Survival and place of delivery following preterm birth: 1994-96

Variation in hospital mortality in an Australian neonatal intensive care unit network

BACKGROUND

Studying centre-to-centre (CTC) variation in mortality rates is important because inferences about quality of care can be made permitting changes in practice to improve outcomes. However, comparisons between hospitals can be misleading unless there is adjustment for population characteristics and severity of illness.

OBJECTIVE

We sought to report the risk-adjusted CTC variation in mortality among preterm infants born <32 weeks and admitted to all eight tertiary neonatal intensive care units (NICUs) in the New South Wales and the Australian Capital Territory Neonatal Network (NICUS), Australia.

METHODS

We analysed routinely collected prospective data for births between 2007 and 2014. Adjusted mortality rates for each NICU were produced using a multiple logistic regression model. Output from this model was used to construct funnel plots.

RESULTS

A total of 7212 live born infants <32 weeks gestation were admitted consecutively to network NICUs during the study period. NICUs differed in their patient populations and severity of illness.The overall unadjusted hospital mortality rate for the network was 7.9% (n=572 deaths). This varied from 5.3% in hospital E to 10.4% in hospital C. Adjusted mortality rates showed little CTC variation. No hospital reached the +99.8% control limit level on adjusted funnel plots.

CONCLUSION

Characteristics of infants admitted to NICUs differ, and comparing unadjusted mortality rates should be avoided. Logistic regression-derived risk-adjusted mortality rates plotted on funnel plots provide a powerful visual graphical tool for presenting quality performance data. CTC variation is readily identified, permitting hospitals to appraise their practices and start timely intervention.

Labor and delivery nurse staffing as a cost-effective safety intervention

Numerous studies have identified a relationship between staffing levels and nurse-sensitive outcomes for medical and surgical patients, but little has been published on the impact of nurse-sensitive outcomes for the childbearing family and even less that examines the relationship of intrapartum staffing on adverse perinatal outcomes. Using a derivation of Donabedian's classic structure, process, and outcomes framework, a model is proposed, which would allow obstetrical primary care providers and administrators alike the opportunity to examine the influence of nurse staffing on adverse obstetrical events, including unanticipated cesarean birth in low-risk women or newborn intensive care unit admissions. It is recognized that hospitals carry a significant burden in the prevention of adverse outcomes that range from nurse staffing levels to the internal process and infrastructure of the hospital setting. Patient outcomes are a direct result not only of the patient's health status and characteristics (eg, socioeconomic position and ethnicity), but also of interactions with the healthcare delivery system. As such, the opportunity to examine hospital characteristics (structure and processes) that may be detrimental to safe patient outcomes is of paramount importance in providing optimal outcomes for childbearing women and their families.

Ethnic variations in the incidence and outcome of severe retinopathy of prematurity

BACKGROUND

The aim of this study was to assess the incidence and outcome of severe retinopathy of prematurity (ROP) among different ethnic groups in a geographically defined population in the U.K. Severe ROP was defined as any stage 3 or worse disease.

METHODS

This was a retrospective study of children born over a 6-year period with a birth weight of 1250 g or less. Threshold ROP was treated with diode laser.

RESULTS

Severe disease developed in 37 out of 355 neonates (10.4%) who underwent ROP screening. The difference in the incidence of severe ROP between infants of Caucasian and South Asian ethnic origin was not statistically significant: 10.2% vs. 10.8% (odds ratio = 1.06; 95% confidence interval: 0.44 to 2.57). This conclusion held after single-variable adjustment for birth weight, gestational age, and score on the Clinical Risk Index for Babies. The incidence of threshold ROP was 3% among infants of both Caucasian and South Asian ethnic origin. There was no significant difference in terms of visual outcome between the Caucasian and South Asian infants.

INTERPRETATION

This study showed no statistical evidence for a difference in the incidence or outcome of severe ROP among infants of South Asian ethnic origin compared with those of Caucasian origin. Although the small numbers in our study mean that a clinically important difference cannot be excluded, it is very unlikely that the 5-fold higher incidence in Asian babies described in the literature is correct for the population from which our subjects were drawn.

Characteristics of neonatal units that care for very preterm infants in Europe: results from the MOSAIC study

OBJECTIVES

We sought to compare guidelines for level III units in 10 European regions and analyze the characteristics of neonatal units that care for very preterm infants.

METHODS

The MOSAIC (Models of Organising Access to Intensive Care for Very Preterm Births) project combined a prospective cohort study on all births between 22 and 31 completed weeks of gestation in 10 European regions and a survey of neonatal unit characteristics. Units that admitted > or = 5 infants at < 32 weeks of gestation were included in the analysis (N = 111). Place of hospitalization of infants who were admitted to neonatal care was analyzed by using the cohort data (N = 4947). National or regional guidelines for level III units were reviewed.

