Eliciting the barriers and enablers towards anaesthetists giving penicillin-based antibiotic prophylaxis to low-risk patients who have had their penicillin allergy label removed as part of a preoperative delabelling process.

Background: Some penicillin allergy labels can be removed by non-allergy specialists by direct oral challenge, but there is reluctance amongst anaesthetists to give penicillin to these patients. We aimed to assess anaesthetist beliefs about giving penicillin to patients delabelled by direct oral challenge. Methods: A survey, developed using the Theoretical Domains Framework, was circulated to anaesthetists within a regional research network in England. Domains were rated using 5-point Likert scales. Overall and group medians were used to dichotomize domains rated by group into 'relatively important/unimportant' and 'relative enabler/barrier'. Results: We received 257 responses from six hospitals (response rate 49.7%). Seven domains were rated as important for all stakeholder groups and hospitals: Knowledge, Skills, Belief in Capabilities, Belief in Consequences, Memory/Attention/Decisions, Environmental Context and Resources, and Emotions. Social and Professional Role was also important to all respondents except those in one hospital. Intentions and Optimism were rated as important for some groups/hospitals and unimportant for others. All four other domains were rated as unimportant for all groups/hospitals. All domains rated as important were enablers for all groups/hospitals, with the exception of Memory/Attention/Decisions and Emotions, which were rated as discordant barriers/enablers between groups. This means they were acting as a barrier for some staff groups/hospitals and an enabler for others. Barrier domains (Reinforcement, Goals, Social Influences, Behavioural Regulation) were all rated unimportant. Conclusions: Behavioural influences on giving penicillin prophylaxis to a delabelled patient are complex and nuanced. These findings could inform targeted interventions, both across and within hospitals and staff groups.

Non-allergist healthcare workers views on delivering a penicillin allergy de-labelling inpatient pathway: identifying the barriers and enablers.

Background: Non-allergist delivered PADL is supported by UK and World Health Organization guidelines but is not yet routine in UK hospitals. Understanding the views of healthcare workers (HCWs) on managing patients with penA records and exploring perspectives on delivering a PADL inpatient pathway are required to inform the development of non-allergist delivered PADL pathways. Objective: To explore the perspectives of non-allergist HCWs working in medical specialties on managing patients with penA records, and to explore the enablers and barriers to embedding PADL as a standard of care for inpatients. Methods: Semi-structured interviews with doctors, nurses, pharmacists and medicines optimization pharmacy technicians working in a district general hospital in the UK. Thematic analysis was used to analyse the data. Results: The PADL pathway was considered a shared responsibility of the multidisciplinary team, which needed to be structured and supported by a framework. PADL aligns with HCW roles but time to deliver PADL was a barrier. Training for HCWs on the benefits of PADL and delivering PADL for those patients where a penicillin might be beneficial during the current episode of care would both motivate HCWs to deliver PADL. Discussion and conclusion: The PADL pathway was acceptable to HCWs and aligned with their roles and current healthcare processes but their capacity to deliver PADL in a time pressured environment was a significant barrier.

A multicentre observational study to investigate feasibility of a direct oral penicillin challenge in de-labelling 'low risk' patients with penicillin allergy by non-allergy healthcare professionals (SPACE study): Implications for healthcare systems.

