Variations in very preterm birth rates in 30 high-income countries: are valid international comparisons possible using routine data?

OBJECTIVE: Concerns about differences in registration practices across countries have limited the use of routine data for international very preterm birth (VPT) rate comparisons. DESIGN: Population-based study. SETTING: Twenty-seven European countries, the United States, Canada and Japan in 2010. POPULATION: A total of 9 376 252 singleton births. METHOD: We requested aggregated gestational age data on live births, stillbirths and terminations of pregnancy (TOP) before 32 weeks of gestation, and information on registration practices for these births. We compared VPT rates and assessed the impact of births at 22-23 weeks of gestation, and different criteria for inclusion of stillbirths and TOP on country rates and rankings. MAIN OUTCOME MEASURES: Singleton very preterm birth rate, defined as singleton stillbirths and live births before 32 completed weeks of gestation per 1000 total births, excluding TOP if identifiable in the data source. RESULTS: Rates varied from 5.7 to 15.7 per 1000 total births and 4.0 to 11.9 per 1000 live births. Country registration practices were related to percentage of births at 22-23 weeks of gestation (between 1% and 23% of very preterm births) and stillbirths (between 6% and 40% of very preterm births). After excluding births at 22-23 weeks, rate variations remained high and with a few exceptions, country rankings were unchanged. CONCLUSIONS: International comparisons of very preterm birth rates using routine data should exclude births at 22-23 weeks of gestation and terminations of pregnancy. The persistent large rate variations after these exclusions warrant continued surveillance of VPT rates at 24 weeks and over in high-income countries. TWEETABLE ABSTRACT: International comparisons of VPT rates should exclude births at 22-23 weeks of gestation and terminations of pregnancy.

Linking databases on perinatal health: a review of the literature and current practices in Europe.

BACKGROUND: International comparisons of perinatal health indicators are complicated by the heterogeneity of data sources on pregnancy, maternal and neonatal outcomes. Record linkage can extend the range of data items available and thus can improve the validity and quality of routine data. We sought to assess the extent to which data are linked routinely for perinatal health research and reporting. METHODS: We conducted a systematic review of the literature by searching PubMed for perinatal health studies from 2001 to 2011 based on linkage of routine data (data collected continuously at various time intervals). We also surveyed European health monitoring professionals about use of linkage for national perinatal health surveillance. RESULTS: 516 studies fit our inclusion criteria. Denmark, Finland, Norway and Sweden, the US and the UK contributed 76% of the publications; a further 29 countries contributed at least one publication. Most studies linked vital statistics, hospital records, medical birth registries and cohort data. Other sources were specific registers for: cancer (70), congenital anomalies (56), ART (19), census (19), health professionals (37), insurance (22) prescription (31), and level of education (18). Eighteen of 29 countries (62%) reported linking data for routine perinatal health monitoring. CONCLUSION: Research using linkage is concentrated in a few countries and is not widely practiced in Europe. Broader adoption of data linkage could yield substantial gains for perinatal health research and surveillance.

Preterm birth time trends in Europe: a study of 19 countries.

OBJECTIVE: To investigate time trends in preterm birth in Europe by multiplicity, gestational age, and onset of delivery. DESIGN: Analysis of aggregate data from routine sources. SETTING: Nineteen European countries. POPULATION: Live births in 1996, 2000, 2004, and 2008. METHODS: Annual risk ratios of preterm birth in each country were estimated with year as a continuous variable for all births and by subgroup using log-binomial regression models. MAIN OUTCOME MEASURES: Overall preterm birth rate and rate by multiplicity, gestational age group, and spontaneous versus non-spontaneous (induced or prelabour caesarean section) onset of labour. RESULTS: Preterm birth rates rose in most countries, but the magnitude of these increases varied. Rises in the multiple birth rate as well as in the preterm birth rate for multiple births contributed to increases in the overall preterm birth rate. About half of countries experienced no change or decreases in the rates of singleton preterm birth. Where preterm birth rates rose, increases were no more prominent at 35-36 weeks of gestation than at 32-34 weeks of gestation. Variable trends were observed for spontaneous and non-spontaneous preterm births in the 13 countries with mode of onset data; increases were not solely attributed to non-spontaneous preterm births. CONCLUSIONS: There was a wide variation in preterm birth trends in European countries. Many countries maintained or reduced rates of singleton preterm birth over the past 15 years, challenging a widespread belief that rising rates are the norm. Understanding these cross-country differences could inform strategies for the prevention of preterm birth.

[Trends in interregional migration in Estonia since 1947]. / L'evolution des migrations inter-regionales en Estonie depuis 1947.

Migration trends in Estonia since 1947 are reviewed. The analysis indicates that the country's age distribution began to change earlier than that of other Eastern European countries. "Immigration started earlier too, first with the influx from the Estonia hinterland into the capital, then, after the second world war, with the gradual common workforce influx from the Republics of the Soviet Union." The author concludes that in-migration, combined with greater migration among younger people, has resulted in increased demographic aging, a trend that has to be taken into account when developing social policy. (SUMMARY IN ENG AND SPA)