Whole-of-Life Inclusion in Bayesian Adaptive Platform Clinical Trials.

Importance: There is a recognized unmet need for clinical trials to provide evidence-informed care for infants, children and adolescents. This Special Communication outlines the capacity of 3 distinct trial design strategies, sequential, parallel, and a unified adult-pediatric bayesian adaptive design, to incorporate children into clinical trials and transform this current state of evidence inequity. A unified adult-pediatric whole-of-life clinical trial is demonstrated through the Staphylococcus aureus Network Adaptive Platform (SNAP) trial. Observations: Bayesian methods provide a framework for synthesizing data in the form of a probability model that can be used in the design and analysis of a clinical trial. Three trial design strategies are compared: (1) a sequential adult-pediatric bayesian approach that involves a separate, deferred pediatric trial that incorporates existing adult trial data into the analysis model to potentially reduce the pediatric trial sample size; (2) a parallel adult-pediatric bayesian trial whereby separate pediatric enrollment occurs in a parallel trial, running alongside an adult randomized clinical trial; and (3) a unified adult-pediatric bayesian adaptive design that supports the enrollment of both children and adults simultaneously in a whole-of-life bayesian adaptive randomized clinical trial. The SNAP trial whole-of-life design uses a bayesian hierarchical model that allows information sharing (also known as borrowing) between trial age groups by linking intervention effects of children and adults, thereby improving inference in both groups. Conclusion and Relevance: Bayesian hierarchical models may provide more precision for estimates of safety and efficacy of treatments in trials with heterogenous populations compared to traditional methods of analysis. They facilitate the inclusion of children in clinical trials and a shift from children deemed therapeutic orphans to the vision of no child left behind in clinical trials to ensure evidence for clinical practice exists across the life course. The SNAP trial provides an example of a bayesian adaptive whole-of-life inclusion design that enhances trial population inclusivity and diversity overall, as well as generalizability and translation of findings into clinical practice.

Australian Group on Antimicrobial Research surveillance outcome programs - bloodstream infections and antimicrobial resistance patterns from patients less than 18 years of age, January 2020 - December 2021.

Abstract: From 1 January 2020 to 31 December 2021, thirty-eight institutions across Australia submitted data to the Australian Group on Antimicrobial Resistance (AGAR) from patients aged < 18 years (AGAR-Kids). Over the two years, 1,679 isolates were reported from 1,611 patients. This AGAR-Kids report aims to describe the population of children and adolescents with bacteraemia reported to AGAR and the proportion of resistant isolates. Overall, there were 902 gram-negative isolates reported: 800 Enterobacterales, 61 Pseudomonas aeruginosa and 41 Acinetobacter spp. Among the Enterobacterales, 12.9% were resistant to third generation cephalosporins; 11.6% to gentamicin/tobramycin; and 11.2% to piperacillin-tazobactam. In total, 14.5% of Enterobacterales were multi-drug resistant (MDR). Only 3.3% of P. aeruginosa were resistant to carbapenems and 4.9% were MDR. Resistance in Acinetobacter spp was uncommon. Of 607 Staphylococcus aureus isolates, 12.9% were methicillin-resistant (MRSA). Almost half of S. aureus isolates from the Northern Territory were MRSA. In S. aureus, resistance to erythromycin was 13.2%; 12.4% to clindamycin; and 5.3% to ciprofloxacin. Resistance to all antibiotics tested was higher in MRSA. Overall, 6.5% of S. aureus were MDR, of which 65% were MRSA. Almost three-quarters of the 170 Enterococcus spp. reported were E. faecalis, and half were from patients < 1 year old. Ampicillin resistance in enterococci was 19.6%. Eight isolates were vancomycin resistant and three isolates were teicoplanin resistant. Five E. faecium isolates were classified as MDR. This AGAR-Kids report highlights clear differences in the geographic distribution of pathogens and resistance profiles across Australia.

An overview of risk factors, management and prevention of cochlear implant infections.

PURPOSE OF REVIEW: With cochlear implantation becoming increasingly performed worldwide, an understanding of the risk factors, preventive measures, and management of cochlear implant (CI) infection remains important given the significant morbidity and cost it conveys. RECENT FINDINGS: At the turn of the 21st century there was a decrease in rates of CI infection, particularly meningitis, following the discontinuation of positioner use for CI. However, in more recent years rates of CI infection have remained largely static. Recently, studies evaluating preventive measures such as pneumococcal vaccination, S. aureus decolonization and surgical antibiotic prophylaxis have emerged in the literature. SUMMARY: Prompt recognition of CI infection and appropriate investigation and management are key, however at present treatment is largely informed by cohort and case-control studies and expert opinion. Preventive measures including pneumococcal vaccination, S. aureus decolonization and preoperative antibiotic prophylaxis play a role in reducing rates of CI infection. However, there remains a need for well designed clinical trials to provide higher level evidence to better guide preventive measures for, and management decisions of, CI infections in the future.

Invasive aspergillosis in adult patients in Australia and New Zealand: 2017-2020.

Background: New and emerging risks for invasive aspergillosis (IA) bring the need for contemporary analyses of the epidemiology and outcomes of IA, in order to improve clinical practice. Methods: The study was a retrospective, multicenter, cohort design of proven and probable IA in adults from 10 Australasian tertiary centres (January 2017-December 2020). Descriptive analyses were used to report patients' demographics, predisposing factors, mycological characteristics, diagnosis and management. Accelerated failure-time model was employed to determine factor(s) associated with 90-day all-cause mortality (ACM). Findings: Of 382 IA episodes, 221 (in 221 patients) fulfilled inclusion criteria - 53 proven and 168 probable IA. Median patient age was 61 years (IQR 51-69). Patients with haematologic malignancies (HM) comprised 49.8% of cases. Fifteen patients (6.8%) had no pre-specified immunosuppression and eleven patients (5.0%) had no documented comorbidity. Only 30% of patients had neutropenia. Of 170 isolates identified, 40 (23.5%) were identified as non-Aspergillus fumigatus species complex. Azole-resistance was present in 3/46 (6.5%) of A. fumigatus sensu stricto isolates. Ninety-day ACM was 30.3%. HM (HR 1.90; 95% CI 1.04-3.46, p = 0.036) and ICU admission (HR 4.89; 95% CI 2.93-8.17, p < 0.001) but not neutropenia (HR 1.45; 95% CI 0.88-2.39, p = 0.135) were associated with mortality. Chronic kidney disease was also a significant predictor of death in the HM subgroup (HR 3.94; 95% CI 1.15-13.44, p = 0.028). Interpretation: IA is identified in high number of patients with mild/no immunosuppression in our study. The relatively high proportion of non-A. fumigatus species complex isolates and 6.5% azole-resistance rate amongst A. fumigatus sensu stricto necessitates accurate species identification and susceptibility testing for optimal patient outcomes. Funding: This work is unfunded. All authors' financial disclosures are listed in detail at the end of the manuscript.

Consumer perspectives on simplified, layered consent for a low risk, but complex pragmatic trial.

BACKGROUND: For decades, the research community has called for participant information sheets/consent forms (PICFs) to be improved. Recommendations include simplifying content, reducing length, presenting information in layers and using multimedia. However, there are relatively few studies that have evaluated health consumers' (patients/carers) perspectives on the type and organisation of information, and the level of detail to be included in a PICF to optimise an informed decision to enter a trial. We aimed to elicit consumers' views on a layered approach to consent that provides the key information for decision-making in a short PICF (layer 1) with additional optional information that is accessed separately (layer 2). We also elicited consumers' views on the optimal content and layout of the layered consent materials for a large and complex Bayesian adaptive platform trial (the SNAP trial). METHODS: We conducted a qualitative multicentre study (4 focus groups and 2 semi-structured interviews) involving adolescent and adult survivors of Staphylococcus aureus bloodstream infection (22) and their carers (2). Interview transcripts were examined using inductive thematic analysis. RESULTS: Consumers supported a layered approach to consent. The primary theme that emerged was the value of agency; the ability to exert some control over the amount of information read before the consent form is signed. Three other themes emerged; the need to prioritise participants' information needs; the importance of health literacy; the importance of information about a trial's benefits (over its risks) for decision-making and the interplay between the two. CONCLUSIONS: Our findings suggest that consumers may challenge the one-size-fits-all approach currently applied to the development of PICFs in countries like Australia. Consumers supported a layered approach to consent that offers choice in the amount of information to be read before deciding whether to enter a trial. A 3-page PICF was considered sufficient for decision-making for the SNAP trial, provided that further information was available and accessible.

The Impact of a Multifaceted Tertiary Pediatric Hospital's Antimicrobial Stewardship Service.

BACKGROUND: Antimicrobials are the most commonly prescribed drug class in children. Overuse through inappropriate prescribing is a key driver of antimicrobial resistance and is recognized as one of the top 10 threats to global health by the World Health Organization. METHODS: A prospective observational cohort study was performed following implementation of a multifaceted Antimicrobial Stewardship (AMS) program (January 2014 to December 2020). Data were collected on AMS and "handshake" ward rounds from patient information sources and directly from clinicians responsible for patient care. Primary outcomes include appropriateness of therapy (drug, dose, antimicrobial spectrum, duration and route), compliance with prescribing guidelines, antimicrobial expenditure, use of high-priority antimicrobials and duration of hospitalization. We compared outcomes across 3 time periods; January 2014-December 2015, January 2016-December 2017 and January 2018-December 2020. RESULTS: The appropriateness of individual antimicrobial orders improved across the study periods from 6111/7040 (79.4%) in the first 2 years following implementation of the AMS program to 17,819/19,229 (92.3%) in the latter period. Guideline compliance increased from 5426/7700 (70.5%) to 17,822/19,316 (92.3%). A reduction in overall antimicrobial expenditure (34% reduction, equivalent to $12.52 per bed day) and a decrease in antifungal expenditure (37% reduction, equivalent to $5.56 per bed day) was observed across the time periods. CONCLUSIONS: This study quantifies a comprehensive pediatric AMS program's sustained impact on reducing inappropriate antimicrobial use and expenditure and improving compliance with guidelines. The effectiveness of these interventions has been demonstrated and should be considered by institutions seeking to improve rational antimicrobial use in children.

Urinary tract infections in children: building a causal model-based decision support tool for diagnosis with domain knowledge and prospective data.

BACKGROUND: Diagnosing urinary tract infections (UTIs) in children in the emergency department (ED) is challenging due to the variable clinical presentations and difficulties in obtaining a urine sample free from contamination. Clinicians need to weigh a range of observations to make timely diagnostic and management decisions, a difficult task to achieve without support due to the complex interactions among relevant factors. Directed acyclic graphs (DAG) and causal Bayesian networks (BN) offer a way to explicitly outline the underlying disease, contamination and diagnostic processes, and to further make quantitative inference on the event of interest thus serving as a tool for decision support. METHODS: We prospectively collected data on children present to ED with suspected UTIs. Through knowledge elicitation workshops and one-on-one meetings, a DAG was co-developed with clinical domain experts (the Expert DAG) to describe the causal relationships among variables relevant to paediatric UTIs. The Expert DAG was combined with prospective data and further domain knowledge to inform the development of an application-oriented BN (the Applied BN), designed to support the diagnosis of UTI. We assessed the performance of the Applied BN using quantitative and qualitative methods. RESULTS: We summarised patient background, clinical and laboratory characteristics of 431 episodes of suspected UTIs enrolled from May 2019 to November 2020. The Expert DAG was presented with a narrative description, elucidating how infection, specimen contamination and management pathways causally interact to form the complex picture of paediatric UTIs. Parameterised using prospective data and expert-elicited parameters, the Applied BN achieved an excellent and stable performance in predicting Escherichia coli culture results, with a mean area under the receiver operating characteristic curve of 0.86 and a mean log loss of 0.48 based on 10-fold cross-validation. The BN predictions were reviewed via a validation workshop, and we illustrate how they can be presented for decision support using three hypothetical clinical scenarios. CONCLUSION: Causal BNs created from both expert knowledge and data can integrate case-specific information to provide individual decision support during the diagnosis of paediatric UTIs in ED. The model aids the interpretation of culture results and the diagnosis of UTIs, promising the prospect of improved patient care and judicious use of antibiotics.

Whole genome sequencing and molecular epidemiology of paediatric Staphylococcus aureus bacteraemia.

OBJECTIVES: The role Staphylococcus aureus antimicrobial resistance genes and toxins play in disease severity, management and outcome in childhood is an emerging field requiring further exploration. METHODS: A prospective multisite study of Australian and New Zealand children hospitalised with S. aureus bacteraemia (SAB) occurred over 24 months (2017-2018). Whole genome sequencing (WGS) data were paired with clinical information from the ISAIAH cohort. RESULTS: 353 SAB isolates were sequenced; 85% methicillin-susceptible S. aureus ([MSSA], 301/353) and 15% methicillin-resistant S. aureus ([MRSA], 52/353). There were 92 sequence types (STs), most commonly ST5 (18%) and ST30 (8%), grouped into 23 clonal complexes (CCs), most frequently CC5 (21%) and CC30 (12%). MSSA comprised the majority of healthcare-associated SAB (87%, 109/125), with principal clones CC15 (48%, 11/21) and CC8 (33%, 7/21). Panton-Valentine leukocidin (PVL)-positive SAB occurred in 22% (76/353); predominantly MSSA (59%, 45/76), community-onset (92%, 70/76) infections. For community-onset SAB, the only microbiological independent predictor of poor outcomes was PVL positivity (aOR 2.6 [CI 1.0-6.2]). CONCLUSION: From this WGS paediatric SAB data, we demonstrate the previously under-recognized role MSSA has in harbouring genetic virulence and causing healthcare-associated infections. PVL positivity was the only molecular independent predictor of poor outcomes in children. These findings underscore the need for further research to define the potential implications PVL-producing strains may have on approaches to S. aureus clinical management.

