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.

Fulminant Wilson's disease with haemolysis and renal failure: copper studies and assessment of dialysis regimens.

Two girls, aged 12 and 17 years, presented with hepatocellular dysfunction and severe haemolysis due to Wilson's disease (hepatolenticular degeneration). This was accompanied by acute renal failure. In the absence of renal function sufficient for the urinary excretion of penicillamine, studies were performed to assess the potential of peritoneal dialysis, ascites removal by ultrafiltration-reinfusion, and haemodialysis as alternative excretory pathways for copper. The greatest amount of copper, as judged by rising bath concentrations, seemed to be eliminated with haemodialysis. But this was accompanied by a progressive increase in serum copper concentrations with rapid clinical and biochemical deterioration leading to death within 48 hours. A small amount of copper was lost with ascites removal. Significant amounts of copper were removed during peritoneal dialysis (36 mumol/day (2287 microgram/day)), although a clinical response was not evident before haemodialysis was introduced. The administration of penicillamine orally, intravenously, or intraperitoneally produced no measurable increase in copper excretion into the peritoneal dialysate. Hence peritoneal dialysis alone appears to offer the greatest potential benefit with regard to both eliminating copper and altering the course of this fulminant form of Wilson's disease.