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Journal articleLongford NT, 2017,
Estimation under model uncertainty
, Statistica Sinica, Vol: 27, Pages: 859-877, ISSN: 1017-0405Model selection has had a virtual monopoly on dealing with model uncertainty ever since models were identified as important conduits for statisticalinference. Model averaging alleviates some of its deficiencies, but does not offer apractical solution in all settings. We propose an alternative based on linear combinations of the candidate models’ estimators. The general proposal is elaboratedfor ordinary regression and is illustrated with examples. Some estimators based oninvalid models contribute to efficient estimation of certain quantities.
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Journal articleHunter L, Sparrow E, Modi N, et al., 2017,
Advancing child health research in the UK: the Royal College of Paediatrics and Child Health Infants' Children's and Young People's Research Charter
, Archives of Disease in Childhood, Vol: 102, Pages: 299-300, ISSN: 1468-2044 -
Journal articleDarlow BA, Lui K, Kusuda S, et al., 2017,
International variations and trends in the treatment for retinopathy of prematurity
, BRITISH JOURNAL OF OPHTHALMOLOGY, Vol: 101, Pages: 1399-1404, ISSN: 0007-1161 -
Journal articleWebbe J, Brunton G, Afonso E, et al., 2017,
The importance of core outcome sets and developing one for neonatal care
, Infant, Vol: 13, Pages: 70-72, ISSN: 1745-1205It has been estimated that 85% of all clinical research is wasted. Suboptimal outcome selection is an important cause of waste because it leads to research that cannot be compared and may not be clinically relevant. A solution to this problem is the use of a core outcome set, a standardised set of outcomes recorded whenever research in a specific field is carried out. The methodology behind developing a core outcome set and how this is being applied in the Core Outcomes in Neonatology (COIN) project is described.
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ReportOugham K, Modi N, 2017,
The NDAU report 2016
, The NDAU report 2016, London, UK, Publisher: The Neonatal Data Analysis Unit, Imperial College London, 5 -
Journal articleModi N, McColgan M, Winch R, et al., 2017,
Comparison of UK paediatric consultants’ participation in child health research between 2011 and 2015
, Archives of Disease in Childhood. Fetal and Neonatal Edition, Vol: 102, Pages: 702-706, ISSN: 1359-2998Objective To identify whether there have been changes over time in the capacity of paediatric consultants to undertake research and if the activity differs between men and women.Design Comparison of data from two surveys of UK paediatric consultants.Subjects UK consultant members of the Royal College of Paediatrics and Child Health.Interventions Surveys carried out in 2011 and 2015.Main outcome measures The proportion of consultants with allocated time in job plans for research, academic appointments, postgraduate qualifications, publications, grant funding and supervision of PhD students.Results The 2015 survey demonstrated 20% of consultants had one or more programmed activities (PAs) for research, but the average paid PA for research was 0.39 PA. Between the surveys, the proportion of consultants with honorary contracts had declined, and the proportion with a PhD or MDRes was 32% in 2011 compared with 26% in 2015 (p<0.001). In 2015, only 12% of consultants had at least one current grant. In 2011 and 2015, 51% and 54% respectively of consultants had not authored a publication in the preceding 2 years. In 2015, 92% of consultants were not currently supervising a PhD student, and 88% had never supervised a PhD student. In 2015, 25% of men and 12% of women had PAs for research (p<0.001). Women were less likely to hold an honorary or primary academic contract, have authored a publication or supervised a PhD student (all p<0.001).Conclusions Research activity among paediatric consultants remains low, particularly among women.
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Journal articleHanson M, Mullins E, Modi N, 2017,
Time for the UK to commit to tackling child obesity
, BMJ, Vol: 356, ISSN: 1756-1833The UK government published its report Childhood Obesity: a Plan for Action, after a protracted delay, on 18 August 2016, when parliament was in recess and the nation was focused on the success of Team GB at the Rio Olympics.1 The plan received very little media coverage or public response. There was, however, an immediate outcry from the medical and public health communities, who had hoped for much more.23456 The draft version had been 50 pages in length, but the published plan ran to just 10 pages; strong actions were conspicuous by their absence, and the desired discussion of anti-obesogenic medicine had been watered down to an emphasis on voluntary actions by industry, consumers, and schools.One of the most important omissions was reference to the recommendations of the World Health Organization Commission on Ending Childhood Obesity (ECHO).7 The final ECHO report, published in January 2016, was the culmination of about 18 months of evidence review and wide consultation. It was presented at the World Health Assembly in May 2016,8 where a decision was made to request the director general to develop an implementation plan to guide further action on the recommendations, in consultation with member states. The implementation report is now available.
