Introduction
Methods
Participants
Diagnostic Assessment
The Autism Diagnostic Interview-Revised (ADI-R)
The Autism Diagnostic Observation Schedule (ADOS)
Statistical Analyses
Results
Demographic Characteristics
Girls with ASD | Boys with ASD | Effect size | t/χ2
|
P
| |
---|---|---|---|---|---|
Mean (SD) | Mean (SD) | ||||
n
| 228 | 836 | 0.03 | 0.84 | 0.361 |
Verbal (%) | 134 (58.77%) | 463 (55.38%) | |||
Non-verbal (%) | 94 (41.23%) | 373 (44.62%) | |||
Age in months
| |||||
Verbal | 52.04 (17.86) | 55.07 (16.32) | 0.18 | 1.85 | 0.065 |
Non-verbal | 35.49 (10.79) | 36.37 (10.84) | 0.06 | 0.71 | 0.48 |
Word speech delay (n, %) | 155 (67.98) | 423 (50.60) | 0.14 | 21.82 | <0.001 |
Phrase speech delay (n, %) | 103 (45.18) | 294 (35.17) | 0.09 | 7.67 | 0.006 |
Diagnosis (n, %) | |||||
Autism | 204 (89.47) | 761 (91.03) | 0.06 | 0.51 | 0.474 |
Asperger’s disorder | 17 (7.46) | 64 (7.66) | 0.01 | 0.01 | 0.92 |
PDD-NOS | 7 (3.07) | 11 (1.31) | 0.18 | 3.32 | 0.069 |
Sex Differences in Social Reciprocity and Communication Domains
Scores | Girls with ASD | Boys with ASD | Effect size |
F
|
P
|
---|---|---|---|---|---|
Mean (SD) | Mean (SD) | ||||
Non-verbal behaviors to regulate social interaction (A1)
| |||||
Verbal | 3.20 (1.22) | 3.04 (1.18) | 0.13 | 1.69 | 0.194 |
Non-verbal | 3.69 (1.25) | 3.56 (1.30) | 0.10 | 0.86 | 0.353 |
Develop peer relationships (A2)
| |||||
Verbal | 4.13 (1.85) | 4.13 (1.90) | 0.00 | 1.17 | 0.279 |
Non-verbal | 3.20 (1.60) | 3.17 (1.55) | 0.02 | 0.33 | 0.568 |
Share enjoyment (A3)
| |||||
Verbal | 3.77 (1.48) | 3.62 (1.52) | 0.10 | 0.46 | 0.499 |
Non-verbal | 4.59 (1.27) | 4.60 (1.35) | 0.01 | 0.01 | 0.907 |
Socio-emotional reciprocity (A4)
| |||||
Verbal | 4.99 (1.98) | 4.62 (1.60) | 0.22 | 3.89 | 0.049 |
Non-verbal | 6.35 (1.84) | 5.70 (1.65) | 0.38 | 11.08 | 0.001 |
ADI-R social reciprocity domain (A)
| |||||
Verbal | 16.10 (4.83) | 15.41 (4.02) | 0.16 | 3.30 | 0.070 |
Non-verbal | 17.83 (4.57) | 17.03 (4.21) | 0.19 | 3.12 | 0.078 |
ADOS social reciprocity domain (A)
| |||||
Verbal | 8.93 (2.74) | 8.80 (2.80) | 0.04 | 0.13 | 0.715 |
Non-verbal | 9.86 (2.33) | 9.42 (2.68) | 0.17 | 1.97 | 0.161 |
Scores | Girls with ASD | Boys with ASD | Effect size |
F
|
P
|
---|---|---|---|---|---|
Mean (SD) | Mean (SD) | ||||
Gesture communication (B1)
| |||||
Verbal | 4.12 (2.06) | 3.27 (2.07) | 0.40 | 14.54 | <0.001 |
Non-verbal | 5.78 (1.71) | 5.62 (1.92) | 0.08 | 0.52 | 0.473 |
