Decomposition of time-resolved tomographic PIV

International audienceAn experimental study has been conducted on a transitional water jet at a Reynolds number of Re = 5000. Flow fields have been obtained by means of time-resolved tomographic particle image velocimetry (TR-TOMO PIV) capturing all relevant spatial and temporal scales. The measured three-dimensional flow fields have then been postprocessed by the dynamic mode decomposition (DMD) which identifies coherent structures that contribute significantly to the dynamics of the jet. Where the jet exhibits a primary axisymmetric instability followed by a pairing of the vortex rings, dominant dynamic modes have been extracted together with their amplitude distribution. These modes represent a basis for the low-dimensional description of the dominant flow features

The 2013 face recognition evaluation in mobile environment

Automatic face recognition in unconstrained environments is a challenging task. To test current trends in face recognition algorithms, we organized an evaluation on face recognition in mobile environment. This paper presents the results of 8 different participants using two verification metrics. Most submitted algorithms rely on one or more of three types of features: local binary patterns, Gabor wavelet responses including Gabor phases, and color information. The best results are obtained from UNILJ-ALP, which fused several image representations and feature types, and UC-HU, which learns optimal features with a convolutional neural network. Additionally, we assess the usability of the algorithms in mobile devices with limited resources. © 2013 IEEE

Socioeconomic status and infectious intestinal disease in the community: a longitudinal study (IID2 Study)

Background Infectious intestinal diseases (IID) are common, affecting around 25% of people in the UK each year at an estimated annual cost to the economy, individuals and the NHS of £1.5 billion. Whilst there is evidence of higher IID hospital admissions in more disadvantaged groups, the association between socioeconomic status (SES) and risk of IID infection remains unclear. This study aims to investigate the relationship between SES and IID in a large community cohort. Methods Longitudinal analysis of a prospective community cohort in the UK following 6,836 participants of all ages was undertaken. Hazard ratios for IID by SES were estimated using Cox proportional hazard, adjusting for follow-up time and potential confounding factors. Results In the fully adjusted analysis, hazard rate of IID was significantly lower amongst routine/manual occupations compared to managerial/professional occupations (HR 0.75, 95%CI 0.61-0.91). Conclusion In this large community cohort, lower SES was associated with lower IID risk. This may be partially explained by the low response rate which varied by SES. However it may be related to differences in exposure or in recognition of IID symptoms by SES. Higher hospital admissions associated with lower SES observed in some studies could relate to more severe consequences, rather than increased infection risk

Volunteer Bias in Recruitment, Retention, and Blood Sample Donation in a Randomised Controlled Trial Involving Mothers and Their Children at Six Months and Two Years: A Longitudinal Analysis

BACKGROUND: The vulnerability of clinical trials to volunteer bias is under-reported. Volunteer bias is systematic error due to differences between those who choose to participate in studies and those who do not. METHODS AND RESULTS: This paper extends the applications of the concept of volunteer bias by using data from a trial of probiotic supplementation for childhood atopy in healthy dyads to explore 1) differences between a) trial participants and aggregated data from publicly available databases b) participants and non-participants as the trial progressed 2) impact on trial findings of weighting data according to deprivation (Townsend) fifths in the sample and target populations. 1) a) Recruits (n = 454) were less deprived than the target population, matched for area of residence and delivery dates (n = 6,893) (mean [SD] deprivation scores 0.09[4.21] and 0.79[4.08], t = 3.44, df = 511, p<0.001). b) i) As the trial progressed, representation of the most deprived decreased. These participants and smokers were less likely to be retained at 6 months (n = 430[95%]) (OR 0.29,0.13-0.67 and 0.20,0.09-0.46), and 2 years (n = 380[84%]) (aOR 0.68,0.50-0.93 and 0.55,0.28-1.09), and consent to infant blood sample donation (n = 220[48%]) (aOR 0.72,0.57-0.92 and 0.43,0.22-0.83). ii) Mothers interested in probiotics or research or reporting infants' adverse events or rashes were more likely to attend research clinics and consent to skin-prick testing. Mothers participating to help children were more likely to consent to infant blood sample donation. 2) In one trial outcome, atopic eczema, the intervention had a positive effect only in the over-represented, least deprived group. Here, data weighting attenuated risk reduction from 6.9%(0.9-13.1%) to 4.6%(-1.4-+10.5%), and OR from 0.40(0.18-0.91) to 0.56(0.26-1.21). Other findings were unchanged. CONCLUSIONS: Potential for volunteer bias intensified during the trial, due to non-participation of the most deprived and smokers. However, these were not the only predictors of non-participation. Data weighting quantified volunteer bias and modified one important trial outcome. TRIAL REGISTRATION: This randomised, double blind, parallel group, placebo controlled trial is registered with the International Standard Randomised Controlled Trials Register, Number (ISRCTN) 26287422. Registered title: Probiotics in the prevention of atopy in infants and children

