Recommendations for data collection in cohort studies of preterm born individuals - The RECAP Preterm Core Dataset.

BACKGROUND: Preterm birth (before 37 completed weeks of gestation) is associated with an increased risk of adverse health and developmental outcomes relative to birth at term. Existing guidelines for data collection in cohort studies of individuals born preterm are either limited in scope, have not been developed using formal consensus methodology, or did not involve a range of stakeholders in their development. Recommendations meeting these criteria would facilitate data pooling and harmonisation across studies. OBJECTIVES: To develop a Core Dataset for use in longitudinal cohort studies of individuals born preterm. METHODS: This work was carried out as part of the RECAP Preterm project. A systematic review of variables included in existing core outcome sets was combined with a scoping exercise conducted with experts on preterm birth. The results were used to generate a draft core dataset. A modified Delphi process was implemented using two stages with three rounds each. Three stakeholder groups participated: RECAP Preterm project partners; external experts in the field; people with lived experience of preterm birth. The Delphi used a 9-point Likert scale. Higher values indicated greater importance for inclusion. Participants also suggested additional variables they considered important for inclusion which were voted on in later rounds. RESULTS: An initial list of 140 data items was generated. Ninety-six participants across 22 countries participated in the Delphi, of which 29% were individuals with lived experience of preterm birth. Consensus was reached on 160 data items covering Antenatal and Birth Information, Neonatal Care, Mortality, Administrative Information, Organisational Level Information, Socio-economic and Demographic information, Physical Health, Education and Learning, Neurodevelopmental Outcomes, Social, Lifestyle and Leisure, Healthcare Utilisation and Quality of Life. CONCLUSIONS: This core dataset includes 160 data items covering antenatal care through outcomes in adulthood. Its use will guide data collection in new studies and facilitate pooling and harmonisation of existing data internationally.

Methods for Constructing Normalised Reference Scores: An Application for Assessing Child Development at 24 Months of Age.

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.

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

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.

Differentiating the Preterm Phenotype: Distinct Profiles of Cognitive and Behavioral Development Following Late and Moderately Preterm Birth.

OBJECTIVES: To explore patterns of comorbidity in cognitive and behavioral outcomes at 2 years' corrected age among children born late or moderately preterm (LMPT) and to identify predictors of different patterns of comorbidity. STUDY DESIGN: Geographical, prospective population-based cohort study of 1139 infants born LMPT (320/7 to 366/7 weeks' gestation) and 1255 infants born at term (370/7 to 426/7 weeks' gestation). Parent questionnaires were obtained to identify impaired cognitive and language development, behavioral problems, delayed social-emotional competence, autistic features, and clinically significant eating difficulties at 24 months corrected age for 638 (57%) children born LMPT and 765 (62%) children born at term. RESULTS: Latent class analysis revealed 2 profiles of development among the term group: optimal (84%) and a profile of social, emotional, and behavioral impairments termed "nonoptimal" (16%). These 2 profiles were also identified among the LMPT group (optimal: 67%; nonoptimal: 26%). In the LMPT group, a third profile was identified (7%) that was similar to the phenotype previously identified in infants born very preterm. Nonwhite ethnicity, socioeconomic risk, and not receiving breast milk at hospital discharge were risk factors for nonoptimal outcomes in both groups. Male sex, greater gestational age, and pre-eclampsia were only associated with the preterm phenotype. CONCLUSIONS: Among children born LMPT with parent-reported cognitive or behavioral impairments, most had problems similar to the profile of difficulties observed in children born at term. A smaller proportion of children born LMPT had impairments consistent with the "very preterm phenotype" which are likely to have arisen through a preterm pathway. These results suggest that prematurity may affect development through several etiologic pathways in the late and moderately preterm population.

Infants born late/moderately preterm are at increased risk for a positive autism screen at 2 years of age.