Infectious complications and optimising infection prevention for children with cochlear implants.

AIM: To describe the clinical epidemiology of children receiving cochlear implants, as well as the management and outcomes of cochlear implant infections and adherence to infection prevention measures. METHODS: A retrospective observational study was conducted in children ≤18 years who received cochlear implants in Western Australia's tertiary paediatric hospital. Information was obtained from medical and laboratory records regarding demographics, indication for implant, implant infection and preoperative Staphylococcus aureus screening/decolonisation. Immunisation history was examined using the Australian Immunisation Register. RESULTS: Overall, 118 children received cochlear implants, with 158 devices inserted (599 cochlear implant insertion-years). An implant infection rate of 3.8% (6/158) was identified during the study period (four pneumococcal and two community-acquired methicillin resistant S. aureus infections). All required surgical management, with an overall median duration of antibiotic therapy of 37 days (interquartile range (IQR) 29-48) and median length of stay of 8 days (IQR 8-9.5). All devices were retained and there were no relapses or deaths. Half of the children who developed cochlear implant infections (50%, 3/6) were up-to-date with additional pneumococcal vaccinations and no children (0%, 0/118) received S. aureus screening/decolonisation before implant insertion. CONCLUSIONS: Favourable outcomes were achieved with cochlear implant retention; however, the treatment was burdensome for families. We demonstrate significant scope to improve adherence to existing infection prevention strategies and provide direction for optimising preventative measures in the future. These include ensuring parental education, additional pneumococcal vaccinations and S. aureus decolonisation which are delivered as an infection prevention bundle to the growing population of infants receiving cochlear implants.

Status epilepticus following vaccination in children aged ≤24 months: A five-year retrospective observational study.

BACKGROUND: Status epilepticus is associated with significant morbidity and mortality. While vaccine-proximate status epilepticus (VP-SE) has rarely been associated with cases of Dravet syndrome, it is not known whether VP-SE differs clinically from non-vaccine proximate status epilepticus (NVP-SE). METHODS: Medical records of children aged ≤24 months, presenting to one of five Australian tertiary pediatric hospitals with their first episode of status epilepticus from 2013 to 2017 were identified using ICD-coded discharge diagnoses. Vaccination history was obtained from the Australian Immunisation Register. Hospitalization details, subsequent epilepsy diagnosis, and vaccination uptake were compared between VP-SE and NVP-SE cases. RESULTS: Of 245 first status epilepticus hospitalization with immunization records, 35 (14%) were VP-SE and 21 (60%) followed measles-containing vaccines. Vaccine-proximate status epilepticus cases had a median age of 12.5 months [IQR 7.1-14.73], 23 (66%) were in males, 15 (43%) were febrile status epilepticus and 17 (49%) had an infection confirmed. There were no significant differences in hospitalization duration (P = 0.50) or intensive care unit admission (P = 0.42) between children with VP-SE compared to children with NVP-SE. Children with no history of seizures at their first VP-SE had longer hospitalizations, were more likely to require intensive care unit admission, but were less likely to have a subsequent diagnosis of epilepsy than children with previous seizures at their first VP-SE. CONCLUSION: First VP-SE was predominantly associated with a measles-containing vaccine at 12-months of age. Seizure severity was no different between first VP-SE and first NVP-SE. In children with VP-SE, subsequent seizure admissions and epilepsy diagnosis were associated with having seizure prior to their first SE.

Pediatric Staphylococcus aureus Bacteremia: Clinical Spectrum and Predictors of Poor Outcome.

