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Stevens R, Gurmu E, Negash A, Ewart E, Alvergne A. 'They will be like a person with a disease': a qualitative investigation of variation in contraceptive side-effect experiences in Central Oromia, Ethiopia. J Biosoc Sci 2024:1-19. [PMID: 39301837 DOI: 10.1017/s0021932024000294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2024]
Abstract
Contraceptive side effects are consistently given as the main reason why women are dissatisfied with contraception or choose not to use it. However, why some women suffer more from side effects remains unknown. Through inductive analysis of in-depth interviews and focus group discussions with 40 contraceptive users and 3 key informants in Central Oromia, Ethiopia, we explored women's rationales for variation in side-effect experiences. The data first reveal the wide diversity in type and severity of side-effect experiences reported by users of contraception. Second, we found that women's rationales for why some individuals suffer more side effects from contraception invoke economic and physical hardship (food insecurity and heavy workloads), as well as interindividual differences in biology (one's blood must 'fit' with contraception). Finally, the analysis revealed the tension many women face in trying to negotiate the trade-off between the consequences of these side effects and those of an unwanted pregnancy. The results show the value of using a biosocial approach, which centres women's voices and experiences, for informing the measurement of contraceptive side effects within population health surveys and clinical trials. Additionally, the findings help gain an understanding of how an individual's social, biological, and cultural contexts drive variation in when and why different side effects manifest.
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Héreil A, Guillaume M, Duboscq R, Carretero Y, Pelpoir E, Bitton F, Giraud C, Karlova R, Testerink C, Stevens R, Causse M. Characterisation of a major QTL for sodium accumulation in tomato grown in high salinity. PLANT, CELL & ENVIRONMENT 2024. [PMID: 39148196 DOI: 10.1111/pce.15082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 07/09/2024] [Accepted: 07/30/2024] [Indexed: 08/17/2024]
Abstract
Soil salinity is a serious concern for tomato culture, affecting both yield and quality parameters. Although some genes involved in tomato salt tolerance have been identified, their genetic diversity has been rarely studied. In the present study, we assessed salt tolerance-related traits at juvenile and adult stages in a large core collection and identified salt tolerance quantitative trait loci (QTLs) by genome-wide association study (GWAS). The results suggested that a major QTL is involved in leaf sodium accumulation at both physiological stages. We were able to identify the underlying candidate gene, coding for a well-known sodium transporter, called SlHKT1.2. We showed that an eQTL for the expression of this gene in roots colocalized with the above ground sodium content QTL. A polymorphism putatively responsible for its variation was identified in the gene promoter. Finally, to extend the applicability of these results, we carried out the same analysis on a test-cross panel composed of the core collection crossed with a distant line. The results indicated that the identified QTL retained its functional impact even in a hybrid genetic context: this paves the way for its use in breeding programs aimed at improving salinity tolerance in tomato cultivars.
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Jones C, Jakubowski BE, Stevens R, Roberts N, McManus RJ, Tucker KL. The diagnostic Accuracy of Visual versus automated dipstick proteinuria testing in Pregnancy: A systematic review and Meta-Analysis. Pregnancy Hypertens 2024; 35:73-81. [PMID: 38262144 DOI: 10.1016/j.preghy.2024.01.133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 01/15/2024] [Accepted: 01/15/2024] [Indexed: 01/25/2024]
Abstract
OBJECTIVE To evaluate the diagnostic accuracy of point-of-care (POC) tests for detecting proteinuria in pregnant women. DESIGN Systematic review and meta-analysis. DATA SOURCES MEDLINE and EMBASE databases were searched from inception to 13 November 2020. ELIGIBILITY CRITERIA AND DATA ANALYSIS Included studies measured the sensitivity and specificity ofPOC proteinuria testing compared to laboratory reference standards (protein-creatinine ratio (PCR), 24-hour urine collection). Bivariate meta-analyses determined pooled sensitivity and specificity. Random-effects inverse-variance model determinedheterogeneity. MAIN OUTCOME MEASURES The primary outcome was overall sensitivity and specificity, stratified by method of POC testing and reference standard. Secondary outcomes were sensitivity and specificity within thesubgroupstest brand, reference standard, and hypertension status. RESULTS 1078 studies were identified, 17 studies comprising 23 comparisons were included. The meta-analysis included 13 studies with 19 comparisons. Pooled sensitivity and specificity of visual dipsticks against PCR was 72 % (95 % CI: 56 % to 84 %) and 92 % (95 % CI: 76 % to 98 %), respectively. Pooled sensitivity and specificity of visual dipsticks against 24-hour collection was 69 % (55 % to 80 %) and 70 % (51 % to 84 %), respectively. Pooled sensitivity and specificity for automated readers against PCR was 73 % (53 % to 86 %) and 91 % (83 % to 95 %), respectively. Pooled sensitivity and specificity of automated readers against 24-hour collection was 65 % (42 % to 83 %) and 82 % (46 % to 96 %), respectively. CONCLUSION Visual dipsticks have comparable accuracy to automated readers, yet are notadequate as a rule-out test for proteinuria. Proteinuria POC testing maybe beneficial inantenatal care when repeatfollow-up tests are performed. PROSPERO Registration Number: CRD42021231914.
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Tenaillon MI, Burban E, Huynh S, Wojcik A, Thuillet AC, Manicacci D, Gérard PR, Alix K, Belcram H, Cornille A, Brault M, Stevens R, Lagnel J, Dogimont C, Vigouroux Y, Glémin S. Crop domestication as a step towards reproductive isolation. AMERICAN JOURNAL OF BOTANY 2023:e16173. [PMID: 37087742 DOI: 10.1002/ajb2.16173] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/12/2023] [Accepted: 04/13/2023] [Indexed: 05/03/2023]
Abstract
Speciation, Darwin's mystery of mysteries, is a continuous process that results in genomic divergence accompanied by the gradual increment of reproductive barriers between lineages. Since the beginning of research on the genetics of speciation, several questions have emerged such as: What are the genetic bases of incompatibilities? How many loci are necessary to prevent hybridization and how are they distributed along genomes? Can speciation occur despite gene flow and how common is ecological speciation? Early stages of divergence are key to understand the ecology and genetics of speciation, and semi-isolated species where hybrids can still be produced are particularly relevant This article is protected by copyright. All rights reserved.