OBJECTIVES: To assess the prevalence of positive screens using the Modified Checklist for Autism in Toddlers (M-CHAT) questionnaire and follow-up interview in late and moderately preterm (LMPT; 32-36 weeks) infants and term-born controls. STUDY DESIGN: Population-based prospective cohort study of 1130 LMPT and 1255 term-born infants. Parents completed the M-CHAT questionnaire at 2-years corrected age. Parents of infants with positive questionnaire screens were followed up with a telephone interview to clarify failed items. The M-CHAT questionnaire was re-scored, and infants were classified as true or false positives. Neurosensory, cognitive, and behavioral outcomes were assessed using parent report. RESULTS: Parents of 634 (57%) LMPT and 761 (62%) term-born infants completed the M-CHAT questionnaire. LMPT infants had significantly higher risk of a positive questionnaire screen compared with controls (14.5% vs 9.2%; relative risk [RR] 1.58; 95% CI 1.18, 2.11). After follow-up, significantly more LMPT infants than controls had a true positive screen (2.4% vs 0.5%; RR 4.52; 1.51, 13.56). This remained significant after excluding infants with neurosensory impairments (2.0% vs 0.5%; RR 3.67; 1.19, 11.3). CONCLUSIONS: LMPT infants are at significantly increased risk for positive autistic screen. An M-CHAT follow-up interview is essential as screening for autism spectrum disorders is especially confounded in preterm populations. Infants with false positive screens are at risk for cognitive and behavioral problems.

Modelling time to death or discharge in neonatal care: an application of competing risks.

BACKGROUND: Understanding length of stay for babies in neonatal care is vital for planning services and for counselling parents. While previous work has focused on the length of stay of babies who survive to discharge, when investigating resource use within neonatal care, it is important to also incorporate information on those babies who die while in care. We present an analysis using competing risks methodology which allows the simultaneous modelling of babies who die in neonatal care and those who survive to discharge. METHODS: Data were obtained on 2723 babies born at 24-28 weeks gestational age in 2006-10 and admitted to neonatal care. Death and discharge alive are two mutually exclusive events and can be treated as competing risks. A flexible parametric modelling approach was used to analyse these two competing events and obtain estimates of the absolute probabilities of death or discharge. RESULTS: The absolute probabilities of death or discharge are presented in graphical form showing the cause-specific cumulative incidence over time by gender, gestational age and birthweight. The discharge of babies alive generally occurred over a longer time period for babies of lower gestational age and smaller birthweight than for bigger babies. CONCLUSION: This study has presented a useful statistical method for modelling the length of stay where there are significant rates of in-unit mortality. In health care systems that are increasingly focusing on costs and resource planning, it is essential to consider not only length of stay of survivors but also for those patients who die before discharge.

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

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.

The probability of being identified as an outlier with commonly used funnel plot control limits for the standardised mortality ratio.

BACKGROUND: Emphasis is increasingly being placed on the monitoring of clinical outcomes for health care providers. Funnel plots have become an increasingly popular graphical methodology used to identify potential outliers. It is assumed that a provider only displaying expected random variation (i.e. 'in-control') will fall outside a control limit with a known probability. In reality, the discrete count nature of these data, and the differing methods, can lead to true probabilities quite different from the nominal value. This paper investigates the true probability of an 'in control' provider falling outside control limits for the Standardised Mortality Ratio (SMR). METHODS: The true probabilities of an 'in control' provider falling outside control limits for the SMR were calculated and compared for three commonly used limits: Wald confidence interval; 'exact' confidence interval; probability-based prediction interval. RESULTS: The probability of falling above the upper limit, or below the lower limit, often varied greatly from the nominal value. This was particularly apparent when there were a small number of expected events: for expected events ≤ 50 the median probability of an 'in-control' provider falling above the upper 95% limit was 0.0301 (Wald), 0.0121 ('exact'), 0.0201 (prediction). CONCLUSIONS: It is important to understand the properties and probability of being identified as an outlier by each of these different methods to aid the correct identification of poorly performing health care providers. The limits obtained using probability-based prediction limits have the most intuitive interpretation and their properties can be defined a priori. Funnel plot control limits for the SMR should not be based on confidence intervals.

