer people injecting drugs in public, an increase in referrals to social services and addiction counselling, a decrease in the number of publicly discarded syringes, no apparent increase in police reports of drug dealing or crime, and no observed increase in new initiates into drug use. [3][4][5] Although an expert advisory committee recently concluded that the Vancouver facility has beneficial effects, prominent law enforcement groups have argued that the resources allocated to the facility would be more effectively spent elsewhere. 6,7 We used computer simulation to estimate the projected impact of Vancouver's supervised injection site on survival, rates of HIV and hepatitis C virus infection, referral to methadone maintenance treatment and associated costs. Our goal was to assess the cost-effectiveness of the facility and thus provide important insights into this policy debate. Methods Simulation modelWe developed a dynamic compartmental model to simulate the population of Vancouver, British Columbia. The population included injection drug users, non-users, persons with HIV and hepatitis C virus infection, and those with combinations of these states. Our model categorized populations into discrete compartments. By defining the probabilities of moving between compartments, we were able to project the prevalence of each model state throughout the time horizon of the simulation. Tracking the time spent in each state allowed us to estimate survival. Assigning a cost to each state allowed us to estimate net costs of treatment. The perspective of the model was that of a health care system. Accordingly, we included direct medical costs but did not include indirect medical costs or other societal costs. We used a time horizon of 10 years and updated the proportion in each model state every 0.1 years. We used a discount rate of 5% for both costs and life expectancy.

Examining the potential role of a supervised injection facility in Saskatoon, Saskatchewan, to avert HIV among people who inject drugs

“…The first model was initially used in Edmonton, Alberta's evaluation of a needle exchange program in 1999. Later, the model was used in an economic evaluation of Insite (14)(15)(16)(17)(18)25,26). In addition, the model has been used to estimate the cost-benefit/cost-effectiveness of a SIF potential in Montreal, Quebec, and Ottawa, Ontario (10,19).…”

“…Previous costing studies have illustrated that SIF prevent shared or 'dirty' injections (10,(15)(16)(17)(18)(19)28,29). Behavioral changes for those who attend SIF has been highlighted as an important factor in previous literature as well (30,31).…”

“…Some of the noted effects are reduction in overdose deaths, needle sharing, public injection and public discarded needles (12)(13)(14). In addition, most empirical analysis have reported cost-effectiveness of Insite in reducing HIV, HCV and overdose cases (4,(15)(16)(17)(18). More recently, a longitudinal study has suggested that the rate of needle sharing decreased substantially overtime along with a secondary effect in the reduction of HIV contractions (11).…”

Applying Total Quality Management Cost Model in Drug Intervention Programme

“…The introduction of harm reduction, particularly needle exchange, was met with much public opposition [7]- [10]. However, transmission of HIV is found largely due to sharing of syringes among drug users and practicing unsafe sex.…”

Commentary on Salmon et al. (2010): The case for safer inhalation facilities—waiting to inhale

“…Empirical data on SIFs lagged well behind their scale-up, but SIFs have now been shown to decrease HIV risk behaviors [1], overdose deaths [2] and public disorder [3], and increase uptake of detoxification services [4]. In this issue, Salmon and colleagues [5] demonstrate dramatic decreases in ambulance attendances at opioid-related overdoses in the period following the opening of the Sydney SIF, a finding that supports program cost-effectiveness [6]. While SIFs remain controversial, there are at least 90 SIFs in 40 cities globally.…”