The PREM score: a graphical tool for predicting survival in very preterm births

Identification of the Best Predictive Model for Mortality in Outborn Neonates-Retrospective Cohort Study

BACKGROUND

Transportation of sick newborns is a major predictor of outcome. Prompt identification of the sickest newborns allows adequate intervention and outcome optimization. An optimal scoring system has not yet been identified.

AIM

To identify a rapid, accurate, and easy-to-perform score predictive for neonatal mortality in outborn neonates.

MATERIAL AND METHODS

All neonates admitted by transfer in a level III regional neonatal unit between 1 January 2015 and 31 December 2021 were included. Infants with congenital critical abnormalities were excluded (N = 15). Gestational age (GA), birth weight (BW), Apgar score, place of birth, time between delivery and admission (AT), early onset sepsis, and sick neonatal score (SNS) were collected from medical records and tested for their association with mortality, including in subgroups (preterm vs. term infants); GA, BW, and AT were used to develop MSNS-AT score, to improve mortality prediction. The main outcome was all-cause mortality prediction. Univariable and multivariable analysis, including Cox regression, were performed, and odds ratio and hazard ratios were calculated were appropriate.

RESULTS

418 infants were included; 217/403 infants were born prematurely (53.8%), and 20 died (4.96%). Compared with the survivors, the non-survivors had lower GA, BW, and SNS scores (p < 0.05); only the SNS scores remained lower in the subgroup analysis. Time to admission was associated with an increased mortality rate in the whole group and preterm infants (p < 0.05). In multiple Cox regression models, a cut-off value of MSNS-AT score ≤ 10 was more precise in predicting mortality as compared with SNS (AUC 0.735 vs. 0.775) in the entire group and in the preterm infants group (AUC 0.885 vs. 0.810).

CONCLUSIONS

The new MSNS-AT score significantly improved mortality prediction at admission in the whole study group and in preterm infants as compared with the SNS score, suggesting that, besides GA and BW, AT may be decisive for the outcome of outborn preterm infants.

Mortality and severe neurological morbidity in extremely preterm growth-restricted fetuses

OBJECTIVE

To develop a model for the prediction of adverse perinatal outcome in growth-restricted fetuses requiring delivery before 28 weeks in order to provide individualized patient counseling.

METHODS

This was a retrospective multicenter cohort study of singleton pregnancies with antenatal suspicion of fetal growth restriction requiring delivery before 28 weeks' gestation between January 2010 and January 2020 in six tertiary public hospitals in the Barcelona area, Spain. Separate predictive models for mortality only and mortality or severe neurological morbidity were created using logistic regression from variables available antenatally. For each model, predictive performance was evaluated using receiver-operating-characteristics (ROC)-curve analysis. Predictive models were validated externally in an additional cohort of growth-restricted fetuses from another public tertiary hospital with the same inclusion and exclusion criteria.

RESULTS

A total of 110 cases were included. The neonatal mortality rate was 37.3% and, among the survivors, the rate of severe neurological morbidity was 21.7%. The following factors were retained in the multivariate analysis as significant predictors of mortality: magnesium sulfate neuroprotection, gestational age at birth, estimated fetal weight, male sex and Doppler stage. This model had a significantly higher area under the ROC curve (AUC) compared with a model including only gestational age at birth (0.810 (95% CI, 0.730-0.889) vs 0.695 (95% CI, 0.594-0.795); P = 0.016). At a 20% false-positive rate, the model showed a sensitivity, negative predictive value and positive predictive value of 66%, 80% and 66%, respectively. For the prediction of the composite adverse outcome (mortality or severe neurological morbidity), the model included: gestational age at birth, male sex and Doppler stage. This model had a significantly higher AUC compared with a model including only gestational age at birth (0.810 (95% CI, 0.731-0.892) vs 0.689 (95% CI, 0.588-0.799); P = 0.017). At a 20% false-positive rate, the model showed a sensitivity, negative predictive value and positive predictive value of 55%, 63% and 74%, respectively. External validation of both models yielded similar AUCs that did not differ significantly from those obtained in the original sample.

CONCLUSIONS

Estimated fetal weight, fetal sex and Doppler stage can be combined with gestational age to improve the prediction of death or severe neurological sequelae in growth-restricted fetuses requiring delivery before 28 weeks. This approach may be useful for parental counseling and decision-making. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Predicting the risk of HIV infection among internal migrant MSM in China: An optimal model based on three variable selection methods

Introduction

Internal migrant Men who have sex with men (IMMSM), which has the dual identity of MSM and floating population, should be more concerned among the vulnerable groups for HIV in society. Establishing appropriate prediction models to assess the risk of HIV infection among IMMSM is of great significance to against HIV infection and transmission.

Methods

HIV and syphilis infection were detected using rapid test kits, and other 30 variables were collected among IMMSM through questionnaire. Taking HIV infection status as the dependent variable, three methods were used to screen predictors and three prediction models were developed respectively. The Hosmer-Lemeshow test was performed to verify the fit of the models, and the net classification improvement and integrated discrimination improvement were used to compare these models to determine the optimal model. Based on the optimal model, a prediction nomogram was developed as an instrument to assess the risk of HIV infection among IMMSM. To quantify the predictive ability of the nomogram, the C-index measurement was performed, and internal validation was performed using bootstrap method. The receiver operating characteristic (ROC) curve, calibration plot and dynamic component analysis (DCA) were respectively performed to assess the efficacy, accuracy and clinical utility of the prediction nomogram.

Results

In this study, 12.52% IMMSMs were tested HIV-positive and 8.0% IMMSMs were tested syphilis-positive. Model A, model B, and model C fitted well, and model B was the optimal model. A nomogram was developed based on the model B. The C-index of the nomogram was 0.757 (95% CI: 0.701-0.812), and the C-index of internal verification was 0.705.

Conclusions

The model established by stepwise selection methods incorporating 11 risk factors (age, education, marriage, monthly income, verbal violence, syphilis, score of CUSS, score of RSES, score of ULS, score of ES and score of DS) was the optimal model that achieved the best predictive power. The risk nomogram based on the optimal model had relatively good efficacy, accuracy and clinical utility in identifying internal migrant MSM at high-risk for HIV infection, which is helpful for developing targeted intervention for them.

Predicting risk of severe neonatal outcomes in preterm infants born from mother with prelabor rupture of membranes

BACKGROUND

Perinatal complications are common burdens for neonates born from mother with pPROM. Physicians and parents sometimes need to make critical decisions about neonatal care with short- and long-term implications on infant's health and families and it is important to predict severe neonatal outcomes with high accuracy.

METHODS

The study was based on our prospective study on 1001 preterm infants born from mother with pPROM from August 1, 2017, to March 31, 2018 in three hospitals in China. Multivariable logistic regression analysis was applied to build a predicting model incorporating obstetric and neonatal characteristics available within the first day of NICU admission. We used enhanced bootstrap resampling for internal validation.

RESULTS

One thousand one-hundred pregnancies with PROM at preterm with a single fetus were included in our study. SNO was diagnosed in 180 (17.98%) neonates. On multivariate analysis of the primary cohort, independent factors for SNO were respiratory support on the first day,, surfactant on day 1, and birth weight, which were selected into the nomogram. The model displayed good discrimination with a C-index of 0.838 (95%CI, 0.802-0.874) and good calibration performance. High C-index value of 0.835 could still be reached in the internal validation and the calibration curve showed good agreement. Decision curve analysis showed if the threshold is > 15%, using our model would achieve higher net benefit than model with birthweight as the only one predictor.

CONCLUSION

Variables available on the first day in NICU including respiratory support on the first day, the use of surfactant on the first day and birthweight could be used to predict the risk of SNO in infants born from mother with pPROM with good discrimination and calibration performance.

Prognostic Models Predicting Mortality in Preterm Infants: Systematic Review and Meta-analysis

CONTEXT

Prediction models can be a valuable tool in performing risk assessment of mortality in preterm infants.

OBJECTIVE

Summarizing prognostic models for predicting mortality in very preterm infants and assessing their quality.

DATA SOURCES

Medline was searched for all articles (up to June 2020).

STUDY SELECTION

All developed or externally validated prognostic models for mortality prediction in liveborn infants born <32 weeks' gestation and/or <1500 g birth weight were included.

DATA EXTRACTION

Data were extracted by 2 independent authors. Risk of bias (ROB) and applicability assessment was performed by 2 independent authors using Prediction model Risk of Bias Assessment Tool.

RESULTS

One hundred forty-two models from 35 studies reporting on model development and 112 models from 33 studies reporting on external validation were included. ROB assessment revealed high ROB in the majority of the models, most often because of inadequate (reporting of) analysis. Internal and external validation was lacking in 41% and 96% of these models. Meta-analyses revealed an average C-statistic of 0.88 (95% confidence interval [CI]: 0.83-0.91) for the Clinical Risk Index for Babies score, 0.87 (95% CI: 0.81-0.92) for the Clinical Risk Index for Babies II score, and 0.86 (95% CI: 0.78-0.92) for the Score for Neonatal Acute Physiology Perinatal Extension II score.

LIMITATIONS

Occasionally, an external validation study was included, but not the development study, because studies developed in the presurfactant era or general NICU population were excluded.

CONCLUSIONS

Instead of developing additional mortality prediction models for preterm infants, the emphasis should be shifted toward external validation and consecutive adaption of the existing prediction models.

Short Term Outcome and Predictors of Mortality Among Very Low Birth Weight Infants - A Descriptive Study

OBJECTIVE

To assess the short term outcome and predictors of mortality among very low birth weight (VLBW) neonates.

METHODS

This descriptive study from a tertiary care teaching institute in south India included 239 VLBW neonates who were uniformly managed as per unit's protocol and followed up till discharge or death, whichever was earlier. Univariate analysis and logistic regression analysis were done to determine the predictors of mortality. Two logistic regression models were developed and to evaluate their discriminative performance, area under the receiver operating characteristic curves were calculated.

RESULTS

Mean gestational age and mean birth weight of neonates were 31.4 ± 3 wk and 1191 ± 245 g respectively. Among the 239 infants, 49 (20.5%) expired and 190 (70.5%) survived. Mortality among extremely low birth weight (ELBW) and extreme preterm infants were 69.3% and 73.3% respectively. Univariate analysis showed multiple perinatal factors and neonatal morbidities were associated with mortality. On adjusted multivariate logistic regression, birth weight < 1000 g (OR 9.27), severe grade of intraventricular hemorrhage (IVH) (OR 29.2), hyperglycemia (OR 7.8) and respiratory distress syndrome (RDS) requiring surfactant therapy (OR 6.2) were the significant predictors of mortality. Both logistic regression models developed showed good prediction of mortality.

CONCLUSIONS

VLBW mortality rate is 20% in the population studied. Birth weight < 1000 g, severe grade of IVH, hyperglycemia, and RDS requiring surfactant therapy were the significant predictors of mortality among VLBW neonates. Both prediction models developed showed good prediction of mortality.

Prediction of In-Hospital Mortality After 24 Hours in Very Low Birth Weight Infants

BACKGROUND AND OBJECTIVES

The existing prediction formulas for in-hospital mortality of very low birth weight (VLBW) infants were mostly developed in the 1990s or 2000s and thus may not reflect the recently improved levels of neonatal care. We conducted this study to build a model for predicting the in-hospital mortality using perinatal factors available soon after birth.

METHODS

We gathered data on VLBW infants from the Korean Neonatal Network, a nationwide, prospective, Web-based registry that enrolled patients from 2013 to 2017. Perinatal variables that were significantly associated with mortality in univariate logistic regression or those with apparent clinical importance were included in the multivariable logistic regression model. The final formula was constructed by considering the collinearity, parsimony, goodness of fit, and clinical interpretation.

RESULTS

A total of 9248 VLBW infants were analyzed, including 1105 (11.9%) who died during hospitalization. The mean gestational age was 29.0 ± 2.9 weeks and the mean birth weight was 1096 ± 280 g. Significant variables used in the final equation included polyhydramnios, oligohydramnios, gestational age, Apgar score at 1 minute, intubation at birth, birth weight, and base excess. In internal validation, the area under the curve (AUC) for the prediction of in-hospital mortality was 0.870 and the optimism-corrected AUC was 0.867. The prediction equation revealed good discrimination and calibration in the external validation as well (AUC: 0.876).

CONCLUSIONS

The newly developed Korean Neonatal Network prediction formula for in-hospital mortality could be a useful tool in counseling by providing a reliable prediction for the in-hospital mortality of VLBW infants.

Society for Maternal-Fetal Medicine Consult Series #52: Diagnosis and management of fetal growth restriction: (Replaces Clinical Guideline Number 3, April 2012)

