Antibiotic Review Kit for Hospitals (ARK-Hospital): a stepped wedge cluster randomised controlled trial (preprint)

Background Strategies to reduce antibiotic overuse in hospitals depend on clinicians taking decisions to stop unnecessary antibiotics. There is a lack of evidence on how support clinicians do this effectively. We evaluated a multifaceted behaviour change intervention (ARK) which aims to reduce antibiotic consumption in hospitals by increasing decisions to stop antibiotics at clinical review. Methods We performed a stepped-wedge, hospital-level, cluster-randomised controlled trial using computer-generated sequence randomisation of 39 acute hospitals to 7 calendar-time blocks (12/February/2018–01/July/2019). Co-primary outcomes were monthly antibiotic defined-daily-doses (DDD) per acute/medical admission (organisation-level, superiority) and all-cause 30-day mortality (patient-level, non-inferiority, margin 5%). Clusters were eligible if they admitted non-elective medical patients, could identify an intervention “champion” and provide pre-intervention data from February/2016. Sites were followed up for a minimum of 14 months. Intervention effects were assessed using interrupted time series analyses in each cluster. Overall effects were derived through random-effects meta-analysis, using meta-regression to assess heterogeneity in effects across prespecified factors. Trial registration was ISRCTN12674243 . Findings Adjusted estimates showed a year-on-year reduction in antibiotic consumption (−4.8%, 95%CI: -9.1%,-0.2%, p=0.042) following the ARK intervention. Among 7,160,421 acute/medical admissions, we observed a -2.7% (95%CI: -5.7%,+0.3%, p=0.079) immediate and +3.0% (95%CI: - 0.1%,+6.2%, p=0.060) sustained change in adjusted 30-day mortality. This mortality trend was not related to the magnitude of antibiotic reduction achieved (Spearman’s ρ=0.011, p=0.949). Whilst 90-day mortality odds appeared to increase over time (+3.9%, 95%CI:+0.5%,+7.4%, p=0.023), this was not observed among admissions before COVID-19 onset (+3.2%, 95%CI:-1.5%,+8.2%, p=0.182). Length of hospital stay was unaffected. Interpretation The weak, inconsistent effects of the intervention on mortality are likely to be explained by the COVID-19 pandemic onset during the post-implementation phase. We conclude that the ARK-intervention resulted in sustained, safe reductions in hospital antibiotic use. Funding NIHR Programme Grants for Applied Research, RP-PG-0514-20015. Research in context Evidence before this study Acutely ill patients often need to receive antibiotics before full diagnostic information is available. Consequently, reducing overuse of antibiotics in hospitals requires clinicians to review and where appropriate, stop unnecessary antibiotic prescriptions. Evidence-based tools to support clinicians stop unnecessary antibiotics do not exist. We searched PubMed, with no language or date restrictions, on 31/January/2022 for clinical studies focused on improving antibiotic use for hospitalised adults using the terms “anti-bacterial agents therapeutic use” AND “antibiotic stewardship”. Among the 427 studies found, the great majority were uncontrolled evaluations of different approaches to education, decision support and feedback. These included one before-after study, which found no impact of unsupported clinician-led prescription review. Three small, hospital-level cluster-randomised trials were identified. One evaluated different approaches to feedback, one compared different hospital specialties and one found intense feedback to be effective. All were small and none considered clinical outcomes or sustainability. There is a need for research to deliver proven interventions ready for implementation into practice. Added value of this study We evaluated a multifaceted “Antibiotic Review Kit” (ARK) intervention to support prescribers to appropriately stop antibiotics at clinical review. ARK comprises a prescription decision-aid supported by a brief online training tool, guidance on implementation (including regular data collection and feedback) and a patient information leaflet. We found that the intervention was associated with a sustained reduction in hospital-level antibiotic use overall and of oral and narrow-spectrum antibiotics specifically. Weak trends were observed for 30-day mortality in opposite directions for immediate and sustained impact. Although there was a sustained increase in 90-day mortality after the intervention, this was only seen when analyses included patients admitted after the start of the COVID-19 pandemic. Taken together we conclude that these mortality effects are unrelated to the intervention. Implications of all available evidence The ARK intervention is safe and effective in reducing antibiotic use among adult medical hospital admissions. The tools used are now freely available for adoption into practice.

Preserved C-reactive protein responses to blood stream infections following tocilizumab treatment for COVID-19 (preprint)

C-reactive protein (CRP) levels are elevated following bacterial infections but may be attenuated by the IL-6-receptor antagonist tocilizumab. In hospitalised COVID-19 patients, tocilizumab induced a transient (<21 day) fall in CRP but retained CRP responses to nosocomial blood stream infections, and therefore its utility in guiding antibiotic prescribing.

Exclusion of bacterial co-infection in COVID-19 using baseline inflammatory markers and their response to antibiotics (preprint)

BackgroundCOVID-19 is infrequently complicated by secondary bacterial infection, but nevertheless antibiotic prescriptions are common. We used community-acquired pneumonia (CAP) as a benchmark to define the processes that occur in a bacterial pulmonary infection, and tested the hypothesis that baseline inflammatory markers and their response to antibiotic therapy could distinguish CAP from COVID-19. MethodsIn patients admitted to Royal Free Hospital (RFH) and Barnet Hospital (BH) we defined CAP by lobar consolidation on chest radiograph, and COVID-19 by SARS-CoV-2 detection by PCR. Data were derived from routine laboratory investigations. ResultsOn admission all CAP and >90% COVID-19 patients received antibiotics. We identified 106 CAP and 619 COVID-19 patients at RFH. CAP was characterised by elevated white cell count (WCC) and C-reactive protein (CRP) compared to COVID-19 (median WCC 12.48 (IQR 8.2-15.3) vs 6.78 (IQR 5.2-9.5) x106 cells/ml and median CRP CRP 133.5 (IQR 65-221) vs 86 (IQR 42-160) mg/L). Blood samples collected 48-72 hours into admission revealed decreasing CRP in CAP but not COVID-19 (CRP difference -33 (IQR -112 to +3.5) vs +15 (IQR -15 to +70) mg/L respectively). In the independent validation cohort (BH) consisting of 169 CAP and 181 COVID-19 patients, admission WCC >8.2x106 cells/ml or falling CRP during admission identified 95% of CAP cases, and predicted the absence of bacterial co-infection in 45% of COVID-19 patients. ConclusionsWe propose that in COVID-19 the absence of both elevated baseline WCC and antibiotic-related decrease in CRP can exclude bacterial co-infection and facilitate antibiotic stewardship efforts.

Organisms causing secondary pneumonias in COVID-19 patients at 5 UK ICUs as detected with the FilmArray test (preprint)

ABSTRACT Introduction. Several viral respiratory infections - notably influenza - are associated with secondary bacterial infection and additional pathology. The extent to which this applies for COVID-19 is unknown. Accordingly, we aimed to define the bacteria causing secondary pneumonias in COVID-19 ICU patients using the FilmArray Pneumonia Panel, and to determine this tests potential in COVID-19 management. Methods. COVID-19 ICU patients with clinically-suspected secondary infection at 5 UK hospitals were tested with the FilmArray at point of care. We collected patient demographic data and compared FilmArray results with routine culture. Results. We report results of 110 FilmArray tests on 94 patients (16 had 2 tests): 69 patients (73%) were male, the median age was 59 yrs; 92 were ventilated. Median hospital stay before testing was 14 days (range 1-38). Fifty-nine (54%) tests were positive, with 141 bacteria detected. Most were Enterobacterales (n=55, including Klebsiella spp. [n= 35]) or Staphylococcus aureus (n=13), as is typical of hospital and ventilator pneumonia. Community pathogens, including Haemophilus influenzae (n=8) and Streptococcus pneumoniae (n=1), were rarer. FilmArray detected one additional virus (Rhinovirus/Enterovirus) and no atypical bacteria. Fewer samples (28 % vs. 54%) were positive by routine culture, and fewer species were reported per sample; Klebsiella species remained the most prevalent pathogens. Conclusion. FilmArray had a higher diagnostic yield than culture for ICU COVID-19 patients with suspected secondary pneumonias. The bacteria found mostly were Enterobacterales, S. aureus and P. aeruginosa, as in typical HAP/VAP, but with Klebsiella spp. more prominent. We found almost no viral co-infection. Turnaround from sample to results is around 1h 15 min compared with the usual 72h for culture, giving prescribers earlier data to inform antimicrobial decisions.