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.

Establishing essential metrics for antifungal stewardship in hospitals: the results of an international Delphi survey

BACKGROUND

Guidance on assessment of the quantity and appropriateness of antifungal prescribing is required to assist hospitals to interpret data effectively and structure quality improvement programmes.

OBJECTIVES

To achieve expert consensus on a core set of antifungal stewardship (AFS) metrics and to determine their feasibility for implementation.

METHODS

A literature review was undertaken to develop a list of candidate metrics. International experts were invited to participate in sequential web-based surveys to evaluate the importance and feasibility of metrics in the area of AFS using Delphi methodology. Three surveys were completed. Consensus was predefined as ≥80% agreement on the importance of each metric.

RESULTS

Eighty-two experts consented to participate from 17 different countries. Response rate for each survey was >80%. The panel included adult and paediatric physicians, microbiologists and pharmacists with diverse content expertise. Consensus was achieved for 38 metrics considered important to routinely include in AFS programmes, and related to antifungal consumption (n = 5), quality of antifungal prescribing and management of invasive fungal infection (IFI) (n = 24), and clinical outcomes (n = 9). Twenty-one consensus metrics were considered to have moderate to high feasibility for routine collection.

CONCLUSIONS

The identified core AFS metrics will provide a framework to comprehensively assess the quantity and quality of antifungal prescribing within hospitals to develop quality improvement programmes aimed at improving IFI prevention, management and patient-centred outcomes. A standardized approach will support collaboration and benchmarking to monitor the efficacy of current prophylaxis and treatment guidelines, and will provide important feedback to guideline developers.

Consensus guidelines for optimising antifungal drug delivery and monitoring to avoid toxicity and improve outcomes in patients with haematological malignancy, 2014

Antifungal agents may be associated with significant toxicity or drug interactions leading to sub-therapeutic antifungal drug concentrations and poorer clinical outcomes for patients with haematological malignancy. These risks may be minimised by clinical assessment, laboratory monitoring, avoidance of particular drug combinations and dose modification. Specific measures, such as the optimal timing of oral drug administration in relation to meals, use of pre-hydration and electrolyte supplementation may also be required. Therapeutic drug monitoring (TDM) of antifungal agents is warranted, especially where non-compliance, non-linear pharmacokinetics, inadequate absorption, a narrow therapeutic window, suspected drug interaction or unexpected toxicity are encountered. Recommended indications for voriconazole and posaconazole TDM in the clinical management of haematology patients are provided. With emerging knowledge regarding the impact of pharmacogenomics upon metabolism of azole agents (particularly voriconazole), potential applications of pharmacogenomic evaluation to clinical practice are proposed.

Cost effectiveness of caspofungin vs. voriconazole for empiric therapy in Turkey

Invasive fungal infections from febrile neutropenia are associated with significant cost and mortality. The mainstay of treatment has been liposomal amphotericin B, however, echinocandins and azoles have shown promise as alternative treatments. Data on clinical efficacy exist, however, data incorporating pharmacoeconomic considerations are required in Turkey. The aim of this study was to investigate the cost effectiveness of caspofungin vs. voriconazole in empiric treatment of febrile neutropenia in Turkey. A decision analytic model was utilised, built upon two randomised-controlled trials and supplemented with expert panel input from clinicians in Turkey. A five-point composite outcome measure was utilised and sensitivity analyses were performed to demonstrate the robustness of the model. The base case scenario resulted in caspofungin being preferred by TL2,533, TL29,256 and TL2,536 per patient treated, successfully treated patient and patient survival, respectively (approx. USD1414, 16 328 and 1415); sensitivity analyses did not change the outcome. Monte Carlo simulation highlighted a 78.8% chance of favouring caspofungin. The result was moderately sensitive to treatment duration and acquisition cost of the antifungal agents compared. This is the first pharmacoeconomic study comparing caspofungin to voriconazole within Turkey, resulting in an advantage towards caspofungin. The study will aid in formulary decision-making based on the clinical and economic consequences of each agent in the Turkish health care setting.

Enterococcal bacteraemia: factors influencing mortality, length of stay and costs of hospitalization