Etiology of overactive bladder: a diet and lifestyle model for diabetes and obesity in older women.

OBJECTIVE: To evaluate a coherent, evidence-based hypothesis that specific modifiable lifestyle factors implicated in the development of diabetes and associated obesity are related to the onset of OAB. METHODS: A hypothetical causative model for OAB involving modifiable lifestyle factors implicated in the development of diabetes and obesity was constructed, based on a systematic literature review. Secondary analysis of data was undertaken in a prospective cohort of women aged 40 and over, living in Leicestershire, UK. Subjects included 3,411 women free from OAB at baseline and 277 incident cases of OAB. Reported diet, lifestyle, morbid, and social factors were measured at baseline and incident cases at 1-year follow-up. Graphical chain modeling was used to estimate the associations between variables and identify likely pathways involved. RESULTS: All hypothesized lifestyle factors (physical activity, high glycemic index, and high energy intake) plus diabetes and obesity were retained within the graph as potential contributors. However, low physical activity was the only direct risk factor linked prospectively to the onset of OAB (RR 2.47; 95% CI 1.82, 3.36), in addition to older age. CONCLUSIONS: Poor lifestyle factors causally linked to diabetes and obesity may contribute to the onset of OAB; low physical activity appears to be an important modifiable causal factor for OAB operating directly as well as indirectly via pathways involving obesity or diabetes. Further research is needed to demonstrate a causal link between lifestyle and OAB.

Understanding ethnic inequalities in stillbirth rates: a UK population-based cohort study.

OBJECTIVES: To investigate inequalities in stillbirth rates by ethnicity to facilitate development of initiatives to target those at highest risk. DESIGN: Population-based perinatal mortality surveillance linked to national birth and death registration (Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries across the UK). SETTING: UK. PARTICIPANTS: 4 391 569 singleton births at ≥24+0 weeks gestation between 2014 and 2019. MAIN OUTCOME MEASURES: Stillbirth rate difference per 1000 total births by ethnicity. RESULTS: Adjusted absolute differences in stillbirth rates were higher for babies of black African (3.83, 95% CI 3.35 to 4.32), black Caribbean (3.60, 95% CI 2.65 to 4.55) and Pakistani (2.99, 95% CI 2.58 to 3.40) ethnicities compared with white ethnicities. Higher proportions of babies of Bangladeshi (42%), black African (39%), other black (39%) and black Caribbean (37%) ethnicities were from most deprived areas, which were associated with an additional risk of 1.50 stillbirths per 1000 births (95% CI 1.32 to 1.67). Exploring primary cause of death, higher stillbirth rates due to congenital anomalies were observed in babies of Pakistani, Bangladeshi and black African ethnicities (range 0.63-1.05 per 1000 births) and more placental causes in black ethnicities (range 1.97 to 2.24 per 1000 births). For the whole population, over 40% of stillbirths were of unknown cause; however, this was particularly high for babies of other Asian (60%), Bangladeshi (58%) and Indian (52%) ethnicities. CONCLUSIONS: Stillbirth rates declined in the UK, but substantial excess risk of stillbirth persists among babies of black and Asian ethnicities. The combined disadvantage for black, Pakistani and Bangladeshi ethnicities who are more likely to live in most deprived areas is associated with considerably higher rates. Key causes of death were congenital anomalies and placental causes. Improved strategies for investigation of stillbirth causes are needed to reduce unexplained deaths so that interventions can be targeted to reduce stillbirths.

EPICE cohort: two-year neurodevelopmental outcomes after very preterm birth.