BACKGROUND: Staphylococcus aureus is a common cause of bacteremia, yet the epidemiology and predictors of poor outcome remain inadequately defined in childhood. METHODS: ISAIAH (Invasive Staphylococcus aureus Infections and Hospitalizations in children) is a prospective, cross-sectional study of S. aureus bacteremia (SAB) in children hospitalized in Australia and New Zealand over 24 months (2017-2018). RESULTS: Overall, 552 SABs were identified (incidence 4.4/100 000/year). Indigenous children, those from lower socioeconomic areas and neonates were overrepresented. Although 90-day mortality was infrequent, one-third experienced the composite of: length of stay >30 days (26%), intensive care unit admission (20%), relapse (4%), or death (3%). Predictors of mortality included prematurity (adjusted odds ratio [aOR],16.8; 95% confidence interval [CI], 1.6-296.9), multifocal infection (aOR, 22.6; CI, 1.4-498.5), necrotizing pneumonia (aOR, 38.9; CI, 1.7-1754.6), multiorgan dysfunction (aOR, 26.5; CI, 4.1-268.8), and empiric vancomycin (aOR, 15.7; CI, 1.6-434.4); while infectious diseases (ID) consultation (aOR, 0.07; CI .004-.9) was protective. Neither MRSA nor vancomycin trough targets impacted survival; however, empiric vancomycin was associated with nephrotoxicity (OR, 3.1; 95% CI 1.3-8.1). CONCLUSIONS: High SAB incidence was demonstrated and for the first time in a pediatric setting, necrotizing pneumonia and multifocal infection were predictors of mortality, while ID consultation was protective. The need to reevaluate pediatric vancomycin trough targets and limit unnecessary empiric vancomycin exposure to reduce poor outcomes and nephrotoxicity is highlighted. One in 3 children experienced considerable SAB morbidity; therefore, pediatric inclusion in future SAB comparator trials is paramount to improve outcomes.

Re-examining Hepatitis B Postexposure Prophylaxis Following Pediatric Community-acquired Needle-stick Injury in an Era of a National Immunization Registry.

BACKGROUND: Long-term hepatitis B immunity has been demonstrated following the completion of the primary vaccination series in childhood. Some guidelines recommend a hepatitis B surface antibody (anti-HBs) directed approach following community-acquired needle-stick injury (CANSI) to inform hepatitis B postexposure prophylaxis (PEP) management. We assessed the utility of anti-HBs testing post-CANSI, as well as the costing of, and adherence to PEP at a pediatric hospital. METHODS: Children presenting to an Australian tertiary pediatric hospital post-CANSI (2014-2019) were identified retrospectively using medical and laboratory records. Immunization status was obtained from the Australian Immunisation Registry. RESULTS: Fifty-six children with CANSI were identified. Of those with immunization records, all had completed hepatitis B vaccinations (n = 52). At presentation, 44% (n = 23) had anti-HBs <10 IU/L, which was more likely in older (≥6 years, 68%) versus younger children (OR 4.59, P < 0.02). HBIG and hepatitis B vaccine adherence was 65% (15/23) and 78% (18/23), respectively. All children (n = 14) with anti-HBs ≥4 weeks postvaccination ±HBIG, demonstrated an anamnestic response. No hepatitis B infections were detected. Using completed immunizations versus anti-HBs levels as a marker of immunity to direct PEP resulted in a projected cost savings of AUD$ 4234. CONCLUSION: Anti-HBs levels <10 IU/L, despite previous vaccinations, were frequent in children post-CANSI, with many demonstrating an anamnestic response. Adherence to postexposure HBIG and hepatitis B vaccine was suboptimal using an anti-HBs directed approach. These data support re-evaluating PEP in an era of the national immunization registry; completion of hepatitis B vaccinations as a marker of immunity provides a practical approach, ensuring optimized care for pediatric CANSI.

Case Report: Neonatal Varicella Acquired From Maternal Zoster.

The incidence of neonatal varicella has decreased dramatically since the introduction of the varicella vaccination. Although the varicella zoster virus is often associated with a mild infection, it may cause severe morbidity and mortality, particularly in the neonatal period and immunocompromised hosts. We report a case of neonatal varicella acquired from maternal zoster in a mother on biological immunosuppressive therapy. Following the diagnosis, the baby improved on antiviral therapy without any neurological sequelae. This case highlights the limited published data on neonatal varicella following herpes zoster reactivation to inform practice. This includes the role of varicella zoster immunoglobulin in neonates exposed to maternal zoster, the degree of trans-placental immunity and optimum antiviral dosing and duration.

Revaccination outcomes of children with vaccine proximate seizures.