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Stevens R, Machiyama K, Mavodza CV, Doyle AM. Misconceptions, Misinformation, and Misperceptions: A Case for Removing the "Mis-" When Discussing Contraceptive Beliefs. Stud Fam Plann 2023; 54:309-321. [PMID: 36753058 DOI: 10.1111/sifp.12232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Beliefs about contraception are commonly conceptualized as playing an important role in contraceptive decision-making. Interventions designed to address beliefs typically include counseling to dispel any "myths" or "misconceptions." These interventions currently show little evidence for impact in reducing beliefs. This commentary delves into the problems associated with using implicitly negative terminology to refer to contraceptive beliefs, which come laden with assumptions as to their validity. By conceptualizing women as getting it wrong or their beliefs as invalid, it sets the scene for dubious treatment of women's concerns and hampers the design of fruitful interventions to address them. To replace the multitude of terms used, we suggest using "belief" going forward to maintain value-free curiosity and remove any implicit assumptions about the origin or validity of a belief. We provide recommendations for measuring beliefs to help researchers understand the drivers and impacts of the belief they are measuring. Finally, we discuss implications for intervention design once different types of belief are better understood. We argue that tailored interventions by belief type would help address the root causes of beliefs and better meet women's broader contraceptive needs, such as the need for contraceptive autonomy and satisfaction.
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Sprumont J, Stevens R, Gilbert A, Khamis J, Philippet P. [An intracranial haemorrhage in a febrile newborn]. REVUE MEDICALE DE LIEGE 2022; 77:689-691. [PMID: 36484743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A 15 days old newborn was admitted to the emergency room for a recent fever onset. In newborns, the priority is to rule out any bacterial infection and initiate broad spectrum antibiotics. The hemorrhagic appearance of the cerebrospinal fluid after lumbar puncture can sometimes be the only sign to suspect, other than obvious infectious aetiology, an intracranial haemorrhage.
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Stevens R, Malbos B, Gurmu E, Riou J, Alvergne A. Anemic Women are More at Risk of Injectable Contraceptive Discontinuation due to Side Effects in Ethiopia. Stud Fam Plann 2022; 53:193-208. [DOI: 10.1111/sifp.12186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Pour H, Subramani K, Stevens R, Sinha P. An overview of orthodontic malpractice liability based on a survey and case assessment review. J Clin Exp Dent 2022; 14:e694-e704. [PMID: 36158769 PMCID: PMC9498637 DOI: 10.4317/jced.59785] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/08/2022] [Indexed: 11/05/2022] Open
Abstract
Background The purpose of this survey study and case review was to identify 1) the common causes related to filing a malpractice claim against an orthodontist and, 2) the factors mitigating against a potential malpractice claim in the United States (U.S). The objectives of the case review were to examine the current state of orthodontic malpractice litigation from a cause and mitigating point of view.
Material and Methods Data for this research was collected and reviewed using the following two methods:
1) A survey questionnaire on aspects of malpractice liability was electronically distributed to 2,241 active U.S. members of the American Association of Orthodontists (AAO).
2) Legal cases were reviewed on the online legal research database Lexis Advance Research, and 35 cases were analyzed.
Results Survey questionnaire results and legal case review results are as follows:
1) 77 orthodontists completed the survey. 9.1% of the respondents reported a malpractice claim having been filed against them with periodontal issues accounting for most of the claims. Survey participants reported good doctor-patient communication as being the most relevant contributory factor and most relevant mitigating factor in malpractice claims.
2) Negligence is the main reason patients sue a doctor for clinically related litigation, and failure to obtain a proper informed consent from the patient is the main cause of action for non-clinically related litigation.
Conclusions Most respondents reported doctor-patient communication, periodontal issues, and a lack of informed consent as the main triggering elements of a lawsuit, which is similar to other studies and case review analysis. Good doctor-patient rapport was ranked as being most helpful in mitigating a potential claim, which is also similar to other studies. Another aspect of the survey questionnaire that was evaluated was whether a non-orthodontist can provide expert testimony against an orthodontist, with most respondents reporting that this is not possible. It has been ruled, though, that a general dentist can be an expert witness and provide expert testimony against an orthodontist in a lawsuit depending on the circumstances. Negligence was the most common cause of clinically related orthodontic litigation, and a failure of the practitioner to obtain a proper informed consent from the patient was the most common cause of non-clinically related orthodontic litigation. Key words:Orthodontist, malpractice, legal, lawsuit, liability, medicolegal.
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Acosta-Lenis C, Bollu P, Chaudhry K, Stevens R, Subramani K. Public Perceptions and Understanding of Risks Associated with Do-It-Yourself Orthodontics: A Survey Study. J Clin Exp Dent 2022; 14:e712-e718. [PMID: 36158777 PMCID: PMC9498639 DOI: 10.4317/jced.59911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 08/16/2022] [Indexed: 11/19/2022] Open
Abstract
Background The purpose of this study was to evaluate general public’s perception, knowledge and preferences on orthodontic treatment rendered by an orthodontist versus the “Do-It-Yourself” orthodontics (DIYO) concept without professional supervision. The secondary objective was to assess laypeople’s awareness on the risks and limitations of DIYO.
Material and Methods A 24-question online survey questionnaire was administered to 526 laypeople who had no professional experience or background in dentistry and orthodontics. All data was collected over 3 days (July 20-23, 2020) by Qualtrics server and forwarded to the principal investigator. Statistical analysis was done with statistical software SPSS® version 26.
