Modelling the cost-effectiveness of a rapid diagnostic test (IgMFA) for uncomplicated typhoid fever in Cambodia

Cost-effectiveness analysis of a multiplex lateral flow rapid diagnostic test for acute non-malarial febrile illness in rural Cambodia and Bangladesh

Background

Multiplex lateral flow rapid diagnostic tests (LF-RDTs) may aid management of patients with acute non-malarial febrile illness (NMFI) in rural south and southeast Asia. We aimed to evaluate the cost-effectiveness in Cambodia and Bangladesh of a putative, as-yet-undeveloped LF-RDT capable of diagnosing enteric fever and dengue, as well as measuring C-reactive protein (CRP) to guide antibiotic prescription, in primary care patients with acute NMFI.

Methods

A country-specific decision tree model-based cost-effectiveness analysis was conducted from a health system plus limited societal perspective considering the cost of antimicrobial resistance. Parameters were based on data from a large observational study on the regional epidemiology of acute febrile illness, published studies, and procurement price lists. Costs were expressed in US$ (value in 2022), and cost-effectiveness evaluated by comparing incremental cost-effectiveness ratios with conservative opportunity cost-based willingness-to-pay thresholds and the more widely used threshold of per capita gross domestic product (GDP).

Findings

Compared to standard of care, LF-RDT-augmented clinical assessment was dominant in Cambodia, being more effective and cost-saving. The cost per disability-adjusted life year (DALY) averted in Bangladesh was US$482, slightly above the conservative opportunity cost-based willingness-to-pay threshold of US$388 and considerably lower than the GDP-based threshold of US$2687. The intervention remained dominant in Cambodia and well below the GDP-based threshold in Bangladesh when antimicrobial resistance costs were disregarded.

Interpretation

These findings provide guidance for academic, industry, and policymaker stakeholders involved in acute NMFI diagnostics. While definitive conclusions cannot be made in the absence of established thresholds, our results suggest that similar results are highly likely in some target settings and possible in others.

Funding

Wellcome Trust, UK Government, Royal Australasian College of Physicians, and Rotary Foundation.

The cost-effectiveness of using rapid diagnostic tests for the diagnosis of typhoid fever in patients with suspected typhoid fever: a systematic review

INTRODUCTION

Despite the availability of several commercial rapid diagnostic tests (RDTs) developed to detect typhoid fever, the cost-effectiveness in resource-limited settings is unclear. This review aimed to explore the literature on typhoid economic evaluations in order to assess the cost-effectiveness of using typhoid RDTs in resource-limited settings.

AREAS COVERED

A systematic review was conducted focusing on the identification of economic evaluations of typhoid RDTs to diagnose patients with suspected typhoid fever. Two studies were identified and included for narrative synthesis. Whilst highlighting a gap in the published literature, this review shows the use of typhoid RDTs to potentially be cost-effective in resource-limited settings. Factors that appeared as significant in determining cost-effectiveness related to test characteristics (such as sensitivity, specificity, and cost) and the prevalence of typhoid fever and should factor into any future evaluations.

EXPERT OPINION

Concerted effort is needed in resource-limited settings with regard to medical device regulation to ensure that clinically effective and cost-effective typhoid RDTs are widely available and introduced into clinical practice. Typhoid modeling (with respect to typhoid testing and treatment strategies) represents an understudied area and further work is needed.

Cost-effectiveness of nucleic acid amplification testing to guide treatment for vaginitis: a decision-modeling analysis

We evaluated the cost-effectiveness of test-and-treat scenarios for vaginitis, scenarios based on clinical and microscopic examination (CME), nucleic acid amplification testing (NAAT), or nonamplified nucleic acid probe (probe) testing. The symptom resolution outcome and the payer cost of diagnosis and treatment were estimated in decision analytical models in a hypothetical patient population. Compared with probe testing, NAAT resulted in symptom resolution in more patients (615 versus 475 per 1000 tested) at a cost of $210 per incremental symptom resolution, a cost lower than the willingness to pay for symptom resolution ($871) implied by payer coverage for probe testing. Following a negative CME, the NAAT scenario resulted in symptom resolution in more patients (650 per 1000 patients tested) than did either CME (525) or the CME probe testing-based scenario (602) at incremental cost-effectiveness ratios lower than the willingness to pay implied by coverage for CME. Therefore, NAAT is likely to cost-effectively improve health outcomes for patients with vaginitis.