Fetal growth restriction can result from a variety of maternal, fetal, and placental conditions. It occurs in up to 10% of pregnancies and is a leading cause of infant morbidity and mortality. This complex obstetrical problem has disparate published diagnostic criteria, relatively low detection rates, and limited preventative and treatment options. The purpose of this Consult is to outline an evidence-based, standardized approach for the prenatal diagnosis and management of fetal growth restriction. The recommendations of the Society for Maternal-Fetal Medicine are as follows: (1) we recommend that fetal growth restriction be defined as an ultrasonographic estimated fetal weight or abdominal circumference below the 10th percentile for gestational age (GRADE 1B); (2) we recommend the use of population-based fetal growth references (such as Hadlock) in determining fetal weight percentiles (GRADE 1B); (3) we recommend against the use of low-molecular-weight heparin for the sole indication of prevention of recurrent fetal growth restriction (GRADE 1B); (4) we recommend against the use of sildenafil or activity restriction for in utero treatment of fetal growth restriction (GRADE 1B); (5) we recommend that a detailed obstetrical ultrasound examination (current procedural terminology code 76811) be performed with early-onset fetal growth restriction (<32 weeks of gestation) (GRADE 1B); (6) we recommend that women be offered fetal diagnostic testing, including chromosomal microarray analysis, when fetal growth restriction is detected and a fetal malformation, polyhydramnios, or both are also present regardless of gestational age (GRADE 1B); (7) we recommend that pregnant women be offered prenatal diagnostic testing with chromosomal microarray analysis when unexplained isolated fetal growth restriction is diagnosed at <32 weeks of gestation (GRADE 1C); (8) we recommend against screening for toxoplasmosis, rubella, or herpes in pregnancies with fetal growth restriction in the absence of other risk factors and recommend polymerase chain reaction for cytomegalovirus in women with unexplained fetal growth restriction who elect diagnostic testing with amniocentesis (GRADE 1C); (9) we recommend that once fetal growth restriction is diagnosed, serial umbilical artery Doppler assessment should be performed to assess for deterioration (GRADE 1C); (10) with decreased end-diastolic velocity (ie, flow ratios greater than the 95th percentile) or in pregnancies with severe fetal growth restriction (estimated fetal weight less than the third percentile), we suggest weekly umbilical artery Doppler evaluation (GRADE 2C); (11) we recommend Doppler assessment up to 2-3 times per week when umbilical artery absent end-diastolic velocity is detected (GRADE 1C); (12) in the setting of reversed end-diastolic velocity, we suggest hospitalization, administration of antenatal corticosteroids, heightened surveillance with cardiotocography at least 1-2 times per day, and consideration of delivery depending on the entire clinical picture and results of additional evaluation of fetal well-being (GRADE 2C); (13) we suggest that Doppler assessment of the ductus venosus, middle cerebral artery, or uterine artery not be used for routine clinical management of early- or late-onset fetal growth restriction (GRADE 2B); (14) we suggest weekly cardiotocography testing after viability for fetal growth restriction without absent/reversed end-diastolic velocity and that the frequency be increased when fetal growth restriction is complicated by absent/reversed end-diastolic velocity or other comorbidities or risk factors (GRADE 2C); (15) we recommend delivery at 37 weeks of gestation in pregnancies with fetal growth restriction and an umbilical artery Doppler waveform with decreased diastolic flow but without absent/reversed end-diastolic velocity or with severe fetal growth restriction with estimated fetal weight less than the third percentile (GRADE 1B); (16) we recommend delivery at 33-34 weeks of gestation for pregnancies with fetal growth restriction and absent end-diastolic velocity (GRADE 1B); (17) we recommend delivery at 30-32 weeks of gestation for pregnancies with fetal growth restriction and reversed end-diastolic velocity (GRADE 1B); (18) we suggest delivery at 38-39 weeks of gestation with fetal growth restriction when the estimated fetal weight is between the 3rd and 10th percentile and the umbilical artery Doppler is normal (GRADE 2C); (19) we suggest that for pregnancies with fetal growth restriction complicated by absent/reversed end-diastolic velocity, cesarean delivery should be considered based on the entire clinical scenario (GRADE 2C); (20) we recommend the use of antenatal corticosteroids if delivery is anticipated before 33 6/7 weeks of gestation or for pregnancies between 34 0/7 and 36 6/7 weeks of gestation in women without contraindications who are at risk of preterm delivery within 7 days and who have not received a prior course of antenatal corticosteroids (GRADE 1A); and (21) we recommend intrapartum magnesium sulfate for fetal and neonatal neuroprotection for women with pregnancies that are <32 weeks of gestation (GRADE 1A).

Prediction of mortality in very low birth weight neonates in Spain

Objective

Predictive models for preterm infant mortality have been developed internationally, albeit not valid for all populations. This study aimed to develop and validate different mortality predictive models, using Spanish data, to be applicable to centers with similar morbidity and mortality.

Methods

Infants born alive, admitted to NICU (BW<1500 g or GA<30 w), and registered in the SEN1500 database, were included. There were two time periods; development of the predictive models (2009–2012) and validation (2013–2015). Three models were produced; prenatal (1), first 24 hours of life (2), and whilst admitted (3). For the statistical analysis, hospital mortality was the dependent variable. Significant variables were used in multivariable regression models. Specificity, sensitivity, accuracy, and area under the curve (AUC), for all models, were calculated.

Results

Out of 14953 included newborns, 2015 died; 373 (18.5%) in their first 24 hours, 1315 (65.3%) during the first month, and 327 (16.2%) thereafter, before discharge. In the development stage, mortality prediction AUC was 0.834 (95% CI: 0.822–0.846) (p<0.001) in model 1 and 0.872 (95% CI: 0.860–0.884) (p<0.001) in model 2. Model 3’s AUC was 0.989 (95% CI: 0.983–0.996) (p<0.001) and 0.942 (95% CI: 0.929–0.956) (p<0.001) during the 0–30 and >30 days of life, respectively. During validation, models 1 and 2 showed moderate concordance, whilst that of model 3 was good.

Conclusion

Using dynamic models to predict individual mortality can improve outcome estimations. Development of models in the prenatal period, first 24 hours, and during hospital admission, cover key stages of mortality prediction in preterm infants.

Addition of sildenafil citrate for treatment of severe intrauterine growth restriction: a double blind randomized placebo controlled trial

Background: Severe intrauterine growth restriction complicates approximately 0.4% of the pregnancies. It increases the risk of perinatal morbidity and mortality.Subjects and methods: A double blind placebo controlled trial was conducted in Beni Suef University hospitals during 2017. It included 46 pregnant women with severe intrauterine growth restriction. Women were randomly allocated into two groups each included 23 patients. Intervention group received sildenafil citrate 20 mg orally three times a day, in addition to fish oil and zinc supplementation. Control group received tablets similar to sildenafil and the same treatment as intervention group. Primary outcomes included improvement in umbilical and middle cerebral arteries pulsatility indices and abdominal circumference.Results: Umbilical and middle cerebral arteries Doppler indices showed significant difference between groups after intake of sildenafil. Umbilical artery pulsatility index decreased significantly (p value = .001) while middle cerebral artery pulsatility index increased significantly in intervention group (p value0.001). Moreover, abdominal circumference growth velocity improved after two weeks of sildenafil intake (p value = .001).Conclusions: Sildenafil citrate may improve uteroplacental and fetal cerebral perfusion in pregnancies complicated by severe intrauterine growth restriction. It also improves abdominal circumference growth velocity. A wide scale randomized trials are needed for evaluation of neonatal and long term morbidity and mortality outcomes of pregnancies treated by sildenafil citrate.

[Prediction of mortality in premature neonates. An updated systematic review]

INTRODUCTION

Extreme prematurity is associated with high mortality rates. The probability of death at different points in time is a priority for professionals and parents, and needs to be established on an individual basis. The aim of this study is to carry out a systematic review of predictive models of mortality in premature infants that have been published recently.

METHODS

A double search was performed for article published in PubMed on models predicting mortality in premature neonates. The population studied were premature neonates with a gestational age of ≤30 weeks and / or a weight at birth of ≤1500g. Works published with new models from June 2010 to July 2019 after a systematic review by Medlock (2011) were included. An assessment was made of the population, characteristics of the model, variables used, measurements of functioning, and validation.

