Rafael Perera

University of Oxford | OX

Objective To better understand testing patterns in children, we measured temporal trends in paediatric testing from 2005 to 2019 in Oxfordshire, UK. Design Descriptive study of population-based secondary data. Setting Oxfordshire University Hospitals National Health Service Trust laboratories. Participants Children aged 0–15 years in Oxfordshire...

Background and objective: Point-of-care lateral flow device antigen testing has been used extensively to identify individuals with active SARS-CoV-2 infection in the community. This study aimed to evaluate the diagnostic accuracy of two point-of-care tests (POCTs) for SARS-CoV-2 in routine community care. Methods: Adults and children with sympto...

Aim: To determine the quality of paediatric guidelines relevant to diagnosis of three of the most common conditions in primary care: fever, gastroenteritis and constipation. Methods: We undertook a meta-epidemiological study of paediatric guidelines for fever, gastroenteritis and gastroenteritis. We systematically searched MEDLINE, Embase, Trip...

1501 Background: Delays in cancer diagnosis can lead to increased mortality, leading to specialized diagnostic pathways for symptomatic patients when cancer is suspected. Identification of circulating tumour DNA can stratify individuals into those more or less likely to have cancer and predict the cancer origin. This could both expedite cancer diag...

Background: Analysis of circulating tumour DNA could stratify cancer risk in symptomatic patients. We aimed to evaluate the performance of a methylation-based multicancer early detection (MCED) diagnostic test in symptomatic patients referred from primary care. Methods: We did a multicentre, prospective, observational study at National Health Se...

Background: Asthma is one of the most frequent reasons children visit a general practitioner (GP). The diagnosis of childhood asthma is challenging, and a variety of diagnostic tests for asthma exist. GPs may refer to clinical practice guidelines when deciding which tests, if any, are appropriate, but the quality of these guidelines is unknown. O...

Background Influenza and influenza-like illness place significant burden on the NHS. Children with underlying health conditions are vulnerable to developing bacterial complications. Objective To strengthen the evidence base underlying antibiotic use in at-risk children with influenza-like illness. Design This programme comprised five separate wor...

Background Simple blood tests can play an important role in identifying patients for cancer investigation. The current evidence base is limited almost entirely to tests used in isolation. However, recent evidence suggests combining multiple types of blood tests and investigating trends in blood test results over time could be more useful to select...

Diagnostic tests play an essential role in childrens health. Previous work has shown variation in the use of diagnostic tests for adults. However, comparatively little is known about the use of tests in children. We aimed to analyze temporal trends in laboratory testing for children aged 0 to 15 from 2005 to 2019 in Oxfordshire, United Kingdom. Met...

Background Simple blood tests can play an important role in identifying patients for cancer investigation. The current evidence base is limited almost entirely to tests used in isolation. However, recent evidence suggests combining multiple types of blood tests and investigating trends in blood test results over time could be more useful to select...

Background: Evidence for kidney function monitoring intervals in primary care is weak, and based mainly on expert opinion. In the absence of trials of monitoring strategies, an approach combining a model for the natural history of kidney function over time combined with a cost-effectiveness analysis offers the most feasible approach for comparing t...

Background The optimal time for initiation of dialysis and which modality to choose as the starting therapy is currently unclear. This systematic review aimed to assess the recommendations across high-quality clinical practice guidelines (CPGs) related to the start of dialysis. Methods We systematically searched MEDLINE, EMBASE, Web of Science, LI...

Background Substantial variation has been demonstrated in the use of diagnostic tests across primary and secondary care. Most of this research focuses on tests requested for adults and there is a paucity of comprehensive data that quantifies and analyses diagnostic test use in children. It is unknown what proportion of tests occur in primary care c...

Background Around one million individuals in the UK have heart failure (HF), a chronic disease that causes significant morbidity and mortality. N-terminal pro–B-type natriuretic peptide (NT-proBNP) monitoring could help improve the care of patients with HF in the community. Aim The aim of this study is to provide evidence to support the routine us...

Background It remains unclear to what extent reductions in urgent referrals for suspected cancer during the COVID-19 pandemic were the result of fewer patients attending primary care compared to GPs referring fewer patients. Methods Cohort study including electronic health records data from 8,192,069 patients from 663 English practices. Weekly con...