OBJECTIVE: To determine whether the variation in neurodevelopmental disability rates between populations persists after adjustment for demographic, maternal and infant characteristics for an international very preterm (VPT) birth cohort using a standardised approach to neurodevelopmental assessment at 2 years of age. DESIGN: Prospective standardised cohort study. SETTING: 15 regions in 10 European countries. PATIENTS: VPT births: 22+0-31+6 weeks of gestation. DATA COLLECTION: Standardised data collection tools relating to pregnancy, birth and neonatal care and developmental outcomes at 2 years corrected age using a validated parent completed questionnaire. MAIN OUTCOME MEASURES: Crude and standardised prevalence ratios calculated to compare rates of moderate to severe neurodevelopmental impairment between regions grouped by country using fixed effects models. RESULTS: Parent reported rates of moderate or severe neurodevelopmental impairment for the cohort were: 17.3% (ranging 10.2%-26.1% between regions grouped by country) with crude standardised prevalence ratios ranging from 0.60 to 1.53. Adjustment for population, maternal and infant factors resulted in a small reduction in the overall variation (ranging from 0.65 to 1.30). CONCLUSION: There is wide variation in the rates of moderate to severe neurodevelopmental impairment for VPT cohorts across Europe, much of which persists following adjustment for known population, maternal and infant factors. Further work is needed to investigate whether other factors including quality of care and evidence-based practice have an effect on neurodevelopmental outcomes for these children.

Interventions in the management of serum lipids for preventing stroke recurrence.

BACKGROUND: Studies have shown that interventions which reduce total and low-density lipoprotein cholesterol levels also reduce coronary heart disease (CHD) and stroke events in those with a history of CHD. However, it is uncertain whether treatment to alter cholesterol levels can prevent recurrence of either stroke or subsequent cardiovascular events and whether differences in outcomes exist between classes of lipid-lowering therapy. This is an update of a Cochrane review first published in 2002. OBJECTIVES: To investigate the effect of altering serum lipids pharmacologically for preventing subsequent cardiovascular disease and stroke recurrence in patients with a history of stroke. SEARCH STRATEGY: We searched the Cochrane Stroke Group Trials Register (last searched December 2008), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2008), MEDLINE (1966 to December 2008) and EMBASE (1980 to December 2008). We contacted pharmaceutical companies known to produce a lipid-lowering agent for information on relevant publications or unpublished work. SELECTION CRITERIA: Unconfounded randomised trials of participants aged 18 years and over with a history of stroke or transient ischaemic attack (TIA). DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials, assessed quality and extracted data. MAIN RESULTS: We included eight studies involving approximately 10,000 participants. The active interventions were pravastatin, atorvastatin, simvastatin, clofibrate, and conjugated oestrogen. Fixed-effect analysis showed no overall effect on stroke recurrence but statin therapy alone had a marginal benefit in reducing subsequent cerebrovascular events in those with a previous history of stroke or TIA (odds ratio (OR) 0.88, 95% confidence interval (CI) 0.77 to 1.00). There was no evidence that such intervention reduced all-cause mortality or sudden death (OR 1.00, 95% CI 0.83 to 1.20). Three statin trials showed a reduction in subsequent serious vascular events (OR 0.74, 95% CI 0.67 to 0.82). AUTHORS' CONCLUSIONS: There is evidence that statin therapy in patients with a history of ischaemic stroke or TIA significantly reduces subsequent major coronary events but only marginally reduces the risk of stroke recurrence. There is no clear evidence of beneficial effect from statins in those with previous haemorrhagic stroke and it is unclear whether statins should be started immediately post stroke or later. In view of this and the evidence of the benefit of statin therapy in those with a history of CHD, patients with ischaemic stroke or TIA, with or without a history of established CHD, should receive statins.

Estimating neonatal length of stay for babies born very preterm.