RESULTS

Of the 7744 references (1st search) and 1435 (2nd search) found, 31 works were selected, with 8 new models finally being included. Five models (62.5%) were developed in North America and 2 (25%) in Europe. A sequential model (Ambalavanan) enables predictions of mortality to be made at birth, 7, 28 days of life, and 36 weeks post-menstrual. A multiple logistic regression analysis was performed on 87.5% of the models. The population discrimination was measured using Odds Ratio (75%) and the area under the curve (50%). "Internal Validation" had been carried out on 5 models. Three models can be accessed on-line. There are no predictive models validated in Spain.

CONCLUSIONS

The making of decisions based on predictive models can lead to the care given to the premature infant being more individualised and with a better use of resources. Predictive models of mortality in premature neonates in Spain need to be developed.

The heterogeneous causal effects of neonatal care: a model of endogenous demand for multiple treatment options based on geographical access to care

Neonatal units in the UK are organised into three levels, from highest Neonatal Intensive Care Unit (NICU), to Local Neonatal Unit (LNU) to lowest Special Care Unit (SCU). We model the endogenous treatment selection of neonatal care unit of birth to estimate the average and marginal treatment effects of different neonatal designations on infant mortality, length of stay and hospital costs. We use prognostic factors, survival and hospital care use data on all preterm births in England for 2014-2015, supplemented by national reimbursement tariffs and instrumental variables of travel time from a geographic information system. The data were consistent with a model of demand for preterm birth care driven by physical access. In-hospital mortality of infants born before 32 weeks was 8.5% overall, and 1.2 (95% CI: -0.7, 3.2) percentage points lower for live births in hospitals with NICU or SCU compared to those with an LNU according to instrumental variable estimates. We find imprecise differences in average total hospital costs by unit designation, with positive unobserved selection of those with higher unexplained absolute and incremental costs into NICU. Our results suggest a limited scope for improvement in infant mortality by increasing in-utero transfers based on unit designation alone.

Heparin therapy in placental insufficiency: Systematic review and meta-analysis

INTRODUCTION

The objective of this study was to establish whether heparin improves the neonatal outcome of fetuses with suspected placental insufficiency.

MATERIAL AND METHODS

Before data extraction, the project was registered in the PROSPERO International Prospective Register of Systematic Reviews (registration number: CRD42019117627). A systematic search was performed to identify relevant studies, using PubMed, SCOPUS, ISI Web of Knowledge, and PROSPERO database for meta-analysis. Suspected placental insufficiency was defined as either an estimated fetal weight or abdominal circumference below the 10th centile or when at least 2 of the following criteria were met: (1) abnormal biochemical markers, (2) sonographic evidence of abnormal placental morphology, or (3) abnormal uterine artery Doppler. Heparin in any commercial presentation was defined as the intervention. Mean difference (MD) by random effects model was used. Heterogeneity between studies was assessed using Cochran's Q, H, and I² statistics.

RESULTS

From 1159 assessed studies, two were retained for analysis. The results showed a significantly higher birthweight (MD 365; 95% CI 236 to 494; P < 0.001) and a significant increase of gestational age at birth by 1 week in those women treated with heparin (MD 0.806; 95% CI 0.354 to 1.258; P < 0.001). However, there were no significant differences in Apgar scores, neonatal admission, neonatal mortality, or composite neonatal morbidity.

CONCLUSIONS

In women with very high suspicion of placental insufficiency, heparin may increase fetal growth and prolong pregnancy. There is no evidence for a beneficial effect of heparin in reducing neonatal adverse outcomes.

Developing routinely recorded clinical data from electronic patient records as a national resource to improve neonatal health care: the Medicines for Neonates research programme

Background

Clinical data offer the potential to advance patient care. Neonatal specialised care is a high-cost NHS service received by approximately 80,000 newborn infants each year.

Objectives

(1) To develop the use of routinely recorded operational clinical data from electronic patient records (EPRs), secure national coverage, evaluate and improve the quality of clinical data, and develop their use as a national resource to improve neonatal health care and outcomes. To test the hypotheses that (2) clinical and research data are of comparable quality, (3) routine NHS clinical assessment at the age of 2 years reliably identifies children with neurodevelopmental impairment and (4) trial-based economic evaluations of neonatal interventions can be reliably conducted using clinical data. (5) To test methods to link NHS data sets and (6) to evaluate parent views of personal data in research.

Design

Six inter-related workstreams; quarterly extractions of predefined data from neonatal EPRs; and approvals from the National Research Ethics Service, Health Research Authority Confidentiality Advisory Group, Caldicott Guardians and lead neonatal clinicians of participating NHS trusts.

Setting

NHS neonatal units.

Participants

Neonatal clinical teams; parents of babies admitted to NHS neonatal units.

Interventions

In workstream 3, we employed the Bayley-III scales to evaluate neurodevelopmental status and the Quantitative Checklist of Autism in Toddlers (Q-CHAT) to evaluate social communication skills. In workstream 6, we recruited parents with previous experience of a child in neonatal care to assist in the design of a questionnaire directed at the parents of infants admitted to neonatal units.

Data sources

Data were extracted from the EPR of admissions to NHS neonatal units.

Main outcome measures

We created a National Neonatal Research Database (NNRD) containing a defined extract from real-time, point-of-care, clinician-entered EPRs from all NHS neonatal units in England, Wales and Scotland (n = 200), established a UK Neonatal Collaborative of all NHS trusts providing neonatal specialised care, and created a new NHS information standard: the Neonatal Data Set (ISB 1595) (see http://webarchive.nationalarchives.gov.uk/±/http://www.isb.nhs.uk/documents/isb-1595/amd-32–2012/index_html; accessed 25 June 2018).

Results

We found low discordance between clinical (NNRD) and research data for most important infant and maternal characteristics, and higher prevalence of clinical outcomes. Compared with research assessments, NHS clinical assessment at the age of 2 years has lower sensitivity but higher specificity for identifying children with neurodevelopmental impairment. Completeness and quality are higher for clinical than for administrative NHS data; linkage is feasible and substantially enhances data quality and scope. The majority of hospital resource inputs for economic evaluations of neonatal interventions can be extracted reliably from the NNRD. In general, there is strong parent support for sharing routine clinical data for research purposes.

Limitations

We were only able to include data from all English neonatal units from 2012 onwards and conduct only limited cross validation of NNRD data directly against data in paper case notes. We were unable to conduct qualitative analyses of parent perspectives. We were also only able to assess the utility of trial-based economic evaluations of neonatal interventions using a single trial. We suggest that results should be validated against other trials.

Conclusions

We show that it is possible to obtain research-standard data from neonatal EPRs, and achieve complete population coverage, but we highlight the importance of implementing systematic examination of NHS data quality and completeness and testing methods to improve these measures. Currently available EPR data do not enable ascertainment of neurodevelopmental outcomes reliably in very preterm infants. Measures to maintain high quality and completeness of clinical and administrative data are important health service goals. As parent support for sharing clinical data for research is underpinned by strong altruistic motivation, improving wider public understanding of benefits may enhance informed decision-making.

