Causal models for monitoring the progress of infants with low birthweight

We study the weight (body mass) of infants born premat urely and with low birthweight during the first postnatal year. The infants are enrolled in the Casa Canguro programme in Valle de Cauca, a department (province) of Colom bia. The current weight and other physiological measurements are recorded at their vi sits to participating health- care facilities. We compare two groups of infants: those bor n at 31 weeks of gestational age or earlier (extremely preterm) and those born at 33 weeks or later (preterm). The comparisons are made using the potential outcomes framewor k, regarding the two groups as treatments and selecting from them pairs matched on an exte nsive set of covariates. Matching is accomplished by propensity scoring. The outcom es (weight and height) at a particular age are approximated by interpolation. We conclude that the average weight-handicap of the extremely preterm infants first incre ases, from about 600 grams at birth to 900 grams on average at three months, and then is re duced, so that by the first birthday they are only about 250 grams lighter on averag e

Analysis of a marker for cancer of the thyroid with a limit of detection

Limit of detection (LoD) is a common problem in the analysis of data generated by instruments that cannot detect very small concentra- tions or other quantities, resulting in left-censored measurements. Methods intended for data that are not subject to this problem are often difficult to modify for censoring. We adapt the simulation- extrapolation method, devised originally for fitting models with measurement error, to dealing with LoD in conjunction with a mix- ture analysis. The application relates the levels of thyroglobulin in individuals with cancer of the thyroid before and after treatment with radioactive iodine I–131. We conclude that the fitted mixture components correspond to levels of effectiveness of the treatment

Outcomes following early parenteral nutrition use in preterm neonates: Protocol for an observational study

Introduction Preterm babies are among the highest users of parenteral nutrition (PN) of any patient group, but there is wide variation in commencement, duration, and composition of PN and uncertainty around which groups will benefit from early introduction. Recent studies in critically unwell adults and children suggest that harms, specifically increased rates of nosocomial infection, outweigh the benefits of early administration of PN. In this study, we will describe early PN use in neonatal units in England, Wales and Scotland. We will also evaluate if this is associated with differences in important neonatal outcomes in neonates born between 30+0 and 32+6 weeks+days gestation. Methods and analysis We will use routinely collected data from all neonatal units in England, Wales and Scotland, available in the National Neonatal Research Database (NNRD). We will describe clinical practice in relation to any use of PN during the first 7 postnatal days among neonates admitted to neonatal care between 1 January 2012 and 31 December 2017. We will compare outcomes in neonates born between 30+0 and 32+6 weeks+days gestation who did or did not receive PN in the first week after birth using a propensity score-matched approach. The primary outcome will be survival to discharge home. Secondary outcomes will include components of the neonatal core outcome set: outcomes identified as important by former patients, parents, clinicians and researchers. Ethics and dissemination We have obtained UK National Research Ethics Committee approval for this study (Ref: 18/NI/0214). The results of this study will be presented at academic conferences; the UK charity Bliss will aid dissemination to former patients and parents

Outcomes in relation to early parenteral nutrition use in preterm neonates born between 30 and 33 weeks gestation: a propensity score matched observational study

Objective To evaluate whether in preterm neonates parenteral nutrition use in the first seven postnatal days, compared with no parenteral nutrition use, is associated with differences in survival and other important morbidities. Randomised trials in critically ill older children show that harms, such as nosocomial infection, outweigh benefits of early parenteral nutrition administration; there is a paucity of similar data in neonates. Design Retrospective cohort study using propensity matching including 35 maternal, infant and organisational factors to minimise bias and confounding. Setting National, population-level clinical data obtained for all National Health Service neonatal units in England and Wales. Patients Preterm neonates born between 30+0 and 32+6 weeks+days . Interventions The exposure was parenteral nutrition administered in the first seven days of postnatal life; the comparator was no parenteral nutrition. Main outcome measures The primary outcome was survival to discharge from neonatal care. Secondary outcomes comprised the neonatal core outcome set. Results 16,292 neonates were compared in propensity score matched analyses. Compared with matched neonates not given parenteral nutrition in the first postnatal week, neonates who received parenteral nutrition had higher survival at discharge (absolute rate increase 0.91%; 95% CI 0.53% to 1.30%), but higher rates of necrotising enterocolitis (absolute rate increase 4.6%), bronchopulmonary dysplasia (absolute rate increase 3.9%), late-onset sepsis (absolute rate increase 1.5%) and need for surgical procedures (absolute rate increase 0.92%). Conclusions In neonates born between 30+0 and 32+6 weeks gestation, those given parenteral nutrition in the first postnatal week had a higher rate of survival but higher rates of important neonatal morbidities. Clinician equipoise in this area should be resolved by prospective, randomised trials

