A Cost Analysis of Overdose Management at a Supervised Consumption Site in Calgary, Canada

Background and Aims: We report on a cost study, using population level data to determine the impact of emergency overdose management at supervised consumption services (SCS) versus conventional services. Design: We completed a cost analysis from a payer’s perspective. In this setting, there is a single-payer model of service delivery. Setting: In Calgary, ‘Safeworks Harm Reduction Program,’ was established in late 2017 and offers 24/7 access to SCS. T he facility is a nurse-led service, available for client drop-in. We conducted a cost analysis for the entire duration of the program. T his covers two years and three months. Measurements: We assessed costs using the following factors, using government health databases: monthly operational costs of providing services for drug consumption, cost of providing EMS for clients with overdoses who could not be revived at the facility, and benefit of EMS costs averted from overdoses that were successfully managed at the SCS. Findings: T he proportion of clients who have overdosed at the SCS has decreased Qeios, CC-BY 4.0 · Article, June 9, 2020 Qeios ID: J6MQ0E · https://doi.org/10.32388/J6MQ0E 1/10 steadily for the duration of the program. T he number of overdoses that can be managed on site at the SCS has trended upward, currently 98%. Each overdose that is managed at the SCS produces approximately $1,600 CAD in cost savings, with a savings of over $2.3 million for the lifetime of the program. Conclusions: Overdose management at an SCS creates cost savings by offsetting costs required for managing overdoses using emergency services. Introduction Supervised consumption services (SCS) are a harm reduction intervention to provide a sanctioned area for clients to use illicit substances, under medical supervision, without crimination (1). A primary aim of SCS is overdose prevention and SCS are widely accepted as decreasing fatal accidental overdoses (2). SCS in Canada began with the creation of Insite in Vancouver in 2003 (1). Before SCS were introduced, conventional services, including ambulance response and emergency departments, are used to support people with overdoses who need medical attention. T here is substantial evidence of the benefits of SCS. Insite, in Vancouver, has been widely studied and demonstrated social and economic benefits across a range of measures (1-6). T he cost savings relating to HIV infections alone were enough to offset Insite’s operating costs (1, 5). Estimates related to the prevention of Hepatitis C transmission also showed evidence of significant cost savings (1, 4). Proposals for SCS illustrated projected cost effectiveness in T oronto (7), Victoria (8), Ottawa (7, 9), San Francisco (10) and Baltimore (11). While there are well documented benefits of SCS, studies are limited to a few sites (6). Cost-benefit analyses have tended to focus on HIV prevention or economic benefit of prevented deaths, without including other aspects of the SCS programs (6). T here are also challenges in evaluating cost benefits. Clients at SCS may not be required to provide personal health numbers or identifying information, to avoid potential crimination. However, SCS do collect population level data about service use. Our cost analysis study overcomes these limitations by evaluating the population level benefit of decreased use of emergency services, at an SCS site that has not been previously reported in the literature. In this article, we use population level data in a cost analysis, to determine the impact of emergency overdose management at SCS versus conventional services. Please note that all currencies are reported in Canadian dollars. At time of writing, $1 CAD = £0.59 GBP. Methods Overdose management was the point of analysis in this study. Overdose (OD) Qeios, CC-BY 4.0 · Article, June 9, 2020 Qeios ID: J6MQ0E · https://doi.org/10.32388/J6MQ0E 2/10 management in this study is defined as the application of a medical intervention to a client who is not rousable, following consumption of an illicit substance. T his includes application of oxygen, administration of naloxone, or calling Emergency Medical Services (EMS). Verbally rousing the client, or a client with a ‘heavy nod’ were excluded from definitions of overdose in this study, limiting the definition of overdose to objectively verifiable information. Oxygen is considered a medical intervention, because the primary cause of overdose related death is hypoxia (12). Research Site In Calgary, a large city in Canada, ‘Safeworks Harm Reduction Program,’ was established in late 2017 and offers 24/7 access to SCS (13). T he facility is a nurse-led service, available for client drop-in. Registered Nurses are always available to reverse an overdose or resuscitate a client. T he nurses are equipped to administer oxygen and naloxone, if needed. We conducted a cost analysis for the entire duration of the program. T his covers two years and three since the service began. Study Desig n T his cost analysis was completed from a payer’s perspective. A payer in this study refers to the entity (provincial government) providing funding to run the service. T he following factors were chosen based on the availability of data to evaluate the cost effectiveness of the site: monthly operational costs of providing service for drug consumption, cost of providing EMS for clients with overdoses who could not be revived at the facility, and benefit of EMS costs averted from overdoses that were successfully managed at the SCS. Data Overdose data was extracted from the monthly, publicly available Government opioid reports (14-16) for the months of November 2017 to January 2020. Some data was imputed, and the methodology is provided in Appendix A. Analytic methods We computed descriptive statistics for the dataset. In addition, we examined the trend in the number of clients who overdosed at the SCS site. T o develop an accurate visualization of the data, we have calculated a percentage for the number of overdoses for each month per number of total visits for drug consumption to the SCS, illustrating an overall trend line for overdose rates. Qeios, CC-BY 4.0 · Article, June 9, 2020 Qeios ID: J6MQ0E · https://doi.org/10.32388/J6MQ0E 3/10 Costs T he costs were divided into two categories: 1) operating costs for providing services at the SCS and 2) cost of EMS for clients who overdosed at the site but required additional intervention. Operating Costs at the SCS site T he first component of the analysis comprised of the operating costs at SCS site. A recent study (13) by the government of Alberta reports that the average cost per visit for drug consumption is $62.19. T he operating cost at the SCS was calculated by employing the following formula:


Introduction Introduction
Supervised consumption services (SCS) are a harm reduction intervention to provide a sanctioned area for clients to use illicit substances, under medical supervision, without crimination (1). A primary aim of SCS is overdose prevention and SCS are widely accepted as decreasing fatal accidental overdoses (2). SCS in Canada began with the creation of Insite in Vancouver in 2003 (1). Before SCS were introduced, conventional services, including ambulance response and emergency departments, are used to support people with overdoses who need medical attention. T here is substantial evidence of the benefits of SCS. Insite, in Vancouver, has been widely studied and demonstrated social and economic benefits across a range of measures (1)(2)(3)(4)(5)(6). T he cost savings relating to HIV infections alone were enough to offset Insite's operating costs (1,5). Estimates related to the prevention of Hepatitis C transmission also showed evidence of significant cost savings (1,4). Proposals for SCS illustrated projected cost effectiveness in T oronto (7), Victoria (8), Ottawa (7,9), San Francisco (10) and Baltimore (11).
While there are well documented benefits of SCS, studies are limited to a few sites (6).
Cost-benefit analyses have tended to focus on HIV prevention or economic benefit of prevented deaths, without including other aspects of the SCS programs (6). T here are also challenges in evaluating cost benefits. Clients at SCS may not be required to provide personal health numbers or identifying information, to avoid potential crimination.
However, SCS do collect population level data about service use. Our cost analysis study overcomes these limitations by evaluating the population level benefit of decreased use of emergency services, at an SCS site that has not been previously reported in the literature. In this article, we use population level data in a cost analysis, to determine the impact of emergency overdose management at SCS versus conventional services.
Please note that all currencies are reported in Canadian dollars. At time of writing, $1 CAD = £0.59 GBP.

M ethods M ethods
Overdose management was the point of analysis in this study. Overdose (OD) to the entity (provincial government) providing funding to run the service. T he following factors were chosen based on the availability of data to evaluate the cost effectiveness of the site: monthly operational costs of providing service for drug consumption, cost of providing EMS for clients with overdoses who could not be revived at the facility, and benefit of EMS costs averted from overdoses that were successfully managed at the SCS.

Data Data
Overdose data was extracted from the monthly, publicly available Government opioid reports (14)(15)(16) for the months of November 2017 to January 2020. Some data was imputed, and the methodology is provided in Appendix A.

Analytic methods Analytic methods
We computed descriptive statistics for the dataset. In addition, we examined the trend in the number of clients who overdosed at the SCS site. T o develop an accurate visualization of the data, we have calculated a percentage for the number of overdoses for each month per number of total visits for drug consumption to the SCS, illustrating an overall trend line for overdose rates.

T otal B enef it, N et Saving s, B enef it-Cost Ratios and Cost Ef f ectiveness Ratios T otal B enef it, N et Saving s, B enef it-Cost Ratios and Cost Ef f ectiveness Ratios
We added the values for overdose EMS costs that were averted to determine the total benefits of overdose management at the SCS.

Preliminary Analysis
Preliminary Analysis

Overdose trends
Overdose trends T he data shows that the number of overdoses at the site have been increasing over time. However, the number of visits for drug consumption have also increased over time.
T he linear trend line in Figure 1 shows that the percentage of overdoses declined between November 2017 to January 2020. T hese costs use the minimum billing fee for the payer and exclude overdose related hospitalization costs, and thus, likely underestimate total costs saved.

Discussion Discussion
T his study focuses on a harm reduction service that is part of a complement of programs to address substance misuse, in the context of an opioid crisis. Our study demonstrates that SCS can be justified in part by their benefits in managing overdoses.
T he declining trend of overdoses indicates the effectiveness of the program in preventing overdoses, as well as managing them. A reduction in the number of overdoses would result in lowering the rate of overdose related deaths and saving more lives, which adds value to the economy and society.
T he cost savings of overdose management at the SCS, although substantial, were not sufficient to offset the operating cost of the program. However, this study examined only one aspect of the SCS's potential cost benefits. Several authors found significant cost savings associated with reduced needle sharing at SCS sites (1,3). It is likely that the T his study was conducted using available data since the inception of the SCS site in late 2017. Some missing data had to be inferred from similar studies conducted in other provinces and countries. Given the limitations of the anonymous service in this study, more in-depth data on hospitalization and other social service referrals also could not be obtained. Future studies could explore other ways to measure cost-benefit without identifying information from clients.
T he study does not employ an economic evaluation methodology due to time and data restrictions. T he SCS site is currently under review and have been assigned limited time to present evidence of cost evaluation. As a result, the scope and underlying methodologies are brief and allow limited analysis. Moreover, due to the COVID-19 pandemic, movements are restricted, rendering it infeasible to conduct primary surveys.
T his analysis demonstrates the need to conduct economic evaluations of SCS sites.
Literature on SCS widely documents the direct benefits of reduced HIV and Hepatitis C infections, skin and soft-tissue infections, economic benefits of overdose related deaths prevented and the indirect benefits of social service referrals; adding these factors to Qeios, CC-BY 4.0 · Article, June 9, 2020 Qeios ID: J6MQ0E · https://doi.org/10.32388/J6MQ0E 8/10 overdose management will improve the analysis.

Conclusion Conclusion
In this study, we identified notable cost savings produced through overdose management at SCS. T his reduced the reliance on emergency services. In addition, the number of overdoses at the SCS has decreased. T he SCS thus offers direct savings, and secondary benefits from fewer visits to emergency departments. Future studies could explore these benefits in more depth.

Ref erences
Ref erences