Abstract
OBJECTIVE: To assess the relationship between the 5 min Apgar score and developmental vulnerability at 5 years of age. DESIGN: Population-based retrospective cohort study. SETTING: Manitoba, Canada. PARTICIPANTS: All children born between 1999 and 2006 at term gestation, with a documented 5 min Apgar score. EXPOSURE: 5 min Apgar score. MAIN OUTCOME MEASURES: Childhood development at 5 years of age, expressed as vulnerability (absent vs present) on five domains of the Early Development Instrument: physical health, social competence, emotional maturity, language and cognitive development, and communication skills. RESULTS: Of the 33,883 children in the study, most (82%) had an Apgar score of 9; 1% of children had a score <7 and 5.6% had a score of 10. Children with Apgar scores <10 had higher odds of vulnerability on the physical domain at age 5 years compared with children with a score of 10 (eg, adjusted OR (aOR) for Apgar 9=1.23, 95% CI 1.05 to 1.44). Similarly, children with Apgar scores of <10 were more vulnerable on the emotional domain (eg, aOR for Apgar 9=1.20, 95% CI 1.03 to 1.41). Nevertheless, the Apgar-based prognostic model had a poor sensitivity for physical vulnerability (19%, 95% CI 18% to 20%). Although the Apgar score-based prognostic model had reasonable calibration ability and risk-stratification accuracy for identifying developmentally vulnerable children, classification accuracy was poor. CONCLUSIONS: The risk of developmental vulnerability at 5 years of age is inversely associated with the 5 min Apgar score across its entire range, and the score can serve as a population-level indicator of developmental risk.