Results The most important reason for laypeople to opt for DIYO is financial reason. People who have undergone orthodontic treatment know the difference between a general dentist and an orthodontist, whereas people who have not had orthodontic treatment are less likely to know the difference. Of the 285 people who did not receive orthodontic treatment before by a dental professional, 43 have considered DIYO. 122 of the 526 people considered DIYO, and 79 of the 122 had orthodontic treatment before. 26 of the 122 did not consider the clinical exam and diagnostic records important and would be comfortable without in-person supervision. 83 of the 122 would be comfortable not having in-person supervision, and still considered this treatment modality “Doctor-Directed”.
Conclusions The main reason laypeople utilize DIYO is the low cost. Some DIYO users do not consider risks involved and a small percentage consider their own dentist to be responsible if any issues arise with DIYO. One third of survey respondents will consider DIYO in the future. Key words:Do-It-Yourself (DIY), Direct-To-Consumer (DTC), Adult, Orthodontics, Dentistry, Surveys and Questionnaires.
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Yee CS, Gordon C, Akil M, Lanyon P, Edwards CJ, Isenberg D, Rahman A, Teh LS, Tosounidou S, Stevens R, Prabu A, Griffiths B, Mchugh N, Bruce IN, Ahmad Y, Khamashta M, Farewell V. POS0106 BILAG-2004 LDA AND BST LDA ARE VALID TREAT TO TARGET IN SLE. Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Background:Low disease activity state has been defined using SLEDAI and used as treatment target in SLE. However, there has not been any such definition using BILAG-2004 index (BILAG-2004).Objectives:This study was to determine if low disease activity state according to BILAG-2004 is valid for use as treatment target in SLE. We also assessed disease activity longitudinally using BILAG-2004 systems tally (BST). BST is an alternative way of representing BILAG-2004 scores that combines the flexibility and simplification of numerical scoring of BILAG-2004 with the clinical intuitiveness of BILAG-2004 structure.Methods:This was a prospective multi-centre longitudinal study in the UK of an inception cohort of SLE patients (recruited within 12 months of achieving 1997 ACR revised criteria for SLE). Data were collected on disease activity (BILAG-2004 and BILAG2004-Pregnancy Index during pregnancy), SLICC/ACR DI (SDI), cumulative drug exposure and death at every visit. This study ran from 1st January 2005 to 31st December 2017. Four low disease activity states (LDA) were defined using BILAG-2004: 1) BILAG-2004 LDA when all 9 systems had scores of C, D or E on assessment (no Grade A or B), 2) BST LDA when there was persistent score of C, D or E in all 9 systems between 2 consecutive visits (equivalent to 2 consecutive visits with BILAG-2004 LDA), 3) BILAG-2004 Remission when all 9 systems had scores of D or E on assessment and 4) Persistent Remission when there was persistent score of D or E in all 9 systems between 2 consecutive visits. Longitudinal analysis using Poisson regression with random effects model was used with development of new damage as the outcome of interest. Gender, cardiovascular risk factors, antiphospholipid syndrome status and most drugs (except hydroxychloroquine, glucocorticoids, mycophenolate and cyclophosphamide) were excluded from the model as they were not associated with development of damage in univariate analysis.Results:273 patients were recruited (91.2% female, 59.3% Caucasian, 17.2% African/Caribbean, 17.2% South Asian) with mean age at recruitment of 38.5 years (SD 14.8). 97.8% had no damage at recruitment (2.2% had SDI score of 1). Median follow-up was 73.4 months (range: 1.8, 153.8) with total follow-up of 1767 patient-years. There were 13 deaths and 114 new damage items occurred during follow-up. There were 6674 assessments with disease activity score: 319 assessments with Grade A activity in 95 patients (84.6% had only 1 system with grade A, range: 1 - 4) and 1704 assessments with Grade A or B activity in 239 patients (78.7% had only 1 system with Grade A or B, range: 1 - 5).BILAG-2004 LDA was achieved in 74.5% of assessments (from 271 patients). BILAG-2004 Remission occurred in 28.2% of assessments (from 234 patients).6401 observations with BST were available (1 observation derived from change in activity between 2 consecutive assessments) and 63.7% were in BST LDA. There was no observation with Persistent Remission between consecutive visits.Table 1 summarises multivariate analysis which showed BILAG-2004 LDA to be inversely associated with damage. Similar results were obtained with BILAG-2004 Remission (RR 0.60 with 95% CI 0.38, 0.96) and BST LDA (RR 0.65 with 95% CI 0.43, 0.99). Cumulative drug exposure since recruitment for mycophenolate was protective against new damage (RR 0.99 with 95% CI 0.99, 0.99).Table 1.VariableRelative Risk (95% CI) for New DamageEthnicityAfro-Caribbean1.22 (0.68, 2.18)South Asian1.81 (0.97, 3.38)Others2.22 (0.63, 7.85)Age at diagnosis1.06 (1.04, 1.08)Prior SDI score0.68 (0.43, 1.06)BILAG-2004 LDA0.60 (0.39, 0.94)Hydroxychloroquine since last visit (per g)0.99 (0.98, 0.99)Steroids since last visit (per 100mg)1.02 (1.01, 1.03)Cyclophosphamide since last visit (per g)1.67 (1.15, 2.41)Conclusion:BILAG-2004 LDA and BST LDA are valid treatment targets in SLE. BILAG-2004 Remission and Persistent Remission are uncommon, which make them unrealistic as a treatment target.References:[1]Yee C. S., et al. The BILAG-2004 systems tally – a novel way of representing the BILAG-2004 index scores longitudinally. Rheumatology (Oxford) 2012; 51[11]: 2099-2105.Acknowledgements :Versus Arthritis, Vifor PharmaDisclosure of Interests:Chee-Seng Yee Consultant of: Bristol Myers Squibb, ImmuPharma, Grant/research support from: Vifor Pharma, Caroline Gordon Speakers bureau: UCB, Consultant of: Center for Disease Control, Astra-Zeneca, MGP, Sanofi and UCB, Mohammed Akil: None declared, Peter Lanyon: None declared, Christopher John Edwards Consultant of: Glaxo Smith Kline, Roche, Grant/research support from: Glaxo Smith Kline, Roche, David Isenberg: None declared, Anisur Rahman: None declared, Lee-Suan Teh: None declared, Sofia Tosounidou: None declared, Robert Stevens: None declared, Ahtiveer Prabu: None declared, Bridget Griffiths: None declared, Neil McHugh: None declared, Ian N. Bruce: None declared, Yasmeen Ahmad: None declared, Munther Khamashta: None declared, Vernon Farewell: None declared