BACKGROUND: Seizures, whether febrile or afebrile, occurring within 14 days following vaccination can be considered as vaccine proximate seizures (VPSs). While the attributable risk and clinical severity of first febrile VPS is well known, the risk and clinical outcomes of VPS recurrence is less well defined. METHODS: We conducted a retrospective review of revaccination management and outcomes in children who experienced a VPS as their first seizure seen in Australian Specialist Immunisation Clinics between 2013 and 2017. Vaccination outcomes were compared between children who had a VPS as their only seizure (VPS only) and children who had further non-vaccine proximate seizures following their initial VPS (VPS+) prior to review at the clinic. RESULTS: We identified 119 children with a VPS as their first seizure, of which 61 (51%) went on to have other seizures (VPS+). Children with VPS+ were more likely to present at a younger age (6.2 vs 12.5 months, P = 0.03), with afebrile seizures (42.6% vs 15.5%, P = 0.002) compared to VPS only children. VPS recurrence on revaccination was uncommon in both groups, but more common in VPS+ children (12.5% vs 2.4%, P = 0.07). Having an epilepsy diagnosis, specifically Dravet syndrome, was associated with VPS recurrence (P < 0.001). Of the four children with Dravet syndrome who had VPS recurrence, all had status epilepticus following revaccination. CONCLUSION: In children who presented with a single VPS as their only seizure, VPS recurrence on revaccination was uncommon. Children who had multiple non-vaccine proximate seizures following their initial VPS (VPS+) were more likely to present with afebrile VPS, at a younger age and have a VPS recurrence with vaccination. In these children, particularly those aged < 12 months, assessment and investigation for diagnosis of Dravet syndrome should be considered and additional precautions for revaccination undertaken as they are at highest risk of VPS recurrence.

Pre- and post-intervention study examining immunisation rates, documentation, catch-up delivery and the impact of a dedicated immunisation service at a tertiary paediatric hospital.

AIM: To explore immunisation rates and catch-up delivery to children admitted to hospital before and after an immunisation service was commenced. METHODS: This pre- and post-intervention study examined 300 admissions prior to (cohort 1) and 300 following (cohort 2) the introduction of an immunisation service. Immunisation rates, documentation, catch-up delivery and accuracy of the Australian Immunisation Register (AIR) were examined. RESULTS: On admission, 75% (cohort 1) and 89% (cohort 2) were up-to-date with immunisations. Immunisation history was documented in the medical record in 78% and requirement for catch-up documented in 10%. AIR was incorrect in one-third of cases. By 3 months following discharge, 28% (cohort 1) and 64% (cohort 2) of patients were immunised. CONCLUSIONS: Children admitted to hospital have lower immunisation rates than the national average. Documentation was poor, opportunities for catch-up were missed and AIR is error-prone. Catch-up rates increased following the introduction of an immunisation service.

Do rapid diagnostic methods improve antibiotic prescribing in paediatric bacteraemia?

AIM: Rapid blood culture pathogen identification facilitated by matrix-assisted laser desorption ionisation time-of-flight and GeneXpert has the potential to improve antibiotic prescribing. This study investigates the impact of these rapid diagnostics on the timeliness of effective and optimal antibiotic prescribing in paediatric patients with bacteraemia. METHODS: A single centre retrospective cohort study was performed comparing paediatric bacteraemia cases pre- and post-rapid diagnostic implementation. Primary outcomes were the proportion of cases receiving, and median time to administration of effective and optimal antibiotics from blood culture collection. Secondary outcomes included hospital length of stay, intensive care unit admissions, and all-cause mortality. RESULTS: A total of 255 bacteraemia cases were subject to final data analysis, 129 in the control cohort (pre-implementation of rapid diagnostics) and 126 in the rapid diagnostics cohort. The median time to effective (2.3 vs. 1.8 h, P = 0.20) and optimal therapy (44.4 vs. 39.1 h, P = 0.66) did not differ significantly between the cohorts. There was also no significant difference found in the number of cases reaching effective (120 vs. 116, P = 0.77) and optimal therapy (66 vs. 62, P = 0.76), length of stay (7 vs. 9 days), all-cause mortality (1.6 vs. 1.6%) and number of intensive care unit admissions (20 vs. 15). CONCLUSION: The implementation of rapid diagnostics, when used in isolation, resulted in no improvement in antibiotic prescribing or patient clinical outcomes. To be effective, rapid diagnostics must be coupled with active real-time antimicrobial stewardship promotion, de-escalation or modification based on early laboratory results.