Lucy K Smith1, Naho Morisaki2, Nils-Halvdan Morken3, Mika Gissler4, Paromita Deb-Rinker5, Jocelyn Rouleau5, Stellan Hakansson6, Michael R Kramer7, Michael S Kramer8. 1. Department of Health Sciences, University of Leicester, Leicester, United Kingdom. 2. National Center for Child Health and Development, Tokyo, Japan; morisaki-n@ncchd.go.jp. 3. Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway. 4. National Institute for Health and Welfare, Helsinki, Finland. 5. Public Health Agency of Canada, Ottawa, Canada. 6. Department of Clinical Sciences, Umeå University, Umeå, Sweden. 7. Department of Epidemiology, Emory University, Atlanta, Georgia; and. 8. Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Canada.
Abstract
OBJECTIVES: To explore international differences in the classification of births at extremely low gestation and the subsequent impact on the calculation of survival rates. METHODS: We used national data on births at 22 to 25 weeks' gestation from the United States (2014; n = 11 144), Canada (2009-2014; n = 5668), the United Kingdom (2014-2015; n = 2992), Norway (2010-2014; n = 409), Finland (2010-2015; n = 348), Sweden (2011-2014; n = 489), and Japan (2014-2015; n = 2288) to compare neonatal survival rates using different denominators: all births, births alive at the onset of labor, live births, live births surviving to 1 hour, and live births surviving to 24 hours. RESULTS: For births at 22 weeks' gestation, neonatal survival rates for which we used live births as the denominator varied from 3.7% to 56.7% among the 7 countries. This variation decreased when the denominator was changed to include stillbirths (ie, all births [1.8%-22.3%] and fetuses alive at the onset of labor [3.7%-38.2%]) or exclude early deaths and limited to births surviving at least 12 hours (50.0%-77.8%). Similar trends were seen for infants born at 23 weeks' gestation. Variation diminished considerably at 24 and 25 weeks' gestation. CONCLUSIONS: International variation in neonatal survival rates at 22 to 23 weeks' gestation diminished considerably when including stillbirths in the denominator, revealing the variation arises in part from differences in the proportion of births reported as live births, which itself is closely connected to the provision of active care.
OBJECTIVES: To explore international differences in the classification of births at extremely low gestation and the subsequent impact on the calculation of survival rates. METHODS: We used national data on births at 22 to 25 weeks' gestation from the United States (2014; n = 11 144), Canada (2009-2014; n = 5668), the United Kingdom (2014-2015; n = 2992), Norway (2010-2014; n = 409), Finland (2010-2015; n = 348), Sweden (2011-2014; n = 489), and Japan (2014-2015; n = 2288) to compare neonatal survival rates using different denominators: all births, births alive at the onset of labor, live births, live births surviving to 1 hour, and live births surviving to 24 hours. RESULTS: For births at 22 weeks' gestation, neonatal survival rates for which we used live births as the denominator varied from 3.7% to 56.7% among the 7 countries. This variation decreased when the denominator was changed to include stillbirths (ie, all births [1.8%-22.3%] and fetuses alive at the onset of labor [3.7%-38.2%]) or exclude early deaths and limited to births surviving at least 12 hours (50.0%-77.8%). Similar trends were seen for infants born at 23 weeks' gestation. Variation diminished considerably at 24 and 25 weeks' gestation. CONCLUSIONS: International variation in neonatal survival rates at 22 to 23 weeks' gestation diminished considerably when including stillbirths in the denominator, revealing the variation arises in part from differences in the proportion of births reported as live births, which itself is closely connected to the provision of active care.
Authors: Andrei S Morgan; Jennifer Zeitlin; Karin Källén; Elizabeth S Draper; Karel Maršál; Mikael Norman; Fredrik Serenius; Stef van Buuren; Samantha Johnson; Valérie Benhammou; Véronique Pierrat; Monique Kaminski; Laurence Foix L'Helias; Pierre-Yves Ancel; Neil Marlow Journal: Acta Paediatr Date: 2021-09-12 Impact factor: 4.056
Authors: Matthew A Rysavy; Katrin Mehler; André Oberthür; Johan Ågren; Satoshi Kusuda; Patrick J McNamara; Regan E Giesinger; Angela Kribs; Erik Normann; Susan J Carlson; Jonathan M Klein; Carl H Backes; Edward F Bell Journal: J Pediatr Date: 2021-03-07 Impact factor: 6.314