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Journal articleHines D, Modi N, Lee SK, et al., 2017,
Scoping review shows wide variation in the definitions of bronchopulmonary dysplasia in preterm infants and calls for a consensus
, ACTA PAEDIATRICA, Vol: 106, Pages: 366-374, ISSN: 0803-5253 -
Journal articleAchana F, Petrou S, Khan K, et al., 2017,
A methodological framework for assessing agreement between cost-effectiveness outcomes estimated using alternative sources of data on treatment costs and effects for trial-based economic evaluations.
, European Journal of Health Economics, Vol: 19, Pages: 75-86, ISSN: 1618-7601A new methodological framework for assessing agreement between cost-effectiveness endpoints generated using alternative sources of data on treatment costs and effects for trial-based economic evaluations is proposed. The framework can be used to validate cost-effectiveness endpoints generated from routine data sources when comparable data is available directly from trial case report forms or from another source. We illustrate application of the framework using data from a recent trial-based economic evaluation of the probiotic Bifidobacterium breve strain BBG administered to babies less than 31 weeks of gestation. Cost-effectiveness endpoints are compared using two sources of information; trial case report forms and data extracted from the National Neonatal Research Database (NNRD), a clinical database created through collaborative efforts of UK neonatal services. Focusing on mean incremental net benefits at £30,000 per episode of sepsis averted, the study revealed no evidence of discrepancy between the data sources (two-sided p values >0.4), low probability estimates of miscoverage (ranging from 0.039 to 0.060) and concordance correlation coefficients greater than 0.86. We conclude that the NNRD could potentially serve as a reliable source of data for future trial-based economic evaluations of neonatal interventions. We also discuss the potential implications of increasing opportunity to utilize routinely available data for the conduct of trial-based economic evaluations.
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Journal articleBattersby CWS, Longford N, Costeloe K, et al., 2017,
Development of a gestational age–specific case definition for neonatal necrotizing enterocolitis
, JAMA Pediatrics, Vol: 171, Pages: 256-263, ISSN: 2168-6211Importance Necrotizing enterocolitis (NEC) is a major cause of neonatal morbidity and mortality. Preventive and therapeutic research, surveillance, and quality improvement initiatives are hindered by variations in case definitions.Objective To develop a gestational age (GA)–specific case definition for NEC.Design, Setting, and Participants We conducted a prospective 34-month population study using clinician-recorded findings from the UK National Neonatal Research Database between December 2011 and September 2014 across all 163 neonatal units in England. We split study data into model development and validation data sets and categorized GA into groups (group 1, less than 26 weeks’ GA; group 2, 26 to less than 30 weeks’ GA; group 3, 30 to less than 37 weeks’ GA; group 4, 37 or more weeks’ GA). We entered GA, birth weight z score, and clinical and abdominal radiography findings as candidate variables in a logistic regression model, performed model fitting 1000 times, averaged the predictions, and used estimates from the fitted model to develop an ordinal NEC score and cut points to develop a dichotomous case definition based on the highest area under the receiver operating characteristic curves [AUCs] and positive predictive values [PPVs].Exposures Abdominal radiography performed to investigate clinical concerns.Main Outcomes and Measures Ordinal NEC likelihood score, dichotomous case definition, and GA-specific probability plots.Results Of the 3866 infants, the mean (SD) birth weight was 2049.1 (1941.7) g and mean (SD) GA was 32 (5) weeks; 2032 of 3663 (55.5%) were male. The total included 2978 infants (77.0%) without NEC and 888 (23.0%) with NEC. Infants with NEC in group 1 were less likely to present with pneumatosis (31.1% vs 47.2%; P = .01), blood in stool (11.8% vs 29.6%; P < .001), or mucus in stool (2.1% vs 5.6%; P = .048) but more likely to present with gasless abdominal radiograp
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