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Table 1 Sample characteristics of extremely preterm participants and term-born controls assessed and not assessed at 19 years of age

From: Extremely preterm birth and autistic traits in young adulthood: the EPICure study

Variable EP assessed
N = 129
EPa not assessed
N = 177
Difference EP assessed vs. not assessed
p valuec
Controls assessed
N = 65
Controlsb not assessed
N = 88
Difference controls assessed vs. not assessed
p valuec
Difference EP vs. controls assessed
p valuec
Characteristics at 19 years
Age at 19 year assessment, years
 Mean (SD)
19.3 (0.6) 19.2 (0.5) 0.162
Male Sex
 n/N (%)
61/129 (47.3) 87/177 (49.2) 0.747 25/65 (38.5) 39/88 (44.3) 0.440 0.243
Gestational age, weeks        
 22 weeks, n/N (%) 2/129 (1.6) 0/177 (0.0) 0.280
 23 weeks, n/N (%) 13/129 (10.1) 13/177 (7.3)  
 24 weeks, n/N (%) 37/129 (28.7) 60/177 (33.9)  
 25 weeks, n/N (%) 77/129 (59.7) 104/177 (58.8)  
Birth weight grams
 Mean (SD)
740.8 (121.9) 751.4 (108.9) 0.422
Parent SES category at 19 yearsd        
 Higher professional/managerial n/N (%) 69/125 (55.2) 39/64 (60.9) 0.322
 Intermediate occupations n/N (%) 22/125 (17.6) 15/64 (23.4)  
 Routine/manual occupations n/N (%) 22/125 (17.6) 7/64 (10.9)  
 Other n/N (%) 12/125 (9.6) 3/64 (4.7)  
WASI-II FSIQe
Mean (SD)
85.9 (16.7)
(n = 127)
103.9 (10.2)
(n = 64)
< 0.001
Cognitive impairment (IQ < 70)
n/N (%)
20/127 (15.8) 0/64 (0)
Outcome data at 11 years
Parent SES categoryd        
  Professional/managerial n/N (%) 57/110 (51.8) 21/69 (30.4) 0.002 36/60 (60.0) 41/78 (52.6) 0.789 0.657
 Intermediate occupations n/N (%) 27/110 (24.5) 17/69 (24.6)   10/60 (16.7) 13/78 (16.7)   
 Routine/manual n/N (%) 24/110 (21.8) 22/69 (31.9)   13/60 (21.7) 22/78 (28.2)   
 Other n/N (%) 2/110 (1.8) 9/69 (13.0)   1/60 (1.7) 2/78 (2.6)   
KABC MPCf
Mean (SD)
86.3 (16.2)
(n = 121)
80.8 (19.3)
(n = 95)
0.028 105.7 (11.2)
(n = 65)
102.9 (10.9) (n = 88) 0.111 < 0.001
Cognitive impairment (IQ < 70)
n/N (%)
10/121 (8.3) 19/95 (20.0) 0.012 0/65 (0.0) 0/88 (0.0) 0.017
DAWBA Autism Diagnosisg
n/N (%)
10/116 (8.6) 6/84 (7.1) 0.704 0/62 (0.0) 0/81 (0.0) 0.017
SCQ total scoreh
Mean (SD)
8.0 (7.8)
(n = 109)
7.1 (6.6)
(n = 73)
0.414 2.5 (2.5)
(n = 58)
3.6 (3.9)
(n = 79)
0.061 < 0.001
  1. aDenominator: N = 306 survivors at 19 years
  2. bDenominator: N = 153 controls assessed at 11 years
  3. cTwo-sided p values were calculated using x [2] test for categorical variables and t test for continuous variables
  4. dSES Socio-economic category classified using UK Office for National Statistics Socio-Economic Classification System: (1) high: higher managerial, administrative and professional occupation; (2) medium: intermediate occupation; (3) low: routine and manual occupation; and (4) other. For participants with missing SES data at 19 years, data collected at 11 years of age were used to minimise data loss
  5. eWASI-II FSIQ indicates Full-Scale IQ from the Wechsler Abbreviated Intelligence Scale, 2nd Edition. fKABC MPC indicates Kaufman-Assessment Battery for Children, Mental Processing Composite
  6. gDAWBA indicates the Development and Well-Being Assessment
  7. hSCQ indicates Social Communication Questionnaire