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Khamis K, Bradley C, Gunter HJ, Basevi G, Stevens R, Hannah DM. Calibration of an in-situ fluorescence-based sensor platform for reliable BOD 5 measurement in wastewater. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 83:3075-3091. [PMID: 34185701 DOI: 10.2166/wst.2021.197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Reliance on biochemical oxygen demand (BOD5) as an indicator of wastewater quality has hindered the development of efficient process control due to the associated uncertainty and lag-times. Surrogate measurements have been proposed, with fluorescence spectroscopy a promising technique. Yet, assessment of in-situ fluorescence sensors across multiple wastewater treatment plants (WwTPs), and at different treatment stages, is limited. In this study a multi-parameter sonde (two fluorescence peaks, turbidity, temperature and electrical conductivity) was used to provide a BOD5 surrogate measurement. The sonde was deployed at three WwTPs, on post primary settlement tanks (PST) and final effluent (FE). Triplicate laboratory measurements of BOD5, from independent laboratories were used to calibrate the sensor, with high variability apparent for FE samples. Site and process specific sensor calibrations yielded the best results (R2cv = 0.76-0.86; 10-fold cross-validation) and mean BOD5 of the three laboratory measurements improved FE calibration. When combining PST sites a reasonable calibration was still achieved (R2cv = 0.67) suggesting transfer of sensors between WwTPs may be possible. This study highlights the potential to use online optical sensors as robust BOD5 surrogates in WwTPs. However, careful calibration (i.e. replicated BOD5 measurements) is required for FE as laboratory measurements can be associated with high uncertainty.
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Yee CS, Farewell V, Akil M, Lanyon P, Edwards CJ, Isenberg D, Rahman A, Teh LS, Tosounidou S, Stevens R, Prabu A, Griffiths B, Mchugh N, Bruce IN, Ahmad Y, Khamashta M, Gordon C. POS0111 DEVELOPMENT OF DAMAGE AND MORTALITY IN AN INCEPTION COHORT OF SLE PATIENTS. Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:There had been very limited data on the development of damage and mortality in an inception cohort of SLE patients who were recruited very soon after diagnosis.Objectives:This study aimed to analyse the development of damage and death in an inception cohort of SLE patients recruited within 1 year of diagnosis with up to 13 years of follow-up.Methods:This was a prospective multi-centre longitudinal study in the UK of SLE patients recruited within 12 months of achieving 1997 ACR revised criteria for SLE. Data were collected on BILAG-2004, BILAG2004-Pregnancy Index (during pregnancy), SLICC/ACR DI (SDI), cumulative drug exposure and death at every visit. Information on cardiovascular risk factors and antiphospholipid syndrome status were also collected. This study ran from 1st January 2005 to 31st December 2017. Mortality and development of damage were analysed.Results:There were 273 patients recruited (91.2% female, 59.3% Caucasian, 17.2% African/Caribbean, 17.2% South Asian) with mean age at recruitment of 38.5 years (SD 14.8). 97.8% had no damage at recruitment (2.2% had SDI score of 1). Median follow-up was 73.4 months (range: 1.8, 153.8) with total follow-up of 1767 patient-years.There were 13 deaths (4.8%): 76.9% female, 84.6% Caucasian, 15.4% South Asian, mean age 62.6 years (± SD 15.8) and mean disease duration 3 years (± SD 1.8). Causes of death were cancer in 5 (38.5%), infection in 3 (23.1%), ischaemic heart disease in 1 (7.7%) and unknown in 4 (30.8%).114 new damage items in 83 patients occurred during follow-up. The distribution of damage was musculoskeletal (21, 18.4%), ophthalmic (18, 15.8%), neuropsychiatric (18, 15.8%), renal (14, 12.3%), malignancy (12, 10.5%), cutaneous (7, 6.1%), GIT (7, 6.1%), cardiac (6, 5.3%), pulmonary (4, 3.5%), diabetes mellitus (4, 3.5%) and vascular (3, 2.6%). The rate of development of damage appears to be higher in the first 3 years which subsequently stabilised (Table 1).Table 1.Incidence rate of development of damage over period of follow-up at 3 yearly intervalsPeriod of follow-up (year)Person-years at riskNumber of new items of damageIncidence rate, per 1000 person-years (95% CI)0 – 3753.46079.6 (61.8, 102.6)3 – 6534.03158.1 (40.8, 82.6)6 – 9321.21237.4 (21.2, 35.8)9 – 12152.5532.8 (13.6, 78.7)> 125.90-Conclusion:Mortality is uncommon during the first 12 years of follow-up for newly diagnosed SLE patients. However, development of damage appears to be higher in the first 3 years before stabilizing to a lower rate subsequently.Acknowledgements:Versus Arthritis, VIfor PharmaDisclosure of Interests:Chee-Seng Yee Consultant of: Bristol Myer Squibb, ImmuPharma, Grant/research support from: Vifor Pharma, Vernon Farewell: None declared, Mohammed Akil: None declared, Peter Lanyon: None declared, Christopher John Edwards Consultant of: Glaxo Smith Kline, Roche, Grant/research support from: Glaxo Smith Kline, Roche, David Isenberg: None declared, Anisur Rahman: None declared, Lee-Suan Teh: None declared, Sofia Tosounidou: None declared, Robert Stevens: None declared, Ahtiveer Prabu: None declared, Bridget Griffiths: None declared, Neil McHugh: None declared, Ian N. Bruce: None declared, Yasmeen Ahmad: None declared, Munther Khamashta: None declared, Caroline Gordon Speakers bureau: UCB, Consultant of: Center for Disease Control, Astra-Zeneca, MGP, Sanofi and UCB
