Cost Effectiveness of Candida Polymerase Chain Reaction Detection and Empirical Antifungal Treatment among Patients with Suspected Fungal Peritonitis in the Intensive Care Unit

Health-Related Quality-of-Life and Cost Utility Analyses in Critical Care: A Systematic Review

OBJECTIVES

Cost utility analyses compare the costs and health outcome of interventions, with a denominator of quality-adjusted life year, a generic health utility measure combining both quality and quantity of life. Cost utility analyses are difficult to compare when methods are not standardized. It is unclear how cost utility analyses are measured/reported in critical care and what methodologic challenges cost utility analyses pose in this setting. This may lead to differences precluding cost utility analyses comparisons. Therefore, we performed a systematic review of cost utility analyses conducted in critical care. Our objectives were to understand: 1) methodologic characteristics, 2) how health-related quality-of-life was measured/reported, and 3) what costs were reported/measured.

DESIGN

Systematic review.

DATA SOURCES

We systematically searched for cost utility analyses in critical care in MEDLINE, Embase, American College of Physicians Journal Club, CENTRAL, Evidence-Based Medicine Reviews' selected subset of archived versions of UK National Health Service Economic Evaluation Database, Database of Abstracts of Reviews of Effects, and American Economic Association electronic databases from inception to April 30, 2020.

SETTING

Adult ICUs.

PATIENTS

Adult critically ill patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 8,926 citations, 80 cost utility analyse studies were eligible. The time horizon most commonly reported was lifetime (59%). For health utility reporting, health-related quality-of-life was infrequently measured (29% reported), with only 5% of studies reporting baseline health-related quality-of-life. Indirect utility measures (generic, preference-based health utility measurement tools) were reported in 85% of studies (majority Euro-quality-of-life-5 Domains, 52%). Methods of estimating health-related quality-of-life were seldom used when the patient was incapacitated: imputation (19%), assigning fixed utilities for incapacitation (19%), and surrogates reporting on behalf of incapacitated patients (5%). For cost utility reporting transparency, separate incremental costs and quality-adjusted life years were both reported in only 76% of studies. Disaggregated quality-adjusted life years (reporting separate health utility and life years) were described in only 34% of studies.

CONCLUSIONS

We identified deficiencies which warrant recommendations (standardized measurement/reporting of resource use/unit costs/health-related quality-of-life/methodological preferences) for improved design, conduct, and reporting of future cost utility analyses in critical care.

Molecular Diagnosis of Yeast Infections

PURPOSE OF REVIEW

The use of molecular tests to aid the diagnosis of invasive yeast infection, in particular invasive candidosis, has been described for over two decades, yet widespread application is limited, and diagnosis remains heavily dependent on classical microbiology. This article will review developments from the past decade in attempt to build on existing knowledge. It will highlight clinical performance and limitations while reviewing developments on recognized procedures; it will also provide insight into novel approaches incorporated in response to clinical demand (e.g. C. auris and antifungal resistance) or technological advances (e.g. next-generation sequencing).

RECENT FINDINGS

Limited methodological standardization and, until recently, unavailability of commercial options have hindered the integration of molecular diagnostics for yeasts. The development of certain, novel commercial methods has received considerable evaluation allowing a greater understanding of individual assay performance, but widespread multicentre evaluation of most commercial kits is lacking. The detection of emerging pathogens (e.g. C. auris) has been enhanced by the development of molecular tests. Molecular methods are providing a better understanding of the mycobiome, mechanisms of resistance and epidemiology/phylogeny.

SUMMARY

Despite over two decades of use, the incorporation of molecular methods to enhance the diagnosis of yeast infections remains limited to certain specialist centres. While the development of commercial tests will provide stimulus for broader application, further validation and reduced costs are required. Over the same period of time, Aspergillus PCR has become more widely accepted driven by international efforts to standardize methodology; it is critical that yeast PCR follows suit. Next-generation sequencing will provide significant information on the mycobiome, antifungal resistance mechanism and even broad-range detection directly from the specimen, which may be critical for the molecular detection of yeasts other than Candida species, which is currently limited.

A New Age in Molecular Diagnostics for Invasive Fungal Disease: Are We Ready?

