Author
Affilliation
Abstract
Rates of Down syndrome (DS) show considerable international
variation, but a systematic assessment of this variation is lacking.
The goal of this study was to develop and test a method to assess
the validity of DS rates in surveillance programs, as an indicator
of quality of ascertainment. The proposed method compares the
observed number of cases with DS (livebirths plus elective
pregnancy terminations, adjusted for spontaneous fetal losses
that would have occurred if the pregnancy had been allowed to
continue) in each single year of maternal age, with the expected
number of cases based on the best-published data on rates by year
of maternal age. To test this method we used data from birth
years 2000 to 2005 from 32 surveillance programs of the International
Clearinghouse for Birth Defects Surveillance and Research.
We computed the adjusted observed versus expected
ratio (aOE) of DS birth prevalence among women 25–44 years
old. The aOE ratio was close to unity in 13 programs (the 95%
confidence interval included 1), above 1 in 2 programs and below
1 in 18 programs (P < 0.05). These findings suggest that DS rates
internationally can be evaluated simply and systematically, and
underscores how adjusting for spontaneous fetal loss is crucial
and feasible. The aOE ratio can help better interpret and compare
the reported rates, measure the degree of under- or over-registration,
and promote quality improvement in surveillance programs
that will ultimately provide better data for research,
service planning, and public health programs. 2010 Wiley-Liss, Inc.
Publisher
Wiley
Citation
LEONCINI, Emanuele; et al. How Valid Are the Rates of Down Syndrome Internationally? Findings from the International Clearinghouse for Birth Defects Surveillance and Research. American Journal of Medical Genetics Part A., 152A, p.1670-1680, 2010.
DOI
10.1002/ajmg.a.33493
ISSN
0148-7299
Notes
Collaborative International Birth Defects Surveillance and Program / Emanuele Leoncini,1 Lorenzo D. Botto,2 Guido Cocchi,3 Goran Anner en,4,5 Carol Bower,6 Jane Halliday,7
Emmanuelle Amar,8 Marian K. Bakker,9 Sebastiano Bianca,10 Maria Aurora Canessa Tapia,11
Eduardo E. Castilla,12,13 Melinda Cs aky-Szunyogh,14 Saeed Dastgiri,15 Marcia L. Feldkamp,2
Miriam Gatt,16 Fumiki Hirahara,17 Danielle Landau,18 R. Brian Lowry,19 Lisa Marengo,20
Robert McDonnell,21 Triphti M. Mathew,22 Margery Morgan,23 Osvaldo M. Mutchinick,24 Anna Pierini,25
Simone Poetzsch,26 Annukka Ritvanen,27 Gioacchino Scarano,28 Csaba Siffel,29 Antonin S ıpek,30
Elena Szabova,31 Giovanna Tagliabue,32 Stein Emil Vollset,33 Wladimir Wertelecki,34
Ludmila Zhuchenko,35 and Pierpaolo Mastroiacovo1
* 1
Centre of the International Clearinghouse for Birth Defects Surveillance and Research, Roma, Italy
2
Division of Medical Genetics, Department of Pediatrics, University of Utah Health Sciences Center, Salt Lake City, Utah
3
Istituto Clinico di Pediatria Preventiva e Neonatologia, Universita di Bologna, Bologna, Italy
4
Departments of Genetics and Pathology, Uppsala University, Uppsala, Sweden
5
The Swedish Birth Defects Registry, Stockholm, Sweden
6
Western Australia Birth Defects Registry, Perth, Australia
7
Victoria Birth Defects Registry, Melbourne, Australia
8
Registre des Malformations en Rhone Alpes (REMERA), Facult e Laennec, Lyon, France
9
Eurocat Northern Netherlands, Department of Genetics, University Medical Center Groningen, Groningen, the Netherlands
10Sicilian Registry of Congenital Malformations (ISMAC), Genetica Medica—Dipartimento Materno Infantile ARNAS Garibaldi Nesima, Catania,
Italy
11Regional Register Congenital Malformation Maule Health Service (RRMC-SSM), Linares, Chile
12INAGEMP, and ECLAMC at CEMIC, Argentina
13Instituto Oswaldo Cruz, Brazil
14Hungarian Congenital Abnormality Registry (HCAR), Budapest, Hungary
15Tabriz Registry of Congenital Anomalies (TRoCA) and National Public Health Management Centre (NPMC), Tabriz University of Medical Sciences,
Tabriz, Iran
16Malta Congenital Anomalies Registry, Department of Health Information and Research, Guardamangia, Malta
17Department of Obstetrics, Gynecology and Molecular Reproductive Science, Yokohama City University School of Medicine, Yokohama, Japan
18Israel Birth Defects Surveillance Program (IBDSP), Beer-Sheva, Israel
19Alberta Congenital Anomalies Surveillance System, Alberta Health & Wellness, Department of Clinical Genetics, Alberta Children’s Hospital,
Calgary, AB, Canada
20Texas Department of State Health Services, Birth Defects Epidemiology and Surveillance Branch, Austin, Texas
21Dublin EUROCAT Registry, Health Service Executive, Dublin, Ireland
22March of Dimes/California Birth Defects Monitoring Program, Emeryville, California
23CARIS—Welsh Congenital Anomaly Register, Swansea, Wales, UK
24RYVEMCE, Department of Genetics, National Institute of Medical Sciences and Nutrition Salvador Zubir an, Mexico City, Mexico
25Tuscany Registry of Congenital Defects (RTDC), Epidemiology Unit, IFC-CNR, Pisa, Italy
26Malformation Monitoring Centre, Saxony-Anhalt, Germany
27National Research and Development Centre for Welfare and Health (STAKES), Helsinki, Finland
28Birth Defects Campania Registry, Medical Genetics Department, General Hospital ‘‘G. Rummo’’, Benevento, Italy
29Metropolitan Atlanta Congenital Defects Program, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control
and Prevention, Atlanta, Georgia
30Department of Medical Genetics, Thomayer University Hospital, Prague, Czech Republic
31Slovak Teratologic Information Centre, Slovak Medical University, Bratislava, Slovak Republic
32Lombardy Birth Defects Registry (LBDR), National Cancer Institute, Milano, Italy
33Medical Birth Registry of Norway, Norwegian Institute of Public Health, Department of Public Health and Primary Health Care, University of
Bergen, Bergen, Norway
34OMNI-Net Ukraine, Department of Medical Genetics, University of South Alabama, Mobile, Alabama
35Moscow Regional Research Scientific Institute of Obstetrics and Gynecology, Moskow, Russia
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