OBJECTIVE: To predict length of stay in neonatal care for all admissions of very preterm singleton babies. SETTING: All neonatal units in England. PATIENTS: Singleton babies born at 24-31 weeks gestational age from 2011 to 2014. Data were extracted from the National Neonatal Research Database. METHODS: Competing risks methods were used to investigate the competing outcomes of death in neonatal care or discharge from the neonatal unit. The occurrence of one event prevents the other from occurring. This approach can be used to estimate the percentage of babies alive, or who have been discharged, over time. RESULTS: A total of 20 571 very preterm babies were included. In the competing risks model, gestational age was adjusted for as a time-varying covariate, allowing the difference between weeks of gestational age to vary over time. The predicted percentage of death or discharge from the neonatal unit were estimated and presented graphically by week of gestational age. From these percentages, estimates of length of stay are provided as the number of days following birth and corrected gestational age at discharge. CONCLUSIONS: These results can be used in the counselling of parents about length of stay and the risk of mortality.

Standardisation of the Parent Report of Children's Abilities-Revised (PARCA-R): a norm-referenced assessment of cognitive and language development at age 2 years.

BACKGROUND: The Parent Report of Children's Abilities-Revised (PARCA-R) can be used to identify preterm born children at risk for developmental delay at age 24 months. However, standardised scores for assessing all children in the general population and quantifying development relative to the norm are unavailable, thus limiting the use of the questionnaire. We aimed to develop scores that are standardised by age and sex for the PARCA-R to assess children's cognitive and language development at age 24-27 months. METHODS: Anonymised data from PARCA-R questionnaires that were completed by parents of 2-year-old children in three previous studies were obtained to form a standardisation sample that was representative of the UK general population. Anonymised data were obtained from three further studies to assess the external validity and clinical validity of the standardised scores. We used the lambda-mu-sigma (lambda for skewness, mu for median, sigma for the coefficient of variation) method to develop scores that are standardised by age and sex for three scales (non-verbal cognitive development, language development, and total parent report composite [PRC]) for children in four 1-month age bands, spanning age 23·5-27·5 months. FINDINGS: We included 6402 children (mean age 25 months and 1 day [range 23 months and 16 days to 27 months and 15 days]) in the standardisation sample and 709 (mean age 24 months and 19 days [23 months and 16 days to 27 months and 15 days]) to test the external validity and 1456 (mean age 24 months and 8·5 days [23 months and 16 days to 27 months and 15 days]) to test the clinical validity of the standardised scores. For all PARCA-R scales, mean standardised scores approximated 100 (SD 15) in both sexes and all age groups. These scores were independent of socioeconomic status. Standardised scores were close to 100 (15) in the external validation sample, showing the validity of the scores. Standardised scores for the total PRC scale for children born very preterm (<32 weeks' gestation) were 0·47 SD lower on average than the normative mean, and for children with neonatal sepsis were 0·73 SD lower on average than the normative mean. These scores were equivalent to a standardised score of 93 (95% CI 91-94) for children born very preterm and 89 (88-91) for children with neonatal sepsis, thus showing clinical validity. INTERPRETATION: The PARCA-R provides a norm-referenced, standardised assessment of cognitive and language development at 24-27 months of age. The questionnaire is available non-commercially in English with translations available in 14 other languages, thus providing clinicians and researchers with a cost-effective tool for assessing development and identifying children with delay. FUNDING: Action Medical Research (Ref: GN2580).

Assessing the deprivation gap in stillbirths and neonatal deaths by cause of death: a national population-based study.

