Ushering in Antifungal Stewardship: Perspectives of the Hematology Multidisciplinary Team Navigating Competing Demands, Constraints, and Uncertainty

Using Behavior Change Theory to Identify Drivers and Barriers for Antifungal Treatment Decisions: A Case Study in a Large Teaching Hospital in the East of England, UK

INTRODUCTION

Antifungal stewardship (AFS) programs are recognized to contribute to optimizing antifungal prescribing for treatment and prophylaxis. However, only a small number of such programs are implemented. Consequently, evidence on behavioral drivers and barriers of such programs and learnings from existing successful AFS programs is limited. This study aimed to leverage a large AFS program in the UK and derive learnings from it. The objective was to (a) investigate the impact of the AFS program on prescribing habits, (a) use a Theoretical Domains Framework (TDF) based on the COM-B (Capability, Opportunity, and Motivation for Behavior) to qualitatively identify drivers and barriers for antifungal prescribing behaviors across multiple specialties, and (c) semiquantitatively investigate trends in antifungal prescribing habits over the last 5 years.

METHODS

Qualitative interviews and a semiquantitative online survey were conducted across hematology, intensive care, respiratory, and solid organ transplant clinicians at Cambridge University Hospital. The discussion guide and survey used were developed to identify drivers of prescribing behavior, based on the TDF.

RESULTS

Responses were received from 21/25 clinicians. Qualitative outcomes demonstrated that the AFS program was effective in supporting optimal antifungal prescribing practices. We found seven TDF domains influencing antifungal prescribing decisions-five drivers and two barriers. The key driver was collective decision-making among the multidisciplinary team (MDT) while key barriers were lack of access to certain therapies and fungal diagnostic capabilities. Furthermore, over the last 5 years and across specialties, we observed an increasing tendency for prescribing to focus on more targeted rather than broad-spectrum antifungals.

CONCLUSIONS

Understanding the basis for linked clinicians' prescribing behaviors for identified drivers and barriers may inform interventions on AFS programs and contribute to consistently improving antifungal prescribing. Collective decision-making among the MDT may be leveraged to improve clinicians' antifungal prescribing. These findings may be generalized across specialty care settings.

When Azoles Cannot Be Used: The Clinical Effectiveness of Intermittent Liposomal Amphotericin Prophylaxis in Hematology Patients

Background

Patients unable to take azoles are a neglected group lacking a standardized approach to antifungal prophylaxis. We evaluated the effectiveness and safety of intermittent liposomal amphotericin B (L-AMB) prophylaxis in a heterogenous group of hematology patients.

Methods

A retrospective cohort of all hematology patients who received a course of intravenous L-AMB, defined as 1 mg/kg thrice weekly from July 1, 2013 to June 30, 2018, were identified from pharmacy records. Outcomes included breakthrough-invasive fungal disease (BIFD), reasons for premature discontinuation, and acute kidney injury.

Results

There were 198 patients who received 273 courses of L-AMB prophylaxis. Using a conservative definition, the BIFD rate was 9.6% (n = 19 of 198) occurring either during L-AMB prophylaxis or up to 7 days from cessation in patients who received a course. Probable/proven BIFD occurred in 13 patients (6.6%, 13 of 198), including molds in 54% (n = 7) and non-albicans Candidemia in 46% (n = 6). Cumulative incidence of BIFD was highest in patients with acute myeloid leukemia (6.8%) followed by acute lymphoblastic leukemia (2.7%) and allogeneic stem cell transplantation (2.5%). The most common indication for L-AMB was chemotherapy, or anticancer drug-azole interactions (75% of courses) dominated by vincristine, or acute myeloid leukemia clinical trials, followed by gut absorption concerns (13%) and liver function abnormalities (8.8%). Acute kidney injury, using a modified international definition, complicated 27% of courses but was not clinically significant, accounting for only 3.3% (9 of 273) of discontinuations.

Conclusions

Our findings demonstrate a high rate of BIFD among patients receiving L-AMB prophylaxis. Pragmatic trials will help researchers find the optimal regimen of L-AMB prophylaxis for the many clinical scenarios in which azoles are unsuitable, especially as targeted anticancer drugs increase in use.