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Bird C, Hayward GN, Turner PJ, Wasala D, Merrick V, Lyttle MD, Mullen N, Fanshawe TR. Infections diagnosed in children and young people screened for malaria in UK emergency departments: a retrospective multi-centre study. Paediatr Int Child Health 2024; 44:1-7. [PMID: 38212934 DOI: 10.1080/20469047.2023.2299576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 12/19/2023] [Indexed: 01/13/2024]
Abstract
BACKGROUND Data on imported infections in children and young people (CYP) are sparse. AIMS To describe imported infections in CYP arriving from malaria-endemic areas and presenting to UK emergency departments (ED) who were screened for malaria. METHODS This is a retrospective, multi-centre, observational study nested in a diagnostic accuracy study for malaria rapid diagnostic tests. Any CYP < 16 years presenting to a participating ED with a history of fever and travel to a malaria-endemic area between 1 January 2016 and 31 December 2017 and who had a malaria screen as a part of standard care were included. Geographical risk was calculated for the most common tropical infections. RESULTS Of the 1414 CYP screened for malaria, 44.0% (n = 622) arrived from South Asia and 33.3% (n = 471) from sub-Saharan Africa. Half (50.0%) had infections common in both tropical and non-tropical settings such as viral upper respiratory tract infection (URTI); 21.0% of infections were coded as tropical if gastro-enteritis is included, with a total of 4.2% (60) cases of malaria. CYP diagnosed with malaria were 7.44 times more likely to have arrived from sub-Saharan Africa than from South Asia (OR 7.44, 3.78-16.41). CONCLUSION A fifth of CYP presenting to participating UK EDs with fever and a history of travel to a malaria-endemic area and who were screened for malaria had a tropical infection if diarrhoea is included. A third of CYP had no diagnosis. CYP arriving from sub-Saharan Africa had the greatest risk of malaria.Abbreviations: CYP: children and young people; ED: emergency department; PERUKI: Paediatric Emergency Research in the UK and Ireland; RDT: rapid diagnostic test; VFR: visiting friends and relatives.
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Affiliation(s)
- Chris Bird
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
- Infection, Respiratory and Acute Care, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Gail N Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Philip J Turner
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Desha Wasala
- Emergency Department, Bristol Royal Hospital for Children, UK
| | - Vanessa Merrick
- Emergency Department, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Mark D Lyttle
- Emergency Department, Bristol Royal Hospital for Children, UK
- Research in Emergency Care Avon Collaborative Hub (REACH), University of the West of England, Bristol, UK
| | - Niall Mullen
- Emergency Department, South Tyneside and Sunderland NHS Foundation Trust, UK
| | - Thomas R Fanshawe
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
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2
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Dorward J, Govender K, Moodley P, Lessells R, Samsunder N, Sookrajh Y, Fanshawe TR, Turner PJ, Butler CC, Drain PK, Hayward GN, Garrett N. Urine tenofovir and dried blood spot tenofovir diphosphate concentrations and viraemia in people taking efavirenz and dolutegravir-based antiretroviral therapy. AIDS 2024; 38:697-702. [PMID: 38126342 PMCID: PMC7615742 DOI: 10.1097/qad.0000000000003818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 12/02/2023] [Accepted: 12/11/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE We aimed to determine whether urine tenofovir (TFV) and dried blood spot (DBS) tenofovir diphosphate (TFV-DP) concentrations are associated with concurrent HIV viraemia. DESIGN Cross-sectional study among people with HIV (PWH) receiving tenofovir disoproxil fumarate (TDF)-based antiretroviral therapy (ART). METHODS We used dual tandem liquid chromatography and mass spectrometry to measure urine TFV and DBS TFV-DP concentrations, and evaluated their associations with concurrent viraemia at least 1000 copies/ml using logistic regression models. In exploratory analyses, we used receiver operating curves (ROCs) to estimate optimal urine TFV and DBS TFV-DP thresholds to predict concurrent viraemia. RESULTS Among 124 participants, 68 (54.8%) were women, median age was 39 years [interquartile range (IQR) 34-45] and 74 (59.7%) were receiving efavirenz versus 50 (40.3%) receiving dolutegravir. Higher concentrations of urine TFV [1000 ng/ml increase, odds ratio (OR) 0.97 95% CI 0.94-0.99, P = 0.005] and DBS TFV-DP (100 fmol/punch increase, OR 0.76, 95% CI 0.67-0.86, P < 0.001) were associated with lower odds of viraemia. There was evidence that these associations were stronger among people receiving dolutegravir than among people receiving efavirenz (urine TFV, P = 0.072; DBS TFV-DP, P = 0.003). Nagelkerke pseudo- R2 for the DBS TFV-DP models was higher for the urine TFV models, demonstrating a stronger relationship between DBS TFV-DP and viraemia. Among people receiving dolutegravir, a DBS TFV-DP concentration of 483 fmol/punch had 88% sensitivity and 85% specificity to predict concurrent viraemia ≥1000 copies/ml. CONCLUSION Among PWH receiving TDF-based ART, urine TFV concentrations, and in particular DBS TFV-DP concentrations, were strongly associated with concurrent viraemia, especially among people receiving dolutegravir.
