Cost-Effectiveness of Treating Hepatitis C in Clients on Opioid Agonist Therapy in Community Pharmacies Compared to Primary Healthcare in Australia

Abstract

Meeting the World Health Organisation 2030 target of treating 80% of people with hepatitis C virus (HCV) in Australia requires accessible testing and treatment services for at-risk populations. Previous clinical trials, including those in Australia, have demonstrated the efficacy of outreach programmes to community pharmacies offering opioid agonist therapy (OAT). This analysis evaluates the potential cost-effectiveness of introducing an outreach programme in community pharmacies. Using a decision analytic model, we estimated the impact of adding a temporary hepatitis C outreach and treatment programme in community pharmacies to the standard treatment pathway available through general practice. We compared the expected number of tests, diagnoses, cures and costs occurring through the addition of this outreach and treatment programme to those expected through general practice alone over a 12-month time horizon. We examined costs from the perspective of the health system and conducted one-way and probabilistic sensitivity analyses to assess uncertainty in model parameters and test key assumptions. In the model adding the outreach programme pathway increased the number of tests from 4178 to 8737, the number of diagnoses from 615 to 1285 and the number of cures from 223 to 777 among people on OAT over a 12-month period. Each additional cure achieved through the addition of the outreach programme was estimated to incur $48,964 (AUD 2023) to the health system, with > 85% of these costs attributable to medication and dispensing expenses. The average cost per cure was estimated to be $49,152 through routine care and $49,018 in the outreach programme. Although outreach models of care incur large upfront costs, they can capture otherwise unreached populations and result in comparable or favourable cost per cure, due to higher levels of engagement and lower rates of loss to follow-up.

Keywords: cost‐effectiveness analysis; hepatitis C; opiate substitution treatment; pharmacies.

FIGURE 1

Diagram of model structure. Simplified diagram of decision analytic model. In Strategy 1, individuals on OAT can receive testing and treatment through the GP Pathway. In Strategy 2, the population can either flow through the GP Pathway or the Pharmacy Pathway. LTFU, Lost to follow up; Tx, Treatment; ‘+ve’, Positive; ‘‐ve’, Negative.

FIGURE 2

Tornado diagram of one‐way sensitivity analysis. The diagram shows the impact of 9 parameters on the Incremental Cost‐effectiveness Ratio (ICER). The ICER is the incremental cost incurred by the health system per incremental HCV cure gained in Strategy 2 compared to Strategy 1. All costs are AUD 2023. ICER, Incremental Cost‐effectiveness Ratio; OAT, Opioid agonist therapy; P, Probability; Tx, Treatment.

FIGURE 3

Incremental cost‐effectiveness scatter plot showing incremental cost and benefit of adding the pharmacy outreach intervention to GP care (Strategy 2) versus GP care alone (Strategy 1). Each grey diamond represents the incremental costs and cures estimated in a single iteration of the Monte Carlo simulation. All costs are AUD 2023, from the perspective of the health system. GP, General practice; PSA, Probabilistic sensitivity analysis; LB, Lower bound of Uncertainty Interval; UB, Upper bound of Uncertainty Interval.

FIGURE 4

Cost‐effectiveness acceptability curve of adding the pharmacy outreach intervention to GP care (Strategy 2) versus GP care alone (Strategy 1). The curve shows the proportion of Monte Carlo iterations where the ICER of adding the pharmacy outreach intervention to the GP Pathway (Strategy 2) compared to the GP Pathway alone (Strategy 1) was below the cost‐effectiveness thresholds shown on the x‐axis. All costs are AUD 2023. GP: General practice.