OBJECTIVE: The huge burden of inaccurate penicillin allergy labels (PALs) is an important driver of antimicrobial resistance. This is magnified by insufficient allergy specialists and lack of 'point-of-care' tests. We investigated the feasibility of non-allergy healthcare professionals (HCPs) delivering direct oral penicillin challenges (DPCs) for penicillin allergy de-labelling. METHODS: This prospective observational study was conducted in three hospitals in England across three settings (acute medical, pre-surgical and haematology-oncology). Patients with a PAL were screened and stratified as low risk/high risk. Low risk patients (non-immune mediated symptoms, benign rash, tolerated amoxicillin since and family history) underwent a DPC. RESULTS: N = 2257 PALs were screened, 1054 were eligible; 643 were approached, 373 declined, 270 consented and 259 risk stratified (low risk = 155; high risk = 104). One hundred and twenty-six low risk patients underwent DPC, 122 (96.8%) were de-labelled with no serious allergic reactions. Conversion rate from screening-to-consent was 12% [3.3% and 17.9% in acute and elective settings respectively; odds ratios for consent were 3.42 (p < 0.001) and 5.53 (p < 0.001) in haematology-oncology and pre-surgical setting respectively. Common reasons for failure to progress in the study included difficulty in reaching patients, clinical instability/medical reasons, lacking capacity to consent and psychological factors. INTERPRETATION: DPCs can be delivered by non-allergy HCPs. A high proportion of patients with PALs did not progress in the study pathway. Strategies to deliver DPC at optimal points of the care pathway are needed to enhance uptake. Elective settings offer greater opportunities than acute settings for DPC. The safety and simplicity of DPCs lends itself to adoption by healthcare systems beyond the UK, including in resource-limited settings.

Experiences of an inpatient penicillin allergy de-labelling pathway: capturing the patient voice.

Background: Non-allergist-delivered penicillin allergy de-labelling (PADL) is supported by UK and other national guidelines but is not yet routine practice in UK hospitals. Those who have undergone PADL report high rates of acceptance, but it is unknown why some continue to avoid penicillin, and why some decline testing. Objectives: To explore the experiences of patients recently approached for penicillin allergy (penA) assessment and de-label by non-allergists in a UK hospital to determine the barriers and enablers to patient acceptance of PADL. Methods: Qualitative study using semi-structured interviews with patients who were penA assessed and de-labelled during an inpatient stay between November 2022 and January 2023. Thematic analysis was used to analyse the data. Results: Nineteen patients were interviewed. Patients were largely unaware of the negative impact of penA on their healthcare. Patients had differing views on challenging their penA status while they were acutely unwell, some agreeing that it is the right time to test and others not. Patients declined testing because they felt they were at higher potential risk because they were older or had multiple comorbidities. Some patients who declined testing felt they would have been persuaded if they had received a better explanation of the risks and benefits of PADL. Conclusions: Patients who were successfully de-labelled were positive about the experience. Those who declined testing did so for a variety of reasons including frailty/comorbidities or a fear of testing whilst unwell. Patients highlighted the importance of good communication about the personalized risks and benefits of testing.

Penicillin allergy de-labelling by non-allergists: a comparison of testing protocols.

Optimizing penicillin allergy de-labelling (PADL) to ensure patients with an incorrect penicillin allergy record are de-labelled with minimal patient harm is important for antibiotic stewardship. The heterogeneity of inclusion and exclusion criteria in the published penicillin allergy testing protocols risks suboptimal delivery of PADL. We compared the similarities and the differences between non-allergist-delivered PADL testing protocols and make suggestions for harmonization. The observed variation in testing practice has two broad elements: (i) definitions and terminology; and (ii) differences in the acceptability of perceived risk. All direct drug provocation testing (DDPT) protocols included patients with benign delayed rash as eligible for testing, although the remoteness of the rash, and the terminology used to describe the rash, differed. Patients with features of potential IgE reactions were excluded from most DDPT protocols, but not all of them. There was differing advice on how to manage patients who had subsequently tolerated penicillin since the index reaction and differences in which patients were considered ineligible for DDPT due to acuity of illness, comorbidities and concomitant medications. Standardization of the terminology used in penicillin allergy testing protocols and consensus on inclusion and exclusion criteria are required for safe and efficient PADL delivery at scale by non-allergists.

Developing a model for decision-making around antibiotic prescribing for patients with COVID-19 pneumonia in acute NHS hospitals during the first wave of the COVID-19 pandemic: qualitative results from the Procalcitonin Evaluation of Antibiotic use in COVID-19 Hospitalised patients (PEACH Study).