Conversation (B2)
| |||||
Verbal | 2.69 (1.38) | 2.90 (1.44) | 0.14 | 1.70 | 0.192 |
Repetitive speech (B3)
| |||||
Verbal | 2.78 (1.01) | 3.10 (1.16) | 0.29 | 9.04 | 0.003 |
Play (B4)
| |||||
Verbal | 3.87 (1.31) | 4.03 (1.33) | 0.12 | 1.42 | 0.233 |
Non-verbal | 4.99 (1.07) | 4.97 (1.01) | 0.02 | 0.04 | 0.85 |
ADI-R communication domain (B)
| |||||
Verbal | 13.46 (3.44) | 13.30 (3.63) | 0.05 | 0.05 | 0.824 |
Non-verbal | 10.77 (2.36) | 10.59 (2.50) | 0.07 | 0.39 | 0.533 |
ADOS communication domain (B)
| |||||
Verbal | 5.87 (1.88) | 5.50 (2.07) | 0.18 | 2.32 | 0.128 |
Non-verbal | 6.56 (1.58) | 5.99 (1.85) | 0.32 | 7.65 | 0.006 |
Sex Differences in RRBs Domain
Scores | Girls (n = 228) | Boys (n = 836) |
Z
|
P
| ||||
---|---|---|---|---|---|---|---|---|
0 | 1 | 2 | 0 | 1 | 2 | |||
Unusual preoccupation
| ||||||||
Verbal | 90 (39.47%) | 33 (14.47%) | 11 (4.82%) | 252 (30.14%) | 137 (16.39%) | 74 (8.85%) | 2.83 | 0.005 |
Non-verbal | 60 (26.32%) | 28 (12.28%) | 6 (2.63%) | 200 (23.92%) | 116 (13.88%) | 57 (6.82%) | 2.15 | 0.032 |
Circumscribed interest
| ||||||||
Verbal | 68 (29.82%) | 54 (23.68%) | 12 (5.26%) | 201 (24.04%) | 158 (18.90%) | 104 (12.44%) | 2.54 | 0.011 |
Non-verbal | 64 (28.07%) | 25 (10.96%) | 5 (2.19%) | 285 (34.09%) | 62 (7.42%) | 26 (3.11%) | 1.45 | 0.141 |
Verbal rituals*
| ||||||||
Verbal | 91 (39.91%) | 37 (16.23%) | 6 (2.63%) | 261 (31.22%) | 126 (15.07%) | 76 (9.09%) | 2.98 | 0.003 |
Compulsions/rituals
| ||||||||
Verbal | 58 (25.44%) | 55 (24.12%) | 21 (9.21%) | 257 (30.74%) | 110 (13.16%) | 96 (11.48%) | 1.45 | 0.148 |
Non-verbal | 54 (23.68%) | 31 (13.60%) | 9 (3.95%) | 247 (29.55%) | 69 (8.25%) | 57 (6.82%) | 0.97 | 0.331 |
Hand and finger mannerisms
| ||||||||
Verbal | 87 (38.16%) | 36 (15.79%) | 11 (4.82%) | 325 (38.88%) | 83 (9.93%) | 55 (6.58%) | 0.77 | 0.442 |
Non-verbal | 51 (22.37%) | 28 (12.28%) | 15 (6.58%) | 248 (29.67%) | 80 (9.57%) | 45 (5.38%) | 2.13 | 0.033 |
Stereotyped body movements
| ||||||||
Verbal | 81 (35.53%) | 39 (17.11%) | 14 (6.14%) | 256 (30.62%) | 114 (13.64%) | 93 (11.12%) | 1.67 | 0.096 |
Non-verbal | 34 (14.91%) | 40 (17.54%) | 20 (8.77%) | 201 (24.04%) | 92 (11.00%) | 81 (9.69%) | 2.22 | 0.026 |
Repetitive use of objects/interest in parts of objects
| ||||||||
Verbal | 72 (31.58%) | 50 (21.93%) | 12 (5.26%) | 73 (8.73%) | 206 (24.64%) | 184 (22.01%) | 9.22 | <0.001 |
Non-verbal | 37 (16.23%) | 43 (18.86%) | 14 (6.14%) | 33 (3.95%) | 145 (17.34%) | 195 (23.33%) | 7.95 | <0.001 |