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Affiliation(s)
- Jienchi Dorward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu–Natal
| | | | - Pravikrishnen Moodley
- Department of Virology, University of KwaZulu-Natal and National Health Laboratory Service, Inkosi Albert Luthuli Central Hospital, KwaZulu-Natal
| | - Richard Lessells
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu–Natal
- KwaZulu-Natal Research and Innovation Sequencing Platform (KRISP), University of KwaZulu-Natal, Durban
| | - Natasha Samsunder
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu–Natal
| | | | - Thomas R. Fanshawe
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Philip J. Turner
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Christopher C. Butler
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Paul K. Drain
- Department of Global Health, Schools of Medicine and Public Health
- Department of Medicine, School of Medicine
- Department of Epidemiology, School of Public Health, University of Washington, Seattle, USA
| | - Gail N. Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Nigel Garrett
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu–Natal
- Discipline of Public Health Medicine, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
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Fanshawe TR, Tonner S, Turner PJ, Cogdale J, Glogowska M, de Lusignan S, Okusi C, Perera R, Sebastianpillai P, Williams A, Zambon M, Nicholson BD, Hobbs FDR, Hayward GN. Diagnostic accuracy of a point-of-care antigen test for SARS-CoV-2 and influenza in a primary care population (RAPTOR-C19). Clin Microbiol Infect 2024; 30:380-386. [PMID: 38103638 DOI: 10.1016/j.cmi.2023.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/20/2023] [Accepted: 12/08/2023] [Indexed: 12/19/2023]
Abstract
OBJECTIVES Limited evidence exists for the diagnostic performance of point-of-care tests for SARS-CoV-2 and influenza in community healthcare. We carried out a prospective diagnostic accuracy study of the LumiraDx™ SARS-CoV-2 and influenza A or B assay in primary care. METHODS Total of 913 adults and children with symptoms of current SARS-CoV-2 infection were recruited from 18 UK primary care practices during a period when Omicron was the predominant COVID variant of concern (June 2022 to December 2022). Trained health care staff performed the index test, with diagnostic accuracy parameters estimated for SARS-CoV-2 and influenza against real-time reverse-transcription PCR (rtRT-PCR). RESULTS 151/887 participants were SARS-CoV-2 rtRT-PCR positive, 109 positive for Influenza A, 6 for Influenza B. Index test sensitivity for SARS-CoV-2 was 80.8% (122 of the 151, 95% CI, 73.6-86.7%) and specificity 98.9% (728 of the 736, 95% CI, 97.9-99.5%). For influenza A, sensitivity was 61.5% (67 of the 109, 95% CI, 51.7-70.6%) and specificity 99.4% (771 of the 776, 95% CI, 98.5-99.8%). Sensitivity to detect SARS-CoV-2 and influenza dropped sharply at rtRT-PCR cycle thresholds (Ct) > 30. DISCUSSIONS The LumiraDx™ SARS-CoV-2 and influenza A/B assay had moderate sensitivity for SARS-CoV-2 in symptomatic patients in primary care, with lower performance with high rtRT-PCR Ct. Negative results in this patient group cannot definitively rule out SARS-CoV-2 or influenza.
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Affiliation(s)
- Thomas R Fanshawe
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
| | - Sharon Tonner
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Philip J Turner
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Jade Cogdale
- Virus Reference Department, Respiratory Virus Unit, UK Health Security Agency, UK
| | - Margaret Glogowska
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Simon de Lusignan
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Cecilia Okusi
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Rafael Perera
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Praveen Sebastianpillai
- Immunization and Vaccine Preventable Diseases Division and Public Health Programmes, UK Health Security Agency, UK
| | - Alice Williams
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Maria Zambon
- Influenza and Respiratory Virology and Polio Reference Service, UK Health Security Agency, UK; NIHR Health Protection Research Unit, Imperial College London, UK
| | - Brian D Nicholson
- Virus Reference Department, Respiratory Virus Unit, UK Health Security Agency, UK
| | - F D Richard Hobbs
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK; Virus Reference Department, Respiratory Virus Unit, UK Health Security Agency, UK
| | - Gail N Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK; Virus Reference Department, Respiratory Virus Unit, UK Health Security Agency, UK