RESULTS

Six of 9 guidelines for level III units included minimum size criteria, based on number of intensive care beds (6 guidelines), neonatal admissions (2), ventilated patients (1), obstetric intensive care beds (1), and deliveries (2). The characteristics of level III units varied, and many were small or unspecialized by recommended criteria: 36% had fewer than 50 very preterm annual admissions, 22% ventilated fewer than 50 infants annually, and 28% had fewer than 6 intensive care beds. Level II units were less specialized, but some provided mechanical ventilation (57%) or high-frequency ventilation (20%) or had neonatal surgery facilities (17%). Sixty-nine percent of level III and 36% of level I or II units had continuous medical coverage by a qualified pediatrician. Twenty-two percent of infants who were < 28 weeks of gestation were treated in units that admitted fewer than 50 very preterm infants annually (range: 2%-54% across the study regions).

CONCLUSIONS

No consensus exists in Europe about size or other criteria for NICUs. A better understanding of the characteristics associated with high-quality neonatal care is needed, given the high proportion of very preterm infants who are cared for in units that are considered small or less specialized by many recommendations.

Mortality patterns among very preterm babies: a comparative analysis of two European regions in France and England

OBJECTIVE

To explore the differences in outcome of very preterm pregnancies between two geographically defined populations in Europe with similar socioeconomic characteristics and healthcare provision but different organisational arrangements for perinatal care.

DESIGN

Prospective cohort study.

SETTING

Nord Pas-de-Calais (NPC), France, and Trent, UK.

PARTICIPANTS

All pregnancy outcomes 22(+0) to 32(+6) weeks' gestational age for resident mothers.

OUTCOME MEASURES

Mortality patterns (antepartum death, intrapartum death, labour ward death and neonatal unit death) among very preterm babies were analysed by region. Multinomial logistic regression was used to model regional differences for a variety of pregnancy outcomes and to adjust for regional differences in the organisation of perinatal care.

RESULTS

Delivery of very preterm infants was significantly higher in Trent compared with NPC (1.9% v 1.5% of all births, respectively (p<0.001)). Stillbirth rate was significantly higher in NPC than in Trent (23.0%, 95% CI 20.0% to 26.5% v 14.4%, 95% CI 12.3% to 16.6%, respectively (p<0.001)) and survival to discharge was higher in Trent than in NPC (74.6%, 95% CI 71.9% to 77.1% v 66.7%, 95% CI 63.3% to 69.9%, respectively (p<0.001)). Probability of intrapartum and labour ward death in NPC was more than five times higher than Trent (relative risk 5.3, 95% CI 2.2 to 13.1 (p<0.001)).

CONCLUSION

The high rate of very preterm deliveries and the larger proportion of these infants recorded as live born in Trent appear to be the cause of the excess neonatal mortality seen in the routine statistics. Information about very preterm babies (not usually included in routine statistics) is vital to avoid inappropriate interpretation of international perinatal and infant data. This study highlights the importance of including deaths before transfer to neonatal care and emphasises the need to include the outcome of all pregnancies in a population in any comparative analysis.

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.

Nurse staffing in relation to risk-adjusted mortality in neonatal care

OBJECTIVE

To assess whether risk-adjusted mortality in very low birthweight or preterm infants is associated with levels of nursing provision.

DESIGN

Prospective study of risk-adjusted mortality in infants admitted to a random sample of neonatal units.

SETTING

Fifty four UK neonatal intensive care units stratified by: patient volume; consultant availability; nurse:cot ratios.

PATIENTS

A group of 2585 very low birthweight (birthweight <1500 g) or preterm (<31 weeks gestation) infants.

MAIN OUTCOME MEASURE

Death before discharge or planned deaths at home, excluding lethal malformations, after adjusting for initial risk 12 hours after birth using gestation at birth and measures of illness severity in relation to nursing provision calculated for each baby's neonatal unit stay.

RESULTS

A total of 57% of nursing shifts were understaffed, with greater shortages at weekends. Risk-adjusted mortality was inversely related to the provision of nurses with specialist neonatal qualifications (OR 0.67; 95% CI 0.42 to 0.97). Increasing the ratio of nurses with neonatal qualifications to intensive care and high dependency infants to 1:1 was associated with a decrease in risk-adjusted mortality of 48% (OR: 0.52, 95% CI: 0.33, 0.83).

CONCLUSIONS

Risk-adjusted mortality did not differ across neonatal units. However, survival in neonatal care for very low birthweight or preterm infants was related to proportion of nurses with neonatal qualifications per shift. The findings could be used to support specific standards of specialist nursing provision in neonatal and other areas of intensive and high dependency care.

Establishing neonatal networks: the reality

Managed clinical networks for neonatal care were established in England from 2004. Their structure and effectiveness varies widely over the country. Changes in medical manpower and the scarcity of neonatal nurses make the move towards networks urgent, but there is little evidence of a coordinated approach to improving capacity in the tertiary centres, who will have to absorb the activity that follows reconfiguration. Changes in the governance of hospitals, NHS authority boundaries and in commissioning specialist services, with the drive towards reducing health costs, places the process at some considerable risk. Despite these challenges, the development of coordinated clinical networks will be an important force in improving outcome for very preterm babies in the UK. The development of some form of national coordination of network activities and greater sharing of good practice would enhance the value of the managed clinical neonatal networks.