Introduction Successful adoption of POCTs (Point-of-Care tests) for COVID-19 in care homes requires the identification of ideal use cases and a full understanding of the contextual and usability factors that affect test results and minimise biosafety risks. This paper presents a scoping-usability and test performance study of a microfluidic immunof...

Background During the COVID-19 pandemic in 2020, the UK government began a mass SARS-CoV-2 testing programme. This study aimed to determine the feasibility and acceptability of organised regular self-testing for SARS-CoV-2. Methods This was a mixed methods observational cohort study in asymptomatic students and staff at University of Oxford, who p...

Objectives: Successful implementation of asymptomatic testing programmes using lateral flow tests (LFTs) depends on several factors, including feasibility, acceptability and how people act on test results. We aimed to examine experiences of university students and staff of regular asymptomatic self-testing using LFTs, and their subsequent behaviou...

Introduction Clinically complex patients often require multiple medications. Polypharmacy is associated with inappropriate prescriptions, which may lead to negative outcomes. Few effective tools are available to help physicians optimise patient medication. This study assesses whether an electronic medication management support system (eMMa) reduces...

Background Unexpected weight loss (UWL) is a presenting feature of cancer in primary care. Existing research proposes simple combinations of clinical features (risk factors, symptoms, signs, and blood test data) that, when present, warrant cancer investigation. More complex combinations may modify cancer risk to sufficiently rule-out the need for i...

Objective To explore factors that potentially impact external validation performance while developing and validating a prognostic model for hospital admissions (HAs) in complex older general practice patients. Study design and setting Using individual participant data from four cluster-randomised trials conducted in the Netherlands and Germany, we...

Background Long-term monitoring is important in chronic condition management. Despite considerable costs of monitoring, there is no or poor evidence on how, what and when to monitor. The aim of this study was to improve understanding, methods, evidence base and practice of clinical monitoring in primary care, focusing on two areas: chronic kidney d...

Background: Monitoring is the mainstay of chronic kidney disease management in primary care. There is little evidence on how best to monitor. Aim: To compare the effectiveness of eGFR derived from creatinine or cystatin C, to predict renal function decline among those with a recent eGFR of 30-89 ml/min/1.73m². Design and setting: Observational...

Introduction Successful adoption of POCTs (Point-of-Care tests) for COVID-19 in care homes requires the identification of ideal use cases and a full understanding of contextual and usability factors that affect test results and minimise biosafety risks. This paper presents findings from a scoping-usability and test performance study of a microfluid...

Introduction: Reliable rapid testing for COVID-19 is needed in care homes to reduce the risk of outbreaks and enable timely care. This study aimed to examine the usability and test performance of a point of care polymerase chain reaction (PCR) test for detection of SARS-COV2 (POCKITTM Central) in care homes. Methods: POCKITTM Central was evaluat...

Background Unsolicited feedback can solicit changes in prescribing. Objectives Determine whether a low-cost intervention increases clinicians’ engagement with data, and changes prescribing; with or without behavioural science techniques. Methods Randomized trial (ISRCTN86418238). The highest prescribing practices in England for broad-spectrum ant...

Background There has been an increased interest from governments in implementing mass testing for COVID-19 of asymptomatic individuals using Lateral Flow Tests (LFTs). Successful implementation of such programmes depends on several factors, including feasibility, acceptability and how people act on test results. There is a paucity of studies examin...

Introduction The UK government stockpiles co-amoxiclav to treat bacterial complications during influenza pandemics. This pragmatic trial examines whether early co-amoxiclav use reduces re-consultation due to clinical deterioration in “at risk” children presenting with influenza-like illness (ILI) in primary or ambulatory care. Methods “At risk” ch...

Background Chronological age is the strongest risk factor for most chronic diseases. Developing a biomarker-based age and understanding its most important contributing biomarkers may shed light on the effects of age on later life health and inform opportunities for disease prevention. Methods A subpopulation of 141,254 individuals healthy at basel...

