The latest statistical analyses was indeed presented making use of the SAS 9.step three software program (SAS Institute, Cary, NC, USA). This new ORs and you can CRs due to their 95 % depend on intervals was projected toward GENMOD procedure.
Efficiency
The features of the data cohorts is displayed within the Table step one, for the amount of male and female infants created from inside the for each and every GA category during the 1973–1978 and you will 1995–2010. The fresh new ratio of midterm births (74.6 % in the early vs. 70.5 % throughout the later months) is high in early cohort, additionally the proportion away from very early name births (21.0 % in the early against. 25.5 % in the later several months) is actually low in the early cohort. The brand new ratio of late preterm births was comparable on the a few cohorts (4.step three % in early vs. cuatro.0 % in the late months). Suggest maternal age the very first time months (1973–1978) try 27 decades (SD = 5), and you can indicate maternal ages from the later time (1995–2010) is actually 29 (SD = 5).