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. 2016 Jan 4;142(5):498–545. doi: 10.1037/bul0000037

Table 4. Group Comparisons in Studies of Preschool Children.

Construct Comparison type Mean effect size (d) [95% CI] Number of studies [N family-risk (N control)] I2 Tau2
Note. CI = confidence interval.
* p < 0.05.
Panel A: General cognitive abilities and perceptual skills
 Nonverbal IQ Family-risk children vs. controls not at-risk −.35 [−.55, −.14]* 7 [315, (336)] 46.40 .04
Family-risk children with dyslexia vs. controls not at-risk −.21 [−.48, .06] 6 [201, (276)] 50.59 .06
Family-risk children without dyslexia vs. controls not at-risk −.06 [−.30, .18] 6 [227, (242)] 33 .03
 Auditory processing Family-risk children vs. controls not at-risk −.31 [−.59, −.03]* 2 [100, (100)] 0 0
Family-risk children with dyslexia vs. controls not at-risk −.80 [−1.57, −.04]* 1 [9, (22)] — —
Family-risk children without dyslexia vs. controls not at-risk −.21 [−.77, .35] 1 [26, (22)] — —
 Visual processing Family-risk children vs. controls not at-risk −.11 [−.29, .07] 2 [217, (2148)] 0 0
Family-risk children with dyslexia vs. controls not at-risk −.34 [−.82, .13] 1 [26, (47)] — —
Family-risk children without dyslexia vs. controls not at-risk −.08 [−.59, .43] 1 [21, (47)] — —
 Motor skills Family-risk children vs. controls not at-risk .25 [−.03, .53] 1 [101, (89)] — —
Panel B: Oral language skills
 Articulatory accuracy Family-risk children vs. controls not at-risk −.79 [−.79, −.01]* 3 [164, (133)] 61.43 .07
Family-risk children with dyslexia vs. controls not at-risk −.41 [−.94, .11] 4 [125, (187)] 46.69 .22
Family-risk children without dyslexia vs. controls not at-risk −.31 [−.69, .08] 4 [87, (187)] 33.84 .05
 Vocabulary knowledge Family-risk children vs. controls not at-risk −.65 [−.91, −.38]* 6 [436, (374)] 54.61 .06
Family-risk children with dyslexia vs. controls not at-risk −.83 [−1.42, −.24]* 6 [259, (235)] 88.38 .47
Family-risk children without dyslexia vs. controls not at-risk −.34 [−.54, −.15]* 5 [236, (192)] 0 0
 Grammar Family-risk children vs. controls not at-risk −.26 [−.66, .15] 6 [340, (276)] 81.35 .19
Family-risk children with dyslexia vs. controls not at-risk −.72 [−1.05, −.40]* 2 [55, (121)] 0 0
Family-risk children without dyslexia vs. controls not at-risk −.28 [−.54, −.02]* 3 [101, (134)] 0 0
 Phonological memory Family-risk children vs. controls not at-risk −.57 [−.79, −.35]* 4 [174, (151)] 0 0
Family-risk children with dyslexia vs. controls not at-risk −1.11 [−1.39, −.84]* 5 [98, (180)] 0 0
Family-risk children without dyslexia vs. controls not at-risk −.47 [−.72, −.22]* 5 [101, (180)] 0 0
 Verbal short-term memory Family-risk children vs. controls not at-risk −.45 [−.89, −.04]* 4 [216, (190)] 74.07 .13
Family-risk children with dyslexia vs. controls not at-risk −.65 [−1.18, −.12]* 6 [168, (182)] 80.93 .35
Family-risk children without dyslexia vs. controls not at-risk −.15 [−.40, .11] 5 [143, (135)] 10.69 .01
Panel C: Decoding specific skills
 Letter knowledge Family-risk children vs. controls not at-risk −.47 [−.60, −.34]* 7 [447, (478)] 0 0
Family-risk children with dyslexia vs. controls not at -risk −.94 [−1.42, −.45]* 7 [206, (337)] 83.74 .35
Family-risk children without dyslexia vs. controls not at-risk −.32 [−.50, −.13]* 7 [226, (290)] 4.41 .002
 Phoneme awareness Family-risk children vs. controls not at-risk −.56 [−.70, −.43]* 6 [482, (453)] 0 0
Family-risk children with dyslexia vs. controls not at-risk −.83 [−1.17, −.48]* 11 [218, (376)] 73.74 .23
Family-risk children without dyslexia vs. controls not at-risk −.32 [−.53, −.10]* 10 [262, (350)] 39.28 .05
 Rhyme awareness Family-risk children vs. controls not at-risk −.90 [−1.36, −.44]* 2 [106, (94)] 54.85 .06
Family-risk children with dyslexia vs. controls not at-risk −1.00 [−1.70, −.23]* 1 [37, (25)] — —
Family-risk children without dyslexia vs. controls not at-risk −.55 [−1.12, .02] 1 [19, (25)] — —
 Rapid naming Family-risk children vs. controls not at-risk −.61 [−.80, −.41]* 6 [381, (385)] 36.08 .02
Family-risk children with dyslexia vs. controls not at-risk −1.03 [−1.37, −.69]* 5 [119, (206)] 29.4 .04
Family-risk children without dyslexia vs. controls not at-risk −.47 [−.71, −.22]* 5 [185, (206)] 0 0