The effect of birth in secondary- or tertiary-level hospitals in Finland on mortality in very preterm infants: a birth-register study

OBJECTIVE

Our goal was to test the hypothesis that the level of the delivery hospital affects 1-year mortality of very preterm infants in Finland.

PATIENTS AND METHODS

This retrospective national medical birth-register study included 2291 very preterm infants (gestational age of < 32 weeks at birth or birth weight of < or = 1500 g) born in 14 level II (central) and 5 level III (university) hospitals in 2000-2003. The main outcome measures were adjusted total mortality (including stillbirths) and mortality of live-born infants until the age of 1 year.

RESULTS

Both the total 1-year mortality and the 1-year mortality of live-born infants were higher in level II hospitals compared with level III hospitals. Total mortality was higher in very preterm infants who were not born during office hours. In theory, delivery of all very preterm infants in level III instead of level II hospitals translates into an annual prevention of 69 of the 170 total deaths and prevention of 18 of the 45 deaths of live-born infants.

CONCLUSIONS

Resources in neonatal intensive care should be increased, especially during non-office hours, to have an equally distributed service through the 24-hour day. More efficient regionalization of very preterm deliveries may improve 1-year survival of very preterm infants in Finland.

Extremely growth-retarded infants: is there a viability centile?

BACKGROUND

It is known that extremely premature infants do less well than more mature infants, and this fact has led some countries to adopt a "cutoff for viability" using birth weight or gestation. Infants affected by intrauterine growth retardation are at additional risk of poor outcome. There are few data to inform decisions about viability and (dis)continuation of intensive care when both extreme prematurity and severe growth retardation are present.

OBJECTIVE

We focused on (1) premature infants affected by marked intrauterine growth retardation to determine if there was a cutoff weight centile below which the mortality sharply increased and (2) the short-term outcome of extremely premature and growth-retarded infants to determine a cutoff for viability.

METHODS

We evaluated preterm infants of 22-32 weeks' gestation if they were alive at the onset of labor and born to European mothers resident in the Trent (United Kingdom) health region between 1994 and 2003. Infants were categorized into 6 weight centiles, and infants in each category were assessed for survival to discharge from the neonatal unit, duration of respiratory support, length of stay in the neonatal unit, and the age at death in nonsurvivors.

RESULTS

We identified a total of 8228 infants who met the study criteria. Of these, 4448 infants were male, 6194 were from singleton pregnancies, and 2887 were born at < or = 28 completed weeks of gestation. Survival to discharge was markedly reduced in the infants born at < or = 28 weeks of gestation with a birth weight less than the 2nd centile. Stillbirth was inversely related to birth weight centile in infants born before 29 weeks of gestation.

CONCLUSIONS

The survival for infants born at < or = 28 weeks' gestation and having a birth weight in less than the 2nd centile is poor, and consideration should be given to modifying their management.

Managing safe staffing

Low staffing numbers in intensive care are associated with a number of adverse sequelae, including increased mortality. This article explores the evidence behind recommendations for safe staffing of neonatal units within the UK. Increasing pressure to reduce the hours all medical staff work and the increasing duration of neonatal nurse training requires all units to reflect on how they develop and maintain staff skills and prioritise training. To ensure safe staffing, numerous examples of innovative practice exist within the UK. Examples include network-wide workforces, clinical support workers and neonatal housekeepers.

Neonatal disease severity scoring systems

Illness severity scores have become widely used in neonatal intensive care. Primarily this has been to adjust the mortality observed in a particular hospital or population for the morbidity of their infants, and hence allow standardised comparisons to be performed. However, although risk correction has become relatively commonplace in relation to audit and research involving groups of infants, the use of such scores in giving prognostic information to parents, about their baby, has been much more limited. The strengths and weaknesses of the existing methods of disease severity correction in the newborn are presented in this review.

Trends in the incidence of severe retinopathy of prematurity in a geographically defined population over a 10-year period

OBJECTIVE

To examine trends in the incidence of severe (> or =grade 3) retinopathy of prematurity (ROP) in infants with birth weight of < or =1250 g in a geographically defined population over a 10-year period.

METHODS

An observational study was conducted of all infants who had a birth weight < or =1250 g and were born to mothers who were resident in the county of Leicestershire, United Kingdom, during the period January 1, 1990, to December 30, 1999. Cases were identified by the Trent Neonatal Survey. The incidence of severe ROP (> or =grade 3) was compared in 2 successive 5-year periods: 1990-1994 and 1995-1999.

RESULTS

Comparing the first 5-year period (1990-1994) with the second (1995-1999), the total number of live births fell (60 789 vs 56 564). However, there was a significant increase in the number of births with birth weight < or =1250 g (including live and dead; 615 vs 734; live births only: 455 vs 556). Survival to 42 weeks of infants who were born at < or =1250 g was significantly better in the latter time period (203 vs 302; odds ratio [OR] for death: 0.54; 95% confidence interval [CI]: 0.39-0.75). The number of cases of severe ROP was 4 times higher during the second time period compared with the first (9 vs 36). A significantly increased risk for the development of severe ROP was seen during the second time period (OR: 2.92; 95% CI: 1.37-6.20). Even after allowing for the change in gestation induced by the improved survival during the second time period, the increased risk remained (OR: 2.81; 95% CI: 1.27-6.21).