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L A Cross E, Quan TP, Hayward GN, Walker AS, Llewelyn MJ. Development and validation of the Baseline Recurrence Risk in Cellulitis (BRRISC) score. J Infect 2024; 88:103-111. [PMID: 38128701 DOI: 10.1016/j.jinf.2023.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 11/16/2023] [Accepted: 12/14/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVES Cellulitis is often treated with antibiotics for longer than recommended by guidelines. Prolonged therapy may reduce recurrence in certain patients, but it is not known which patients are at greatest risk. Our objective was to develop and temporally validate a risk prediction score to identify patients attending hospital with cellulitis at highest risk of recurrence. METHODS We included UK adult patients with cellulitis attending hospital in an electronic health records (EHR) study to identify demographic, comorbid, physiological, and laboratory factors predicting recurrence (before death) within 90 days, using multivariable logistic regression with backwards elimination in complete cases. A points-based risk score integerised model coefficients for selected predictors. Performance was assessed using the C-index in development and temporal validation samples. RESULTS The final model included 4938 patients treated for median 8 days (IQR 6-11); 8.8% (n = 436) experienced hospitalisation-associated recurrence. A risk score using eight variables (age, heart rate, urea, platelets, albumin, previous cellulitis, venous insufficiency, and liver disease) ranged from 0-15, with C-index = 0.65 (95%CI: 0.63-0.68). Categorising as low (score 0-1), medium (2-5) and high (6-15) risk, recurrence increased fourfold; 3.2% (95%CI: 2.3-4.4%), 9.7% (8.7-10.8%), and 16.6% (13.3-20.4%). Performance was maintained in the validation sample (C-index = 0.63 (95%CI: 0.58-0.67)). Among patients at high risk, four distinct clinical phenotypes were identified using hierarchical clustering 1) young, acutely unwell with liver disease; 2) comorbid with previous cellulitis and venous insufficiency; 3) chronic renal disease with severe renal impairment; and 4) acute severe illness, with substantial inflammatory responses. CONCLUSIONS Risk of cellulitis recurrence varies markedly according to individual patient factors captured in the Baseline Recurrence Risk in Cellulitis (BRRISC) score. Further work is needed to optimise the score, considering baseline and treatment response variables not captured in EHR data, and establish the utility of risk-based approaches to guide optimal antibiotic duration.
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Affiliation(s)
- Elizabeth L A Cross
- Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Falmer BN1 9PS, UK
| | - T Phuong Quan
- Nuffield Department of Medicine, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; NIHR Biomedical Research Centre, Oxford OX3 9DU, UK; National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, University of Oxford, Oxford OX3 9DU, UK
| | - Gail N Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Primary Care Building, Radcliffe Observatory Quarter, Woodstock Rd, Oxford OX2 6GG, UK
| | - A Sarah Walker
- Nuffield Department of Medicine, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; NIHR Biomedical Research Centre, Oxford OX3 9DU, UK; National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, University of Oxford, Oxford OX3 9DU, UK
| | - Martin J Llewelyn
- Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Falmer BN1 9PS, UK.
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Nicholson BD, Turner PJ, Fanshawe TR, Williams AJ, Amirthalingam G, Tonner S, Zambon M, Body R, Davies K, Perera R, de Lusignan S, Hayward GN, Hobbs FDR. Evaluation of the diagnostic accuracy of two point-of-care tests for COVID-19 when used in symptomatic patients in community settings in the UK primary care COVID diagnostic accuracy platform trial (RAPTOR-C19). PLoS One 2023; 18:e0288612. [PMID: 37478103 PMCID: PMC10361479 DOI: 10.1371/journal.pone.0288612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 07/02/2023] [Indexed: 07/23/2023] Open
Abstract
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 symptoms consistent with suspected current COVID-19 infection were prospectively recruited from 19 UK general practices and two COVID-19 testing centres between October 2020 and October 2021. Participants were tested by trained healthcare workers using at least one of two index POCTs (Roche-branded SD Biosensor Standard™ Q SARS-CoV-2 Rapid Antigen Test and/or BD Veritor™ System for Rapid Detection of SARS-CoV-2). The reference standard was laboratory triplex reverse transcription quantitative PCR (RT-PCR) using a combined nasal/oropharyngeal swab. Diagnostic accuracy parameters were estimated, with 95% confidence intervals (CIs), overall, in relation to RT-PCR cycle threshold and in pre-specified subgroups. RESULTS Of 663 participants included in the primary analysis, 39.2% (260/663, 95% CI 35.5% to 43.0%) had a positive RT-PCR result. The SD Biosensor POCT had sensitivity 84.0% (178/212, 78.3% to 88.6%) and specificity 98.5% (328/333, 96.5% to 99.5%), and the BD Veritor POCT had sensitivity 76.5% (127/166, 69.3% to 82.7%) and specificity 98.8% (249/252, 96.6% to 99.8%) compared with RT-PCR. Sensitivity of both devices dropped substantially at cycle thresholds ≥30 and in participants more than 7 days after onset of symptoms. CONCLUSIONS Both POCTs assessed exceed the Medicines and Healthcare products Regulatory Agency target product profile's minimum acceptable specificity of 95%. Confidence intervals for both tests include the minimum acceptable sensitivity of 80%. In symptomatic patients, negative results on these two POCTs do not preclude the possibility of infection. Tests should not be expected to reliably detect disease more than a week after symptom onset, when viral load may be reduced. REGISTRATION ISRCTN142269.
