15,879 research outputs found
Effect of individual-level and socioeconomic factors on long-term survival after cataract surgery over a 30-year period
Purpose:
To evaluate survival and the risk for mortality after cataract surgery in relation to individual-level and socioeconomic factors in Scotland over 3 decades.
Setting:
Linked healthcare data, United Kingdom.
Design:
Representative population-based study.
Methods:
A 5% random sample of Scottish decedents linked to hospital records (1981 to 2012) was assessed. Survival time, survival probability, and determinants of mortality were evaluated after the first and second recorded hospital episodes for cataract surgery. Cox proportional-hazards regression models were used to assess the effect of individual-level and socioeconomic factors including age, geographic location, socioeconomic status, and comorbidity on mortality.
Results:
The study evaluated linked administrative healthcare data from 9228 deceased patients who had cataract surgery. The mean survival time was 2383 days Âą 1853 (SD). The survival probability decreased from 98% 90 days after surgery to 22% at 10 years, 2% at 20 years, and 0% after 30 years. The mean age was 77 Âą 9 years. Age (hazard ratio [HR] 3.66; 95% confidence interval [CI], 2.97-3.80; P < .001) and severe comorbidity (HR 1.68; 95% CI, 1.47-1.91; P < .001) were associated with an increased risk for mortality; women had a 20% lower risk than men (HR 0.80; 95% CI, 0.76-0.83; P < .001). Socioeconomic status and rural geographic locations were not linked to mortality.
Conclusions:
Long-term survival after cataract surgery was determined by individual-level characteristics reflecting the mortality patterns of aging populations. The mortality risk was independent of socioeconomic and geographic factors per se
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Prevention of stillbirth
Key content:
⢠Most of the variability in stillbirth risk is not due to maternal risk factors. Hence, modifying maternal risk factors, or screening women using maternal risk factors to assess risk has limited potential impact.
⢠The only intervention that prevents stillbirth is delivery. The overall risk of perinatal death is lowest at 39 weeks gestational age, and induction of labour at term does not increase a woman's risk of emergency caesarean section.
⢠The most promising approach to screening low risk women for stillbirth risk may be to improve identification of small for gestational age infants. However, there is an absence of high quality evidence around the optimal approach to achieving this goal.
Learning objectives
⢠To understand the relationship between maternal risk factors, obstetric complications and fetal size in relation to stillbirth risk.
⢠To understand the approach to fetal assessment and elective delivery as methods to prevent stillbirth.
Ethical issues
⢠Screening for stillbirth risk has the potential to do good by preventing deaths. However, if programmes of screening and intervention are developed, many more women may be harmed due to high false positive rates.This is the accepted manuscript. The final version is available at http://onlinelibrary.wiley.com/doi/10.1111/tog.12197/abstrac
Variation in caesarean section rates in the US: outliers, damned outliers, and statistics.
Gordon C. Smith discusses the study by Katy Kozhimannil and colleagues that examines variations in cesarean section rates in the US and argues for the need for high-quality routine data collection to better understand the reasons for these variations. Please see later in the article for the Editors' Summary.This is the final version. It was first published by PLoS Medicine at http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1001746
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Screening and prevention of stillbirth.
Stillbirth is delivery of a baby at or after 24 weeks of gestational age (UK definition) not showing any signs of life. It affects almost one in 200 pregnancies and is the single major cause of perinatal death. Stillbirth is associated with a wide range of maternal demographic characteristics, but most of the variations in stillbirth risk are independent of these characteristics. Stillbirth is the end point of multiple processes, but the single most common cause is probably placental dysfunction. Stillbirth is associated with a wide range of biochemical and ultrasonic predictors, but there is limited evidence to support population-based screening. However, the evidence based is weak due to the use of poorly characterised screening tests, the failure to couple risk assessment with a clearly effective intervention for those who screen positive and inadequate study sample sizes. Basic research needs to identify better predictors, and clinical trials need to adopt more rigorous methodologies.This is the author accepted manuscript. The final version is available from Elsevier via https://doi.org/10.1016/j.bpobgyn.2016.08.00
The STRIDER trial: one step forward, one step back.
Severe, early onset fetal growth restriction (FGR) is characterised by a fetus presenting at a gestational age at the borderline of viability which is extremely small for gestational age by ultrasonic biometry and exhibits other signs of utero-placental insufficiency, such as abnormal patterns of uterine or umbilical blood flow. Following diagnosis, there is, currently, no disease modifying therapy other than medically indicated delivery, which carries a high risk of neonatal death or, if the infant survives, severe neurodisability in later life. Conversely, expectant management carries a substantial risk of intra-uterine fetal death. Balancing these conflicting risks is a day to day element of practice in Maternal-Fetal Medicine. Practitioners looks to a future of disease modifying therapies other than delivery. Unfortunately, the STRIDER trial suggests that one of the promising candidates, sildenafil citrate, is very unlikely to offer hope in this dismal situation. The study was powered to detect a 7 day prolongation in pregnancy. In reality, the trend was towards a reduction in the duration of pregnancy and the 95% confidence interval indicates that the best one could expect is a 1.3 day prolongation. In reality, it is more likely that the drug hastens delivery rather than postpones it.GCSS reports grants from Scottish Government (Chief Scientist Office Division), Medical Research Council, Stillbirth and Neonatal Death Society, and National Institute of Health Research (UK), grants and personal fees from GlaxoSmithKline Research and Development Limited, and personal fees and non-financial support from Roche Diagnostics International Limited, outside of the submitted work, and has a patent pending (PCT/EP2014/062602)
Looking for Design in Materials Design
Despite great advances in computation, materials design is still science
fiction. The construction of structure-property relations on the quantum scale
will turn computational empiricism into true design.Comment: 3 pages, 1 figur
Assessing the short-term outcomes of a community-based intervention for overweight and obese children: The MEND 5-7 programme
Objective The aim of this study was to report outcomes of the UK service level delivery of MEND (Mind,Exercise,Nutrition...Do it!) 5-7, a multicomponent, community-based, healthy lifestyle intervention designed for overweight and obese children aged 5â7â
years and their families.