CONCLUSIONS

There is strong evidence that the incidence of severe ROP among infants with birth weight < or =1250 g increased in the latter half of the last decade. The increased risk seems to be independent of the increase in survival.

The potential impact on costs and staffing of introducing clinical networks and British Association of Perinatal Medicine standards to the delivery of neonatal care

OBJECTIVE

To produce models to estimate the impact of introducing clinical networks and the 2001 BAPM standards to the delivery of neonatal care.

DESIGN

Prospective observational study using a geographically defined population and data collected by questionnaire on staffing levels and cot availability.

SETTING

Trent Health Region UK.

SUBJECTS

All infants born to Trent resident mothers at or before 32 weeks gestation between 1 January 1998 and 31 December 1999. Staffing numbers and cot availability for neonatal care in 2001.

METHODS

A modelling exercise was carried out using information for all neonatal admissions for Trent resident infants. Three models were investigated: (a). the current care provision; (b). a network where three lead centres provided the intensive care for the region and the remaining units provided either high dependency or special care alone; (c). a network where six lead centres provided the intensive care for the region and the remaining units provided either high dependency or special care alone. Overall costings, staffing levels, and cot requirements were calculated for each model. Data on staffing levels and cot availability were used to calculate current care provision costings.

RESULTS

The current cost of running the service is approximately pound 33.35 million, although a proportion of nursing posts are currently unfilled. Estimates for the introduction of a three centre model meeting BAPM 2001 standards range from pound 37.31 to pound 43.40 million. Equivalent figures for the six centre model were: pound 36.32 to pound 42.62 million. Approximately 370 and 230 babies a year would be involved in transfer in the three and six centre models respectively. This is in contrast with 374 and 368 urgent transfers that actually took place in 1998 and 1999 respectively.

CONCLUSION

The costs associated with the introduction of managed clinical networks and meeting BAPM standards of care are not excessive, especially when considered against the likely implementation timetable of perhaps 7-10 years. Attracting and retaining sufficient staff will pose the major challenge.

Regionalization of perinatal care in Europe

This review describes European health policies related to the place of birth of very preterm babies, and the organizational context in which these policies were enacted using data from two European studies. It also compiles available information on the place of birth of very preterm babies from the published literature. In Europe, there is significant diversity in approaches to the provision of intensive care services for the small proportion of pregnant women and babies that need it, both in terms of health policies and the supply and characteristics of maternity and neonatal units. These diverse models in countries with similar levels of development and medical technology could offer an opportunity to understand how different organizational characteristics affect access to care, health outcomes and resource use.

Associations between perinatal interventions and hospital stillbirth rates and neonatal mortality

BACKGROUND

Previous studies suggest that high risk and low birthweight babies have better outcomes if born in hospitals with level III neonatal intensive care units. Relations between obstetric care, particularly intrapartum interventions and perinatal outcomes, are less well understood, however.

OBJECTIVE

To investigate effects of obstetric, paediatric, and demographic factors on rates of hospital stillbirths and neonatal mortality.

METHODS

Cross sectional data on all 65 maternity units in all Thames Regions, 1994-1996, covering 540 834 live births and stillbirths. Hospital level analyses investigated associations between staffing rates (consultant/junior paediatricians, consultant/junior obstetricians, midwives), facilities (consultant obstetrician/anaesthetist sessions, delivery beds, special care baby unit, neonatal intensive care unit cots, etc), interventions (vaginal births, caesarean sections, forceps, epidurals, inductions, general anaesthetic), parental data (parity, maternal age, social class, deprivation, multiple births), and birthweight standardised stillbirth rates and neonatal mortality.

RESULTS

Unifactorial analyses showed consistent negative associations between measures of obstetric intervention and stillbirth rates. Some measures of staffing, facilities, and parental data also showed significant associations. Scores for interventional, organisational, and parental variables were derived for multifactorial analysis to overcome the statistical problems caused by high intercorrelations between variables. A higher intervention score and higher number of consultant obstetricians per 1000 births were both independently and significantly associated with lower stillbirth rates. Organisational and parental factors were not significant after adjustment. Only Townsend deprivation score was significantly associated with neonatal mortality (positive correlation).

CONCLUSIONS

Birthweight adjusted stillbirth rates were significantly lower in units that took a more interventionalist approach and in those with higher levels of consultant obstetric staffing. There were no apparent associations between neonatal death rates and the hospital factors measured here.

Extreme prematurity in the UK and Denmark: population differences in viability

BACKGROUND

Previous studies comparing different models of neonatal intensive care have generally not been population based. The objective of this study was to compare the perinatal services of two total populations.

