Modelling the cost-effectiveness of population-level HAART expansion in British Columbia

2015 | Lancet HIV

Program(s): Epidemiology and Population Health |
Topic(s): Treatment as Prevention® |

Abstract:

Background

Widespread HIV screening and access to highly-active antiretroviral treatment (HAART) has been deemed cost-effective using mathematical models, though its population-level implementation has raised questions regarding cost, value and feasibility. We aimed to determine the cost-effectiveness of HAART scale-up in British Columbia (BC), Canada compared to scenarios of constrained treatment access.

Methods

Using comprehensive linked population-level data, we populated a dynamic, compartmental transmission model to simulate the HIV/AIDS epidemic in BC from 1997–2010. HIV incidence, prevalence, mortality, costs (in 2010$CDN) and quality-adjusted life years (QALYs) were estimated. Incremental cost-effectiveness ratios (ICERs) were calculated from societal and third party payer (TPP) perspectives to compare actual practice (true numbers of individuals accessing HAART) to scenarios of constrained expansion (75% and 50% probability of accessing HAART). Structural and parameter uncertainty was investigated.

Findings

Actual practice resulted in 263 and 676 averted incident cases compared to the 75% and 50% HAART access scenarios, respectively. From a TPP perspective, actual practice resulted in ICERs of $23,679/QALY versus 75% access, and $24,250/QALY versus 50% access. From a societal perspective, actual practice was cost-saving within the study period, and, resulted in savings of $25.1M compared to the 75% access scenario, and $65.5M compared to the 50% access scenario with an extended time horizon (2035).

Interpretation

HAART expansion in BC has decreased HIV-related morbidity, mortality and transmission. Resulting ICERs for actual practice, derived within a limited timeframe, were within common cost-effectiveness thresholds, and were cost-saving from a societal perspective.