Unusual sensory interest
| ||||||||
Verbal | 58 (25.44%) | 67 (29.39%) | 9 (3.95%) | 213 (25.48%) | 254 (30.38%) | 26 (3.11%) | 0.45 | 0.881 |
Non-verbal | 26 (14.40%) | 48 (21.05%) | 20 (8.77%) | 114 (13.64%) | 219 (26.20%) | 40 (4.78%) | 1.68 | 0.093 |
Sex Differences in Early Abnormal Development
Age (months) | Girls with ASD | Boys with ASD | Effect size |
F
|
P
|
---|---|---|---|---|---|
Mean (SD) | Mean (SD) | ||||
Age when parents first noticed developmental abnormalities
| |||||
Verbal | 34.71 (12.80) | 29.73 (10.61) | 0.45 | 34.06 | <0.001 |
Non-verbal | 27.27 (11.03) | 21.94 (6.69) | 0.54 | 51.09 | <0.001 |
Age when developmental abnormalities probably first manifest in interviewer’s judgment
| |||||
Verbal | 32.21 (9.72) | 24.50 (7.32) | 0.44 | 114.27 | <0.001 |
Non-verbal | 27.45 (8.88) | 20.26 (5.85) | 0.56 | 115.56 | <0.001 |
Age of first single words
| |||||
Verbal | 23.81 (8.11) | 21.79 (7.85) | 0.25 | 6.94 | 0.009 |
Age of first phrases
| |||||
Verbal | 31.25 (9.51) | 28.98 (8.29) | 0.26 | 8.16 | 0.004 |
Sex Differences in Diagnostic Cut-off Scores
Girls with ASD | Boys with ASD | Effect size | χ2
|
P
| |
---|---|---|---|---|---|
Satisfied cut-off scores (n) | Satisfied cut-off scores (n) | ||||
ADI-R social reciprocity (A)
| |||||
Verbal | 123 (91.79%) | 447 (96.54%) | 0.10 | 5.44 | 0.020 |
Non-verbal | 88 (93.62%) | 361 (96.78%) | 0.07 | 2.03 | 0.154 |
ADI-R communication (B)
| |||||
Verbal | 127 (94.78%) | 450 (97.19%) | 0.06 | 1.87 | 0.171 |
Non-verbal | 91 (96.81%) | 351 (94.10%) | 0.05 | 1.09 | 0.297 |
ADI-R RRBs (C)
| |||||
Verbal | 100 (74.63%) | 416 (89.85%) | 0.19 | 20.53 | <0.001 |
Non-verbal | 69 (73.40%) | 316 (84.72%) | 0.12 | 6.64 | 0.010 |
ADI-R abnormal development before 36 months (D)
| |||||
Verbal | 130 (97.01%) | 458 (98.92%) | 0.06 | 2.54 | 0.111 |
Non-verbal | 93 (98.93%) | 370 (99.20%) | 0.01 | 0.06 | 0.807 |
ADOS communication (B)
| |||||
Verbal | 128 (95.52%) | 426 (92.01%) | 0.06 | 1.92 | 0.166 |
Non-verbal | 93 (98.94%) | 370 (99.20%) | 0.01 | 0.06 | 0.807 |
ADOS social reciprocity (A)
| |||||
Verbal | 131 (97.76%) | 452 (97.62%) | 0.00 | 0.01 | 0.926 |
Non-verbal | 94 (100.00%) | 366 (98.12%) | 0.06 | 1.79 | 0.181 |
ADOS communication + social reciprocity (A + B)
| |||||
Verbal | 130 (97.01%) | 432 (93.30%) | 0.07 | 2.59 | 0.107 |
Non-verbal | 94 (100.00%) | 364 (97.59%) | 0.07 | 2.31 | 0.128 |