METHODS

Observational study based on two geographically defined populations: the whole of Demark (some centralisation of neonatal intensive care but most delivered locally by small perinatal centres-48 in total) and the Trent Health Region of the UK (no formal centralisation however deliveries almost all focussed on 16 major hospitals with > 90% of the intensive care provided by 13 hospitals). Information was recorded about the course of every liveborn infant < 28 weeks gestation and or < 1000g birth weight and > or = 21 weeks gestation in 1994 and 1995.

RESULTS

Despite having a smaller population the number of liveborn children meeting the study criteria was significantly higher in Trent (Demark 461 (3.3 per 1000 births, 95% confidence interval (CI) 3.0 to 3.6); Trent 572 (4.9 per 1000 births, 95% CI 4.5 to 5.3)). In Denmark 91.1% of these infants were admitted for intensive care and 85.5% in Trent. Despite significantly more Trent infants being exposed to antenatal steroids their outcome was worse (median Clinical Risk Index for Babies (CRIB) score 7 v 4; proportion receiving ventilation 87.6% v 40.0%; survival to discharge (uncorrected for disease severity) 42.3% v 35.0%).

CONCLUSION

The population characteristics of Trent seemed to produce a higher prematurity rate compared to Denmark. These infants as a group appeared sicker and, despite more intensive care delivered by a more specialised service, outcomes were worse.

Maternal characteristics associated with place of delivery and neonatal mortality rates among very-low-birthweight infants, Georgia

To determine whether the Healthy People 2000 objective to deliver very-low-birthweight (VLBW) infants at subspecialty perinatal care centres was met, and if improvements in the regional perinatal care system could reduce neonatal mortality further for 2010, we examined place of delivery for VLBW infants, associated maternal characteristics and the potential impact on neonatal mortality. We used linked birth and death records for the 1994-96 Georgia VLBW (i.e. 500-1499 g) birth cohorts. Among 4770 VLBW infants, 77% were delivered at hospitals providing subspecialty perinatal care. The strongest predictor of birth hospital level was the mother's county of residence, defined using three levels: residence in a county with a subspecialty hospital, residence in a county adjacent to one with such a hospital or residence in a non-adjacent county. Eighty-nine per cent of infants born to women who resided in counties with subspecialty care hospitals delivered at such hospitals, compared with 53% of infants born to women who resided in a non-adjacent county. Women were also more likely to deliver outside subspecialty care if they had less than adequate prenatal care [adjusted odds ratio (AOR) 1.5, P-value = 0.0001]. The neonatal mortality rate varied by level of perinatal care at the birth hospital from 132.1/1000 to 283/1000 live births, with the highest death rate for infants born at hospitals offering the lowest level of care. Assuming that the differences in mortality were due to care level of the birth hospital, potentially 16-23% of neonatal deaths among VLBW infants could have been prevented if 90% of infants born outside subspecialty care were delivered at the recommended level. These findings suggest that a state's support of strong, collaborative, regional perinatal care networks is required to ensure that high-risk women and infants receive optimal health care. Improved access to recommended care levels should further reduce neonatal mortality until interventions are identified to prevent VLBW births.

Population-based outcomes after acute antenatal transfer

Acute antenatal transfer to specialist centres is an accepted practice but few or no regular data are collected regarding the numbers of transfers performed or subsequent pregnancy outcome. We wished to determine the numbers, and the maternal and fetal outcomes following acute antenatal transfer between consultant obstetric units in the former Northern Region of the UK over a 12-month period (1 January-31 December 99). This is a geographically defined population in terms of provision of perinatal services. All acute antenatal transfers were notified centrally. Data pertaining to each transfer were collected at the time of transfer. Subsequent maternal and fetal outcomes were determined from patient records and neonatal databases. The regional annual acute antenatal transfer rate was 3.7 per 1000 deliveries. Most were for fetal reasons, although transfer rates varied between hospitals. The decision to transfer was influenced by distance and availability of paediatric staff. Even units that have similar characteristics show considerable variation in their transfer rates. No adverse incidents occurred during transfer and no major changes in maternal management occurred following transfer. Twenty-four per cent of women remained undelivered following transfer. Women with preterm labour in the absence of ruptured membranes were less likely to deliver than those transferred for other reasons and if they did deliver, their infants were also less likely to need intensive care. We believe audit of acute antenatal transfers should be routinely undertaken. Numbers of transfers might be reduced if delivery and the need for neonatal intensive care could be predicted with greater accuracy. The psychological and financial costs of transfer to women and healthcare providers need to be addressed.

Mortality in low birth weight infants according to level of neonatal care at hospital of birth

OBJECTIVE

In 1976, the Committee on Perinatal Health recommended that hospitals with no neonatal intensive care unit (NICU) or intermediate NICUs transfer high-risk mothers and infants that weigh <2000 g to a regional NICU. This standard was based on expert opinion and has not been validated carefully. This study evaluated the effect of NICU level and patient volume at the hospital of birth on neonatal mortality of infants with a birth weight (BW) of <2000 g.

