Background: Caspofungin was shown to be more effective than fluconazole in treating patients with invasive candidiasis and/or candidaemia (IC/C). However, it remains unknown whether caspofungin is cost-effective for treating IC/C in Ethiopia.

Methods: A Markov cohort model was developed to compare the cost-utility of caspofungin versus fluconazole antifungal agents as first-line therapy for adult inpatients with IC/C from the Ethiopian health system perspective. Treatment outcome was categorized as either a clinical success or failure, with clinical failure treatment being switched to a different antifungal medication. Liposomal amphotericin B(L-AmB) was used as a rescue agent for patients who had failed caspofungin treatment, while L-AmB or caspofungin were used for patients who had failed fluconazole treatment. Primary outcomes were expected quality-adjusted life years(QALYs), costs(US$ 2021), and the incremental cost-effectiveness ratio(ICER). QALYs and costs were discounted at 3% annually. Cost data was extracted from hospitals in Addis Ababa while locally unavailable data were derived from the literature. Cost-effectiveness was assessed against the recommended threshold of 50% of GDP/capita. Deterministic and probabilistic sensitivity analyses were conducted to assess the robustness of the findings.

Results: Treatment of IC/C with caspofungin as first-line therapy was more costly (US$7,714) and more effective (12.86 QALYs) compared to fluconazole-initiated treatment followed by caspofungin (US$3,217;12.30 QALYs) or L-AmB (US$2,781;10.92 QALYs). Caspofungin as primary treatment for IC/C was not cost-effective when compared to fluconazole-initiated treatments. Fluconazole-initiated treatment followed by caspofungin was cost-effective compared to fluconazole followed by L-AmB, at US$316/QALY gained. Our findings were sensitive to medication costs, drug effectiveness, infection recurrence, and infection-related mortality rates. Probabilistic sensitivity analysis confirmed the stability of our findings.

Conclusions: Our study showed that the use of caspofungin as primary treatment for IC/C in Ethiopia was not cost-effective when compared with fluconazole-initiated treatment alternatives. The findings supported the use of fluconazole-initiated therapy followed by caspofungin.