Validation of the Antifungal National Antimicrobial Prescribing Survey (AF-NAPS) quality assessment tool.

BACKGROUND: The Antifungal National Antimicrobial Prescribing Survey (AF-NAPS) was developed to undertake streamlined quality audits of antifungal prescribing. The validity and reliability of such tools is not characterized. OBJECTIVES: To assess the validity and reliability of the AF-NAPS quality assessment tool. METHODS: Case vignettes describing antifungal prescribing were prepared. A steering group was assembled to determine gold-standard classifications for appropriateness and guideline compliance. Infectious diseases physicians, antimicrobial stewardship (AMS) and specialist pharmacists undertook a survey to classify appropriateness and guideline compliance of prescriptions utilizing the AF-NAPS tool. Validity was measured as accuracy, sensitivity and specificity compared with gold standard. Inter-rater reliability was measured using Fleiss' kappa statistics. Assessors' responses and comments were thematically analysed to determine reasons for incorrect classification. RESULTS: Twenty-eight clinicians assessed 59 antifungal prescriptions. Overall accuracy of appropriateness assessment was 77.0% (sensitivity 85.3%, specificity 68.0%). Highest accuracy was seen amongst specialist (81%) and AMS pharmacists (79%). Prescriptions with lowest accuracy were in the haematology setting (69%), use of echinocandins (73%), mould-active azoles (75%) and for prophylaxis (71%). Inter-rater reliability was fair overall (0.3906), with moderate reliability amongst specialist pharmacists (0.5304). Barriers to accurate classification were incorrect use of the appropriateness matrix, knowledge gaps and lack of guidelines for some indications. CONCLUSIONS: The AF-NAPS is a valid tool, assisting assessors to correctly classify appropriate prescriptions more accurately than inappropriate prescriptions. Specialist and AMS pharmacists had similar performance, providing confidence that both can undertake AF-NAPS audits to a high standard. Identified reasons for incorrect classification will be targeted in the online tool and educational materials.

Is a biomarker-based diagnostic strategy for invasive aspergillosis cost effective in high-risk haematology patients?

Empirical antifungal therapy is frequently used in hematology patients at high risk of invasive aspergillosis (IA), with substantial cost and toxicity. Biomarkers for IA aim for earlier and more accurate diagnosis and targeted treatment. However, data on the cost-effectiveness of a biomarker-based diagnostic strategy (BDS) are limited. We evaluated the cost effectiveness of BDS using results from a randomized controlled trial (RCT) and individual patient costing data. Data inputs derived from a published RCT were used to construct a decision-analytic model to compare BDS (Aspergillus galactomannan and PCR on blood) with standard diagnostic strategy (SDS) of culture and histology in terms of total costs, length of stay, IA incidence, mortality, and years of life saved. Costs were estimated for each patient using hospital costing data to day 180 and follow-up for survival was modeled to five years using a Gompertz survival model. Treatment costs were determined for 137 adults undergoing allogeneic hematopoietic stem cell transplant or receiving chemotherapy for acute leukemia in four Australian centers (2005-2009). Median total costs at 180 days were similar between groups (US$78,774 for SDS [IQR US$50,808-123,476] and US$81,279 for BDS [IQR US$59,221-123,242], P = .49). All-cause mortality was 14.7% (10/68) for SDS and 10.1% (7/69) for BDS, (P = .573). The costs per life-year saved were US$325,448, US$81,966, and US$3,670 at 180 days, one year and five years, respectively. BDS is not cost-sparing but is cost-effective if a survival benefit is maintained over several years. An individualized institutional approach to diagnostic strategies may maximize utility and cost-effectiveness.

Consensus guidelines for antifungal prophylaxis in haematological malignancy and haemopoietic stem cell transplantation, 2014.

There is a strong argument for the use of antifungal prophylaxis in high-risk patients given the significant mortality associated with invasive fungal disease, the late identification of these infections, and the availability of safe and well-tolerated prophylactic medications. Clinical decisions about which patients should receive prophylaxis and choice of antifungal agent should be guided by risk stratification, knowledge of local fungal epidemiology, the efficacy and tolerability profile of available agents, and estimates such as number needed to treat and number needed to harm. There have been substantial changes in practice since the 2008 guidelines were published. These include the availability of new medications and/or formulations, and a focus on refining and simplifying patient risk stratification. Used in context, these guidelines aim to assist clinicians in providing optimal preventive care to this vulnerable patient demographic.