METHODS

Birth certificates of 16 732 singleton infants who had a BW of <2000 g and were born in nonfederal hospitals in California in 1992 and 1993 were linked to death certificates and to discharge abstracts. The hospitals were classified by the level of NICU: no NICU, no intensive care; intermediate NICU, intermediate intensive care; community NICU, expanded intermediate intensive care; and regional NICU, tertiary intensive care. A logistic regression model that controlled for demographic risks, diagnoses, transfer, average NICU census, and NICU level was estimated using death within the first 28 days or first year of life if continuously hospitalized as the main outcome measure.

RESULTS

Compared with birth in a hospital with a regional NICU, risk-adjusted mortality of infants with BW of <2000 g was higher when birth occurred in hospitals with no NICU (odds ratio [OR]: 2.38; 95% confidence interval [CI]: 1.81-3.13), an intermediate NICU (OR: 1.92; 95% CI: 1.44-2.54), or a small (average census <15) community NICU (OR: 1.42; 95% CI: 1.14-1.76). Risk-adjusted mortality for infants who were born in hospitals with a large (average census > or =15) community NICU was not statistically different compared with those with a regional NICU (OR: 1.11; 95% CI: 0.87-1.43). Except for large community NICUs, all of these ORs are larger when the data are restricted to infants with BW of <1500 g or BW of <1250 g and smaller for BW between 1250 g and 1999 g and 1500 g and 1999 g. For large community NICUs, the results are similar for the smaller BW intervals and significant only for the larger BW interval.

CONCLUSIONS

These results support the recommendation that hospitals with no NICU or intermediate NICUs transfer high-risk mothers with estimated fetal weight of <2000 g to a regional NICU. For infants with BW of <2000 g, birth at a hospital with a regional NICU is associated with a lower risk-adjusted mortality than birth at a hospital with no NICU, intermediate NICU of any size, or small community NICU. Subsequent neonatal transfer to a regional NICU only marginally decreases the disadvantage of birth at these hospitals. The evidence for the few hospitals with large community NICUs is mixed. Although the data point to higher mortality in large community NICUs, they are not conclusive and additional study is needed on the mortality effects of large community NICUs. Greater efforts should be made to deliver infants with expected BW of <2000 g at hospitals with regional NICUs.

Patient volume, staffing, and workload in relation to risk-adjusted outcomes in a random stratified sample of UK neonatal intensive care units: a prospective evaluation

BACKGROUND

UK recommendations suggest that large neonatal intensive-care units (NICUs) have better outcomes than small units, although this suggestion remains unproven. We assessed whether patient volume, staffing levels, and workload are associated with risk-adjusted outcomes, and with costs or staff wellbeing.

METHODS

186 UK NICUs were stratified according to volume of patients, nursing provision, and neonatal consultant provision. Primary outcomes were hospital mortality, mortality or cerebral damage, and nosocomial bacteraemia. We studied 13515 infants of all birthweights consecutively admitted to 54 randomly selected NICUs. Multiple logistic regression analyses were done with every primary outcome as the dependent variable. Staff wellbeing and stress were assessed by anonymous mental health index (MHI)-5 questionnaires.

FINDINGS

Data were available for 13334 (99%) infants. High-volume NICUs treated the sickest infants and had highest crude mortality. Risk-adjusted mortality and mortality or cerebral damage were unrelated to patient volume or staffing provision; however, nosocomial bacteraemia was less frequent in NICUs with low neonatal consultant provision (odds ratio 0.65, 95% CI 0.43-0.98). Mortality was raised with increasing workload in all types of NICUs. Infants admitted at full capacity versus half capacity were about 50% more likely to die, but there was wide uncertainty around this estimate. Most staff had MHI-5 scores that suggested good mental health.

INTERPRETATION

The implications of this report for staffing policy, medicolegal risk management, and ethical practice remain to be tested. Centralisation of only the sickest infants could improve efficiency, provided that this does not create excessive workload for staff. Assessment of increased staffing levels that are closer to those in adult intensive care might be appropriate.

Ethical aspects of cardiopulmonary resuscitation in premature neonates: where do we stand?

Advances in diagnosis, techniques, therapeutic interventions, organisation of perinatal care, and socio-economic factors have all contributed to the survival after resuscitation and intensive care of neonates with extremely low birth weight and gestational age. While morbidity during the first years of life in those infants does not increase, at school age multiple dysfunctions may become apparent. What are the limits of intensive care for the newborn? Is it right to use extreme technical and economic measures for neonates with a borderline chance of survival? What is justifiable for the neonate, the family, the society and how does legislation interfere in a decision process which involves starting, stopping or continuing intensive care? A short historical overview for the care of the newborn is given, followed by the outcome after resuscitation and treatment of the very low birth weight infant. Published management strategies and recommendations are discussed.

Perinatal care regionalization and low birth weight infant mortality rates in Alaska

OBJECTIVE

The purpose of this study was to determine the extent to which the failure of non-tertiary care hospitals to appropriately triage and refer pregnant women and newborns contributes to low birth weight infant death in Alaska.

STUDY DESIGN

Birth certificates from 1993 to 1997 were reviewed for all 2809 infants who were born at less than 2500 g. Death certificates and maternal and infant medical charts were reviewed for all 168 infant deaths that occurred during this time.