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Yee CS, Farewell V, Akil M, Lanyon P, Edwards CJ, Isenberg D, Rahman A, Teh LS, Tosounidou S, Stevens R, Prabu A, Griffiths B, Mchugh N, Bruce IN, Ahmad Y, Khamashta M, Gordon C. POS0705 BILAG-2004 INDEX ACTIVE DISEASE PREDICTS DEVELOPMENT OF DAMAGE. Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:BILAG-2004 Index (BILAG-2004) has undergone construct and criterion validity and is used to assess disease activity in SLE. However, its predictive validity has yet to be established.Objectives:This study was to determine if disease activity according to BILAG-2004 was predictive of development of damage in an inception cohort.Methods:This was a prospective multi-centre longitudinal study in the UK of an inception cohort of SLE patients (recruited within 12 months of achieving 1997 ACR revised criteria for SLE). Data were collected on disease activity (BILAG-2004 and BILAG2004-Pregnancy Index during pregnancy), SLICC/ACR DI (SDI), cumulative drug exposure and death at every visit. Information on cardiovascular risk factors (hypertension, diabetes mellitus, hypercholesterolaemia and smoking status) and antiphospholipid syndrome status were also collected. This study ran from 1st January 2005 to 31st December 2017. Longitudinal analysis using Poisson regression with random effects model was used to determine predictors of development of new damage. Death was not included in the analysis due to small numbers.Results:273 patients were recruited (91.2% female, 59.3% Caucasian, 17.2% African/Caribbean, 17.2% South Asian) with mean age at recruitment of 38.5 years (SD 14.8). 97.8% had no damage at recruitment (2.2% had SDI score of 1). Median follow-up was 73.4 months (range: 1.8, 153.8) with total follow-up of 1767 patient-years. Prevalence of risk factors during follow-up were: hypertension 23.1%, hypercholesterolaemia 35.5%, diabetes mellitus 5.5%, smoker or ex-smoker 44% and antiphospholipid syndrome 7%. There were 13 deaths and 114 new damage items occurred during follow-up.There were 6674 assessments with disease activity score: 293 assessments with Grade A activity in 95 patients (92.4% had only 1 system with grade A, range: 1 - 4) and 1704 assessments with Grade A or B activity in 239 patients (78.7% had only 1 system with Grade A or B, range: 1 - 5).Univariate analysis showed that gender, cardiovascular risk factors, antiphospholipid syndrome and most drug exposure (except hydroxychloroquine, glucocorticoids, mycophenolate and cyclophosphamide) were not associated with new damage (they were not included in the multivariate analysis).Table 1 summarises multivariate analysis. Similar results were obtained when the disease activity variable was changed to Number of Systems with Grade A per assessment (RR 2.04 with 95% CI: 1.05, 3.94). Analysis using BILAG-2004 systems tally showed that persistent minimal disease was protective of development of damage (RR 0.74 with 95% CI: 0.57, 0.95). Cumulative drug exposure since recruitment for mycophenolate was protective against new damage (RR 0.99 with 95% CI 0.99, 0.99) but not cumulative drug exposure since last visit.VariableRisk Ratio (95% CI) for New DamageEthnicity Afro-Caribbean1.21 (0.68, 2.17) South Asian1.81 (0.97, 3.36) Others2.37 (0.68, 8.20)Age at diagnosis1.06 (1.04, 1.08)Prior SDI score0.69 (0.44, 1.08)Constitutional A or Bunreliable estimate due to low numbersMucocutaneous A or B1.80 (1.04, 3.14)Neuropsychiatric A or B4.68 (1.68, 13.05)Musculoskeletal A or B0.76 (0.33, 1.73)Cardiorespiratory A or B0.35 (0.05, 2.59)GIT A or Bunreliable estimate due to low numbersOphthalmic A or Bunreliable estimate due to low numbersRenal A or B2.08 (0.99, 4.40)Haematological A or B4.37 (1.15, 16.65)Hydroxychloroquine since last visit (per g)0.99 (0.98, 0.99)Prednisolone since last visit (per 100mg)1.01 (1.00, 1.02)Cyclophosphamide since last visit (per g)1.42 (0.94, 2.14)Conclusion:Active disease (Grade A or B) according to BILAG-2004 index is predictive of development of new damage in SLE patients.References:[1]Yee C. S., et al. The BILAG-2004 systems tally – a novel way of representing the BILAG-2004 index scores longitudinally. Rheumatology (Oxford) 2012; 51[11]: 2099-2105.Acknowledgements:Versus Arthritis and Vifor PharmaDisclosure of Interests:Chee-Seng Yee Consultant of: Bristol Myers Squibb, ImmuPharma, Grant/research support from: Vifor Pharma, Vernon Farewell: None declared, Mohammed Akil: None declared, Peter Lanyon: None declared, Christopher John Edwards Consultant of: Glaxo Smith Kline, Roche, Grant/research support from: Glaxo Smith Kline, Roche, David Isenberg: None declared, Anisur Rahman: None declared, Lee-Suan Teh: None declared, Sofia Tosounidou: None declared, Robert Stevens: None declared, Ahtiveer Prabu: None declared, Bridget Griffiths: None declared, Neil McHugh: None declared, Ian N. Bruce: None declared, Yasmeen Ahmad: None declared, Munther Khamashta: None declared, Caroline Gordon Speakers bureau: UCB, Consultant of: Center for Disease Control, Astra-Zeneca, MGP, Sanofi and UCB
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Stevens R, Kelaiditi E, Myrissa K. Exploration of the dietary habits, lifestyle patterns and barriers to healthy eating in UK post‐partum women. NUTR BULL 2021. [DOI: 10.1111/nbu.12483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Alvergne A, Stevens R. Cultural change beyond adoption dynamics: Evolutionary approaches to the discontinuation of contraception. EVOLUTIONARY HUMAN SCIENCES 2021; 3:e13. [PMID: 37588536 PMCID: PMC10427300 DOI: 10.1017/ehs.2021.8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Numerous evolutionary mechanisms have been proposed for the origins, spread and maintenance of low fertility. Such scholarship has focused on explaining the adoption of fertility-reducing behaviour, especially the use of contraceptive methods. However, this work has yet to engage fully with the dynamics of contraceptive behaviour at the individual level. Here we highlight the importance of considering not just adoption but also discontinuation for understanding contraceptive dynamics and their impact on fertility. We start by introducing contemporary evolutionary approaches to understanding fertility regulation behaviours, discussing the potential for integrating behavioural ecology and cultural evolution frameworks. Second, we draw on family planning studies to highlight the importance of contraceptive discontinuation owing to side-effects for understanding fertility rates and suggest evolutionary hypotheses for explaining patterns of variation in discontinuation rates. Third, we sketch a framework for considering how individual flexibility in contraceptive behaviour might impact the evolution of contraceptive strategies and the demographic transition. We argue that integrating public health and evolutionary approaches to reproductive behaviour might advance both fields by providing (a) a predictive framework for comparing the effectiveness of various public health strategies and (b) a more realistic picture of behaviour by considering contraceptive dynamics at the individual level more explicitly when modelling the cultural evolution of low fertility.