Future work

We aim to implement a new paradigm for newborn health care in which continuous incremental improvement is achieved efficiently and cost-effectively by close integration of evidence generation with clinical care through the use of high-quality EPR data. In future work, we aim to automate completeness and quality checks and make recording processes more ‘user friendly’ and constructed in ways that minimise the likelihood of missing or erroneous entries. The development of criteria that provide assurance that data conform to prespecified completeness and quality criteria would be an important development. The benefits of EPR data might be extended by testing their use in large pragmatic clinical trials. It would also be of value to develop methods to quality assure EPR data including involving parents, and link the NNRD to other health, social care and educational data sets to facilitate the acquisition of lifelong outcomes across multiple domains.

Study registration

This study is registered as PROSPERO CRD42015017439 (workstream 1) and PROSPERO CRD42012002168 (workstream 3).

Funding

The National Institute for Health Research Programme Grants for Applied Research programme (£1,641,471). Unrestricted donations were supplied by Abbott Laboratories (Maidenhead, UK: £35,000), Nutricia Research Foundation (Schiphol, the Netherlands: £15,000), GE Healthcare (Amersham, UK: £1000). A grant to support the use of routinely collected, standardised, electronic clinical data for audit, management and multidisciplinary feedback in neonatal medicine was received from the Department of Health and Social Care (£135,494).

Providing clarity around ethical discussion: development of a neonatal intervention score

AIM

To develop a Neonatal Intervention Score (NIS) to describe the clinical trajectory of a neonate throughout their neonatal intensive care unit (NICU) admission.

METHODS

The NIS was developed by modifying the Neonatal Therapeutic Intervention Scoring System (NTISS) to reflect illness severity, dependency on life-sustaining interventions and overall life trajectory on a longitudinal basis, rather than illness burden. Validity for longitudinal use within the NICU was tested by calculating the score for 99 preterm babies born less than 28 weeks at predetermined time points throughout their admission to tertiary level care at two institutions.

RESULTS

A total of 1333 NISs were analysed, ranging from 0 to 32.5 (mean 9.77, SD 5.4). Internal consistency (Cronbach alpha) reached 0.8. NIS moderately correlated to both SNAPPE-II and SNAP-II (Spearman's rho = 0.47, p =< 0.001) within the first 24 hours.

CONCLUSION

The NIS is a useful and reliable descriptive tool of relative illness severity and degree of medical interventions throughout a baby's admission. Integrating a longitudinal description of medical dependency of a patient may assist both clinical and ethical decision-making and empirical research by providing an objective account of a baby's clinical trajectory. Establishment of validity within individual institutions is required.

Birth-weight centiles and the risk of serious adverse neonatal outcomes at term

BACKGROUND

Birth-weight is an important determinant of perinatal outcome with low birth-weight being a particular risk factor for adverse consequences.

AIM

To investigate the impact of neonatal sex, mode of birth and gestational age at birth according to birth-weight centile on serious adverse neonatal outcomes in singleton term pregnancies.

MATERIALS AND METHODS

This was a retrospective cohort study of singleton term births at the Mater Mother's Hospital, Brisbane, Australia. Serious adverse neonatal outcome was defined as a composite of severe acidosis at birth (pH ≤7.0 and/or lactate ≥6 mmol/L and/or base excess ≤-12 mmol/L), Apgar <3 at 5 min, neonatal intensive-care unit admission and antepartum or neonatal death. The main exposure variable was birth-weight centile.

RESULTS

Of the 69,210 babies in our study, the overall proportion of serious adverse neonatal outcomes was 9.1% (6327/69,210). Overall, neonates in the <3rd birth-weight centile category had the highest adjusted odds ratio (OR) for serious adverse neonatal outcomes [OR 3.53, 95% confidence interval (CI) 3.06-4.07], whilst those in the ≥97th centile group also had elevated odds (OR 1.51, 95% CI 1.30-1.75). Regardless of birth modality, smaller babies in the <3rd centile group had the highest adjusted OR and predicted probability for serious adverse neonatal outcomes. When stratified by sex, male babies consistently demonstrated a higher predicted probability of serious adverse neonatal outcomes across all birth-weight centiles. The adjusted odds, when stratified by gestational age at birth, were the highest from 37+0 to 38+6 weeks in the <3rd centile group (OR 5.97, 95% CI 4.60-7.75).

CONCLUSIONS

Low and high birth-weights are risk factors for serious adverse neonatal outcomes. The adjusted OR appears to be greatest for babies in the <3rd birth-weight centile group, although an elevated risk was also found in babies within the ≥97th centile category.

Study protocol for a randomised controlled trial: treatment of early intrauterine growth restriction with low molecular weight heparin (TRACIP)

INTRODUCTION

The incidence of intrauterine growth restriction (IUGR) is estimated at about 3% of pregnancies, and it is associated with 30% of all perinatal mortality and severe morbidity with adverse neurodevelopmental and cardiovascular health consequences in adult life. Early onset IUGR represents 20%-30% of all cases and is highly associated with severe placental insufficiency. The existing evidence suggests that low molecular weight heparin (LMWH) has effects beyond its antithrombotic action, improving placental microvessel structure and function of pregnant women with vascular obstetric complications by normalising proangiogenic and antiapoptotic protein levels, cytokines and inflammatory factors. The objective of our study is to demonstrate the effectiveness of LMWH in prolonging gestation in pregnancies with early-onset IUGR.

METHODS AND ANALYSIS

This is a multicentre, triple-blind, parallel-arm randomised clinical trial. Singleton pregnancies qualifying for early (20-32 weeks at diagnosis) placental IUGR (according to Delphi criteria) will be randomised to subcutaneous treatment with bemiparin 3500 IU/0.2 mL/day or placebo from inclusion at diagnosis to the time of delivery. Analyses will be based on originally assigned groups (intention-to-treat). The primary objective will be analysed by comparing gestational age and prolongation of pregnancy (days) in each group with Student's t-tests for independent samples and by comparing Kaplan-Maier survival curves (from inclusion to delivery, log-rank test). A linear regression model for gestational age at birth will consider the following covariates: gestational age at inclusion (continuous) and pre-eclampsia (binary).

ETHICS AND DISSEMINATION

The study will be conducted in accordance with the principles of Good Clinical Practice. This study was approved by the Clinical Research Ethics Committee (CEIC) of Sant Joan de Déu Hospital, on 13 July 2017. The trial is registered in the public registry www.clinicaltrial.gov. according to Science Law 14/2011, and the results will be published in an open access journal.

TRIAL REGISTRATION NUMBER

NCT03324139; Pre-results.

SNAP-II for prediction of mortality and morbidity in extremely preterm infants

OBJECTIVE

To determine the specific Score of Neonatal Acute Physiology (SNAP-II) cut-off scores associated with outcomes in extremely preterm infants, and to examine its contribution to predictive models that include nonmodifiable birth predictors.

STUDY DESIGN

Retrospective observational study of 9240 infants born at 22-28 weeks' gestation and admitted to the Canadian Neonatal Network from 2010 to 2015. Outcomes included early and hospital mortality, composite of mortality/morbidity and individual morbidities. The SNAP-II cut-off to predict each outcome was determined using the Youden index. Additional contributions were evaluated using a base model that adjusted for gestational age, birth weight z-score and sex and by comparing the area under the curve (AUC).

