TABLE 1.
Study characteristics
| Author | Country | Design | Control group | N | Developmental stage (range) | M (SD) in years | % Female |
|---|---|---|---|---|---|---|---|
| Bitsika and Sharpley (2018) | Australia | Cross‐sectional | None | 37 | Childhood (6–11 years) | 8.5 (1.5) | 100% |
| Chistol et al. (2018) | US | Cross‐sectional | Age‐matched NT | 53 AUT | Childhood (3–11 years) | 6.6 (2.1) AUT | 17% AUT |
| 56 NT | 6.7 (2.4) NT | 22% NT | |||||
| Crasta et al. (2014) | India | Cross‐sectional | ID | 41 AUT | Childhood (3–10 years) | 6.42 (1.92) AUT | 26% a |
| 56 ID | 7.15 (1.76) NT | ||||||
| Johnson et al. (2014) | US | Cross‐sectional | None | 256 | Childhood (2–11 years) | 5.4 (2.4) | 16% |
| Koshy (2015) | UK | Cross‐sectional | None | 144 ASD | Childhood and adolescence (2–18 years) | 5.2 ASD | 18.2% ASD |
| 391 autism | 4.2 autism, | 18.8% autism | |||||
| 123 asperger | 7.4 asperger | 12.2% asperger | |||||
| Kral et al. (2015) | US | Cross‐sectional | NT | 25 AUT | Childhood (4–6 years) | 5.0 (0.9) AUT | 28% AUT |
| 30 TD | 5.2 (0.7) NT | 53% NT | |||||
| Lane et al. (2014) | Australia | Cross‐sectional | None | 36 | Childhood (3–10 years) | 6.7 | 20% |
| Leader et al. (2020) | Ireland | Cross‐sectional | None | 136 | Childhood and adolescence (ns) | 8.46 (4.13) | 28% |
| Leader et al. (2021) | Ireland | Cross‐sectional | None | 120 | