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Dive into the research topics where Jim Thornton is active.

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Featured researches published by Jim Thornton.


The Lancet | 2004

Infant wellbeing at 2 years of age in the Growth Restriction Intervention Trial (GRIT): Multicentred randomised controlled trial

Jim Thornton; Janet Hornbuckle; Andy Vail; D. Spiegelhalter; M. Levene

BACKGROUND Although delivery is widely used for preterm babies failing to thrive in utero, the effect of altering delivery timing has never been assessed in a randomised controlled trial. We aimed to compare the effect of delivering early with delaying birth for as long as possible. METHODS 548 pregnant women were recruited by 69 hospitals in 13 European countries. Participants had fetal compromise between 24 and 36 weeks, an umbilical-artery doppler waveform recorded, and clinical uncertainty about whether immediate delivery was indicated. Before birth, 588 babies were randomly assigned to immediate delivery (n=296) or delayed delivery until the obstetrician was no longer uncertain (n=292). The main outcome was death or disability at or beyond 2 years of age. Disability was defined as a Griffiths developmental quotient of 70 or less or the presence of motor or perceptual severe disability. Analysis was by intention-to-treat. This trial has been assigned the International Standard Randomised Controlled Trial Number ISRCTN41358726. FINDINGS Primary outcomes were available on 290 (98%) immediate and 283 (97%) deferred deliveries. Overall rate of death or severe disability at 2 years was 55 (19%) of 290 immediate births, and 44 (16%) of 283 delayed births. With adjustment for gestational age and umbilical-artery doppler category, the odds ratio (95% CrI) was 1.1 (0.7-1.8). Most of the observed difference was in disability in babies younger than 31 weeks of gestation at randomisation: 14 (13%) immediate versus five (5%) delayed deliveries. No important differences in the median Griffiths developmental quotient in survivors was seen. INTERPRETATION The lack of difference in mortality suggests that obstetricians are delivering sick preterm babies at about the correct moment to minimise mortality. However, they could be delivering too early to minimise brain damage. These results do not lend support to the idea that obstetricians can deliver before terminal hypoxaemia to improve brain development.


BMJ | 2010

Induction versus expectant monitoring for intrauterine growth restriction at term: randomised equivalence trial (DIGITAT)

Kim Boers; Sylvia M. C. Vijgen; Denise Bijlenga; J.A. van der Post; Dick J. Bekedam; Anneke Kwee; P.C.M. Van Der Salm; M.G. van Pampus; Marc Spaanderman; K de Boer; Johannes J. Duvekot; Henk A. Bremer; Tom H.M. Hasaart; Friso M.C. Delemarre; K.W. Bloemenkamp; C.A. van Meir; Christine Willekes; Ella Wijnen; Monique Rijken; S. le Cessie; Frans J.M.E. Roumen; Jim Thornton; J. M. M. van Lith; Ben Willem J. Mol; Sicco Scherjon

Objective To compare the effect of induction of labour with a policy of expectant monitoring for intrauterine growth restriction near term. Design Multicentre randomised equivalence trial (the Disproportionate Intrauterine Growth Intervention Trial At Term (DIGITAT)). Setting Eight academic and 44 non-academic hospitals in the Netherlands between November 2004 and November 2008. Participants Pregnant women who had a singleton pregnancy beyond 36+0 weeks’ gestation with suspected intrauterine growth restriction. Interventions Induction of labour or expectant monitoring. Main outcome measures The primary outcome was a composite measure of adverse neonatal outcome, defined as death before hospital discharge, five minute Apgar score of less than 7, umbilical artery pH of less than 7.05, or admission to the intensive care unit. Operative delivery (vaginal instrumental delivery or caesarean section) was a secondary outcome. Analysis was by intention to treat, with confidence intervals calculated for the differences in percentages or means. Results 321 pregnant women were randomly allocated to induction and 329 to expectant monitoring. Induction group infants were delivered 10 days earlier (mean difference −9.9 days, 95% CI −11.3 to −8.6) and weighed 130 g less (mean difference −130 g, 95% CI −188 g to −71 g) than babies in the expectant monitoring group. A total of 17 (5.3%) infants in the induction group experienced the composite adverse neonatal outcome, compared with 20 (6.1%) in the expectant monitoring group (difference −0.8%, 95% CI −4.3% to 3.2%). Caesarean sections were performed on 45 (14.0%) mothers in the induction group and 45 (13.7%) in the expectant monitoring group (difference 0.3%, 95% CI −5.0% to 5.6%). Conclusions In women with suspected intrauterine growth restriction at term, we found no important differences in adverse outcomes between induction of labour and expectant monitoring. Patients who are keen on non-intervention can safely choose expectant management with intensive maternal and fetal monitoring; however, it is rational to choose induction to prevent possible neonatal morbidity and stillbirth. Trial registration International Standard Randomised Controlled Trial number ISRCTN10363217.