Design Repeated measures.
Setting Community venues at 37 locations across the UK.
Participants 440 overweight or obese children (42% boys; mean age 6.1â
years; body mass index (BMI) z-score 2.86) and their parents/carers participated in the intervention.
Intervention MEND 5-7 is a 10-week, family-based, child weight-management intervention consisting of weekly group sessions. It includes positive parenting, active play, nutrition education and behaviour change strategies. The intervention is designed to be scalable and delivered by a range of health and social care professionals.
Primary and secondary outcome measures The primary outcome was BMI z-score. Secondary outcome measures included BMI, waist circumference, waist circumference z-score, children's psychological symptoms, parenting self-efficacy, physical activity and sedentary behaviours and the proportion of parents and children eating five or more portions of fruit and vegetables.
Results 274 (62%) children were measured preintervention and post-intervention (baseline; 10-weeks). Post-intervention, mean BMI and waist circumference decreased by 0.5â
kg/m2 and 0.9â
cm, while z-scores decreased by 0.20 and 0.20, respectively (p<0.0001). Improvements were found in children's psychological symptoms (â1.6 units, p<0.0001), parent self-efficacy (p<0.0001), physical activity (+2.9â
h/week, p<0.01), sedentary activities (â4.1â
h/week, p<0.0001) and the proportion of parents and children eating five or more portions of fruit and vegetables per day (both p<0.0001). Attendance at the 10 sessions was 73% with a 70% retention rate.
Conclusions Participation in the MEND 5-7 programme was associated with beneficial changes in physical, behavioural and psychological outcomes for children with complete sets of measurement data, when implemented in UK community settings under service level conditions. Further investigation is warranted to establish if these findings are replicable under controlled conditions
Pulsational and evolutionary analysis of the double-mode RR Lyrae star BS Com
We derive the basic physical parameters of the field double-mode RR Lyrae
star BS Com from its observed periods and the requirement of consistency
between the pulsational and evolutionary constraints. By using the current
solar-scaled horizontal branch evolutionary models of Pietrinferni et al.
(2004) and our linear non-adiabatic purely radiative pulsational models, we get
M/M(Sun) = 0.698 +/- 0.004, log(L/L(Sun)) = 1.712 +/- 0.005, T(eff) = 6840 +/-
14 K, [Fe/H] = -1.67 +/- 0.01, where the errors are standard deviations
assuming uniform age distribution along the full range of uncertainty in age.
The last two parameters are in a good agreement with the ones derived from the
observed BVIc colours and the updated ATLAS9 stellar atmosphere models. We get
T(eff) = 6842 +/- 10 K, [Fe/H] = -1.58 +/- 0.11, where the errors are purely
statistical ones. It is remarkable that the derived parameters are nearly
independent of stellar age at early evolutionary stages. Later stages,
corresponding to the evolution toward the asymptotic giant branch are most
probably excluded because the required high temperatures are less likely to
satisfy the constraints posed by the colours. We also show that our conclusions
are only weakly sensitive to nonlinear period shifts predicted by current
hydrodynamical models.Comment: Accepted for publication by MNRAS on 2008 February 01. The paper
contains 4 figures and 8 table
Ice cliff dynamics in the Everest region of the Central Himalaya
The importance of ice cliffs for glacier-scale ablation on debris-covered glaciers is now widely recognised. However, a paucity of data exists to describe the spatio-temporal distribution of ice cliffs. In this study we analysed the position and geometry of 8229 ice cliffs and 5582 supraglacial ponds on 14 glaciers in the Everest region between 2000 and 2015. We observed notable ice cliff and pond spatial coincidence. On average across our study glaciers, 77% of supraglacial pond area was associated with an adjacent ice cliff, and 49% of ice cliffs featured an adjacent supraglacial pond. The spatial density of ice cliffs was not directly related to glacier velocity, but did peak within zones of active ice. Furthermore, we found that ice cliff density was glacier-specific, temporally variable, and was positively correlated with surface lowering and decreasing debris thickness for individual glaciers. Ice cliffs predominantly had a north-facing (commonly north-westerly) aspect, which was independent of glacier flow direction, thereby signifying a strong solar radiation control on cliff evolution. Independent field observations indicated that cliff morphology was related to aspect, local debris thickness, and presence of a supraglacial pond, and highlighted the importance of surface runnel formation, which acts as a preferential pathway for meltwater and debris fluxes. Overall, by coupling remote sensing and in-situ observations it has been possible to capture local and glacier-scale ice cliff dynamics across 14 glaciers, which is necessary if explicit parameterisation of ice cliffs in dynamic glacier models is to be achieved
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