OBJECTIVE: To explore and model factors affecting antibiotic prescribing decision-making early in the pandemic. DESIGN: Semistructured qualitative interview study. SETTING: National Health Service (NHS) trusts/health boards in England and Wales. PARTICIPANTS: Clinicians from NHS trusts/health boards in England and Wales. METHOD: Individual semistructured interviews were conducted with clinicians in six NHS trusts/health boards in England and Wales as part of the Procalcitonin Evaluation of Antibiotic use in COVID-19 Hospitalised patients study, a wider study that included statistical analysis of procalcitonin (PCT) use in hospitals during the first wave of the pandemic. Thematic analysis was used to identify key factors influencing antibiotic prescribing decisions for patients with COVID-19 pneumonia during the first wave of the pandemic (March to May 2020), including how much influence PCT test results had on these decisions. RESULTS: During the first wave of the pandemic, recommendations to prescribe antibiotics for patients with COVID-19 pneumonia were based on concerns about secondary bacterial infections. However, as clinicians gained more experience with COVID-19, they reported increasing confidence in their ability to distinguish between symptoms and signs caused by SARS-CoV-2 viral infection alone, and secondary bacterial infections. Antibiotic prescribing decisions were influenced by factors such as clinician experience, confidence, senior support, situational factors and organisational influences. A decision-making model was developed. CONCLUSION: This study provides insight into the decision-making process around antibiotic prescribing for patients with COVID-19 pneumonia during the first wave of the pandemic. The importance of clinician experience and of senior review of decisions as factors in optimising antibiotic stewardship is highlighted. In addition, situational and organisational factors were identified that could be optimised. The model presented in the study can be used as a tool to aid understanding of the complexity of the decision-making process around antibiotic prescribing and planning antimicrobial stewardship support in the context of a pandemic. TRIAL REGISTRATION NUMBER: ISRCTN66682918.

Feasibility, Effectiveness and Safety of Elastomeric Pumps for Delivery of Antibiotics to Adult Hospital Inpatients-A Systematic Review.

Elastomeric infusion pumps (EMPs) have been implemented in many fields, including analgesia, chemotherapy and cardiology. Their application in antimicrobials is mainly limited to the outpatient setting, but with a need to optimise inpatient antimicrobial treatment, the use of EMPs presents a potential option. This review aimed to identify if the use of EMPs within an inpatient setting is feasible, effective and safe for antimicrobial use. Criteria for inclusion were human studies that involved the treatment of an infection with intravenous antimicrobial agents via an EMP. A search strategy was developed covering both the indexed and grey literature, with all study designs included. The review found 1 eligible study enrolling 6 patients. There was strong patient preference for EMPs (6/6), and daily tasks were easily completed whilst attached to the EMP. Nurses (5/5) also preffered the pumps, and the majority reported them as easy to use. The review has identified the need for further research in the area. Evidence for the use of EMPs to administer antibiotics in the inpatient setting is scarce, and more work is needed to understand the advantages to patients, to healthcare workers and from an antimicrobial stewardship perspective. Potential disadvantages that may put patients at risk also need investigating.

Penicillin allergy status and its effect on antibiotic prescribing, patient outcomes and antimicrobial resistance (ALABAMA): protocol for a multicentre, parallel-arm, open-label, randomised pragmatic trial.