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Getty N, Brettin T, Jin D, Stevens R, Xia F. Deep medical image analysis with representation learning and neuromorphic computing. Interface Focus 2021; 11:20190122. [PMID: 33343872 DOI: 10.1098/rsfs.2019.0122] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2020] [Indexed: 11/12/2022] Open
Abstract
Deep learning is increasingly used in medical imaging, improving many steps of the processing chain, from acquisition to segmentation and anomaly detection to outcome prediction. Yet significant challenges remain: (i) image-based diagnosis depends on the spatial relationships between local patterns, something convolution and pooling often do not capture adequately; (ii) data augmentation, the de facto method for learning three-dimensional pose invariance, requires exponentially many points to achieve robust improvement; (iii) labelled medical images are much less abundant than unlabelled ones, especially for heterogeneous pathological cases; and (iv) scanning technologies such as magnetic resonance imaging can be slow and costly, generally without online learning abilities to focus on regions of clinical interest. To address these challenges, novel algorithmic and hardware approaches are needed for deep learning to reach its full potential in medical imaging.
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Stevens R, Hanson P, Tiseo P, Guedes K, Campbell J, Connolly J, Ruggiero S, Corliss M, Smith V, Conaghan PG. OP0187 DETERMINING OPTIMAL COOLING AND ADMINISTRATION METHODS FOR CNTX-4975 INTRA-ARTICULAR INJECTION IN SUBJECTS WITH MODERATE TO SEVERE OSTEOARTHRITIS KNEE PAIN. Ann Rheum Dis 2020. [DOI: 10.1136/annrheumdis-2020-eular.2200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:CNTX-4975 is a highly purified, synthetic capsaicin being developed to provide long-term analgesia after a single intra-articular (IA) injection for patients with moderate to severe osteoarthritis (OA) knee pain. CNTX-4975 IA administration is associated with short-term post-procedural pain that can be attenuated with preemptive joint cooling.Objectives:To evaluate cooling and administration procedures for CNTX-4975 IA injection, with goals of balancing patient comfort and ease of use and assessing clinical response 8 weeks after injection.Methods:This phase 3, open-label, 8-week study (NCT03661996) enrolled subjects aged 40–95 y with Kellgren-Lawrence grade 1–4, BMI ≤45 kg/m2, and stable, moderate to severe OA knee pain and who failed ≥2 therapies. Subjects were assigned to unilateral/bilateral CNTX-4975 1 mg IA injections as determined by OA pain/joint replacement status, then randomized by study site to 1 of 5 treatment regimens (Figure). The primary outcome measure assessed Breg cooling control vs other cooling regimens on day 1 using a combined sum of 1) pain (0, none; 4, severe) 30 minutes after CNTX-4975 injection; 2) subject satisfaction (SS) with cooling/injection procedures; and 3) investigator satisfaction (IS) with procedures. SS and IS were measured on a 1–7 scale (1, completely dissatisfied; 7, completely satisfied); pain was reverse scored and normalized (1, severe; 7, none) for equal weighting. Geometric mean ratios (GMR) with 95% CIs were constructed for each regimen vs Breg control (ANCOVA); lower 95% CI >0.7 was considered clinically acceptable. Secondary endpoints included percentage of subjects by subject type meeting criteria for Outcome Measures in Rheumatology-Osteoarthritis Research Society International (OMERACT-OARSI) responders 8 weeks after injection. Safety assessments included TEAEs.Results:The intent-to-treat population included 848 subjects. The primary combined outcome showed that all cooling and administration regimens were clinically acceptable, with the evaluated cold gel wraps being at least as effective as the Breg circulating ice-water wrap (Table). For subjects with unilateral OA, OMERACT-OARSI response rates were 67% in those with no/mild nonindex knee pain and 81% in those with nonindex knee single joint replacement. For subjects with bilateral knee OA receiving bilateral injections, response rates for index and nonindex knees were 73% and 79%. TEAEs were reported in 22% of subjects; <1% were serious. TEAEs occurring in >2% of subjects were procedural pain (2.9%), arthralgia (2.2%), and nausea (2.1%), with no meaningful differences across groups.Conclusion:All cooling regimens for CNTX-4975 IA administration were clinically acceptable and well tolerated, offering feasible options for use in routine practice. Importantly, high levels of clinical response were observed 8 weeks after unilateral or bilateral knee injections for moderate to severe OA knee pain.Primary Combined Endpoint Outcome in the Index Knee, Normalized Scale, by Cooling and Administration Procedure (ANCOVA Model)Breg Cooling ControlN=162Gel Pack CoolingN=179Shortened Gel Pack CoolingN=175Single Needle Injection,Gel Pack Cooling,2% LidocaineN=160Single Needle Injection,Gel Pack Cooling,1% LidocaineN=172Mean (SD)17.23 (2.660)18.23 (2.023)16.81 (2.891)17.57 (3.049)16.43 (3.138)Geometric LS Mean (SE)17.18 (1.016)18.26 (1.015)16.48 (1.016)17.40 (1.016)16.00 (1.015)95% CI16.66, 17.7217.74, 18.8015.99, 16.9916.87, 17.9515.53, 16.49Comparison vs Breg CoolingGMR (SE)1.06 (1.022)0.96 (1.022)1.01 (1.022)0.93 (1.022)95% CI1.02, 1.110.92, 1.000.97, 1.060.89, 0.97Clinically Acceptable?YesYesYesYesLS, least squares; SD, standard deviation; SE, standard