The Effectiveness, cost-effectiveness and acceptability of Community versus Hospital Eye Service follow-up for patients with neovascular age-related macular degeneration with quiescent disease (ECHoES): a virtual randomised balanced incomplete block trial

BACKGROUND: Patients with neovascular age-related macular degeneration (nAMD) usually attend regular reviews, even when the disease is quiescent. Reviews are burdensome to health services, patients and carers.OBJECTIVES: To compare the proportion of correct lesion classifications made by community-based optometrists and ophthalmologists from vignettes of patients; to estimate the cost-effectiveness of community follow-up by optometrists compared with follow-up by ophthalmologists in the Hospital Eye Service (HES); to ascertain views of patients, their representatives, optometrists, ophthalmologists and clinical commissioners on the proposed shared care model.DESIGN: Community-based optometrists and ophthalmologists in the HES classified lesions from vignettes comprising clinical information, colour fundus photographs and optical coherence tomography images. Participants' classifications were validated against experts' classifications (reference standard).SETTING: Internet-based application.PARTICIPANTS: Ophthalmologists had to have ≥ 3 years post-registration experience in ophthalmology, have passed part 1 of the Royal College of Ophthalmologists, Diploma in Ophthalmology or equivalent examination, and have experience in the age-related macular degeneration service. Optometrists had to be fully qualified, be registered with the General Optical Council for ≥ 3 years and not be participating in nAMD shared care.INTERVENTIONS: The trial sought to emulate a conventional trial in comparing optometrists' and ophthalmologists' decision-making, but vignettes, not patients, were assessed; therefore, there were no interventions. Participants received training prior to assessing vignettes.MAIN OUTCOME MEASURES: Primary outcome - correct classification of the activity status of a lesion based on a vignette, compared with a reference standard. Secondary outcomes - frequencies of potentially sight-threatening errors, participants' judgements about specific lesion components, participant-rated confidence in their decisions and cost-effectiveness of follow-up by community-based optometrists compared with HES ophthalmologists.RESULTS: In total, 155 participants registered for the trial; 96 (48 in each professional group) completed training and main assessments and formed the analysis population. Optometrists and ophthalmologists achieved 1702 out of 2016 (84.4%) and 1722 out of 2016 (85.4%) correct classifications, respectively [odds ratio (OR) 0.91, 95% confidence interval (CI) 0.66 to 1.25; p = 0.543]. Optometrists' decision-making was non-inferior to ophthalmologists' with respect to the pre-specified limit of 10% absolute difference (0.298 on the odds scale). Frequencies of sight-threatening errors were similar for optometrists and ophthalmologists [57/994 (5.7%) vs. 62/994 (6.2%), OR 0.93, 95% CI 0.55 to 1.57; p = 0.789]. Ophthalmologists assessed lesion components as present less often than optometrists and were more confident about their lesion classifications than optometrists. The mean care-pathway cost for assessment was very similar by group, namely £397.33 for ophthalmologists and £410.78 for optometrists. The optometrist-led monitoring reviews were slightly more costly and less effective than ophthalmologist-led reviews, although the differences were extremely small. There was consensus that optometrist-led monitoring has the potential to reduce clinical workload and be more patient-centred. However, potential barriers are ophthalmologists' perceptions of optometrists' competence, the need for clinical training, the ability of the professions to work collaboratively and the financial feasibility of shared care for Clinical Commissioning Groups.CONCLUSIONS: The ability of optometrists to make nAMD retreatment decisions from vignettes is non-inferior to that of ophthalmologists. Various barriers to implementing shared cared for nAMD were identified.FUTURE WORK RECOMMENDATIONS: The Effectiveness, cost-effectiveness and acceptability of Community versus Hospital Eye Service follow-up for patients with neovascular age-related macular degeneration with quiescent disease (ECHoES) study web application was robust and could be used for future training or research. The benefit of reducing HES workload was not considered in the economic evaluation. A framework of programme budgeting and marginal analysis could explicitly explore the resource implications of shifting resources within a given health service area, as the benefit of reducing HES workload was not considered in the economic evaluation. Future qualitative research could investigate professional differences of opinion that were identified in multidisciplinary focus groups.TRIAL REGISTRATION: Current Controlled Trials ISRCTN07479761.FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 80. See the NIHR Journals Library website for further project information

Competency-based (CanMEDS) residency training programme in radiology: systematic design procedure, curriculum and success factors

