1. Objectifs

Intentions :
«High maternal education consistently is associated with a lower risk of preterm birth (PTB), but the association with extremely high education is unclear because studies usually assume linearity or use arbitrary cutpoints to categorize education. [...] Thus, it is unclear if extremely high education is as protective against PTB as moderate education, or if there are thresholds beyond which added education is not necessarily beneficial [...] [W]e sought to (1) evaluate the continuum of education in relation to PTB, (2) assess whether there are thresholds above which education is not as protective against PTB, and (3) determine whether the relationship between education and PTB varies with nativity and advancing maternal age.» (p. 1-2)

2. Méthode

Échantillon/Matériau :
«Vital statistics data compiled from birth registration certificates for all residents of the province of Québec, Canada, were obtained for 1995 through 2005. Live singleton births to Canadian-born and foreign-born mothers aged ≥ 20 years inside metropolitan areas were included (n = 537,525).» (p. 2)

Type de traitement des données :
Analyse statistique

3. Résumé

«First, we found a reverse J-shaped rather than linear relationship between education and PTB. Although this suggests that very high education was not as protective against PTB as slightly lower education, very high levels were never associated with an elevated risk of PTB (relative to 8 years). Other new findings were that (1) threshold levels of education most protective against PTB ranged from 17 to 25 years, and (2) thresholds were lower for Canadian-born than foreign-born mothers (17-21 vs. 22-25 years of education), such that foreign-born mothers required up to 4 more years of education to benefit the most from its protective influence. Finally, education was more protective against PTB in Canadian-born than foreign-born mothers, and associations increased progressively with advancing age, particularly for Canadian-born mothers. These findings suggest that a life course approach addressing maternal education, nativity, and age may be required in PTB prevention programs.» (p.3-4)