Evidence for textile production in Rabati, Georgia, during the Bedeni phase of the Early Kurgan period

Georgian-Australian excavations in the multi-period settlement site of Rabati, located in southwest Georgia, have produced substantial evidence of textile manufacturing in the Early Kurgan, Bedeni period (2400–2000 BCE). The results of Palynological, Non-Pollen Palynomorph (NPP), Archaeobotanical, bone and fired clay tool analyses presented here have identified fibres of flax and hemp. The presence of cotton is the earliest evidence for this fibre in the region, pointing to trade in the commodity rather than its local cultivation. Also identified were coloured fibres and the possible sources of dye found in the Early Kurgan contexts at the site are discussed. The large number of textile manufacturing implements concentrated in one area of Rabati may indicate that this production was commercial rather than a domestic activity. An active, local textile industry during this period of growing social complexity has significant implications for the development of the emerging elite elements in an increasingly stratified society

Fitting multilevel models in complex survey data with design weights: Recommendations

Abstract Background Multilevel models (MLM) offer complex survey data analysts a unique approach to understanding individual and contextual determinants of public health. However, little summarized guidance exists with regard to fitting MLM in complex survey data with design weights. Simulation work suggests that analysts should scale design weights using two methods and fit the MLM using unweighted and scaled-weighted data. This article examines the performance of scaled-weighted and unweighted analyses across a variety of MLM and software programs. Methods Using data from the 2005–2006 National Survey of Children with Special Health Care Needs (NS-CSHCN: n = 40,723) that collected data from children clustered within states, I examine the performance of scaling methods across outcome type (categorical vs. continuous), model type (level-1, level-2, or combined), and software (Mplus, MLwiN, and GLLAMM). Results Scaled weighted estimates and standard errors differed slightly from unweighted analyses, agreeing more with each other than with unweighted analyses. However, observed differences were minimal and did not lead to different inferential conclusions. Likewise, results demonstrated minimal differences across software programs, increasing confidence in results and inferential conclusions independent of software choice. Conclusion If including design weights in MLM, analysts should scale the weights and use software that properly includes the scaled weights in the estimation.</p

Rapid testing and treatment for sexually transmitted infections improve patient care and yield public health benefits

A service evaluation of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) testing and result notification in patients attending a rapid testing service (Dean Street Express [DSE]) compared with those attending an existing ‘standard’ sexual health clinic (56 Dean Street [56DS]), and modelling the impact of the new service from 1 June 2014 to 31 May 2015. Primary outcome: time from patients’ sample collection to notification of test results at DSE compared with 56DS. Secondary outcomes estimated using a model: number of transmissions prevented and the number of new partner visits avoided and associated cost savings achieved due to rapid testing at DSE. In 2014/15, there were a total of 81,352 visits for CT/NG testing across 56DS (21,086) and DSE (60,266). Rapid testing resulted in a reduced mean time to notification of 8.68 days: 8.95 days for 56DS (95% CI 8.91–8.99) compared to 0.27 days for DSE (95% CI 0.26–0.28). Our model estimates that rapid testing at DSE would lead to 196 CT and/or NG transmissions prevented (2.5–97.5% centile range = 6–956) and lead to annual savings attributable to reduced numbers of partner attendances of £124,283 (2.5–97.5% centile range = £4260–590,331). DSE, a rapid testing service for asymptomatic infections, delivers faster time to result notification for CT and/or NG which enables faster treatment, reduces infectious periods and leads to fewer transmissions, partner attendances and clinic costs. </jats:p