OBJECTIVE: To investigate socioeconomic inequalities in cause-specific stillbirth and neonatal mortality to identify key areas of focus for future intervention strategies to achieve government ambitions to reduce mortality rates. DESIGN: Retrospective cohort study. SETTING: England, Wales, Scotland and the UK Crown Dependencies. PARTICIPANTS: All singleton births between 1 January 2014 and 31 December 2015 at ≥24 weeks' gestation. MAIN OUTCOME MEASURE: Cause-specific stillbirth or neonatal death (0-27 days after birth) per 10 000 births by deprivation quintile. RESULTS: Data on 5694 stillbirths (38.1 per 10 000 total births) and 2368 neonatal deaths (15.9 per 10 000 live births) were obtained from Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries across the UK (MBRRACE-UK). Women from the most deprived areas were 1.68 (95% CI 1.56 to 1.81) times more likely to experience a stillbirth and 1.67 (95% CI 1.48 to 1.87) times more likely to experience a neonatal death than those from the least deprived areas, equating to an excess of 690 stillbirths and 231 neonatal deaths per year associated with deprivation. Small for gestational age (SGA) unexplained antepartum stillbirth was the greatest contributor to excess stillbirths accounting for 33% of the deprivation gap in stillbirths. Congenital anomalies accounted for the majority (59%) of the deprivation gap in neonatal deaths, followed by preterm birth not SGA (24-27 weeks, 27%). CONCLUSIONS: Cause-specific mortality rates at a national level allow identification of key areas of focus for future intervention strategies to reduce mortality. Despite a reduction in the deprivation gap for stillbirths and neonatal deaths, public health interventions should primarily focus on socioeconomic determinants of SGA stillbirth and congenital anomalies.

Wide variation in severe neonatal morbidity among very preterm infants in European regions.

OBJECTIVE: To investigate the variation in severe neonatal morbidity among very preterm (VPT) infants across European regions and whether morbidity rates are higher in regions with low compared with high mortality rates. DESIGN: Area-based cohort study of all births before 32 weeks of gestational age. SETTING: 16 regions in 11 European countries in 2011/2012. PATIENTS: Survivors to discharge from neonatal care (n=6422). MAIN OUTCOME MEASURES: Severe neonatal morbidity was defined as intraventricular haemorrhage grades III and IV, cystic periventricular leukomalacia, surgical necrotizing enterocolitis and retinopathy of prematurity grades ≥3. A secondary outcome included severe bronchopulmonary dysplasia (BPD), data available in 14 regions. Common definitions for neonatal morbidities were established before data abstraction from medical records. Regional severe neonatal morbidity rates were correlated with regional in-hospital mortality rates for live births after adjustment on maternal and neonatal characteristics. RESULTS: 10.6% of survivors had a severe neonatal morbidity without severe BPD (regional range 6.4%-23.5%) and 13.8% including severe BPD (regional range 10.0%-23.5%). Adjusted inhospital mortality was 13.7% (regional range 8.4%-18.8%). Differences between regions remained significant after consideration of maternal and neonatal characteristics (P<0.001) and severe neonatal morbidity rates were not correlated with mortality rates (P=0.50). CONCLUSION: Severe neonatal morbidity rates for VPT survivors varied widely across European regions and were independent of mortality rates.

Efficacy of prone ventilation in adult patients with acute respiratory failure: a meta-analysis.

PURPOSE: The use of prone ventilation in acute respiratory failure has been investigated by several randomized controlled trials in the recent past. To date, there has been no systematic review or meta-analysis of these trials. MATERIAL AND METHODS: Systematic literature search was performed between 1966 and July 2006 to identify randomized trials evaluating prone ventilation. Outcome measures included mortality, changes in oxygenation, incidence of pneumonia, duration of mechanical ventilation, intensive care unit (ICU) and hospital stay, cost-effectiveness, and adverse effects including pressure sores, endotracheal tube, or intravascular catheter complications. RESULTS: Prone ventilation was not associated with reduction in mortality, but improvement in oxygenation was statistically significant (mean difference, 21.2 mm Hg; P < .001). There was no significant difference in incidence of pneumonia, ICU stay, and endotracheal tube complications. There was a trend toward an increased incidence of pressure sores in prone ventilated patients (odds ratio = 1.95; 95% confidence interval, 0.09-4.15; P = .08). The data on other outcomes were not suitable for meta-analysis. CONCLUSIONS: The use of prone ventilation is associated with improved oxygenation. It is not associated with a reduction in mortality, pneumonia, or ICU stay and may be associated with an increased incidence of pressure sores.