RESULTS

The mortality/morbidity rate was 63% (5859/9240). Specific SNAP-II cut-offs ranged from 12 to 20 and were associated with each adverse outcome. Adding SNAP-II cut-offs to predictive models that included birth variables significantly improved (p < .05) the prediction of early mortality (AUC 0.84 versus 0.79), hospital mortality (AUC 0.80 versus 0.78), mortality/morbidity (AUC 0.76 versus 0.75), and severe neurological injury (AUC 0.69 versus 0.66) but had little or no effect on predictive models for retinopathy of prematurity, bronchopulmonary dysplasia, necrotizing enterocolitis, and nosocomial infection.

CONCLUSIONS

SNAP-II cut-offs were independently associated with each adverse outcome and using the proposed SNAP-II cut-offs improved the performance of predictive models for certain short-term outcomes.

Comparing very low birth weight versus very low gestation cohort methods for outcome analysis of high risk preterm infants

Background

Compared to very low gestational age (<32 weeks, VLGA) cohorts, very low birth weight (<1500 g; VLBW) cohorts are more prone to selection bias toward small-for-gestational age (SGA) infants, which may impact upon the validity of data for benchmarking purposes.

Method

Data from all VLGA or VLBW infants admitted in the 3 Networks between 2008 and 2011 were used. Two-thirds of each network cohort was randomly selected to develop prediction models for mortality and composite adverse outcome (CAO: mortality or cerebral injuries, chronic lung disease, severe retinopathy or necrotizing enterocolitis) and the remaining for internal validation. Areas under the ROC curves (AUC) of the models were compared.

Results

VLBW cohort (24,335 infants) had twice more SGA infants (20.4% vs. 9.3%) than the VLGA cohort (29,180 infants) and had a higher rate of CAO (36.5% vs. 32.6%). The two models had equal prediction power for mortality and CAO (AUC 0.83), and similarly for all other cross-cohort validations (AUC 0.81–0.85). Neither model performed well for the extremes of birth weight for gestation (<1500 g and ≥32 weeks, AUC 0.50–0.65; ≥1500 g and <32 weeks, AUC 0.60–0.62).

Conclusion

There was no difference in prediction power for adverse outcome between cohorting VLGA or VLBW despite substantial bias in SGA population. Either cohorting practises are suitable for international benchmarking.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0921-x) contains supplementary material, which is available to authorized users.

Assessment of sickness severity of illness in neonates: review of various neonatal illness scoring systems

Sickness severity scores are widely used for neonates admitted to neonatal intensive care units to predict severity of illness and risk of mortality and long-term outcome. These scores are also used frequently for quality assessment among various neonatal intensive care unit and hospital. Accurate and reliable measures of severity of illness are required for unbiased and reliable comparisons especially for benchmarking or comparative quality improvement care studies. These scores also serve to control for population differences when performing studies such as clinical trials, outcome evaluations, and evaluation of resource utilisation. Although presently there are multiple scores designed for neonates' sickness assessment but none of the score is ideal. Each score has its own advantages and disadvantages. We did literature search for identifying all neonatal sickness severity score and in this review article, we discuss these scores along with their merits and demerits.

Gestational age and birthweight for risk assessment of neurodevelopmental impairment or death in extremely preterm infants

BACKGROUND

The risk of poor outcomes in preterm infants is primarily determined by birthweight (BW) and gestational age (GA). It is not known whether BW is a better outcome predictor than GA.

OBJECTIVE

To test whether BW is better than GA (measured in days, rather than completed weeks) for prediction of neurodevelopmental impairment (NDI) and death.

DESIGN/METHODS

Extremely preterm infants born at the National Institute of Child Health and Human Development (NICHD) Neonatal Research Network centres between 1998 and 2009 were studied. For the unadjusted analysis, the associations of GA (in days based on best obstetrical estimate) and BW (in grams) with NDI or death were compared using area under the curve (AUC). Adjusted analyses were performed using birth year, sex, race, antenatal steroids, singleton birth, pre-eclampsia, Apgar score at 5 min and small for GA as covariates.

RESULTS

10 652 preterm infants (89%) had outcome data at 18-22 months' corrected age. The mean BW was 678 g (SD: 155) and the mean GA was 173 days (SD: 10) or 24^5/7 weeks (SD: 1^3/7). The AUC for NDI or death was 80% with BW and 79% with GA (p=0.82). Unadjusted and adjusted analyses did not differ. NDI or death rates decreased with increasing GA through 26 weeks (estimated risk reduction with each additional day of gestation: 2.2%).

CONCLUSION

Both BW in grams and GA in days are good predictors of NDI and death in a preterm population selected on the basis of reliable GA.

TRIAL REGISTRATION NUMBER

NCT00009633.

Early onset fetal growth restriction

Fetal growth restriction remains a challenging entity with significant variations in clinical practice around the world. The different etiopathogenesis of early and late fetal growth restriction with their distinct progression of fetal severity and outcomes, compounded by doctors and patient anxiety adds to the quandary involving its management. This review summarises the literature around diagnosing and monitoring early onset fetal growth restriction (early onset FGR) with special emphasis on optimal timing of delivery as guided by recent research advances.

An Algorithm for Predicting Neonatal Mortality in Threatened Very Preterm Birth

OBJECTIVE

To develop a prediction model for neonatal mortality using information readily available in the antenatal period.

METHODS

A multiple logistic regression model of a complete population-based geographically defined cohort of very preterm infants of 23+0 to 30+6 weeks' gestation was used to identify antenatal factors which were predictive of mortality in this population. Infants lt; 23 weeks and those with major anomalies were excluded.

RESULTS

Between 1996 and 2012, 1240 live born infants lt; 31 weeks' gestation were born to women residing in Nova Scotia. Decreasing gestational age strongly predicted an increased mortality rate. Other factors significantly contributing to increased mortality included classification as small for gestational age, oligohydramnios, maternal psychiatric disorders, antenatal antibiotic therapy, and monochorionic twins. Reduced neonatal mortality was associated with antenatal use of antihypertensive agents and use of corticosteroids of any duration of therapy given at least 24 hours before delivery. An algorithm was developed to estimate the risk of mortality without the need for a calculator.

CONCLUSION

Prediction of the probability of neonatal mortality is influenced by maternal and fetal factors. An algorithm to estimate the risk of mortality facilitates counselling and informs shared decision making regarding obstetric management.

Swiss medical centres vary significantly when it comes to outcomes of neonates with a very low gestational age

Aim

This study quantified the impact of perinatal predictors and medical centre on the outcome of very low‐gestational‐age neonates (VLGANs) born at <32 completed weeks in Switzerland.

Methods

Using prospectively collected data from a 10‐year cohort of VLGANs, we developed logistic regression models for three different time points: delivery, NICU admission and seven days of age. The data predicted survival to discharge without severe neonatal morbidity, such as major brain injury, moderate or severe bronchopulmonary dysplasia, retinopathy of prematurity (≥stage three) or necrotising enterocolitis (≥stage three).

