Candidaemia and a risk predictive model for overall mortality: a prospective multicentre study

Abstract

Background: Candidaemia is associated with high mortality. Variables associated with mortality have been published previously, but not developed into a risk predictive model for mortality. We sought to describe the current epidemiology of candidaemia in Australia, analyse predictors of 30-day all-cause mortality, and develop and validate a mortality risk predictive model.

Methods: Adults with candidaemia were studied prospectively over 12 months at eight institutions. Clinical and laboratory variables at time of blood culture-positivity were subject to multivariate analysis for association with 30-day all-cause mortality. A predictive score for mortality was examined by area under receiver operator characteristic curves and a historical data set was used for validation.

Results: The median age of 133 patients with candidaemia was 62 years; 76 (57%) were male and 57 (43%) were female. Co-morbidities included underlying haematologic malignancy (n = 20; 15%), and solid organ malignancy in (n = 25; 19%); 55 (41%) were in an intensive care unit (ICU). Non-albicans Candida spp. accounted for 61% of cases (81/133). All-cause 30-day mortality was 31%. A gastrointestinal or unknown source was associated with higher overall mortality than an intravascular or urologic source (p < 0.01). A risk predictive score based on age > 65 years, ICU admission, chronic organ dysfunction, preceding surgery within 30 days, haematological malignancy, source of candidaemia and antibiotic therapy for ≥10 days stratified patients into < 20% or ≥ 20% predicted mortality. The model retained accuracy when validated against a historical dataset (n = 741).

Conclusions: Mortality in patients with candidaemia remains high. A simple mortality risk predictive score stratifying patients with candidaemia into < 20% and ≥ 20% 30-day mortality is presented. This model uses information available at time of candidaemia diagnosis is easy to incorporate into decision support systems. Further validation of this model is warranted.

Keywords: Candida blood stream infection; Candidaemia; Invasive fungal infection; Mortality; Risk stratification score.

Fig. 1

Kaplan-Meier survival curve of all patients with candidaemia stratified by source; genitourinary/intravascular or gastrointestinal/unknown. Source was grouped to produce a binary variable of favourable versus unfavourable outcome. Log-rank test statistic for equality of curves: chi-squared = 6.7 on 1 degrees of freedom, p = 0.00967. Shaded areas are pointwise 95% confidence intervals, showing the curves are well-separated

Fig. 2

Area under the curve (AUC) = 0.81 for derivation cohort. When applied to n=741 historical cohort data (2001-2004), AUC = 0.74