Human Reproduction Update | 2011

The prevalence of congenital uterine anomalies in unselected and high-risk populations: a systematic review

Y.Y. Chan; K. Jayaprakasan; Javier Zamora; Jim Thornton; Nick Raine-Fenning; Arri Coomarasamy

BACKGROUND The prevalence of congenital uterine anomalies in high-risk women is unclear, as several different diagnostic approaches have been applied to different groups of patients. This review aims to evaluate the prevalence of such anomalies in unselected populations and in women with infertility, including those undergoing IVF treatment, women with a history of miscarriage, women with infertility and recurrent miscarriage combined, and women with a history of preterm delivery. METHODS Searches of MEDLINE, EMBASE, Web of Science and the Cochrane register were performed. Study selection and data extraction were conducted independently by two reviewers. Studies were grouped into those that used ‘optimal’ and ‘suboptimal’ tests for uterine anomalies. Meta-analyses were performed to establish the prevalence of uterine anomalies and their subtypes within the various populations. RESULTS We identified 94 observational studies comprising 89 861 women. The prevalence of uterine anomalies diagnosed by optimal tests was 5.5% [95% confidence interval (CI), 3.5–8.5] in the unselected population, 8.0% (95% CI, 5.3–12) in infertile women, 13.3% (95% CI, 8.9–20.0) in those with a history of miscarriage and 24.5% (95% CI, 18.3–32.8) in those with miscarriage and infertility. Arcuate uterus is most common in the unselected population (3.9%; 95% CI, 2.1–7.1), and its prevalence is not increased in high-risk groups. In contrast, septate uterus is the most common anomaly in high-risk populations. CONCLUSIONS Women with a history of miscarriage or miscarriage and infertility have higher prevalence of congenital uterine anomalies compared with the unselected population.


BMJ | 1995

Clinical trials and rare diseases: a way out of a conundrum

Richard Lilford; Jim Thornton; David Braunholtz

Currently, clinical trials tend to be individually funded and applicants must include a power calculation in their grant request. However, conventional levels of statistical precision are unlikely to be obtainable prospectively if the trial is required to evaluate treatment of a rare disease. This means that clinicians treating such diseases remain in ignorance and must form their judgments solely on the basis of (potentially biased) observational studies experience, and anecdote. Since some unbiased evidence is clearly better than none, this state of affairs should not continue. However, conventional (frequentist) confidence limits are unlikely to exclude a null result, even when treatments differ substantially. Bayesian methods utilise all available data to calculate probabilities that may be extrapolated directly to clinical practice. Funding bodies should therefore fund a repertoire of small trials, which need have no predetermined end, alongside standard larger studies.