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Affiliation(s)
- Brian D Nicholson
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Philip J Turner
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Thomas R Fanshawe
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Alice J Williams
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Gayatri Amirthalingam
- Immunisation and Vaccine Preventable Diseases Division and Public Health Programmes, UK Health Security Agency, London, United Kingdom
| | - Sharon Tonner
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Maria Zambon
- Influenza and Respiratory Virology & Polio Reference Service, UK Health Security Agency, London, United Kingdom
- NIHR Health Protection Research Unit, Imperial College London, London, United Kingdom
| | - Richard Body
- Division of Cardiovascular Science, University of Manchester, Manchester, United Kingdom
- Emergency Department, Manchester Royal Infirmary, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- Manchester Academic Health Science Centre, & Healthcare Sciences Department, Manchester Metropolitan University, Manchester, United Kingdom
| | - Kerrie Davies
- Healthcare Associated Infections Research Group, Leeds Teaching Hospitals NHS trust and University of Leeds, Leeds, United Kingdom
- NIHR Leeds MedTech In vitro Diagnostic Co-operative, Leeds Teaching Hospitals NHS Trust and University of Leeds, Leeds, United Kingdom
| | - Rafael Perera
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Simon de Lusignan
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Gail N Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - F D Richard Hobbs
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
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Fanshawe TR, Judge RK, Mort S, Butler CC, Hayward GN. Evidence-based appraisal of two guidelines for the diagnosis of suspected, uncomplicated urinary tract infections in primary care: a diagnostic accuracy validation study. J Antimicrob Chemother 2023:dkad212. [PMID: 37401673 PMCID: PMC10393881 DOI: 10.1093/jac/dkad212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 06/23/2023] [Indexed: 07/05/2023] Open
Abstract
OBJECTIVES Given the lack of accurate rapid diagnostics for urinary tract infection (UTI) in women, many countries have developed guidelines aiming to support appropriate antibiotic prescribing, but some guidelines have not been validated. We performed a diagnostic accuracy validation study of two guidelines: Public Health England (GW-1263) and Scottish Intercollegiate Guidelines Network (SIGN160). METHODS We used data from women with symptoms suggestive of uncomplicated UTI from a randomized controlled trial comparing urine collection devices. Symptom information was recorded via baseline questionnaire and primary care assessment. Women provided urine samples for dipstick testing and culture. We calculated the number within each risk category of diagnostic flowcharts who had positive/mixed growth/no significant growth urine culture. Results were presented as positive/negative predictive values, with 95% CIs. RESULTS Of women aged under 65 years, 311/509 (61.1%, 95% CI 56.7%-65.3%) classified to the highest risk category (recommended to consider immediate antibiotic prescribing) and 80/199 (40.2%, 95% CI 33.4%-47.4%) classified to the lowest risk category (recommended to reassure that UTI is less likely) by the GW-1263 guideline (n = 810) had positive culture. For the SIGN160 guideline (n = 814), the proportion with positive culture ranged from 60/82 (73.2%, 95% CI 62.1%-82.1%) in those for whom immediate treatment was indicated to 33/76 (43.4%, 95% CI 32.3%-55.3%) in those recommended a self-care/waiting strategy. CONCLUSIONS Clinicians should be aware of the potential for diagnostic error when using diagnostic guidelines for managing uncomplicated UTI and making antimicrobial prescribing decisions. Infection cannot be excluded on the basis of symptoms and dipstick testing alone.
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Affiliation(s)
- Thomas R Fanshawe
- Nuffield Department of Primary Care Health Sciences, Unversity of Oxford, Oxford, UK
| | - Rebecca K Judge
- Nuffield Department of Primary Care Health Sciences, Unversity of Oxford, Oxford, UK
| | - Sam Mort
- Nuffield Department of Primary Care Health Sciences, Unversity of Oxford, Oxford, UK
| | - Christopher C Butler
- Nuffield Department of Primary Care Health Sciences, Unversity of Oxford, Oxford, UK
| | - Gail N Hayward
- Nuffield Department of Primary Care Health Sciences, Unversity of Oxford, Oxford, UK
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7
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Bird C, Hayward GN, Turner PJ, Merrick V, Lyttle MD, Mullen N, Fanshawe TR. A diagnostic accuracy study to evaluate standard rapid diagnostic test (RDT) alone to safely rule out imported malaria in children presenting to UK emergency departments. J Pediatric Infect Dis Soc 2023; 12:290-297. [PMID: 37070464 DOI: 10.1093/jpids/piad024] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 04/17/2023] [Indexed: 04/19/2023]
Abstract
BACKGROUND Microscopy is the gold standard for malaria diagnosis but is dependent on trained personnel. Rapid diagnostic tests (RDT) form the mainstay of diagnosis in endemic areas without access to high quality microscopy. We aimed to evaluate whether RDT alone could rule out imported malaria in children presenting to UK Emergency Departments (EDs). METHODS UK-based, multi-centre, retrospective, diagnostic accuracy study. Included: any child <16 years presenting to ED with history of fever and travel to a malaria-endemic country, between 01/01/2016 and 31/12/2017. Diagnosis: microscopy for malarial parasites (clinical reference standard) and RDT (index test). UK Health Research Authority approval: 20/HRA/1341. RESULTS There were 47 cases of malaria out of 1,414 eligible cases (prevalence 3·3%) in a cohort of children whose median age was 4 years (IQR 2-9), of whom 43% were female. Cases of Plasmodium falciparum totalled 36 (77%, prevalence 2·5% ).The sensitivity of RDT alone to detect malaria infection due to any Plasmodium species was 93·6% (95% CI 82·5% to 98·7%), specificity 99·4% (95% CI 98·9% to 99·7%), positive predictive value 84·6% (95% CI 71·9% to 93·1%) and negative predictive value 99·8% (95% CI 99·4% to 100·0%). Sensitivity of RDT to detect P. falciparum infection was 100% (90·3% to 100%), specificity 98·8% (98·1% to 99·3%), positive predictive value 69·2% (54·9% to 81·2%, n=46/52) and negative predictive value 100% (99·7% to 100%, n=1362/1362). CONCLUSIONS RDTs were 100% sensitive in detecting P. falciparum malaria. However, lower sensitivity for other malaria species and the rise of pfhrp2 and pfhrp3 (pfhrp2/3) gene deletions in the P. falciparum parasite mandate the continued use of microscopy for diagnosing malaria.