Enterococci are a major cause of nosocomial bacteraemia. The impacts of vanB vancomycin resistance and antibiotic therapy on outcomes in enterococcal bacteraemia are unclear. Factors that affect length of stay (LOS) and costs of managing patients with enterococcal bacteraemia are also unknown. This study aimed to identify factors associated with mortality, LOS and hospitalization costs in patients with enterococcal bacteraemia and the impact of vancomycin resistance and antibiotic therapy on these outcomes. Data from 116 patients with vancomycin-resistant Enterococci (VRE), matched 1:1 with patients with vancomycin-susceptible Enterococcus (VSE), from two Australian hospitals were reviewed for clinical and economic outcomes. Univariable and multivariable logistic and quantile regression analyses identified factors associated with mortality, LOS and costs. Intensive care unit admission (OR, 8.57; 95% CI, 3.99-18.38), a higher burden of co-morbidities (OR, 4.55; 95% CI, 1.83-11.33) and longer time to appropriate antibiotics (OR, 1.02; 95% CI, 1.01-1.03) were significantly associated with mortality in enterococcal bacteraemia. VanB vancomycin resistance increased LOS (4.89 days; 95% CI, 0.56-11.52) and hospitalization costs (AU$ 28 872; 95% CI, 734-70 667), after adjustment for confounders. Notably, linezolid definitive therapy was associated with lower mortality (OR, 0.13; 95% CI, 0.03-0.58) in vanB VRE bacteraemia patients. In patients with VSE bacteraemia, time to appropriate antibiotics independently influenced mortality, LOS and hospitalization costs, and underlying co-morbidities were associated with mortality. The study findings highlight the importance of preventing VRE bacteraemia and the significance of time to appropriate antibiotics in the management of enterococcal bacteraemia.

Quantification of voriconazole in human bronchoalveolar lavage fluid using high-performance liquid chromatography with fluorescence detection

The quantification of voriconazole concentration in lung epithelial lining fluid to facilitate the management of pulmonary fungal colonisation or aspergillosis is of increasing interest. An accurate and reproducible high-performance liquid chromatography method to quantify voriconazole in human bronchoalveolar lavage (BAL) fluid was developed and validated. BAL samples were concentrated by freeze-drying and reconstituted with water prior to deproteinisation. Separation was achieved with a C18 column employing fluorescence detection (excitation: 260nm, emission: 370nm). The calibration curves were linear from 2.5 to 500ng/mL. The intra- and inter-day precisions were within 7%. Accuracies ranged from 102% to 107%. The clinical applicability was established by successful measurement of voriconazole concentrations in lung transplant recipients. The assay provides an alternative approach for those with negligible access to liquid chromatography-tandem mass spectrometry instrumentation.

Antifungal prophylaxis in lung transplantation--a world-wide survey

While variations in antifungal prophylaxis have been previously reported in lung transplant (LTx) recipients, recent clinical practice is unknown. Our aim was to determine current antifungal prophylactic practice in LTx centers world-wide. One nominated LTx clinician from each active center was invited by e-mail to participate in a web-based survey between September 2009 and January 2010. Fifty-seven percent (58/102) responded. The majority of responses were from medical directors of LTx centers (72.4%), and from the United States (44.8%). Within the first 6 months post-LTx, most centers (58.6%) employed universal prophylaxis, with 97.1% targeting Aspergillus species. Voriconazole alone, and in combination with inhaled amphotericin B (AmB), were the preferred first-line agents. Intolerance to side effects of voriconazole (69.2%) was the main reason for switching to alternatives. Beyond 6 months post-LTx, most (51.8%) did not employ antifungal prophylaxis. Fifteen centers (26.0%) conducted routine antifungal therapeutic drug monitoring during prophylactic period. There are differences in strategies employed between U.S. and European centers. Most respondents indicated a need for antifungal prophylactic guidelines. In comparison to earlier findings, there was a major shift toward prophylaxis with voriconazole and an increased use of echinocandins, posaconazole and inhaled lipid formulation AmB.

Multidisciplinary HIV adherence intervention: a randomized study

Maintaining greater than 95% adherence to antiretroviral medication is necessary in order to have the greatest therapeutic impact on HIV infection. Furthermore, evidence suggests that adherence rates of between 70% and 89% are significantly associated with viral rebound and the development of drug resistance. Adherence rates at and above the 95% level are difficult for patients to achieve and maintain. Our aim was to determine if an adherence intervention could improve adherence among patients attending an ambulatory care clinic at a large public hospital. The intervention was delivered by a multidisciplinary team of health care professionals and consisted of education coupled with the provision of devices designed to assist patient memory and adherence. A crucial component of the intervention consisted of the identification of patient specific barriers to adherence and the development of strategies to circumvent these problems. Adherence was assessed using patient self-report over the past 4, 7, and 28 days and by calculation of the Morisky score. The study was conducted as a randomised controlled trial using the stepped wedge design with a total of 68 subjects randomised to receive the intervention over a 20-week period. Adherence before and after the intervention formed the analysis. There was a significant decrease in the number of missed doses over the past 4 (1.9 to 1.0, p < 0.001), 7 (3.0 to 1.8, p < 0.001) and 28 (7.4 to 4.2, p < 0.001) days and a decrease in the Morisky score, indicating an improvement in medication taking behaviour (1.3 to 0.5 p < 0.001).