Economic evaluation of micafungin versus caspofungin for the treatment of candidaemia and invasive candidiasis.

BACKGROUND: Micafungin demonstrated non-inferiority to caspofungin as definitive therapy for candidaemia and invasive candidiasis (IC) in a major randomised clinical trial. AIM: The aim of this study was to investigate if micafungin is a cost-saving option compared with caspofungin for treating candidaemia and IC. METHODS: A decision analytical model was constructed to capture downstream consequences of using either agent as initial therapy for candidaemia and IC. The main outcomes were treatment success and treatment failure (i.e. death, mycological persistence, emergent infection, clinical failure but microbiological success). Outcome probabilities and treatment pathways were derived from the literature. Cost inputs were from the latest Australian resources, and resource use was estimated by expert panel. The analysis was from the Australian hospital perspective. Sensitivity analyses using Monte Carlo simulation were conducted. RESULTS: Micafungin (AU$52 816) was associated with a lower total cost than caspofungin (AU$52 976), with a net cost-saving of $160 per patient. This was primarily due to the lower cost associated with alternative antifungal treatment in the micafungin arm. Hospitalisation was the main cost-driver for both arms. The model outcome was most sensitive to the proportion of treatment success in the micafungin arm. Uncertainty analysis demonstrated that micafungin had a 58% chance of being cost-saving compared with caspofungin. CONCLUSIONS: Micafungin was cost-equivalent to caspofungin in treating candidaemia and IC, with variation in drug acquisition cost the critical factor.

Introduction to the Australian consensus guidelines for the management of neutropenic fever in adult cancer patients, 2010/2011. Australian Consensus Guidelines 2011 Steering Committee.

The current consensus guidelines were developed to standardize the clinical approach to the management of neutropenic fever in adult cancer patients throughout Australian treating centres. The three areas of clinical practice covered by the guidelines, the process for developing consensus opinion, and the system used to grade the evidence and relative strength of recommendations are described. The health economics implications of establishing clinical guidance are also discussed.

The disease and economic burden of neutropenic fever in adult patients in Australian cancer treatment centres 2008: analysis of the Victorian Admitted Episodes Dataset.

BACKGROUND: Although the incidence of neutropenic fever (FN) is estimated to be up to 80% for some malignancies, the epidemiological characteristics and economic burden are not well understood for Australian patients. AIMS: To describe underlying malignant conditions, potential aetiologies, clinical outcomes and healthcare utilization for an Australian population with FN, and to estimate the economic burden of this condition within the Australian healthcare sector. METHODS: Epidemiological features of FN were extracted from a population-based hospital morbidity dataset, the Victorian Admitted Episodes Dataset (VAED), for a 12-month period (2008). These were analysed according for a range of malignancy categories. Economic burden of hospitalizations was estimated according to data presented in the Round 12 National Hospital Cost Data Collection Report. RESULTS: A total of 2599 admitted episodes across 92 Victorian hospitals fulfilled inclusion criteria for FN. Metropolitan hospitalizations accounted for 79% episodes. FN illness comprised underlying solid tumours diagnoses (40%), followed by leukaemia (29.3%), lymphoma (22%) and myeloma (8.5%). Length of hospital stay was >15 days for approximately one-third of hospitalizations. intensive care unit admission rates were 5.9-11.7%. Weighted average costs of hospitalization (AUD) for solid tumours, lymphoma, myeloma and leukaemia were $8309 ± $391, 18,145 ± $1602, $21,764 ± $1289 and $22,596 ± $2618 respectively. CONCLUSIONS: Using VAED indices, epidemiological features of Australian patients with FN appear comparable with international reports. In contrast to US data, estimated healthcare costs are up to 50% lower in the Australian healthcare sector. These data offer important insights for prioritizing of research agendas and resource allocation.