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Affiliation(s)
- Chris Bird
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
- Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Gail N Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Philip J Turner
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | | | - Mark D Lyttle
- University Hospitals Bristol NHS Foundation Trust, UK
- Research in Emergency Care Avon Collaborative Hub (REACH), University of the West of England, Bristol, UK
| | - Niall Mullen
- South Tyneside and Sunderland NHS Foundation Trust, UK
| | - Thomas R Fanshawe
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
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Dixon S, Fanshawe TR, Mwandigha L, Edwards G, Turner PJ, Glogowska M, Gillespie MM, Blair D, Hayward GN. The Impact of Point-of-Care Blood C-Reactive Protein Testing on Prescribing Antibiotics in Out-of-Hours Primary Care: A Mixed Methods Evaluation. Antibiotics (Basel) 2022; 11:antibiotics11081008. [PMID: 35892398 PMCID: PMC9332095 DOI: 10.3390/antibiotics11081008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 02/05/2023] Open
Abstract
Improving prescribing antibiotics appropriately for respiratory infections in primary care is an antimicrobial stewardship priority. There is limited evidence to support interventions to reduce prescribing antibiotics in out-of-hours (OOH) primary care. Herein, we report a service innovation where point-of-care C-Reactive Protein (CRP) machines were introduced to three out-of-hours primary care clinical bases in England from August 2018-December 2019, which were compared with four control bases that did not have point-of-care CRP testing. We undertook a mixed-method evaluation, including a comparative interrupted time series analysis to compare monthly antibiotic prescription rates between bases with CRP machines and those without, an analysis of the number of and reasons for the tests performed, and qualitative interviews with clinicians. Antibiotic prescription rates declined during follow-up, but with no clear difference between the two groups of out-of-hours practices. A single base contributed 217 of the 248 CRP tests performed. Clinicians reported that the tests supported decision making and communication about not prescribing antibiotics, where having 'objective' numbers were helpful in navigating non-prescribing decisions and highlighted the challenges of training a fluctuant staff group and practical concerns about using the CRP machine. Service improvements to reduce prescribing antibiotics in out-of-hours primary care need to be developed with an understanding of the needs and context of this service.
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Affiliation(s)
- Sharon Dixon
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Woodstock Road, Oxford OX2 6GG, UK; (T.R.F.); (L.M.); (G.E.); (P.J.T.); (M.G.); (G.N.H.)
- Correspondence:
| | - Thomas R. Fanshawe
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Woodstock Road, Oxford OX2 6GG, UK; (T.R.F.); (L.M.); (G.E.); (P.J.T.); (M.G.); (G.N.H.)
| | - Lazaro Mwandigha
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Woodstock Road, Oxford OX2 6GG, UK; (T.R.F.); (L.M.); (G.E.); (P.J.T.); (M.G.); (G.N.H.)
| | - George Edwards
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Woodstock Road, Oxford OX2 6GG, UK; (T.R.F.); (L.M.); (G.E.); (P.J.T.); (M.G.); (G.N.H.)
| | - Philip J. Turner
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Woodstock Road, Oxford OX2 6GG, UK; (T.R.F.); (L.M.); (G.E.); (P.J.T.); (M.G.); (G.N.H.)
| | - Margaret Glogowska
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Woodstock Road, Oxford OX2 6GG, UK; (T.R.F.); (L.M.); (G.E.); (P.J.T.); (M.G.); (G.N.H.)
| | - Marjorie M. Gillespie
- Practice Plus Group, Hawker House, 5–6 Napier Court, Napier Road, Reading, Berkshire RG1 8BW, UK;
| | - Duncan Blair
- Queen Elizabeth Memorial Health Centre, St Michaels Avenue, Tidworth Garrison SP9 7EA, UK;
| | - Gail N. Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Woodstock Road, Oxford OX2 6GG, UK; (T.R.F.); (L.M.); (G.E.); (P.J.T.); (M.G.); (G.N.H.)
