No abstract

This paper extends previous work on the distribution-free newsvendor problem, where only partial information about the demand distribution is available. More specifically, the analysis assumes that the demand distribution f belongs to a class of probability distribution functions (pdf) ℱ with mean μ and standard deviation σ. While previous work has examined the expected value of distribution information (EVDI) for a particular order quantity and a particular pdf f, this paper aims at computing the maximum EVDI over all f ∈ ℱ for any order quantity. In addition, an optimization procedure is provided to calculate the order quantity that minimizes the maximum EVDI.

BackgroundThe elderly patients affected by candidemia are growing in proportion to inpatients, but available data are limited. We aimed to determine the epidemiology, antifungal management and clinical risk factors of death in the elderly population with candidemia in China.MethodsThis retrospective study included 63 elderly (≥65 years) and 84 younger patients (16–60 years) at 4 tertiary hospitals. Multivariable logistic regression model was used to identify independent risk factors of death in elderly patients.ResultsThe distribution of Candida species did not differ between elderly and younger patients (p >0.05). Resistance to fluconazole and voriconazole for non-Candida albicans species in elderly patients was approximately double that in younger patients. Host-related risk factors (e.g., underlying solid tumour, diabetes mellitus and chronic renal failure) and hospital-related factors (e.g., prior stay in an intensive care unit, mechanical ventilation, central vascular and urethral catheters placement) were identified more common in elderly patients. Elderly patients less often received triazoles and were less likely to receive antifungal therapies mostly because elderly or their guardians quit antifungal therapies. APACHE II scores and 30-day mortality were higher for elderly than younger patients (31.7% vs. 16.7%, p =0.032). For elderly patients, antifungal therapy administered before microbiological documentation was the only protective factor for death, whereas absence of antifungal therapies, receipt of mechanical ventilation and APACHE II score ≥20 were independent predictors of death.ConclusionsElderly patients with candidemia had poor prognoses characterized by certain host and hospital-related risk factors and special pathogen resistance features. More awareness of the burden of this disease is required, and the absence of antifungal therapies should be avoided to improve the prognoses of elderly patients with this severe infection.