Critical evaluation of national vital statistics: the case of preterm birth trends in Portugal

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Correia, S (Author) FMUP; Rodrigues, T (Author) FMUP; Montenegro, N (Author) Other; Barros H (Author) FMUP

Journal

Title: Acta Obstetricia et Gynecologica Scandinavica

Vol. 94

Pages: 1215-1222

ISSN: 0001-6349

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 6 Citations

Scopus - 7 Citations

Other information

Authenticus ID: P-00G-QGY

DOI: 10.1111/aogs.12730

Abstract (EN): IntroductionUsing vital statistics, the Portuguese National Health Plan predicts that 14% of live births will be preterm in 2016. The prediction was based on a preterm birth rise from 5.9% in 2000 to 8.8% in 2009. However, the same source showed an actual decline from 2010 onwards. To assess the plausibility of national preterm birth trends, we aimed to compare the evolution of preterm birth and low birthweight rates between vital statistics and a hospital database. Material and methodsA time-trend analysis (2004-2011) of preterm birth (<37 gestational weeks) and low birthweight (<2500g) rates was conducted using data on singleton births from the national birth certificates (n=801783) and an electronic maternity unit database (n=21392). Annual prevalence estimates, ratios of preterm birth:low birthweight and adjusted prevalence ratios were estimated to compare data sources. ResultsAlthough the national prevalence of preterm birth increased from 2004 (5.4%), particularly between 2006 and 2009 (highest rate was 7.5% in 2007), and decreased after 2009 (5.7% in 2011), the prevalence at the maternity unit remained constant. Between 2006 and 2009, preterm birth was almost 1.4 times higher in the national statistics (using the national or the catchment region samples) than in the maternity unit, but no differences were found for low birthweight. ConclusionPortuguese preterm birth prevalence seems biased between 2006 and 2009, suggesting that early term babies were misclassified as preterm. As civil registration systems are important to support public health decisions, monitoring strategies should be taken to assure good quality data.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8