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Fanshawe TR, Turner PJ, Gillespie MM, Hayward GN. The comparative interrupted time series design for assessment of diagnostic impact: methodological considerations and an example using point-of-care C-reactive protein testing. Diagn Progn Res 2022; 6:3. [PMID: 35232491 PMCID: PMC8888027 DOI: 10.1186/s41512-022-00118-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 01/13/2022] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND In diagnostic evaluation, it is necessary to assess the clinical impact of a new diagnostic as well as its diagnostic accuracy. The comparative interrupted time series design has been proposed as a quasi-experimental approach to evaluating interventions. We show how it can be used in the design of a study to evaluate a point-of-care diagnostic test for C-reactive protein in out-of-hours primary care services, to guide antibiotic prescribing among patients presenting with possible respiratory tract infection. This study consisted of a retrospective phase that used routinely collected monthly antibiotic prescribing data from different study sites, and a prospective phase in which antibiotic prescribing rates were monitored after the C-reactive protein diagnostic was introduced at some of the sites. METHODS Of 8 study sites, 3 were assigned to receive the diagnostic and 5 were assigned as controls. We obtained retrospective monthly time series of respiratory tract targeted antibiotic prescriptions at each site. Separate ARIMA models at each site were used these to forecast monthly prescription counts that would be expected in the prospective phase, using simulation to obtain a set of 1-year predictions alongside their standard errors. We show how these forecasts can be combined to test for a change in prescription rates after introduction of the diagnostic and estimate power to detect this change. RESULTS Fitted time series models at each site were stationary and showed second-order annual seasonality, with a clear December peak in prescriptions, although the timing and extent of the peak varied between sites and between years. Mean one-year predictions of antibiotic prescribing rates based on the retrospective time series analysis differed between sites assigned to receive the diagnostic and those assigned to control. Adjusting for the trend in the retrospective time series at each site removed these differences. CONCLUSIONS Quasi-experimental designs such as comparative interrupted time series can be used in diagnostic evaluation to estimate effect sizes before conducting a full randomised controlled trial or if a randomised trial is infeasible. In multi-site studies, existing retrospective data should be used to adjust for underlying differences between sites to make outcome data from different sites comparable, when possible.
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Affiliation(s)
- Thomas R Fanshawe
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, OX2 6GG, UK.
| | - Philip J Turner
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, OX2 6GG, UK
| | - Marjorie M Gillespie
- Practice Plus Group, Hawker House, 5-6 Napier Court, Napier Road, Reading, Berkshire, England, RG1 8BW, UK
| | - Gail N Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, OX2 6GG, UK
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10
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Hayward GN, Moore A, Mckelvie S, Lasserson DS, Croxson C. Antibiotic prescribing for the older adult: beliefs and practices in primary care. J Antimicrob Chemother 2020; 74:791-797. [PMID: 30566597 DOI: 10.1093/jac/dky504] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Older adults suffer high morbidity and mortality following serious infections, and hospital admissions with these conditions are increasingly common. Antibiotic prescribing in the older adult population, especially in long-term care facilities, has been argued to be inappropriately high. In order to develop the evidence base and provide support to GPs in achieving antimicrobial stewardship in older adults it is important to understand their attitudes and beliefs toward antibiotic prescribing in this population. OBJECTIVES To understand the attitudes and beliefs held by GPs regarding antibiotic prescribing in older adults. METHODS Semi-structured qualitative interviews were conducted with 28 GPs working in the UK. Data analysis followed a modified framework approach. RESULTS GPs described antibiotic prescribing in older adults as differing from prescribing in other age groups in a number of ways, including prescribing broad-spectrum, longer and earlier antibiotics in this population. There were also rationales for situations where antibiotics were prescribed despite there being no clear diagnosis of infection. Trials of antibiotics were used both as diagnostic aids and in an attempt to avoid admission. The risks of antibiotics were understood, but in some cases restrictions on antibiotic use were thought to hamper optimal management of infection in this age group. CONCLUSIONS Diagnosing serious infections in older adults is challenging and antibiotic prescribing practices reflect this challenge, but also reflect an absence of clear guidance or evidence. Research that can fill the gaps in the evidence base is required in order to support GPs with their critical antimicrobial stewardship role in this population.