RESULTS

Mother-infant pairs who received all care at Alaska's single tertiary care center had a lower mortality rate than those who received some care at a non-tertiary care center (risk ratio, 1.5; 95% confidence interval, 0.86-2.6). Despite this, only 4% of deaths among low birth weight infants (all <1500 g) were associated with care decisions at non-tertiary centers; none of these deaths involved intentional inappropriate retention of infants or mothers.

CONCLUSION

Further emphasizing perinatal care regionalization (including for infants 1500-2499 g birth weight) is unlikely to substantially decrease low birth weight infant mortality rates.

Factors affecting the incidence of chronic lung disease of prematurity in 1987, 1992, and 1997

OBJECTIVE

To determine changes in the incidence of chronic lung disease of prematurity between 1987, 1992, and 1997.

METHODS

Observational study based on data derived from a geographically defined population: Trent Health Region, United Kingdom. Three time periods were compared: 1 February 1987 to 31 January 1988 (referred to as 1987); 1 April 1992 to 31 March 1993 (referred to as 1992); 1997. All infants of < or = 32 completed weeks gestation born to Trent resident mothers within the study periods and admitted to a neonatal unit were included. Rates of chronic lung disease were determined using two definitions: (a) infants who remained dependent on active respiratory support or increased oxygen at 28 days of age; (b) infants who remained dependent on active respiratory support or increased oxygen at a corrected age of 36 weeks gestation.

RESULTS

Between 1987 and 1992 there was a fall in the birth rate, but a significant increase was noted in the number of babies of < or = 32 weeks gestation admitted to a neonatal unit. There was no significant change in survival when the two groups of infants were directly compared. However, mean gestation and birth weight fell. Adjusting for this change showed a significant improvement in survival (28 day survival: odds ratio (OR) = 1.69; 95% confidence interval (95% CI) = 1.23 to 2.33. Survival to 36 week corrected gestation: OR = 1.45; 95% CI = 1.06 to 1.98). These changes were accompanied by a large increase in the incidence of chronic lung disease even after allowing for the change in population characteristics (28 day definition: OR = 2.20; 95% CI = 1.47 to 3.30. 36 week definition: OR = 3.04; 95% CI = 1.91 to 4.83). Between 1992 and 1997 a different pattern emerged. There was a further increase in the number of babies admitted for neonatal care at </= 32 weeks gestation despite a continuing fall in overall birth rate. Survival, using both raw data and data corrected for changes in gestation and birth weight, improved significantly in 1997 (adjusted data: 28 day survival: OR = 1.72 (95% CI = 1.22 to 2.38); survival to 36 week corrected gestation: OR = 1.90 (95% CI = 1.36 to 2.64)). Rates of chronic lung disease showed no significant change between 1992 and 1997 despite improved survival (adjusted data: 28 day definition: OR = 0.72 (95% CI = 0.50 to 1.03); 36 week definition: OR = 0.88 (95% CI = 0.61 to 1.26).

CONCLUSIONS

Current high rates of chronic lung disease are the result of policies to offer neonatal intensive care more widely to the most immature infants. Recent improvements in survival have been achieved without further increases in the risk of infants developing chronic lung disease.

Intrauterine versus postnatal transport of the preterm infant: a short-distance experience

AIM

The purpose of this study was to compare neonatal outcome (mortality, respiratory distress syndrome, intraventricular hemorrhage, necrotising enterocolitis, persisting ductus arteriosus, and septicaemia) after intrauterine transport versus neonatal transport in an area where short-distance transport is the rule.

METHODS

The study was retrospective in nature. The files of all neonates delivered between 24 and 34 weeks from 1994 to 1998 and transported intrauterine or postnatally to the Antwerp University Hospital were reviewed. Cases of intrauterine fetal death and mothers discharged before delivery were excluded, as were infants with lethal congenital anomalies.

RESULTS

A total of 328 deliveries after intrauterine transport, resulting in 416 neonates and 187 neonates transported postnatally were included. The maximum distance patients had to be transported was 40 km. Placental abruption was more frequent in the mothers of the neonatal transport group (13 vs. 5%, P=0.001). Corticosteroids were administered significantly less in the neonatal transport group (67 vs. 13%, P<0.0001). Preterm rupture of the membranes (36 vs. 20%, P<0.0001), preterm labour (73 vs. 36%, P<0.0001), and pre-eclampsia (10 vs. 7%, P<0.0001) were more frequent in the intrauterine transport group and this group had a lower mean birthweight and gestational age. There was no significant difference for overall neonatal mortality, respiratory distress syndrome, intraventricular hemorrhage, necrotising enterocolitis, persisting ductus arteriosus or septicaemia.

National census of availability of neonatal intensive care. British Association for Perinatal Medicine

OBJECTIVE

To determine whether availability of neonatal intensive care cots is a problem in any or all parts of the United Kingdom.

DESIGN

Three month census from 1 April to 30 June 1999 comprising simple data sheets on transfers out of tertiary units.

SETTING

The 37 largest high risk perinatal centres in the United Kingdom.

