Cost-Utility Analysis of Clinical Decision Rules for Group A Streptococcal Pharyngitis Management in Jamaica: A Markov Modelling Study

Abstract

Background
Group A Streptococcal (GAS) pharyngitis management requires clinical expertise to differentiate viral from bacterial aetiology, and also balancing antibiotic stewardship with prevention of acute rheumatic fever (ARF) and rheumatic heart disease (RHD). Jamaica maintains an active ARF and RHD control programme, yet antibiotic overuse remains problematic. This study evaluates the cost-utility of implementing clinical decision rules (CDR) with rapid antigen detection tests (RADT) compared to current pharyngitis management practices.
Methods
We conducted cross-sectional surveys at 22 public health centres and two insurance companies in Kingston and St Andrew to determine 2018 pharyngitis incidence, and at five regional hospitals to calculate direct RF and RHD costs. Data were incorporated into a Markov model comparing four strategies: no treatment, current empirical practice, universal antibiotic treatment, and CDR-guided management with RADT. The model adopted a healthcare system perspective with an 81-year time horizon. Costs were expressed in 2018 US dollar value. Deterministic and probabilistic sensitivity analyses examined parameter uncertainty.
Findings
The CDR strategy dominated all alternatives in both discounted and undiscounted analyses, demonstrating lowest lifetime costs ($7.92 per patient) and highest Disability-adjusted Life Years (DALYs) averted. Compared to current practice, CDR implementation would save $21.84 per person while improving health outcomes. At 15.7% of Jamaica’s 2018 weekly minimum wage, the intervention represents highly acceptable expenditure. Probabilistic sensitivity analysis confirmed CDR dominance with 99% probability of cost-effectiveness at a willingness-to-pay threshold of three GDPs per capita.
Interpretation
Despite implementation costs, including clinician training, protocol development, and RADT procurement, CDR-guided pharyngitis management offers superior clinical outcomes and cost savings compared to current practice in Jamaica. These findings support WHO recommendations for improved GAS pharyngitis diagnostics in RF and RHD prevention programmes and provide actionable evidence for health policy makers in Jamaica and similar resource-limited settings.