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Affiliation(s)
- G N Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, UK
| | - A Moore
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, UK
| | - S Mckelvie
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, UK
| | - D S Lasserson
- Institute of Applied Health Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - C Croxson
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, UK
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11
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Fanshawe TR, Glogowska M, Edwards G, Turner PJ, Smith I, Steele R, Croxson C, Bowen JST, Hayward GN. Pre-analytical error for three point of care venous blood testing platforms in acute ambulatory settings: A mixed methods service evaluation. PLoS One 2020; 15:e0228687. [PMID: 32012203 PMCID: PMC6996845 DOI: 10.1371/journal.pone.0228687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 01/20/2020] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Point of care blood testing to aid diagnosis is becoming increasingly common in acute ambulatory settings and enables timely investigation of a range of diagnostic markers. However, this testing allows scope for errors in the pre-analytical phase, which depends on the operator handling and transferring specimens correctly. The extent and nature of these pre-analytical errors in clinical settings has not been widely reported. METHODS We carried out a convergent parallel mixed-methods service evaluation to investigate pre-analytical errors leading to a machine error reports in a large acute hospital trust in the UK. The quantitative component comprised a retrospective analysis of all recorded error codes from Abbott Point of Care i-STAT 1, i-STAT Alinity and Abbott Rapid Diagnostics Afinion devices to summarise the error frequencies and reasons for error, focusing on those attributable to the operator. The qualitative component included a prospective ethnographic study and a secondary analysis of an existing ethnographic dataset, based in hospital-based ambulatory care and community ambulatory care respectively. RESULTS The i-STAT had the highest usage (113,266 tests, January 2016-December 2018). As a percentage of all tests attempted, its device-recorded overall error rate was 6.8% (95% confidence interval 6.6% to 6.9%), and in the period when reliable data could be obtained, the operator-attributable error rate was 2.3% (2.2% to 2.4%). Staff identified that the most difficult step was the filling of cartridges, but that this could be improved through practice, with a perception that cartridge wastage through errors was rare. CONCLUSIONS In the observed settings, the rate of errors attributable to operators of the primary point of care device was less than 1 in 40. In some cases, errors may lead to a small increase in resource use or time required so adequate staff training is necessary to prevent adverse impact on patient care.
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Affiliation(s)
- Thomas R. Fanshawe
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Margaret Glogowska
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - George Edwards
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Philip J. Turner
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Ian Smith
- Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Rosie Steele
- Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | | | - Jordan S. T. Bowen
- Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Gail N. Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
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12
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McKelvie S, Moore A, Croxson C, Lasserson DS, Hayward GN. Challenges and strategies for general practitioners diagnosing serious infections in older adults: a UK qualitative interview study. BMC Fam Pract 2019; 20:56. [PMID: 31027482 PMCID: PMC6486693 DOI: 10.1186/s12875-019-0941-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 04/02/2019] [Indexed: 11/10/2022]
Abstract
BACKGROUND Serious infections in older people are associated with unplanned hospital admissions and high mortality. Recognising the presence of a serious infection and making an accurate diagnosis are important challenges for General Practice. This study aimed to explore the issues UK GPs face when diagnosing serious infections in older patients. METHODS Qualitative study using semi-structured interviews. 28 GPs from 27 practices were purposively sampled from across the UK to achieve maximum variation in terms of GP role, experience and practice population. Interviews began by asking participants to describe recent or memorable cases where they had assessed older patients with suspected serious infections. Additional questions from the topic guide were used to explore the challenges further. Interview transcripts were coded and analysed using a modified framework approach. RESULTS Diagnosing serious infection in older adults was perceived to be challenging by participating GPs and the diagnosis was often uncertain. Contributing factors included patient complexity, atypical presentations, as well as a lack of knowledge of patients due to a loss in continuity. Diagnostic challenges were present at each stage of the patient assessment. Scoring systems were mainly used as communication tools. Investigations were sometimes used to resolve diagnostic uncertainty, but availability and speed of result limited their practical use. Clear safety-net plans shared with patients and their families helped GPs manage ongoing uncertainty. CONCLUSIONS Diagnostic challenges are present throughout the assessment of an older adult with a serious infection in primary care. Supporting GPs to provide continuity of care may improve the recognition and developing point of care testing for use in community settings may reduce diagnostic uncertainty.
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Affiliation(s)
- Sara McKelvie
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Primary Care Building, Oxford, OX2 6GG UK
| | - Abigail Moore
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Primary Care Building, Oxford, OX2 6GG UK
| | - Caroline Croxson
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Primary Care Building, Oxford, OX2 6GG UK
| | - Daniel S. Lasserson
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
- Department of Elderly Care, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Gail N. Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Primary Care Building, Oxford, OX2 6GG UK
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Fanshawe TR, Ordóñez-Mena JM, Turner PJ, Bruel AVD, Shine B, Hayward GN. Frequencies and patterns of laboratory test requests from general practice: a service evaluation to inform point-of-care testing. J Clin Pathol 2018; 71:1065-1071. [PMID: 30228215 DOI: 10.1136/jclinpath-2018-205242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 07/30/2018] [Accepted: 08/03/2018] [Indexed: 12/13/2022]
Abstract
AIMS The demand for test requests from general practice to laboratory services remains high. Tests performed at the point of care could reduce turnaround time and speed up clinical decision making. Replicating laboratory testing in the community would require panels of tests to be performed simultaneously, which is now approaching technological feasibility. We assessed frequencies and combinations of test requests from community settings to inform the potential future development of multiplex point-of-care panels. METHODS We assessed all laboratory test requests made from general practice in Oxfordshire, UK, from January 2014 to March 2017. We summarised test request frequency overall and in combination, using heatmaps and hierarchical cluster analysis. Results are also presented by age/sex subgroups. We further assessed patterns of tests requested within 7 and 14 days after an initial test request. RESULTS 11 763 473 test requests were made for 413 073 individuals (28% age >65). Of more than 500 test types, 62 were requested at least 5000 times, most commonly renal function tests (approximately 296 000/year), full blood count (278 000/year) and liver function tests (237 000/year). Cluster analysis additionally identified a clear grouping of tests commonly used to investigate anaemia. Follow-up test frequency was much lower than the frequency of multiple tests ordered at initial presentation. CONCLUSIONS The current high volume of single and combination test requests highlights an opportunity for reliable multiplex point-of-care panels to cover a core set of frequently requested tests. The impact on test use of introducing such panels to general practice requires additional research.