Based on the CanMEDS framework and the European Training Charter for Clinical Radiology a new radiology curriculum was designed in the Netherlands. Both the development process and the resulting new curriculum are presented in this paper. The new curriculum was developed according to four systematic design principles: discursiveness, hierarchical decomposition, systematic variation and satisficing (satisficing is different from satisfying; in this context, satisficing means searching for an acceptable solution instead of searching for an optimal solution). The new curriculum is organ based with integration of radiological diagnostic techniques, comprises a uniform national common trunk followed by a 2-year subspecialisation, is competency outcome based with appropriate assessment tools and techniques, and is based on regional collaboration among radiology departments. The application of the systematic design principles proved successful in producing a new curriculum approved by all authorities. The principles led to a structured, yet flexible, development process in which creative solutions could be generated and adopters (programme directors, supervisors and residents) were highly involved. Further research is needed to empirically test the components of the new curriculum

Cost-effectiveness of community versus hospital eye service follow-up for patients with quiescent treated age-related macular degeneration alongside the ECHoES randomised trial

OBJECTIVES: To assess the cost-effectiveness of optometrist-led follow-up monitoring reviews for patients with quiescent neovascular age-related macular degeneration (nAMD) in community settings (including high street opticians) compared with ophthalmologist-led reviews in hospitals.DESIGN: A model-based cost-effectiveness analysis with a 4-week time horizon, based on a 'virtual' non-inferiority randomised trial designed to emulate a parallel group design.SETTING: A virtual internet-based clinical assessment, conducted at community optometry practices, and hospital ophthalmology clinics.PARTICIPANTS: Ophthalmologists with experience in the age-related macular degeneration service; fully qualified optometrists not participating in nAMD shared care schemes.INTERVENTIONS: The participating optometrists and ophthalmologists classified lesions from vignettes and were asked to judge whether any retreatment was required. Vignettes comprised clinical information, colour fundus photographs and optical coherence tomography images. Participants' classifications were validated against experts' classifications (reference standard). Resource use and cost information were attributed to these retreatment decisions.MAIN OUTCOME MEASURES: Correct classification of whether further treatment is needed, compared with a reference standard.RESULTS: The mean cost per assessment, including the subsequent care pathway, was £411 for optometrists and £397 for ophthalmologists: a cost difference of £13 (95% CI -£18 to £45). Optometrists were non-inferior to ophthalmologists with respect to the overall percentage of lesions correctly assessed (difference -1.0%; 95% CI -4.5% to 2.5%).CONCLUSIONS: In the base case analysis, the slightly larger number of incorrect retreatment decisions by optometrists led to marginally and non-significantly higher costs. Sensitivity analyses that reflected different practices across eye hospitals indicate that shared care pathways between optometrists and ophthalmologists can be identified which may reduce demands on scant hospital resources, although in light of the uncertainty around differences in outcome and cost it remains unclear whether the differences between the 2 care pathways are significant in economic terms.TRIAL REGISTRATION NUMBER: ISRCTN07479761; Pre-results.</p

We need timely access to mental health data: implications of the Goldacre review

The Goldacre review, published in April, 2022, 1 is a landmark evaluation of the use, availability, and safety of National Health Service (NHS) data across all four nations of the UK. The review underscores the necessary role of data in driving health-care improvement and innovation, and the potential risks inherent in using data routinely contributed by health service users. The review recommends a radical overhaul in NHS data curation, access, and analysis, and, crucially, argues that substantial new resources must be marshalled to make this aspiration a reality

KIDMAP, a web based system for gathering patients' feedback on their doctors

<p>Abstract</p> <p>Background</p> <p>The gathering of feedback on doctors from patients after consultations is an important part of patient involvement and participation. This study first assesses the 23-item Patient Feedback Questionnaire (PFQ) designed by the Picker Institute, Europe, to determine whether these items form a single latent trait. Then, an Internet module with visual representation is developed to gather patient views about their doctors; this program then distributes the individualized results by email.</p> <p>Methods</p> <p>A total of 450 patients were randomly recruited from a 1300-bed-size medical center in Taiwan. The Rasch rating scale model was used to examine the data-fit. Differential item functioning (DIF) analysis was conducted to verify construct equivalence across the groups. An Internet module with visual representation was developed to provide doctors with the patient's online feedback.</p> <p>Results</p> <p>Twenty-one of the 23 items met the model's expectation, namely that they constitute a single construct. The test reliability was 0.94. DIF was found between ages and different kinds of disease, but not between genders and education levels. The visual approach of the KIDMAP module on the WWW seemed to be an effective approach to the assessment of patient feedback in a clinical setting.</p> <p>Conclusion</p> <p>The revised 21-item PFQ measures a single construct. Our work supports the hypothesis that the revised PFQ online version is both valid and reliable, and that the KIDMAP module is good at its designated task. Further research is needed to confirm data congruence for patients with chronic diseases.</p