Background Autoinflation balloons are used to treat patients with otitis media with effusion to help avoid surgery. Aim To compare the ability of party balloons and Otovent® balloons to produce sufficient pressure for a Valsalva manoeuvre. Design & setting We used pressure testing to determine the number of times each balloon could produce pressu...

Background The aim of RApid community Point-of-care Testing fOR COVID-19 (RAPTOR-C19) is to assess the diagnostic accuracy of multiple current and emerging point-of-care tests (POCTs) for active and past SARS-CoV2 infection in the community setting. RAPTOR-C19 will provide the community testbed to the COVID-19 National DiagnOstic Research and Evalu...

Objective To evaluate design, methods, and reporting of impact studies of cardiovascular clinical prediction rules (CPRs). Study Design and Setting We conducted a systematic review. Impact studies of cardiovascular CPRs were identified by forward citation and electronic database searches. We categorized the design of impact studies as appropriate...

The prevalence of multimorbidity and polypharmacy increases significantly with age and are associated with negative health consequences. However, most current interventions to optimize medication have failed to show significant effects on patient-relevant outcomes. This may be due to ineffectiveness of interventions themselves but may also reflect...

Background The complexity of general practice consultations may be increasing and varies in different settings. A measure of complexity is required to test these hypotheses. Aim To develop a valid measure of general practice consultation complexity applicable to routine medical records. Design and setting Delphi study to select potential indicato...

Background People with reduced kidney function have increased cardiovascular disease (CVD) risk. We present a policy model that simulates individuals' long-term health outcomes and costs to inform strategies to reduce risks of kidney and CVDs in this population.Methods and findingsWe used a United Kingdom primary healthcare database, the Clinical P...

Objective To quantify the impact and recovery in cardiovascular disease monitoring in primary care associated with the first COVID-19 lockdown. Design Retrospective nationwide primary care cohort study, utilising data from 1st January 2018 to 27 th September 2020. Setting We extracted primary care electronic health records data from 514 primary c...

Background: Clinical prediction rules (CPRs) can help general practitioners (GPs) address challenges in cardiovascular disease. A survey published in 2014 evaluated GPs' awareness and use of CPRs in the UK. However, many new CPRs have been published since and it is unknown which cardiovascular CPRs are currently recognised and used. Aim: To iden...

Background Polypharmacy interventions are resource-intensive and should be targeted to those at risk of negative health outcomes. Our aim was to develop and internally validate prognostic models to predict health-related quality of life (HRQoL) and the combined outcome of falls, hospitalisation, institutionalisation and nursing care needs, in older...

Background: National and international guidelines recommend advance care planning (ACP) for patients with heart failure. But clinicians seem hesitant to engage with ACP. Purpose: Our aim was to identify behavioral interventions with the greatest potential to engage clinicians with ACP in heart failure. Methods: A systematic review and meta-ana...

Background: Heart failure (HF) is a chronic and common condition with a rising prevalence, especially in the elderly. Morbidity and mortality rates in people with HF are similar to those with common forms of cancer. Clinical guidelines highlight the need for more detailed prognostic information to optimise treatment and care planning for people wi...

Introduction: Safety-netting in primary care is the best practice in cancer diagnosis, ensuring that patients are followed up until symptoms are explained or have resolved. Currently, clinicians use haphazard manual solutions. The ubiquitous use of electronic health records provides an opportunity to standardise safety-netting practices.A new elec...

Objective To identify key features to be addressed in the reporting of deprescribing trials and to elaborate and explain CONSORT items in this regard. Study Design and Setting As a first step in a multi-stage process and based on a systematic review of deprescribing trials, we elaborated variation in design, intervention, and reporting of the incl...

Background: Sore throat is a common condition associated with a high rate of antibiotic prescriptions, despite limited evidence for the effectiveness of antibiotics. Corticosteroids may improve symptoms of sore throat by reducing inflammation of the upper respiratory tract. This review is an update to our review published in 2012. Objectives: To...

Background: The presence of additional chronic conditions has a significant impact on the treatment and management of type 2 diabetes (T2DM). Little is known about the patterns of comorbidities in this population. The aims of this study are to quantify comorbidity patterns in people with T2DM, to estimate the prevalence of six chronic conditions i...