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Affiliation(s)
- Thomas R Fanshawe
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford , UK
| | - José M Ordóñez-Mena
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford , UK
| | - Philip J Turner
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford , UK
| | - Ann Van den Bruel
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford , UK.,Academic Centre of General Practice, University of Leuven, Leuven, Belgium
| | - Brian Shine
- Clinical Biochemistry, John Radcliffe Hospital, Oxford , UK
| | - Gail N Hayward
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford , UK
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Hayward GN, Fisher RFR, Spence GT, Lasserson DS. Increase in antibiotic prescriptions in out-of-hours primary care in contrast to in-hours primary care prescriptions: service evaluation in a population of 600 000 patients. J Antimicrob Chemother 2016; 71:2612-9. [PMID: 27287234 DOI: 10.1093/jac/dkw189] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 04/25/2016] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The objective of this study was to describe the frequency and nature of antibiotic prescriptions issued by a primary care out-of-hours (OOH) service and compare time trends in prescriptions between OOH and in-hours primary care. METHODS We performed a retrospective audit of 496 931 patient contacts with the Oxfordshire OOH primary care service. Comparison of time trends in antibiotic prescriptions from OOH primary care and in-hours primary care for the same population was made using multiple linear regression models fitted to the monthly data for OOH prescriptions, OOH contacts and in-hours prescriptions between September 2010 and August 2014. RESULTS Compared with the overall population contacting the OOH service, younger age, female sex and patients who were less deprived were independently correlated with an increased chance of a contact resulting in prescription of antibiotics. The majority of antibiotics were prescribed to patients contacting the service at weekends. Despite a reduction in patient contacts with the OOH service [an estimated decrease of 486.5 monthly contacts each year (95% CI -676.3 to -296.8), 5.0% of the average monthly contacts], antibiotic prescriptions from this service rose during the study period [increase of 37.1 monthly prescriptions each year (95% CI 10.6-63.7), 2.5% of the average monthly prescriptions]. A matching increase was not seen for in-hours antibiotic prescriptions; the difference between the year trends was significant (Z test, P = 0.002). CONCLUSIONS We have demonstrated trends in prescribing that could represent a partial displacement of antibiotic prescribing from in-hours to OOH primary care. The possibility that the trends we describe are evident nationally should be explored.
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Affiliation(s)
- G N Hayward
- Nuffield Department of Primary Care Health Sciences, Radcliffe Primary Care Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK
| | - R F R Fisher
- Nuffield Department of Primary Care Health Sciences, Radcliffe Primary Care Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK
| | - G T Spence
- Nuffield Department of Primary Care Health Sciences, Radcliffe Primary Care Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK
| | - D S Lasserson
- Nuffield Department of Medicine, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, UK NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DU, UK
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Liu X, Ford-Dunn HL, Hayward GN, Nandi D, Miall RC, Aziz TZ, Stein JF. The oscillatory activity in the Parkinsonian subthalamic nucleus investigated using the macro-electrodes for deep brain stimulation. Clin Neurophysiol 2002; 113:1667-72. [PMID: 12417218 DOI: 10.1016/s1388-2457(02)00256-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES To investigate the oscillatory activity in the Parkinsonian subthalamic nucleus using the macro-electrodes for deep brain stimulation. METHODS During bilateral deep brain stimulating electrode implantation, spontaneous and evoked field potentials were recorded from the subthalamic nucleus (STN) in two patients with Parkinson's disease (PD) during spontaneous resting tremor, passive manipulation of the wrist, and following electrical stimulation of the contralateral STN. RESULTS Frequency analysis of the STN field potentials recorded during spontaneous resting tremor showed significant coherence with electromyographic activity in the contralateral arm, suggesting a close involvement of the STN in the generation of resting tremor in PD. The STN responded to passive movement of the contralateral wrist, but not to ipsilateral movement. High frequency (100 Hz) electrical stimulation of the STN induced tremor (4 Hz) in both forearms, and also oscillation of the contralateral STN (4 Hz). In contrast, low frequency (5 Hz) stimulation induced contralateral arrhythmic involuntary movement (3 Hz), but without altering the contralateral STN activity. CONCLUSIONS We propose that the functional connection between the STN and arm muscles is mainly contralateral, but cross talk may occur between bilateral STN via a frequency-dependent pathway.
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Affiliation(s)
- X Liu
- University Laboratory of Physiology, University of Oxford, Parks Road, Oxford OX1 3PT, UK.
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