PARTICIPANTS

One obstetric specialist and one neonatal specialist in each centre.

MAIN OUTCOME MEASURES

Suboptimal care resulting directly from pressure on service-that is, transfers out of tertiary units (either in utero or after delivery) because the unit was "full" and not because the hospital was incapable of providing the care needed.

RESULTS

All units provided data. The number of intensive care cots in each unit was between five and 16. During the three months 309 transfers occurred (equivalent to 1236 per year), of which 264 were in utero and 45 postnatal. Sixty five in utero transfers involved multiple births, hence the census related to 382 babies (1528 per year). There was considerable regional variation. The reason for transfer in most cases was "lack of neonatal beds".

CONCLUSIONS

Currently most major perinatal centres in the United Kingdom are regularly unable to meet in-house demand; this has implications for the service as a whole. The NHS has set no standards to help health authorities and primary care groups develop services relating to this specialty; such a step may well be an appropriate lever for change.

Risk adjusted and population based studies of the outcome for high risk infants in Scotland and Australia. International Neonatal Network, Scottish Neonatal Consultants, Nurses Collaborative Study Group

OBJECTIVES

To compare outcomes of care in selected neonatal intensive care units (NICUs) for very low birthweight (VLBW) or preterm infants in Scotland and Australia (study 1) and perinatal care for all VLBW infants in both countries (study 2).

DESIGN

Study 1: risk adjusted cohort study; study 2: population based cohort study.

SUBJECTS

Study 1: all 2621 infants of < 1500 g birth weight or < 31 weeks' gestation admitted to a volunteer sample of hospitals comprising eight of all 17 Scottish NICUs and six of all 12 tertiary NICUs in New South Wales and Queensland in 1993-1994; study 2: all 5986 infants of 500-1499 g birth weight registered as live born in Scotland and Australia in 1993-1994.

MAIN OUTCOMES

Study 1: (a) hospital death; (b) death or cerebral damage, each adjusted for gestation and CRIB (clinical risk index for babies); study 2: neonatal (28 day) mortality.

RESULTS

Study 1. Data were obtained for 1628 admissions in six Australian NICUs, 775 in five Scottish tertiary NICUs, and 148 in three Scottish non-tertiary NICUs. Crude hospital death rates were 13%, 22%, and 22% respectively. Risk adjusted hospital mortality was about 50% higher in Scottish than in Australian NICUs (adjusted mortality ratio 1.46, 95% confidence interval (CI) 1.29 to 1.63, p < 0.001). There was no difference in risk adjusted outcomes between Scottish tertiary and non-tertiary NICUs. After risk adjustment, death or cerebral damage was more common in Scottish than Australian NICUs (odds ratio 1.9, 95% CI 1.5 to 2.5). Both these risk adjusted adverse outcomes remained more common in Scottish than Australian NICUs after excluding all infants < 28 weeks' gestation from the comparison. Study 2. Population based neonatal mortality in infants of 500-1499 g was higher in Scotland (20.3%) than Australia (16.6%) (relative risk 1.22, 95% CI 1.08 to 1. 39, p = 0.002). In a post hoc analysis, neonatal mortality was also higher in England and Wales than in Australia.

CONCLUSIONS

Study 1: outcome was better in the Australian NICUs. Study 2: perinatal outcome was better in Australia. Both results may be consistent, at least in part, with differences in the organisation and implementation of neonatal care.

Severe retinopathy of prematurity and its association with different rates of survival in infants of less than 1251 g birth weight

BACKGROUND

There is controversy over whether improved survival of preterm infants has resulted in a higher incidence of severe (grade 3 or greater) retinopathy of prematurity (ROP).

AIM

To compare survival rates and rates of > or = stage 3 ROP-that is, with a high risk of sequelae-in preterm infants in five English cities where, anecdotally, the incidence of ROP is reported to show considerable variation.

METHODS

All infants of birth weight < 1500 g and or gestational age < 32 weeks, born in 1994 in one of the cities or transferred in within 48 hours, were studied. The populations were adjusted for case mix variation using CRIB (clinical risk index for babies, a disease severity scoring system). The incidence of severe ROP, the actual death rate, and that adjusted for disease severity were determined.

RESULTS

The rate of severe ROP per 1000 births was higher in city 1 than in all the other cities. This increase in comparison with city 2 and city 4 was significant (city 1, 167 (95% confidence interval (CI) 96 to 260); city 2, 24 (6 to 59); city 4, 16 (1 to 84)). A significant difference was not seen between city 1 and cities 3 (23 (1 to 120)) and 5 (74 (21 to 79)). The relative risk of developing severe ROP in city 1 compared with all the other cities was 5.5 (2.5 to 11.9). The actual death rate per 1000 births in city 1 was significantly lower than that predicted by modelling death against CRIB score (city 1: actual 270; predicted 385 (95% CI 339 to 431)). In contrast, the other cities had actual death rates as predicted, or worse than predicted, by CRIB.

INTERPRETATION

A significantly higher incidence of severe ROP was identified in one of the five cities studied. Variation in survival rates among high risk infants may explain this observation.