8 research outputs found

    Methods for constructing normalised reference scores: an application for assessing child development

    No full text
    The use of the lambda-mu-sigma (LMS) method for estimating centiles and producing reference ranges has received much interest in clinical practice, especially for assessing growth in childhood. However, this method may not be directly applicable where measures are based on a score calculated from question response categories that is bounded within finite intervals, for example, in psychometrics. In such cases, the main assumption of normality of the conditional distribution of the transformed response measurement is violated due to the presence of ceiling (and floor) effects, leading to biased fitted centiles when derived using the common LMS method. This paper describes the methodology for constructing reference intervals when the response variable is bounded and explores different distribution families for the centile estimation, using a score derived from a parent-completed assessment of cognitive and language development in 24 month-old children. Results indicated that the z-scores, and thus the extracted centiles, improved when kurtosis was also modeled and that the ceiling effect was addressed with the use of the inflated binomial distribution. Therefore, the selection of the appropriate distribution when constructing centile curves is crucial. </p

    Methods for constructing normalised reference scores: an application for assessing child development

    No full text
    The use of the lambda-mu-sigma (LMS) method for estimating centiles and producing reference ranges has received much interest in clinical practice, especially for assessing growth in childhood. However, this method may not be directly applicable where measures are based on a score calculated from question response categories that is bounded within finite intervals, for example, in psychometrics. In such cases, the main assumption of normality of the conditional distribution of the transformed response measurement is violated due to the presence of ceiling (and floor) effects, leading to biased fitted centiles when derived using the common LMS method. This paper describes the methodology for constructing reference intervals when the response variable is bounded and explores different distribution families for the centile estimation, using a score derived from a parent-completed assessment of cognitive and language development in 24 month-old children. Results indicated that the z-scores, and thus the extracted centiles, improved when kurtosis was also modeled and that the ceiling effect was addressed with the use of the inflated binomial distribution. Therefore, the selection of the appropriate distribution when constructing centile curves is crucial. </p

    Estimated neonatal survival of very preterm births across the care pathway: a UK cohort 2016-2020

    No full text
    Objective Currently used estimates of survival are nearly 10 years old and relate to only those babies admitted for neonatal care. Due to ongoing improvements in neonatal care, here we update estimates of survival for singleton and multiple births at 22+0 to 31+6 weeks gestational age across the perinatal care pathway by gestational age and birth weight. Design Retrospective analysis of routinely collected data. Setting A national cohort from the UK and British Crown Dependencies. Patients Babies born at 22+0 to 31+6 weeks gestational age from 1 January 2016 to 31 December 2020. Interventions None. Main outcome measures Survival to 28 days. Results Estimates of neonatal survival are provided for babies: (1) alive at the onset of care during the birthing process (n=43 763); (2) babies where survival-focused care was initiated (n=42 004); and (3) babies admitted for neonatal care (n=41 158). We have produced easy-to-use survival charts for singleton and multiple births. Generally, survival increased with increasing gestational age at birth and with increasing birth weight. For all births with a birthweight over 1000 g, survival was 90% or higher at all three stages of care. Conclusions Survival estimates are a vital tool to support and supplement clinical judgement within perinatal care. These up-to-date, national estimates of survival to 28 days are provided based on three stages of the perinatal care pathway to support ongoing clinical care. These novel results are a key resource for policy and practice including counselling parents and informing care provision.</p

    Development of a data classification system for preterm birth cohort studies: The RECAP Preterm project

    No full text
    Background The small sample sizes available within many very preterm (VPT) longitudinal birth cohort studies mean that it is often necessary to combine and harmonise data from individual studies to increase statistical power, especially for studying rare outcomes. Curating and mapping data is a vital first step in the process of data harmonisation. To facilitate data mapping and harmonisation across VPT birth cohort studies, we developed a custom classification system as part of the Research on European Children and Adults born Preterm (RECAP Preterm) project in order to increase the scope and generalisability of research and the evaluation of outcomes across the lifespan for individuals born VPT. Methods The multidisciplinary consortium of expert clinicians and researchers who made up the RECAP Preterm project participated in a four-phase consultation process via email questionnaire to develop a topic-specific classification system. Descriptive analyses were calculated after each questionnaire round to provide pre- and post- ratings to assess levels of agreement with the classification system as it developed. Amendments and refinements were made to the classification system after each round. Results Expert input from 23 clinicians and researchers from the RECAP Preterm project aided development of the classification system’s topic content, refining it from 10 modules, 48 themes and 197 domains to 14 modules, 93 themes and 345 domains. Supplementary classifications for target, source, mode and instrument were also developed to capture additional variable-level information. Over 22,000 individual data variables relating to VPT birth outcomes have been mapped to the classification system to date to facilitate data harmonisation. This will continue to increase as retrospective data items are mapped and harmonised variables are created. Conclusions This bespoke preterm birth classification system is a fundamental component of the RECAP Preterm project’s web-based interactive platform. It is freely available for use worldwide by those interested in research into the long term impact of VPT birth. It can also be used to inform the development of future cohort studies.</p

    Neonatal outcomes and delivery of care for infants born late preterm or moderately preterm: A prospective population-based study