INTRODUCTION: Incorrect penicillin allergy records are recognised as an important barrier to the safe treatment of infection and affect an estimated 2.7 million people in England. Penicillin allergy records are associated with worse health outcome and antimicrobial resistance. The ALlergy AntiBiotics And Microbial resistAnce (ALABAMA) trial aims to determine if an intervention package, centred around a penicillin allergy assessment pathway (PAAP) initiated in primary care, is safe and effective in improving patient health outcomes and antibiotic prescribing. METHODS AND ANALYSIS: The ALABAMA trial is a multicentre, parallel-arm, open-label, randomised pragmatic trial with a nested pilot study. Adults (≥18 years) with a penicillin allergy record and who have received antibiotics in the previous 24 months will be eligible for participation. Between 1592 and 2090 participants will be recruited from participating National Health Service general practices in England. Participants will be randomised to either usual care or intervention to undergo a pre-emptive PAAP using a 1:1 allocation ratio. The primary outcome measure is the percentage of treatment response failures within 28 days of an index prescription. 2090 and 1592 participants are estimated to provide 90% and 80% power, respectively, to detect a clinically important absolute difference of 7.9% in primary outcome at 1 year between groups. The trial includes a mixed-methods process evaluation and cost-effectiveness evaluation. ETHICS AND DISSEMINATION: This trial has been approved by London Bridge Research Ethics Committee (ref: 19/LO/0176). It will be conducted in compliance with Good Clinical Practice guidelines according to the Declaration of Helsinki. Informed consent will be obtained from all subjects involved in the study. The primary trial results will be submitted for publication to an international, peer-reviewed journal. TRIAL REGISTRATION: ISRCTN20579216.

Removal of incorrect penicillin allergy labels in a UK hospital.

OBJECTIVES: Penicillin allergy records are common, often incorrect and are associated with broad spectrum antibiotic use. We piloted a pharmacist-led multidisciplinary penicillin allergy de-labelling daily ward round to determine the opportunity for penicillin allergy de-labelling in a UK hospital. METHODS: A daily ward round, delivered by antibiotic pharmacists or junior doctors, identified adult medical and surgical patients between 7 November 2022 and 31 January 2023 with a penicillin allergy record that was preventing first-line penicillin use. An allergy history was taken before risk stratifying likelihood of future harm from penicillin re-exposure and an allergy testing method was determined (direct de-label on history alone or after direct drug provocation testing). After successful allergy de-label, the antibiotic was switched to a penicillin antibiotic. RESULTS: Of 7214 inpatients during the study period, 1133 (15.7%) had a penicillin allergy record. Of 285 allergy histories taken, 105 (36.8%) met high-risk criteria, 45 (15.8%) met low-risk criteria eligible for direct de-label and 73 (25.6%) met criteria eligible for direct drug provocation testing. We were unable to obtain a history for 61 (21.4%) patients. Of 45 low-risk patients eligible for direct de-label, 40 (88.9%) were de-labelled of whom 24 (53.3%) were switched to a penicillin antibiotic. Of 73 patients with a low-risk allergy history eligible for direct drug provocation testing, 16 (21.9%) received direct drug provocation testing, of whom 9 were switched to a penicillin antibiotic. Two direct de-label patients experienced harm (thrush within 5 days and delayed skin reaction after day 5); none of the direct drug provocation testing patients had a reaction by day 5. The switches resulted in reduced alternative antibiotic use by 173 Daily Defined Doses (DDDs). DISCUSSION: Penicillin allergy de-labelling patient pathway delivered by pharmacists and junior doctors was safe and effective and well accepted by patients and the wider clinical teams.

Infective endocarditis: Do we have an effective risk score model? A systematic review.