The New England Journal of Medicine | 2015

Less-Tight versus Tight Control of Hypertension in Pregnancy

Laura A. Magee; Peter von Dadelszen; Evelyne Rey; Susan Ross; Elizabeth Asztalos; Kellie Murphy; Jennifer Menzies; Johanna Sanchez; Joel Singer; Amiram Gafni; Andrée Gruslin; Michael Helewa; Eileen K. Hutton; Shoo K. Lee; Terry Lee; Alexander G. Logan; Wessel Ganzevoort; Ross Welch; Jim Thornton; Jean Marie Moutquin

BACKGROUND The effects of less-tight versus tight control of hypertension on pregnancy complications are unclear. METHODS We performed an open, international, multicenter trial involving women at 14 weeks 0 days to 33 weeks 6 days of gestation who had nonproteinuric preexisting or gestational hypertension, office diastolic blood pressure of 90 to 105 mm Hg (or 85 to 105 mm Hg if the woman was taking antihypertensive medications), and a live fetus. Women were randomly assigned to less-tight control (target diastolic blood pressure, 100 mm Hg) or tight control (target diastolic blood pressure, 85 mm Hg). The composite primary outcome was pregnancy loss or high-level neonatal care for more than 48 hours during the first 28 postnatal days. The secondary outcome was serious maternal complications occurring up to 6 weeks post partum or until hospital discharge, whichever was later. RESULTS Included in the analysis were 987 women; 74.6% had preexisting hypertension. The primary-outcome rates were similar among 493 women assigned to less-tight control and 488 women assigned to tight control (31.4% and 30.7%, respectively; adjusted odds ratio, 1.02; 95% confidence interval [CI], 0.77 to 1.35), as were the rates of serious maternal complications (3.7% and 2.0%, respectively; adjusted odds ratio, 1.74; 95% CI, 0.79 to 3.84), despite a mean diastolic blood pressure that was higher in the less-tight-control group by 4.6 mm Hg (95% CI, 3.7 to 5.4). Severe hypertension (≥160/110 mm Hg) developed in 40.6% of the women in the less-tight-control group and 27.5% of the women in the tight-control group (P<0.001). CONCLUSIONS We found no significant between-group differences in the risk of pregnancy loss, high-level neonatal care, or overall maternal complications, although less-tight control was associated with a significantly higher frequency of severe maternal hypertension. (Funded by the Canadian Institutes of Health Research; CHIPS Current Controlled Trials number, ISRCTN71416914; ClinicalTrials.gov number, NCT01192412.).


BMJ | 1994

Case-control study of whether subfertility in men is familial

Richard Lilford; A M Jones; D T Bishop; Jim Thornton; R Mueller

Abstract Objective : To test the hypothesis that subfertility in men is familial and to examine the distribution of subfertility within families for consistency with a genetic cause. Design : Case-control study and segregation analysis. Setting : Two teaching hospitals in Leeds. Subjects : Cases (probands) were men with an abnormal sperm count who attended a subfertility clinic and whose partners had no major factor contravening fertility. Controls were fathers of two or more children recruited through vasectomy clinics or a maternity department. Main outcome measures : The incidence of involuntary20childlessness among brothers with partners and among sisters and second and third degree male relatives. When possible clinical and laboratory details were obtained from involuntarily childless brothers. Results : Seventeen of the 148 (11.5%) brothers of probands but none of the 169 brothers of controls had sought medical advice for childlessness (P<0.0005). Four probands had more than one involuntarily childless brother. There were six further brothers whose childlessness was thought to be involuntary bringing the total prevalence of subfertility among brothers of probands to 16%. Segregation analysis was consistent with an autosomal recessive mode of inheritance accounting for 60% of subfertility in men. Seventeen of the 346 (4.9%) uncles of probands and 10 of 420 (2.8%) uncles of controls were reported to be involuntarily childless (P=0.09), but there was no difference in childlessness among sisters. In three families sperm counts from “affected” brothers confirmed the diagnosis and showed considerable similarities within but not between families. Conclusion : Subfertility in men has a familial component, and the observations are consistent with an autosomal recessive mode of inheritance in over half the cases. Several different genes are probably involved.


