The contribution of gestational age, area deprivation and mother's country of birth to ethnic variations in infant mortality in England and Wales: A national cohort study using routinely collected data.

OBJECTIVES: We aimed to describe ethnic variations in infant mortality and explore the contribution of area deprivation, mother's country of birth, and prematurity to these variations. METHODS: We analyzed routine birth and death data on singleton live births (gestational age≥22 weeks) in England and Wales, 2006-2012. Infant mortality by ethnic group was analyzed using logistic regression with adjustment for sociodemographic characteristics and gestational age. RESULTS: In the 4,634,932 births analyzed, crude infant mortality rates were higher in Pakistani, Black Caribbean, Black African, and Bangladeshi infants (6.92, 6.00, 5.17 and 4.40 per 1,000 live births, respectively vs. 2.87 in White British infants). Adjustment for maternal sociodemographic characteristics changed the results little. Further adjustment for gestational age strongly attenuated the risk in Black Caribbean (OR 1.02, 95% CI 0.89-1.17) and Black African infants (1.17, 1.06-1.29) but not in Pakistani (2.32, 2.15-2.50), Bangladeshi (1.47, 1.28-1.69), and Indian infants (1.24, 1.11-1.38). Ethnic variations in infant mortality differed significantly between term and preterm infants. At term, South Asian groups had higher risks which cannot be explained by sociodemographic characteristics. In preterm infants, adjustment for degree of prematurity (<28, 28-31, 32-33, 34-36 weeks) fully explained increased risks in Black but not Pakistani and Bangladeshi infants. Sensitivity analyses with further adjustment for small for gestational age, or excluding deaths due to congenital anomalies did not fully explain the excess risk in South Asian groups. CONCLUSIONS: Higher infant mortality in South Asian and Black infants does not appear to be explained by sociodemographic characteristics. Higher proportions of very premature infants appear to explain increased risks in Black infants but not in South Asian groups. Strategies targeting the prevention and management of preterm birth in Black groups and suboptimal birthweight and modifiable risk factors for congenital anomalies in South Asian groups might help reduce ethnic inequalities in infant mortality.

Identifying Possible False Matches in Anonymized Hospital Administrative Data without Patient Identifiers.

OBJECTIVE: To identify data linkage errors in the form of possible false matches, where two patients appear to share the same unique identification number. DATA SOURCE: Hospital Episode Statistics (HES) in England, United Kingdom. STUDY DESIGN: Data on births and re-admissions for infants (April 1, 2011 to March 31, 2012; age 0-1 year) and adolescents (April 1, 2004 to March 31, 2011; age 10-19 years). DATA COLLECTION/EXTRACTION METHODS: Hospital records pseudo-anonymized using an algorithm designed to link multiple records belonging to the same person. Six implausible clinical scenarios were considered possible false matches: multiple births sharing HESID, re-admission after death, two birth episodes sharing HESID, simultaneous admission at different hospitals, infant episodes coded as deliveries, and adolescent episodes coded as births. PRINCIPAL FINDINGS: Among 507,778 infants, possible false matches were relatively rare (n = 433, 0.1 percent). The most common scenario (simultaneous admission at two hospitals, n = 324) was more likely for infants with missing data, those born preterm, and for Asian infants. Among adolescents, this scenario (n = 320) was more common for males, younger patients, the Mixed ethnic group, and those re-admitted more frequently. CONCLUSIONS: Researchers can identify clinically implausible scenarios and patients affected, at the data cleaning stage, to mitigate the impact of possible linkage errors.

Linking maternity data for England, 2005-06: methods and data quality.

INTRODUCTION: Maternity Hospital Episode Statistics (HES) data were linked to birth registration and NHS Numbers for Babies (NN4B) data to bring together some key demographic and clinical data items not otherwise available at a national level. This project added to earlier work involving linkage of birth registration records to NN4B records. METHODS: Birth registration and NN4B records were linked to Maternity HES delivery records and also Maternity HES baby records using the NHS Number or other indirect identifiers if NHS Number was missing.Data quality and completeness of Maternity HES were assessed in relation to birth registration data wherever possible. For information not collected at registration, NN4B data were used to validate quality of Maternity HES. RESULTS: Overall, 91 per cent of Maternity HES delivery records could be linked to the birth registration/NHS Numbers for Babies records and 84 per cent of Maternity HES baby records were linked.In 2005 only 3 per cent of Maternity HES records had mother's NHS number missing, compared with 30 per cent in the NN4B dataset. This did not reflect the extent to which Maternity HES data items were missing or discordant. Over a quarter of all linked Maternity HES records for singleton babies had one or more of the following data items missing: birthweight, gestational age, birth status, sex, and date of birth of the baby. On the other hand, for data items where information was stated such as birthweight, birth status, and sex for singleton babies, there was good agreement between Maternity HES and linked birth registration and NN4B data.Although NN4B records the ethnic category of the baby as defined by the mother, and Maternity HES records mother's ethnic category, 87 per cent of the linked records had the same ethnic group. CONCLUSION: Even though a good linkage rate was obtained, the method used will be simplified before data for 2007 are linked. To gain the maximum benefit from this linkage in future years, improvements are urgently needed in the quality and completeness of the data contained in Maternity HES.List of Tables, 55.

Multivariate analysis of infant death in England and Wales in 2005-06, with focus on socio-economic status and deprivation.

Current health inequality targets include the goal of reducing the differential in infant mortality between social groups. This article reports on a multivariate analysis of risk factors for infant mortality, with specific focus on deprivation and socio-economic status. Data on all singleton live births in England and Wales in 2005-06 were used, and deprivation quintile (Carstairs index) was assigned to each birth using postcode at birth registration. Deprivation had a strong independent effect on infant mortality, risk of death tending to increase with increasing levels of deprivation. The strength of this relationship depended, however, on whether the babies were low birthweight, preterm or small-for-gestational-age. Trends of increasing mortality risk with increasing deprivation were strongest in the postneonatal period. Uniquely, this article reports the number and proportion of all infant deaths which would potentially be avoided if all levels of deprivation were reduced to that of the least deprived group. It estimates that one quarter of all infant deaths would potentially be avoided if deprivation levels were reduced in this way.

Trends of selected malformations in relation to folic acid recommendations and fortification: an international assessment.

BACKGROUND: Two crucial issues relative to the benefits and impact of folic acid in the prevention of birth defects are whether supplementation recommendations alone, without fortification, are effective in reducing the population-wide rates of neural tube defects (NTDs), and whether such policies can reduce the occurrence of other birth defects. Using data from 15 registries, we assessed rates and trends of 14 major defects, including NTDs, in areas with official recommendations or fortification to assess the effectiveness of recommendations and fortification on a wide range of major birth defects. METHODS: We evaluated surveillance data through 2003 on major birth defects from population-based registries from Europe, North America, and Australia. All included ascertainment of pregnancy terminations (where legal). Trends before and after policies or fortification were assessed via Poisson regression and were compared via rate ratios. RESULTS: Significant changes in trends were seen for NTDs in areas with fortification but not in areas with supplementation recommendations alone. For other major birth defects, there was an overall lack of major trend changes after recommendations or fortification. However, some significant declines were observed for select birth defects in individual areas. CONCLUSIONS: Recommendations alone remain an ineffective approach in translating the known protective effect of folic acid in population-wide decline in NTD rates. Fortification appears to be effective in reducing NTDs. The effect on other birth defects remains unclear.