Background: Infective endocarditis (IE) is a rare, highly morbid condition with 17% in-hospital mortality. A total of 25-30% require surgery and there is ongoing debate with regard to markers predicting patient outcomes and guiding intervention. This systematic review aims to evaluate all IE risk scores currently available. Methods: Standard methodology (PRISMA guideline) was used. Papers with risk score analysis for IE patients were included, with attention to studies reporting area under the receiver-operating characteristic curve (AUC/ROC). Qualitative analysis was carried out, including assessment of validation processes and comparison of these results to original derivation cohorts where available. Risk-of-bias analysis illustrated according to PROBAST guidelines. Results: Of 75 articles initially identified, 32 papers were analyzed for a total of 20 proposed scores (range 66-13,000 patients), 14 of which were specific for IE. The number of variables per score ranged from 3 to 14 with only 50% including microbiological variables and 15% including biomarkers. The following scores had good performance (AUC > 0.8) in studies proposing the score (often the derivation cohort); however fared poorly when applied to a new cohort: PALSUSE, DeFeo, ANCLA, RISK-E, EndoSCORE, MELD-XI, COSTA, and SHARPEN. DeFeo score demonstrated the largest discrepancy with initial AUC of 0.88, compared to 0.58 when applied to different cohorts. The inflammatory response in IE has been well documented and CRP has been found to be an independent predictor for worse outcomes. There is ongoing investigation on alternate inflammatory biomarkers which may assist in IE management. Of the scores identified in this review, only three have included a biomarker as a predictor. Conclusion: Despite the variety of available scores, their development has been limited by small sample size, retrospective collection of data and short-term outcomes, with lack of external validation, limiting their transportability. Future population studies and large comprehensive registries are required to address this unmet clinical need.

Health outcomes of penicillin allergy testing in children: a systematic review.

BACKGROUND: Penicillin allergy labels are commonly acquired in childhood and lead to avoidance of first-line penicillin antibiotics. Understanding the health outcomes of penicillin allergy testing (PAT) can strengthen its place in antimicrobial stewardship efforts. OBJECTIVES: To identify and summarize the health outcomes of PAT in children. METHODS: Embase, MEDLINE, Web of Science, Cochrane Library, SCOPUS and CINAHL were searched from inception to 11 Oct 2021 (Embase and MEDLINE updated April 2022). Studies that utilized in vivo PAT in children (≤18 years old) and reported outcomes relevant to the study objectives were included. RESULTS: Thirty-seven studies were included in the review, with a total of 8411 participants. The most commonly reported outcomes were delabelling, subsequent penicillin courses, and tolerability to penicillin courses. Ten studies had patient-reported tolerability to subsequent penicillin use, with a median 93.6% (IQR 90.3%-97.8%) of children tolerating a subsequent course of penicillins. In eight studies, a median 97.3% (IQR 96.4%-99.0%) of children were reported as 'delabelled' after a negative PAT without further definition. Three separate studies verified delabelling by checking electronic or primary care medical records, where 48.0%-68.3% children were delabelled. No studies reported on outcomes relating to disease burden such as antibiotic resistance, mortality, infection rates or cure rates. CONCLUSIONS: Safety and efficacy of PAT and subsequent penicillin use was the focus of existing literature. Further research is required to determine the long-term impact of delabelling penicillin allergies on disease burden.

Expert consensus recommendations for the provision of infective endocarditis services: updated guidance from the Joint British Societies.

Infective endocarditis (IE) remains a difficult condition to diagnose and treat and is an infection of high consequence for patients, causing long hospital stays, life-changing complications and high mortality. A new multidisciplinary, multiprofessional, British Society for Antimicrobial Chemotherapy (BSAC)-ledWorking Party was convened to undertake a focused systematical review of the literature and to update the previous BSAC guidelines relating delivery of services for patients with IE. A scoping exercise identified new questions concerning optimal delivery of care, and the systematic review identified 16 231 papers of which 20 met the inclusion criteria. Recommendations relating to endocarditis teams, infrastructure and support, endocarditis referral processes, patient follow-up and patient information, and governance are made as well as research recommendations. This is a report of a joint Working Party of the BSAC, British Cardiovascular Society, British Heart Valve Society, British Society of Echocardiography, Society of Cardiothoracic Surgeons of Great Britain and Ireland, British Congenital Cardiac Association and British Infection Association.

Addressing the Challenges of Penicillin Allergy Delabeling With Electronic Health Records and Mobile Applications.