error.GMR lower 95% CI >0.7 considered clinically equivalent.Disclosure of Interests:Randall Stevens Shareholder of: Centrexion Therapeutics Corp, Employee of: Centrexion Therapeutics Corp, Peter Hanson Shareholder of: Centrexion Therapeutics Corp, Employee of: Centrexion Therapeutics Corp, Paul Tiseo Employee of: Centrexion Therapeutics Corp, Kimberly Guedes Shareholder of: Centrexion Therapeutics Corp, Employee of: Centrexion Therapeutics Corp, James Campbell Shareholder of: Centrexion Therapeutics Corp, Employee of: Centrexion Therapeutics Corp, James Connolly Employee of: Centrexion Therapeutics Corp, Stephanie Ruggiero Employee of: Centrexion Therapeutics Corp, Meg Corliss Employee of: Centrexion Therapeutics Corp, Valerie Smith Consultant of: Centrexion Therapeutics Corp, Philip G Conaghan Consultant of: AbbVie, BMS, Eli Lilly, EMD Serono, Flexion Therapeutics, Galapagos, GSK, Novartis, Pfizer, Speakers bureau: AbbVie, Eli Lilly, Novartis, Pfizer
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Vyas A, Creswell J, Codlin AJ, Stevens R, Rao VG, Kumar B, Khaparde S, Sahu S. Community-based active case-finding to reach the most vulnerable: tuberculosis in tribal areas of India. Int J Tuberc Lung Dis 2020; 23:750-755. [PMID: 31315709 DOI: 10.5588/ijtld.18.0741] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
<sec> <title>BACKGROUND</title> India has the world's largest indigenous/tribal population. Many areas with large tribal populations suffer from weak infrastructure and services. Surveys have shown a high prevalence of TB among Saharia communities, who rarely access public services. We evaluated a community-based active TB case-finding intervention. </sec> <sec> <title>METHODS</title> Community health workers screened people for TB symptoms in Saharia communities, made referrals, collected sputum for transport to laboratories, and initiated and supported anti-tuberculosis treatment. Microscopy testing was performed at government laboratories. The intervention tracked the people screened, referrals, the people tested, laboratory results, treatment initiation and outcomes. </sec> <sec> <title>RESULTS</title> Community health workers verbally screened 65 230 people, 8723 (13%) of whom had symptoms. Of these, 5600 were tested, 964 (17%) of whom were smear-positive. During the intervention, we observed a +52% increase in people tested at laboratories and an +84% increase in TB case notifications. Pre-treatment loss to follow-up decreased and treatment success increased slightly. </sec> <sec> <title>CONCLUSIONS</title> In India, particularly among tribal populations, many people with TB are missed by current approaches due to poor access. Community-based active case-finding can help identify more people with TB in tribal and remote rural areas by addressing barriers to health seeking as well as help reach ambitious country and global notification targets. </sec>.
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Sheppard JP, Tucker KL, Davison WJ, Stevens R, Aekplakorn W, Bosworth HB, Bove A, Earle K, Godwin M, Green BB, Hebert P, Heneghan C, Hill N, Hobbs FDR, Kantola I, Kerry SM, Leiva A, Magid DJ, Mant J, Margolis KL, McKinstry B, McLaughlin MA, McNamara K, Omboni S, Ogedegbe O, Parati G, Varis J, Verberk WJ, Wakefield BJ, McManus RJ. Self-monitoring of Blood Pressure in Patients With Hypertension-Related Multi-morbidity: Systematic Review and Individual Patient Data Meta-analysis. Am J Hypertens 2020; 33:243-251. [PMID: 31730171 PMCID: PMC7162426 DOI: 10.1093/ajh/hpz182] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 11/11/2019] [Accepted: 11/13/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Studies have shown that self-monitoring of blood pressure (BP) is effective when combined with co-interventions, but its efficacy varies in the presence of some co-morbidities. This study examined whether self-monitoring can reduce clinic BP in patients with hypertension-related co-morbidity. METHODS A systematic review was conducted of articles published in Medline, Embase, and the Cochrane Library up to January 2018. Randomized controlled trials of self-monitoring of BP were selected and individual patient data (IPD) were requested. Contributing studies were prospectively categorized by whether they examined a low/high-intensity co-intervention. Change in BP and likelihood of uncontrolled BP at 12 months were examined according to number and type of hypertension-related co-morbidity in a one-stage IPD meta-analysis. RESULTS A total of 22 trials were eligible, 16 of which were able to provide IPD for the primary outcome, including 6,522 (89%) participants with follow-up data. Self-monitoring was associated with reduced clinic systolic BP compared to usual care at 12-month follow-up, regardless of the number of hypertension-related co-morbidities (−3.12 mm Hg, [95% confidence intervals −4.78, −1.46 mm Hg]; P value for interaction with number of morbidities = 0.260). Intense interventions were more effective than low-intensity interventions in patients with obesity (P < 0.001 for all outcomes), and possibly stroke (P < 0.004 for BP control outcome only), but this effect was not observed in patients with coronary heart disease, diabetes, or chronic kidney disease. CONCLUSIONS Self-monitoring lowers BP regardless of the number of hypertension-related co-morbidities, but may only be effective in conditions such obesity or stroke when combined with high-intensity co-interventions.