Results

From 2002 to 2011, 6892 VLGANs were identified: 5854 (85%) of the live‐born infants survived and 84% of the survivors did not have severe neonatal complications. Predictors for adverse outcome at delivery and on NICU admission were low gestational age, low birthweight, male sex, multiple birth, birth defects and lack of antenatal corticosteroids. Proven sepsis was an additional risk factor on day seven of life. The medical centre remained a statistically significant factor at all three time points after adjusting for perinatal predictors.

Conclusion

After adjusting for perinatal factors, the survival of Swiss VLGANs without severe neonatal morbidity was strongly influenced by the medical centre that treated them.

[Below 26 gestational week prematurity: What support?]

Management and decision whether to begin intensive care for very preterm infants below 26 WG and at borderline viability remains controversial, and survival rates for these children vary greatly and justify discussion with regards to literature data and according to the experience of others countries. If active management is more difficult with very preterm infants 24-25 WG, mortality is increased comparing with newborns of more than 26 WG. This is partly explained by limitations of active neonatal intensive care. Nevertheless, neurocomportemental and cognitive results are not so unfavorable. This justifies a human, medical, and ethical multidiciplinary discussion including the parents' wishes for an active resuscitation or a palliative management. Using the only criteria of gestational age is not a reliable tool to predict survival and neurodevelopmental outcome of preterm infants. It is very important to identify other prenatal factors such prenatal corticosteroid administration, gender, fetal estimated weight, amniotic fluid and absent/reverse end diastolic flow umbilical doppler. Implication and listening the parents' preferences are essential after individual information, objective and a honest counseling including mortality, morbidity and risks of neurocomportmental impairments. Birth and counseling should be done in reference maternofetal center with obstetricians and neonatalogist specialized in this topic. A real difficulty is to consider the route of delivery and the possibility that caesarean section could improve survival rates. Induction of labour is very often a high risk of failure and route of delivery remains controversial and this is a real question in order to improve survival rates. Literature is poor and conflicting without randomized trials. Caesarean section presents maternal risks such as pathologic placentation, haemorrhage delivery and increasing risks for the subsequent gestation. So, if it is not a good idea to recommend a systematic caesarean delivery, it is not ethical to refuse this route of delivery only because of the gestational age even in extremely premature birth.

Nationwide Birth Weight and Gestational Age-specific Neonatal Mortality Rate in Taiwan

BACKGROUND

There are limited nationwide data relating to neonatal mortality rate in Taiwan. This study aims to provide updated national birth weight/gestational age-specific neonatal mortality reference rates.

METHODS

We abstracted the birth registration database from the Ministry of Interior in Taiwan from 1998 to 2002 and linked the data to the death registration database from the Ministry of Health and Welfare in Taiwan between 1998 and 2003. We included 1,331,785 infants born between 20 weeks and 44 weeks of gestation and weighing within the median ± 2 interquartile ranges in their age group in this study. We calculated the birth weight/gestational age-specific neonatal mortality rates of different genders by birth weight increments of 250 g and at gestational age intervals of 1 week. A Poisson regression model was used in modeling the mortality data.

RESULTS

A total of 4,169 deaths occurred within 28 days of life out of a total of 1,331,785 live births between 20 weeks and 44 weeks of gestation, giving a neonatal mortality rate (0-27 days) of 3.39 per 1000 live births for males and 2.80 per 1000 for females. The infant mortality rate remained higher in the male (5.91 per 1000) than the female (5.10 per 1000) population within the 1(st) year of life. Birth weight/gestational age-specific neonatal mortality rates were plotted with curves representing the 10(th) and 90(th) birth weight percentiles. The risk of an early neonatal death (0-6 days) does not exceed 50% except for female neonates < 500 g and ≤ 23 weeks, which implies that the limit of viability is now at 23 weeks for females.

CONCLUSION

We have provided an easy-to-use birth weight/gestational age-specific neonatal mortality rate chart as a reference document that physicians and parents can use to make decisions based on ethical considerations relating to whether to give palliative care or further invasive management. The normative data are crucial for public health policies on neonatal care in Taiwan.

Size at birth by gestational age and hospital mortality in very preterm infants: results of the area-based ACTION project

BACKGROUND

Size at birth is an important predictor of neonatal outcomes, but there are inconsistencies on the definitions and optimal cut-offs.

AIMS

The aim of this study is to compute birth size percentiles for Italian very preterm singleton infants and assess relationship with hospital mortality.

STUDY DESIGN

Prospective area-based cohort study.

SUBJECTS

All singleton Italian infants with gestational age 22-31 weeks admitted to neonatal care in 6 Italian regions (Friuli Venezia-Giulia, Lombardia, Marche, Tuscany, Lazio and Calabria) (n. 1605).

OUTCOME MEASURE

Hospital mortality.

METHODS

Anthropometric reference charts were derived, separately for males and females, using the lambda (λ) mu (μ) and sigma (σ) method (LMS). Logistic regression analysis was used to estimate mortality rates by gestational age and birth weight centile class, adjusting for sex, congenital anomalies and region.

RESULTS

At any gestational age, mortality decreased as birth weight centile increased, with lowest values observed between the 50th and the 89th centiles interval. Using the 75th-89th centile class as reference, adjusted mortality odds ratios were 7.94 (95% CI 4.18-15.08) below 10th centile; 3.04 (95% CI 1.63-5.65) between the 10th and 24th; 1.96 (95% CI 1.07-3.62) between the 25th and the 49th; 1.25 (95% CI 0.68-2.30) between the 50(h) and the 74th; and 2.07 (95% CI 1.01-4.25) at the 90th and above.

CONCLUSIONS

Compared to the reference, we found significantly increasing adjusted risk of death up to the 49th centile, challenging the usual 10th centile criterion as risk indicator. Continuous measures such as the birthweight z-score may be more appropriate to explore the relationship between growth retardation and adverse perinatal outcomes.

Auditing Neonatal Intensive Care: Is PREM a Good Alternative to CRIB for Mortality Risk Adjustment in Premature Infants?

BACKGROUND

Comparing outcomes at different neonatal intensive care units (NICUs) requires adjustment for intrinsic risk. The Clinical Risk Index for Babies (CRIB) is a widely used risk model, but it has been criticized for being affected by therapeutic decisions. The Prematurity Risk Evaluation Measure (PREM) is not supposed to be prone to treatment bias, but has not yet been validated.

OBJECTIVES

We aimed to validate the PREM, compare its accuracy to that of the original and modified versions of the CRIB and CRIB-II, and examine the congruence of risk categorization.

METHODS

Very-low-birth-weight (VLBW) infants with a gestational age (GA) <33 weeks, who were admitted to NICUs in Baden-Württemberg from 2003 to 2008, were identified from the German neonatal quality assurance program. CRIB, CRIB-II and PREM scores were calculated and modified. Omitting variables that directly reflected therapeutic decisions [the applied fraction of inspired oxygen (FiO2)] or that may have been prone to early-treatment bias (base excess and temperature), non-NICU-therapy-influenced scores were obtained. Score performance was assessed by the area under their ROC curve (AUC).