Allergy labels are common, often incorrect, and potentially harmful. There are many opportunities for clinical decision support (CDS) tools integrated in the electronic health record (EHR) and mobile apps to address the challenges with drug allergy management, including penicillin allergy delabeling (PADL). Effective delabeling solutions must consider multidisciplinary clinical workflow and multistep processes, including documentation, assessment, plan (eg, allergy testing and referral), record update, drug allergy alert management, and allergy reconciliation over time. Developing a systematic infrastructure to manage allergies across the EHR is critical to improve the accuracy and completeness of a patient's allergy and avoid inadvertently relabeling. Improving the appropriateness and relevancy of drug allergy alerts is important to reduce alert fatigue. Using alerts to guide clinicians on appropriate antibiotic use may reduce unnecessary ß-lactam avoidance. To date, EHR CDS tools have facilitated non-allergists to provide PADL at the point of care. A mobile app was shown to support PADL and provide specialist support and education. Future research is needed to standardize, integrate, and evaluate innovative CDS tools in the EHR to demonstrate patient safety and clinical utility and facilitate wider adoption.

The effectiveness of interventions that support penicillin allergy assessment and delabeling of adult and pediatric patients by nonallergy specialists: a systematic review and meta-analysis.

OBJECTIVES: Penicillin allergy records are often incorrect and may result in harm. We aimed to systematically review the effectiveness and safety of nonallergist health care worker delivery of penicillin allergy delabeling. METHODS: We searched EMBASE/MEDLINE/CINAHL (Ovid), PsycInfo, Web of Science, and Cochrane CENTRAL from inception to January 21, 2022 and unpublished studies and gray literature. The proportion of patients allergic to penicillin delabeled and harmed was calculated using random-effects models. RESULTS: Overall, 5019 patients were delabeled. Using allergy history alone, 14% (95% confidence interval [CI], 9-21%) of 4350 assessed patients were delabeled without reported harm. Direct drug provocation testing resulted in delabeling in 27% (95% CI, 18-37%) of 4207 assessed patients. Of the 1373 patients tested, 98% were delabeled (95% CI, 97-99%), and nonserious harm was reported in 1% (95% CI, 0-2%). Using skin testing, followed by drug provocation testing, 41% (95% CI, 24-59%) of 2890 assessed patients were delabeled. Of the 1294 tested patients, 95.0% (95% CI, 90-99%) were delabeled, and the reported harm was low (0%; (95% CI 0-1%). CONCLUSION: Penicillin allergy delabeling by nonallergists is efficacious and safe. The proportion of assessed patients who can be delabeled increases with the complexity of testing method, but substantial numbers can be delabeled without skin testing.

Procalcitonin Evaluation of Antibiotic Use in COVID-19 Hospitalised Patients (PEACH): Protocol for a Retrospective Observational Study.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel virus responsible for the coronavirus disease 2019 (COVID-19) pandemic. Although COVID-19 is a viral illness, many patients admitted to hospital are prescribed antibiotics, based on concerns that COVID-19 patients may experience secondary bacterial infections, and the assumption that they may respond well to antibiotic therapy. This has led to an increase in antibiotic use for some hospitalised patients at a time when accumulating antibiotic resistance is a major global threat to health. Procalcitonin (PCT) is an inflammatory marker measured in blood samples and widely recommended to help diagnose bacterial infections and guide antibiotic treatment. The PEACH study will compare patient outcomes from English and Welsh hospitals that used PCT testing during the first wave of the COVID-19 pandemic with those from hospitals not using PCT. It will help to determine whether, and how, PCT testing should be used in the NHS in future waves of COVID-19 to protect patients from antibiotic overuse. PEACH is a retrospective observational cohort study using patient-level clinical data from acute hospital Trusts and Health Boards in England and Wales. The primary objective is to measure the difference in antibiotic use between COVID-19 patients who did or did not have PCT testing at the time of diagnosis. Secondary objectives include measuring differences in length of stay, mortality, intensive care unit admission, and resistant bacterial infections between these groups.

A Systematic Review of the Effect of Therapeutic Drug Monitoring on Patient Health Outcomes during Treatment with Carbapenems.

