Clinical utility of time to positivity in candidemia: prognostic limitations and species-specific implications.

PURPOSE: To evaluate the association between time to positivity (TTP) and 30-day mortality, and to assess species-specific differences in TTP among Candida isolates. METHODS: This single-center, retrospective study included adult patients (≥ 18 years) with candidemia between July 2022 and October 2024. Patients were grouped as survivors and non-survivors, and TTP was compared between the groups. Variables associated with mortality in univariate analysis (p < 0.10) and clinically relevant factors, including Candida species, were included in multivariate logistic regression to assess the independent effect of TTP on 30-day mortality. Species-specific TTP differences were also evaluated. RESULTS: A total of 392 patients with candidemia were included. In multivariate analysis, older age, solid tumor malignancy, chronic cardiac disease, use of total parenteral nutrition, inappropriate antifungal therapy, and higher SOFA scores were independently associated with 30-day mortality (p < 0.05). Time to positivity was not independently associated with mortality (OR 0.989, 95% CI 0.974-1.004; p = 0.142). Significant differences in TTP were observed among Candida species, with the shortest median TTP in Candida tropicalis and the longest in Candida glabrata. TTP demonstrated good discriminatory performance for identifying Candida tropicalis (AUC 0.854), with an optimal cut-off value of 23.5 h. CONCLUSION: TTP was not an independent predictor of 30-day mortality in patients with candidemia. However, TTP demonstrated significant differences among Candida species and may provide an adjunctive clue for early presumptive differentiation of Candida species.