TABLE 2

Group Differences on Cognitive Tasks Among VLBW and Term-born Young Adults, Unadjusted

MeasureTaskVLBW (n = 147), Mean ± SDTerm-born (n = 171), Mean ± SDDifference, % (95% CI)PCohen's d ESa
Reaction time, msbSRT285.00 ± 1.15274.00 ± 1.134.0 (1.1–7.0)c.0070.30
CRT468.00 ± 1.16454.00 ± 1.123.2 (0.3–6.2)c.0320.24
WM655.00 ± 1.23604.00 ± 1.228.4 (3.7–13.4)c<.0010.40
DA336.00 ± 1.22314.00 ± 1.217.2 (2.7–11.9)c.0020.36
AL1299.00 ± 1.251220.00 ± 1.266.4 (1.3–11.9)c.0140.28
Accuracy, hit rate, %dAL80.20 ± 10.1085.70 ± 7.505.5 (3.6–7.5)e<.0010.63
  • a The group mean difference divided by the pooled SD of the group.30

  • b T test comparing logarithm (log 10) reaction times on CogState tasks. As a result of positively skewed distributions, geometric means ± SD are reported.

  • c Group difference; a positive value indicates a longer reaction time for VLBW individuals.

  • d T test comparing percentage of correct responses. The arithmetic mean ± SD is reported.

  • e Mean difference; indicates the absolute percentage difference between groups.