    No full text
    Objective: To describe neonatal outcomes and explore variation in delivery of care for infants born late (34-36 weeks) and moderately (32-33 weeks) preterm (LMPT). Design/setting: Prospective population-based study comprising births in four major maternity centres, one midwifery-led unit and at home between September 2009 and December 2010. Data were obtained from maternal and neonatal records. Participants: All LMPT infants were eligible. A random sample of term-born infants (≥37 weeks) acted as controls. Outcome measures: Neonatal unit admission, respiratory and nutritional support, neonatal morbidities, investigations, length of stay and postnatal ward care were measured. Differences between centres were explored. Results: 1146 (83%) LMPT and 1258 (79% of eligible) term-born infants were recruited. LMPT infants were significantly more likely to receive resuscitation at birth (17.5% v. 7.4%), respiratory (11.8% v. 0.9%) and nutritional support (3.5% v. 0.3%) and were less likely to be fed breast milk (64.2% v. 72.2%) than term infants. For all interventions and morbidities, a gradient of increasing risk with decreasing gestation was evident. Although 60% of late preterm infants were never admitted to a neonatal unit, 83% required medical input on postnatal wards. Clinical management differed significantly between services. Conclusion: LMPT infants place high demands on specialist neonatal services. A substantial amount of previously unreported specialist input is provided in postnatal wards, beyond normal newborn care. Appropriate expertise and planning of early care 5 is essential if such infants are managed away from specialised neonatal settings. Further research is required to clarify optimal and cost-effective postnatal management for LMPT babies

    Towards reducing variations in infant mortality and morbidity: a population-based approach

    Full text link
    Background: Our aims were (1) to improve understanding of regional variation in early-life mortality rates and the UK’s poor performance in international comparisons; and (2) to identify the extent to which late and moderately preterm (LMPT) birth contributes to early childhood mortality and morbidity. Objective: To undertake a programme of linked population-based research studies to work towards reducing variations in infant mortality and morbidity rates. Design: Two interlinked streams: (1) a detailed analysis of national and regional data sets and (2) establishment of cohorts of LMPT babies and term-born control babies. Setting: Cohorts were drawn from the geographically defined areas of Leicestershire and Nottinghamshire, and analyses were carried out at the University of Leicester. Data sources: For stream 1, national data were obtained from four sources: the Office for National Statistics, NHS Numbers for Babies, Centre for Maternal and Child Enquiries and East Midlands and South Yorkshire Congenital Anomalies Register. For stream 2, prospective data were collected for 1130 LMPT babies and 1255 term-born control babies. Main outcome measures: Detailed analysis of stillbirth and early childhood mortality rates with a particular focus on factors leading to biased or unfair comparison; review of clinical, health economic and developmental outcomes over the first 2 years of life for LMPT and term-born babies. Results: The deprivation gap in neonatal mortality has widened over time, despite government efforts to reduce it. Stillbirth rates are twice as high in the most deprived as in the least deprived decile. Approximately 70% of all infant deaths are the result of either preterm birth or a major congenital abnormality, and these are heavily influenced by mothers’ exposure to deprivation. Births at < 24 weeks’ gestation constitute only 1% of all births, but account for 20% of infant mortality. Classification of birth status for these babies varies widely across England. Risk of LMPT birth is greatest in the most deprived groups within society. Compared with term-born peers, LMPT babies are at an increased risk of neonatal morbidity, neonatal unit admission and poorer long-term health and developmental outcomes. Cognitive and socioemotional development problems confer the greatest long-term burden, with the risk being amplified by socioeconomic factors. During the first 24 months of life each child born LMPT generates approximately £3500 of additional health and societal costs. Conclusions: Health professionals should be cautious in reviewing unadjusted early-life mortality rates, particularly when these relate to individual trusts. When more sophisticated analysis is not possible, babies of < 24 weeks’ gestation should be excluded. Neonatal services should review the care they offer to babies born LMPT to ensure that it is appropriate to their needs. The risk of adverse outcome is low in LMPT children. However, the risk appears higher for some types of antenatal problems and when the mother is from a deprived background. Future work: Future work could include studies to improve our understanding of how deprivation increases the risk of mortality and morbidity in early life and investigation of longer-term outcomes and interventions in at-risk LMPT infants to improve future attainment. Funding: The National Institute for Health Research Programme Grants for Applied Research programme

    Clinical outcomes for babies born between 27 – 31 weeks of gestation: Should they be regarded as a single cohort?

    No full text
    Preterm babies born between 27 and 31 weeks of gestation are understudied and historically, have been grouped as a single cohort. Increased evidence relating to clinical outcomes is shaping models of care for babies born ≤26 weeks of gestation. Similar consideration of births between 27 and 31 weeks of gestation is now warranted. To address this, a clear understanding of the impact of progressive maturation in utero on the clinical care required, and on neonatal and infant outcomes of this group of preterm babies is helpful. In this review we highlight the spectrum of clinical presentations for babies born at 27–31 weeks of gestation. We discuss this with respect to key stages of organ/system development occurring in-utero during this five-week period and reveal a consistent trend of decreasing incidence of mortality and major morbidity with increasing gestational age at birth from 27 to 31 weeks. The clinical care required and the outcomes between babies born at either end of this gestational age range appear to be substantially different. This suggests it may be more appropriate to report outcomes by week of gestation rather than as a group in future research. Preterm health service delivery providers and decision makers need to consider this in planning services for the future, especially in environments where neonatal intensive care resources ought to be optimised for those at greatest need
    corecore