Table 2

Academic achievement at 8 years for extremely preterm and control groups born in the state of Victoria, contrasted over different eras

OutcomesBirth years
1991–199219972005
EPControlEPControlEPControl
Word reading96.2 (16.4) n=200103.1 (14.6) n=21197.1 (16.9) n=133105.5 (13.8) n=16894.1 (17.1) n=140109.4 (14.2) n=189
Mean difference (95% CI)*−5.5 (−8.5 to –2.4)−8.1 (−11.8 to –4.5)−12.3 (−16.0 to –8.5)
Spelling93.8 (12.9) n=19999.7 (13.2) n=21096.4 (16.0) n=134104.2 (14.5) n=16893.9 (17.6) n=138108.6 (15.2) n=188
Mean difference (95% CI)*−4.8 (−7.3 to –2.3)−7.7 (−11.3 to –4.1)−12.0 (−15.9 to –8.2)
Mathematics88.8 (14.3) n=19797.9 (13.6) n=21189.9 (17.5) n=13199.0 (14.5) n=16889.4 (18.9) n=140105.1 (13.4) n=188
Mean difference (95% CI)*−8.3 (−10.9 to –5.6)−9.1 (−12.9 to –5.3)−13.1 (−16.9 to –9.2)
  • *Allowing for clustering for multiple births, and adjusted for age of the child at assessment, mother’s age at birth of the child and sociodemographic variables.

  • EP, extremely preterm.