Adjusting dosing regimens based on measurements of carbapenem levels may improve carbapenem exposure in patients. This systematic review aims to describe the effect carbapenem therapeutic drug monitoring (TDM) has on health outcomes, including the emergence of antimicrobial resistance (AMR). Four databases were searched for studies that reported health outcomes following adjustment to dosing regimens, according to measurements of carbapenem concentration. Bias in the studies was assessed with risk of bias analysis tools. Study characteristics and outcomes were tabulated and a narrative synthesis was performed. In total, 2 randomised controlled trials (RCTs), 17 non-randomised studies, and 19 clinical case studies were included. Significant variation in TDM practice was seen; consequently, a meta-analysis was unsuitable. Few studies assessed impacts on AMR. No significant improvement on health outcomes and no detrimental effects of carbapenem TDM were observed. Five cohort studies showed significant associations between achieving target concentrations and clinical success, including suppression of resistance. Studies in this review showed no obvious improvement in clinical outcomes when TDM is implemented. Optimisation and standardisation of carbapenem TDM practice are needed to improve intervention success and enable study synthesis. Further suitably powered studies of standardised TDM are required to assess the impact of TMD on clinical outcomes and AMR.

BSACI guideline for the set-up of penicillin allergy de-labelling services by non-allergists working in a hospital setting.

The Standards of Care Committee of the British Society for Allergy and Clinical Immunology (BSACI) and a committee of experts and key stakeholders have developed this guideline for the evaluation and testing of patients with an unsubstantiated label of penicillin allergy. The guideline is intended for UK clinicians who are not trained in allergy or immunology, but who wish to develop a penicillin allergy de-labelling service for their patients. It is intended to supplement the BSACI 2015 guideline "Management of allergy to penicillin and other beta-lactams" and therefore does not detail the epidemiology or aetiology of penicillin allergy, as this is covered extensively in the 2015 guideline (1). The guideline is intended for use only in patients with a label of penicillin allergy and does not apply to other beta-lactam allergies. The recommendations include a checklist to identify patients at low risk of allergy and a framework for the conduct of drug provocation testing by non-allergists. There are separate sections for adults and paediatrics within the guideline, in recognition of the common differences in reported allergy history and likelihood of true allergy.

Diagnostic accuracy of splinter haemorrhages in patients referred for suspected infective endocarditis.

OBJECTIVE: Splinter haemorrhages are an examination finding that has classically been associated with infective endocarditis (IE), but are not included in current diagnostic algorithms. Splinter haemorrhages have not been evaluated as a diagnostic tool using modern definitions of IE. We determined their sensitivity and specificity in patients with suspected IE and investigated their inclusion in the Duke criteria. METHODS: This is a retrospective diagnostic accuracy study using data from 1119 patients with suspected IE referred to the IE service. Patients were categorised according to the Duke criteria, the current diagnostic gold standard, into Duke 'rejected', 'possible' or 'definite' groups. Definite cases (n=451) served as the true positives and rejected cases (n=486) as the true negatives against which splinter haemorrhages were compared. Duke possible cases (n=182) were used the assess the clinical impact of adding splinter haemorrhages to the Duke criteria. RESULTS: In clinically suspected cases of IE and using the Duke criteria as the gold standard comparator, splinter haemorrhages had a sensitivity of 26% (95% CI 22 to 31) (119 out of 451) and a specificity of 83% (95% CI 79 to 86) (403 out of 486). Inclusion of splinter haemorrhages as a minor vascular phenomenon in the Duke criteria would result in a reclassification of 12% of cases from Duke rejected to possible and 13% from Duke possible to definite. CONCLUSION: Splinter haemorrhages are an insensitive tool in the diagnosis of IE, but their high specificity indicates they do have clinical value in patients with suspected infection. Their inclusion in the Duke criteria as a minor vascular criterion reduces diagnostic uncertainty for some Duke possible cases, while increasing it for a similar proportion of Duke rejected cases.