Background: Advance care planning is widely advocated to improve outcomes in end-of-life care for patients suffering from heart failure. But until now, there has been no systematic evaluation of the impact of advance care planning (ACP) on clinical outcomes. Our aim was to determine the effect of ACP in heart failure through a meta-analysis of ran...

Background: Evidence for kidney function monitoring intervals in primary care is weak, and based mainly on expert opinion. In the absence of trials of monitoring strategies, an approach combining a model for the natural history of kidney function over time combined with a cost-effectiveness analysis offers the most feasible approach for comparing t...

Objective To evaluate the effects of drug interventions that may modify the progression of chronic kidney disease (CKD) in adults with CKD stages 3 and 4. Design Systematic review and meta-analysis. Methods Searching MEDLINE, EMBASE, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Cochrane Database of...

Background The presence of additional chronic conditions has a significant impact on the treatment and management of type 2 diabetes (T2DM). Little is known about the patterns of comorbidities in this population. The aims of this study are to quantify comorbidity patterns in people with T2DM, to estimate the prevalence of six chronic conditions in...

Background GUIDE-IT, the largest trial to date, published in August 2017, evaluating the effectiveness of natriuretic peptide (NP)-guided treatment of heart failure (HF), was stopped early for futility on a composite outcome. However, the reported effect sizes on individual outcomes of all-cause mortality and HF admissions are potentially clinicall...

Background: Financial incentives, monetary or vouchers, are widely used in an attempt to precipitate, reinforce and sustain behaviour change, including smoking cessation. They have been used in workplaces, in clinics and hospitals, and within community programmes. Objectives: To determine the long-term effect of incentives and contingency manage...

Background: Out-of-office blood pressure (BP) is recommended for diagnosing hypertension in primary care due to its increased accuracy compared to office BP. Moreover, being diagnosed as hypertensive has previously been linked to lower wellbeing. There is limited evidence regarding the acceptability of out-of-office BP and its impact on wellbeing....

Objectives To characterise serum creatinine and urinary protein testing in UK general practices from 2005 to 2013 and to examine how the frequency of testing varies across demographic factors, with the presence of chronic conditions and with the prescribing of drugs for which kidney function monitoring is recommended. Design Retrospective open coh...

Objective Advance care planning (ACP) is widely advocated to contribute to better outcomes for patients suffering from heart failure. But clinicians appear hesitant to engage with ACP. Our aim was to identify interventions with the greatest potential to engage clinicians with ACP in heart failure. Methods A systematic review and meta-analysis. We...

Objective: Low disease prevalence poses challenges for diagnostic accuracy studies because of the large sample sizes that are required to obtain sufficient precision. The aim is to collate and discuss designs of diagnostic accuracy studies suited for use in low-prevalence situations. Study design and setting: We conducted a literature search inc...

Background Primary care workload is high and increasing in the United Kingdom. We sought to examine the association between rates of primary care consultation and outcomes in England. Methods Cross sectional observational study of routine electronic health care records in 283 practices from the Clinical Practice Research Datalink from April 2013 t...

Background: Competitions might encourage people to undertake and/or reinforce behaviour change, including smoking cessation. Competitions involve individuals or groups having the opportunity to win a prize following successful cessation, either through direct competition or by entry into a lottery or raffle. Objectives: To determine whether comp...

Background: Oral hormone pregnancy tests (HPTs), such as Primodos, containing ethinylestradiol and high doses of norethisterone, were given to over a million women from 1958 to 1978, when Primodos was withdrawn from the market because of concerns about possible teratogenicity. We aimed to study the association between maternal exposure to oral HPTs...

Purpose: To use recorded weight values to internally validate weight status and weight change coding in the primary care Electronic Health Record (EHR). Patients and methods: We included adult patients with weight-related Read codes recorded in the UK's Clinical Practice Research Datalink EHR between 2000 and 2017. Weight status codes were compa...

Background: Self-monitoring of blood pressure better predicts prognosis than clinic measurement, is popular with patients, and endorsed in hypertension guidelines. However, there is uncertainty over the optimal self-monitoring schedule. We therefore aimed to determine the optimum schedule to predict future cardiovascular events and determine "true...