Invasive fungal diseases (IFDs) present an increasing global burden in immunocompromised and other seriously ill populations, including those caused by pathogens which are inherently resistant or less susceptible to antifungal drugs. Early diagnosis encompassing accurate detection and identification of the causative agent and of antifungal resistance is critical for optimum patient outcomes. Many molecular-based diagnostic approaches have good clinical utility although interpretation of results should be according to clinical context. Where an IFD is in the differential diagnosis, panfungal PCR assays allow the rapid detection/identification of fungal species directly from clinical specimens with good specificity; sensitivity is also high when hyphae are seen in the specimen including in paraffin-embedded tissue. Aspergillus PCR assays on blood fractions have good utility in the screening of high risk hematology patients with high negative predictive value (NPV) and positive predictive value (PPV) of 94 and 70%, respectively, when two positive PCR results are obtained. The standardization, and commercialization of Aspergillus PCR assays has now enabled direct comparison of results between laboratories with commercial assays also offering the simultaneous detection of common azole resistance mutations. Candida PCR assays are not as well standardized with the only FDA-approved commercial system (T2Candida) detecting only the five most common species; while the T2Candida outperforms blood culture in patients with candidemia, its role in routine Candida diagnostics is not well defined. There is growing use of Mucorales-specific PCR assays to detect selected genera in blood fractions. Quantitative real-time Pneumocystis jirovecii PCRs have replaced microscopy and immunofluorescent stains in many diagnostic laboratories although distinguishing infection may be problematic in non-HIV-infected patients. For species identification of isolates, DNA barcoding with dual loci (ITS and TEF1α) offer optimal accuracy while next generation sequencing (NGS) technologies offer highly discriminatory analysis of genetic diversity including for outbreak investigation and for drug resistance characterization. Advances in molecular technologies will further enhance routine fungal diagnostics.

Spontaneous Fungal Peritonitis

This report presents a case of spontaneous fungal peritonitis (SFP) in a patient with cardiogenic ascites. Physicians need to be aware of this life-threatening condition because early suspicion of SFP can improve survival. (Level of Difficulty: Intermediate.)

Fungal peritonitis in peritoneal dialysis: 5-year review from a North China center

PURPOSE

Fungal peritonitis (FP) is a rare but devastating complication in peritoneal dialysis (PD), accounting for high rates of technique failure, morbidity and mortality. This study was conducted to investigate FPs with regard to peritonitis rate, microbiology testing, patient characteristics, clinical features, antifungal treatments, and clinical outcomes in patients on PD.

METHODS

This single-center study retrospectively reviewed all FP episodes diagnosed from June 1, 2012 to June, 2017. All FPs were matched in a 1:5 ratio with PD patients diagnosed with bacterial peritonitis. Clinical, biochemical characteristics and detailed data on peritonitis episodes were recorded.

RESULTS

Eleven fungal peritonitis episodes (rate of 0.0067 episodes per patient-year on dialysis) were identified. All FPs were caused by Candida species (identification and antifungal susceptibility testing were performed with VITEK 2^® compact system), including C. albicans (6/11), C. parapsilosis (4/11) and C. krusei (1/11). Except C. krusei, no Candida resistance to fluconazole was detected. Compared to bacterial peritonitis (matched cases, n = 55), FP group showed higher rate of previous antibiotic use (p = 0.002), higher total effluent cell count (p = 0.007), and lower serum albumin (p = 0.01), higher rate of infection-related surgery (p < 0.001), HD transfer (p = 0.001), and all-cause death (p = 0.006). High prevalence (≥ 50%) of female gender, anuria, CCI ≥ 4, hypoalbuminemia, anemia, and hypokalemia were also observed in FP patients. More than half of the FP patients presented gastrointestinal symptoms (7/11) and extraperitoneal infection (6/11). Eight (72.7%) patients had catheter surgically removed with a median 5.5 lag days, four (36.4%) patients died within 3 months and six (54.5%) cases led to technique failure.

CONCLUSIONS

FP results in high rates of catheter loss and all-cause mortality in 3 months of follow-up, candida species were the commonest pathogens in our center. Variations of clinical features and susceptibility patterns were observed. Gastrointestinal disorders maybe a potential risk factor for FP.