RESULTS

The CRIB showed the largest AUC (0.89), which dropped significantly (to 0.85) after omitting the FiO2. The PREM birth condition model, PREM(bcm) (AUC 0.86), and the PREM birth model, PREM(bm) (AUC 0.82), also demonstrated good discrimination. PREM(bm) was superior to other non-therapy-affected scores and to GA, particularly in infants with <750 g birth weight. Congruence of risk categorization was low, especially among higher-risk cases.

CONCLUSIONS

The CRIB score had the largest AUC, resulting from its inclusion of FiO2. PREM(bm), as the most accurate score among those unaffected by early treatment, seems to be a good alternative for strict risk adjustment in NICU auditing. It could be useful to combine scores.

ECLS for preemies: the artificial placenta

The high mortality and morbidity associated with respiratory failure among extremely low gestational age newborns (ELGANs) remains an unsolved problem. A logical strategy to avoid these complications would involve re-creating the intrauterine environment with extracorporeal membrane oxygenation (ECMO) instead of mechanical ventilation. Such a device, termed an artificial placenta, was first researched over 50 years ago. AP models vary, but all incorporate ECMO involving the umbilical vessels, lack of mechanical ventilation, and low partial pressure of oxygen to preserve fetal circulation. Current research has focused on low-volume pumpless arteriovenous circuits as well as pump-driven venovenous circuits.

Antenatal prediction of neonatal mortality in very premature infants

OBJECTIVE

To develop a prognostic model for antenatal prediction of neonatal mortality in infants threatening to be born very preterm (<32 weeks).

STUDY DESIGN

Nationwide cohort study in The Netherlands between 1999 and 2007. We studied 8500 singletons born between 25(+0) and 31(+6) weeks of gestation where fetus was alive at birth without congenital anomalies. We developed a multiple logistic regression model to estimate the risk of neonatal mortality within 28 days after birth, based on characteristics that are known before birth. We used bootstrapping techniques for internal validation. Discrimination (AUC), accuracy (Brier score) and calibration (graph, c-statistics) were used to assess the model's predictive performance.

RESULTS

Neonatal mortality occurred in 766 (90 per 1000) live births. The final model consisted of seven variables. Predictors were low gestational age, no antental corticosteroids, male gender, maternal age ≥35 years, Caucasian ethnicity, non-cephalic presentation and non-3rd level of hospital. The predicted probabilities ranged from 0.003 to 0.697 (IQR 0.02-0.11). The model had an AUC of 0.83, the Brier score was 0.065. The calibration graph showed good calibration, and the test for the Hosmer Lemeshow c-statistic showed no lack of fit (p=0.43).

CONCLUSIONS

Neonatal mortality can be predicted for very preterm births based on the antenatal factors gestational age, antental corticosteroids, fetal gender, maternal age, ethnicity, presentation and level of hospital. This model can be helpful in antenatal counseling.

Prediction of neonatal outcomes in extremely preterm neonates

OBJECTIVE

To develop and validate a statistical prediction model spanning the severity range of neonatal outcomes in infants born at ≤ 30 weeks' gestation.

METHODS

A national cohort of infants, born at 23 to 30 weeks' gestation and admitted to level III NICUs in Canada in 2010-2011, was identified from the Canadian Neonatal Network database. A multinomial logistic regression model was developed to predict survival without morbidities, mild morbidities, severe morbidities, or mortality, using maternal, obstetric, and infant characteristics available within the first day of NICU admission. Discrimination and calibration were assessed using a concordance C-statistic and the Cg goodness-of-fit test, respectively. Internal validation was performed using a bootstrap approach.

RESULTS

Of 6106 eligible infants, 2280 (37%) survived without morbidities, 1964 (32%) and 1251 (21%) survived with mild and severe morbidities, respectively, and 611 (10%) died. Predictors in the model were gestational age, small (<10th percentile) for gestational age, gender, Score for Neonatal Acute Physiology version II >20, outborn status, use of antenatal corticosteroids, and receipt of surfactant and mechanical ventilation on the first day of admission. High model discrimination was confirmed by internal bootstrap validation (bias-corrected C-statistic = 0.899, 95% confidence interval = 0.894-0.903). Predicted probabilities were consistent with the observed outcomes (Cg P value = .96).

CONCLUSIONS

Neonatal outcomes ranging from mortality to survival without morbidity in extremely preterm infants can be predicted on their first day in the NICU by using a multinomial model with good discrimination and calibration. The prediction model requires additional external validation.

Population-based estimates of in-unit survival for very preterm infants

BACKGROUND

Estimates of the probability of survival of very preterm infants admitted to NICU care are vital for counseling parents, informing care, and planning services. In 1999, easy-to-use charts of survival according to gestation, birth weight, and gender were published in the United Kingdom. These charts are widely used in clinical care and for benchmarking survival, and they form the core of the Clinical Risk Index for Babies II score. Since their publication, the survival of preterm infants has improved, and the charts therefore need updating.

METHODS

A logistic model was fitted with gestational age, birth weight, and gender. Nonlinear functions were estimated by using fractional polynomials. Bootstrap methods were used to assess the internal validity of the final model. The final model was assessed both overall and for subgroups of infants by using Farrington's statistic, the c-statistic, Cox regression coefficients, and the Brier score.

RESULTS

A total of 2995 white singleton infants born at 23(+0) to 32(+6) weeks' gestation in 2008 through 2010 were identified; 2751 (91.9%) infants survived to discharge. A prediction model was estimated and good model fit confirmed (area under receiver-operating characteristics curve = 0.86). Survival ranged from 27.7% (23 weeks) to 99.1% (32 weeks) for boys and from 34.5% (23 weeks) to 99.3% (32 weeks) for girls. Updated charts were produced showing estimated survival according to gestation, birth weight and gender, together with contour plots displaying points of equal survival.

CONCLUSIONS

These survival charts have been updated and will be of use to clinicians, parents, and managers.

Prediction of mortality in very premature infants: a systematic review of prediction models

Context

Being born very preterm is associated with elevated risk for neonatal mortality. The aim of this review is to give an overview of prediction models for mortality in very premature infants, assess their quality, identify important predictor variables, and provide recommendations for development of future models.

Methods

Studies were included which reported the predictive performance of a model for mortality in a very preterm or very low birth weight population, and classified as development, validation, or impact studies. For each development study, we recorded the population, variables, aim, predictive performance of the model, and the number of times each model had been validated. Reporting quality criteria and minimum methodological criteria were established and assessed for development studies.

Results

We identified 41 development studies and 18 validation studies. In addition to gestational age and birth weight, eight variables frequently predicted survival: being of average size for gestational age, female gender, non-white ethnicity, absence of serious congenital malformations, use of antenatal steroids, higher 5-minute Apgar score, normal temperature on admission, and better respiratory status. Twelve studies met our methodological criteria, three of which have been externally validated. Low reporting scores were seen in reporting of performance measures, internal and external validation, and handling of missing data.

Conclusions

Multivariate models can predict mortality better than birth weight or gestational age alone in very preterm infants. There are validated prediction models for classification and case-mix adjustment. Additional research is needed in validation and impact studies of existing models, and in prediction of mortality in the clinically important subgroup of infants where age and weight alone give only an equivocal prognosis.