Ultrasound in Obstetrics & Gynecology | 2011

Reproductive outcomes in women with congenital uterine anomalies: a systematic review

Y.Y. Chan; K. Jayaprakasan; A. Tan; Jim Thornton; Arri Coomarasamy; Nick Raine-Fenning

Congenital uterine anomalies are common but their effect on reproductive outcome is unclear. We conducted a systematic review to evaluate the association between different types of congenital uterine anomaly and various reproductive outcomes.


Social Science & Medicine | 1998

Informed consent for clinical trials: in search of the "best" method

Sarah Edwards; Richard Lilford; Jim Thornton; Jenny Hewison

OBJECTIVE To review the literature on comparisons between different methods of obtaining informed consent for clinical trials. DESIGN Eight hundred and twelve articles were traced, in the process of conducting a systematic review of the ethics of clinical trials, by searching a number of sources: bibliographic databases (Medline, Psychlit and BIDS science and social science indices), hand searches, personal contacts, an original collection and a systematic follow-up of reference lists. Fourteen research reports were found which provided comparative data on different methods of obtaining informed consent. Eleven of these used a randomised design. Studies were classified according to three outcome measures (anxiety, consent rate and understanding). RESULTS The results of the various studies suggest that giving people more information and more time to reflect tends to be associated with a lower consent rate. There seems to be an optimal level of information about side-effects such that patients are not overburdened by detail, while grasping the most important risks. More information in general is associated with greater awareness of the research nature of the trial, voluntariness of participation, right to withdraw and (available) alternative treatments. This result does not, however, extend to explanations of the concept of randomisation on which the literature is contradictory--sometimes more information is associated with increased understanding of the concept and sometimes it is not. Although divulging less information seems to be associated with less anxiety, there is evidence of an interaction with knowledge--high levels of knowledge are significantly associated with less anxiety, irrespective of consent method. The more that patients know before they are invited to participate in a trial, the better equipped they are to cope with the informed consent procedure. CONCLUSION There is some evidence to suggest that there is an optimal amount of information which enhances patient understanding and which might, in turn, reduce anxiety. However. the studies were not altogether conclusive. More work needs to be carried out, especially on public understanding of science and on how different ways of explaining scientific concepts affect that understanding.


BMJ | 1994

Active management of labour: current knowledge and research issues

Jim Thornton; Richard Lilford

Abstract Objectives : To review the evidence that the package of labour interventions collectively called “active management” - namely, strict diagnostic criteria for labour, early amniotomy, early use of oxytocin, and continuous professional support - reduce rates of caesarean sections and operative vaginal delivery in first labours. Design : Review of observational data, supplemented by evidence from four separate overviews of relevant randomised trials previously published as part of the Cochrane Collaboration pregnancy and childbirth database. Results : Observational data do not permit a clear conclusion. There have been no randomised trials of the total package of active management or of the use of strict diagnostic criteria alone, but trials of early amniotomy, early oxytocin, and these interventions combined do not suggest that these interventions are effective in reducing rates of caesarean sections or operative vaginal deliveries. In contrast, the provision of continuous professional support in labour seems to reduce both types of operative delivery, although the effect on caesarean sections is confined to those settings where non-professional companions are not normally present in labour. Conclusions : Delivery units should endeavour to provide continuous professional support in labour, but routine use of amniotomy and early oxytocin is not recommended.


British Journal of Obstetrics and Gynaecology | 2005

Accuracy of ultrasound biometry in the prediction of macrosomia: a systematic quantitative review

Arri Coomarasamy; Martin Connock; Jim Thornton; Khalid S. Khan

Objective  To determine the accuracy of ultrasonographically estimated fetal weight (EFW) and abdominal circumference (AC) in the prediction of macrosomia.

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Kate F. Walker

University of Nottingham

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Evelyne Rey

Université de Montréal

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Jennifer Menzies

University of British Columbia

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Joel Singer

University of British Columbia

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