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Brereton PA, Robb P, Sargent CM, Crews HM, Wood R, Caputi A, Carrington J, Chetaneau B, Cohen S, Davies RW, Davis WS, Dix E, Ennion; RA, Furniss S, Gardner JW, Griffin J, Hampton I, Harrison N, Heide C, Hollywood F, Hopkins J, Liddle P, Meagher J, Osborne PY, Piatt T, Postlethwaite K, Procter J, Reynolds EB, Robinson J, Smith M, Sparkes S, Stangroom SG, Stevens R, Sutton P, Swain S, Turnbull J, Vidal JP, Waller JM, Zaiger K. Determination of Lead in Wine by Graphite Furnace Atomic Absorption Spectrophotometry: Interlaboratory Study. J AOAC Int 2020. [DOI: 10.1093/jaoac/80.6.1287] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
An interlaboratory study of a graphite furnace atomic absorption spectrophotometry (GFAAS) method for the determination of lead in wine was conducted. Seventeen laboratories from France, United States, and the United Kingdom, using a variety of GFAAS instruments, took part in the study. The method incorporated a novel matrix-matching procedure to minimize matrix effects between standards and samples. Six wine test materials were prepared and sent to participants as 12 blind duplicate or split level samples. There was good agreement between results obtained from participants and target values (24–279 μg/L) obtained with an inductively coupled plasma-mass spectrometry method. The precision of the GFAAS method was well within the range predicted by the Horwitz equation for the 6 test materials analyzed. Repeatability standard deviations ranged from 3 to 17%. Reproducibility standard deviations were in the range of 10 to 30%. The method is recommended for use for official purposes.
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Thomas C, Stevens R, West L, Oliver E, Pang J, Griffiths H. Performance evaluation of the VITROS® TSH3* assay on the VITROS® 5600/XT7600 integrated and VITROS® 3600 and ECI/ECIQ immunodiagnostic systems. Clin Chim Acta 2019. [DOI: 10.1016/j.cca.2019.03.699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Stevens R, Chandrasenan J, Ali F, Haslam P, Nicolau N. The reproducibility of manual and fixed tensioning in anterior cruciate ligament reconstruction. Muscles Ligaments Tendons J 2019. [DOI: 10.32098/mltj.02.2018.05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Wu P, Stayman JW, Sisniega A, Zbijewski W, Foos D, Wang X, Aygun N, Stevens R, Siewerdsen JH. Statistical weights for model-based reconstruction in cone-beam CT with electronic noise and dual-gain detector readout. ACTA ACUST UNITED AC 2018; 63:245018. [DOI: 10.1088/1361-6560/aaf0b4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Wu P, Stayman JW, Mow M, Zbijewski W, Sisniega A, Aygun N, Stevens R, Foos D, Wang X, Siewerdsen JH. Reconstruction-of-difference (RoD) imaging for cone-beam CT neuro-angiography. Phys Med Biol 2018; 63:115004. [PMID: 29722296 DOI: 10.1088/1361-6560/aac225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Timely evaluation of neurovasculature via CT angiography (CTA) is critical to the detection of pathology such as ischemic stroke. Cone-beam CTA (CBCT-A) systems provide potential advantages in the timely use at the point-of-care, although challenges of a relatively slow gantry rotation speed introduce tradeoffs among image quality, data consistency and data sparsity. This work describes and evaluates a new reconstruction-of-difference (RoD) approach that is robust to such challenges. A fast digital simulation framework was developed to test the performance of the RoD over standard reference reconstruction methods such as filtered back-projection (FBP) and penalized likelihood (PL) over a broad range of imaging conditions, grouped into three scenarios to test the trade-off between data consistency, data sparsity and peak contrast. Two experiments were also conducted using a CBCT prototype and an anthropomorphic neurovascular phantom to test the simulation findings in real data. Performance was evaluated primarily in terms of normalized root mean square error (NRMSE) in comparison to truth, with reconstruction parameters chosen to optimize performance in each case to ensure fair comparison. The RoD approach reduced NRMSE in reconstructed images by up to 50%-53% compared to FBP and up to 29%-31% compared to PL for each scenario. Scan protocols well suited to the RoD approach were identified that balance tradeoffs among data consistency, sparsity and peak contrast-for example, a CBCT-A scan with 128 projections acquired in 8.5 s over a 180° + fan angle half-scan for a time attenuation curve with ~8.5 s time-to-peak and 600 HU peak contrast. With imaging conditions such as the simulation scenarios of fixed data sparsity (i.e. varying levels of data consistency and peak contrast), the experiments confirmed the reduction of NRMSE by 34% and 17% compared to FBP and PL, respectively. The RoD approach demonstrated superior performance in 3D angiography compared to FBP and PL in all simulation and physical experiments, suggesting the possibility of CBCT-A on low-cost, mobile imaging platforms suitable to the point-of-care. The algorithm demonstrated accurate reconstruction with a high degree of robustness against data sparsity and inconsistency.
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Waller P, Cassell JA, Saunders MH, Stevens R. Governance and oversight of researcher access to electronic health data: the role of the Independent Scientific Advisory Committee for MHRA database research, 2006-2015. J R Coll Physicians Edinb 2018; 47:24-29. [PMID: 28569278 DOI: 10.4997/jrcpe.2017.106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In order to promote understanding of UK governance and assurance relating to electronic health records research, we present and discuss the role of the Independent Scientific Advisory Committee (ISAC) for MHRA database research in evaluating protocols proposing the use of the Clinical Practice Research Datalink. We describe the development of the Committee's activities between 2006 and 2015, alongside growth in data linkage and wider national electronic health records programmes, including the application and assessment processes, and our approach to undertaking this work. Our model can provide independence, challenge and support to data providers such as the Clinical Practice Research Datalink database which has been used for well over 1,000 medical research projects. ISAC's role in scientific oversight ensures feasible and scientifically acceptable plans are in place, while having both lay and professional membership addresses governance issues in order to protect the integrity of the database and ensure that public confidence is maintained.
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