Outcome after neonatal continuous negative-pressure ventilation: follow-up assessment.

BACKGROUND: A previous randomised trial of continuous negative extrathoracic pressure (CNEP) versus standard treatment for newborn infants with respiratory distress syndrome raised public concerns about mortality and neonatal morbidity. We studied the outcome in late childhood of children entered into the trial to establish whether there were long-term sequelae attributable to either mode of ventilation. METHODS: Outpatient assessment of neurological outcome, cognitive function, and disability was done by a paediatrician and a psychologist using standardised tests. 133 of 205 survivors from the original trial were assessed at 9-15 years of age. Of the original pairs randomly assigned to each ventilation mode, the results from 65 complete pairs were available. The primary outcome was death or severe disability. FINDINGS: Primary outcome was equally distributed between groups (odds ratio for the CNEP group 1.0; 95% CI 0.41-2.41). In unpaired analysis there was no significant difference between treatment modalities (1.05; 0.54-2.06). Full IQ did not differ significantly between the groups, but mean performance IQ was 6.8 points higher in the CNEP group than in the conventional-treatment group (95% CI 1.5-12.1). Results of neuropsychological testing were consistent with this finding, with scores on language production and visuospatial skills being significantly higher in the CNEP group. INTERPRETATION: We saw no evidence of poorer long-term outcome after neonatal CNEP whether analysis was by original pairing or by unpaired comparisons, despite small differences in adverse neonatal outcomes. The experience of our study indicates that future studies of neonatal interventions with the potential to influence later morbidity should be designed with longer-term outcomes in mind.

Deprivation and infection among spontaneous very preterm births.

OBJECTIVE: To explore the relationship between infection and socioeconomic deprivation among mothers of spontaneous very preterm infants to contribute to the understanding of the deprivation gap in the incidence of very preterm birth. METHODS: We used comprehensive data from a large retrospective study of very preterm birth in a U. K. health region (representing approximately 1 in 12 U.K. births) between 1994 and 2005. We report the relationship between fetal or maternal infection before birth and deprivation quintile of all singleton live births at 22 0/7 to 32 6/7 weeks of gestation associated with spontaneous onset of labor. RESULTS: Overall, 24% of the 4,987 spontaneous very preterm singleton births had recorded evidence of maternal or fetal infection. Rates of infection increased significantly with increasing deprivation. Spontaneous very preterm births to mothers from the most deprived quintile were at 43% increased odds of being associated with infection compared with those from the least deprived quintile (odds ratio 1.43, 95% confidence interval 1.13-1.80) after adjusting for gestation, year of birth, and mother's age. CONCLUSION: Spontaneous very preterm births to mothers from more deprived areas are more likely to be associated with infection before birth. LEVEL OF EVIDENCE: II.

Impact of service changes on neonatal transfer patterns over 10 years.

INTRODUCTION: Many changes have been made to the staffing and organisation of neonatal care in the UK in the past 10 years. This study assessed the extent to which these changes had affected the transfer of babies between different parts of the service. METHODS: Data from the Trent Neonatal Survey, an ongoing study of neonatal intensive care activity in the former Trent Health Region of the UK, were used to evaluate neonatal inter-hospital transfers over a 10-year period, from 1 January 1995 to 31 December 2004. The number of transfers and the types of transfer were analysed and trends in gestation and disease severity over the study period were assessed. Rates of "inappropriate transfer" were also identified. RESULTS: 8105 babies were transferred over the period; 2294 babies underwent urgent postnatal transfer and this equates to approximately two such transfers every three days. The maximum number of journeys by any one baby was eight. Intensive care activity rose during the 10 years but the number of inappropriate transfers remained persistently high. CONCLUSIONS: Organisational changes in neonatal care during the 10-year period have been insufficient to deal with the rising demand, as reflected by the persistently high rate of inappropriate transfers.