Neonatal blood TSH concentration in Wales (UK): an indicator of iodine sufficiency.

Objective: Population iodine status can be assessed by urinary iodine concentrations, prevalence of goitre, frequency of newborn thyroid-stimulating hormone (TSH) >5 mU/l and blood thyroglobulin concentrations. The UK population has historically been considered to be iodine sufficient; however, a recent survey of UK schoolgirls has demonstrated median urinary iodine concentrations consistent with mild iodine deficiency. The aim of our study was to assess the prevalence of TSH >5 mU/l in the newborn blood spot screening samples from the eligible population in Wales between 2011 and 2013 to assess iodine sufficiency.

The perception of facial asymmetry using 3-dimensional simulated images.

Objective: To investigate the perception of facial asymmetry in young adults to identify the amounts of chin asymmetry that can be regarded as normal and may benefit from correction.

Materials And Methods: Three-dimensional (3D) images of 56 individuals of mixed ethnicity were obtained and used to produce average 3D images of male and female faces. Distortion was then applied to these average faces using a 3D graphics package to simulate different amounts of chin point asymmetry.

Interference in the autoDELFIA(R) hAFP immunoassay and effect on second-trimester Down's syndrome screening.

Background: Falsely decreased serum alphafetoprotein (AFP) concentrations are reported in the autoDELFIA(®) hAFP immunoassay due to interference by complement. AFP is measured, using this assay, as part of second-trimester and integrated Down's syndrome screening tests. Decreased AFP concentrations increase the calculated risk of Down's syndrome; therefore falsely low AFP, due to assay interference, may artificially increase a patient's risk, and have the potential to cause false screen positive results.

Neonatal plasma TSH--estimated upper reference intervals for diagnosis and follow up of congenital hypothyroidism.

Age- and method-dependent plasma TSH reference intervals are essential for the diagnosis and management of congenital hypothyroidism. However, accurate reference intervals for plasma TSH have not been adequately defined due to the difficulties in obtaining samples from a healthy paediatric population. To overcome the difficulties in generating such intervals we estimated method-dependent plasma TSH upper-reference intervals by determining the blood spot TSH upper-reference interval from newborn blood spot TSH screening data (N = 10,697) and then derived method-dependent conversion factors for blood spot TSH to plasma TSH concentration from paired-blood spot and plasma TSH measurements.

A test of association between spatially defined exposure patterns and health outcome risk contours.

Advances in the availability of geographically referenced health and environmental quality data of high spatial resolution have created new opportunities in environmental epidemiology. Novel statistical methods for linking health, exposure, and hazards are required to underpin the development of public health tracking. A test for the association between spatial contours of health risk and exposure is outlined.

First trimester screening for Down syndrome using free beta hCG, total hCG and PAPP-A: an exploratory study.

Objective: To investigate the potential utility of first trimester screening for Down syndrome using Free beta-hCG, total hCG and PAPP-A.

Materials And Methods: Using estimates from the literature, a simulation study was undertaken to estimate the performance of tests incorporating, Free beta-hCG, total hCG and PAPP-A at gestations of 8-12 weeks. We used sensitivity analysis to assess the effect of departures from the assumed model.

The impact of bias in MoM values on patient risk and screening performance for Down syndrome.

Unlabelled: First and second trimester screening protocols for Down syndrome rely on marker values being referred to smoothed median values to produce adjusted multiple of the median (MoM) values to standardise for factors such as assay, gestation, maternal weight, smoking status, and so on. Changes in assay components, such as reagent lot, and inappropriate use of published regression equations for smoothed medians have resulted in biases in reported MoM values that in many applications remain uncorrected. This paper investigates the impact of these biases on patient-specific risk estimates and screening performance, and concludes that a 10% bias for an individual marker can result in an increase of between 1 and 2% in the false positive rate of the programme.

Sonographic screening for trisomy 13 at 11 to 13(+6) weeks of gestation.

Objective: The purpose of this study was to examine the sonographic features of trisomy 13 at 11 to 13(+6) weeks of gestation.

Study Design: This was a retrospective study that examined the features of trisomy 13 at the ultrasound scan at 11 to 13(+6) weeks of gestation, which in our center is performed for the measurement of crown-rump length, nuchal translucency thickness, and fetal heart rate and the examination for major defects.

Results: In the 181 fetuses with trisomy 13, there were holoprosencephaly, exomphalos, and/or megacystis in 92 fetuses (50.

Spatial contouring of risk: a tool for environmental epidemiology.

The possible elevation of disease rates in the proximity of site-specific environmental hazards is much investigated. Single-site studies are subject to problems of reporting bias and statistical power, and multisite studies to heterogeneity of exposure. Both types of studies usually use concentric circular regions centered on a site as a surrogate for defining the exposed and unexposed populations.

Centile charts I: new method of assessment for univariate reference intervals.

Background: We introduce a new criterion, the percentile inclusion probability, for comparing methods for calculating reference intervals. The criterion is compared with a previously published measure of reliability suggested by Linnet (Linnet K. Clin Chem 1987;33:381-6), the ratio of the width of the confidence interval for the percentile to that of the reference interval.

Value of the serum estradiol level for preventing ovarian hyperstimulation syndrome: a retrospective case control study.

Objective: To assess the value of different serum E(2) cut-off levels for predicting women at risk for ovarian hyperstimulation syndrome (OHSS).

Design: Retrospective case-control study of a cohort of women undergoing assisted reproduction treatment (ART) over 12 months.

Setting: Tertiary university hospital.

Modeling the hepatitis C virus epidemic in France using the temporal pattern of hepatocellular carcinoma deaths.

Deuffic et al. developed a compartmentalized model that characterized the evolution and spread of the hepatitis C virus (HCV) within France. There were various parameters defining the age- and sex-dependent transition probabilities between chronic hepatitis and cirrhosis in need of determination to completely specify their model.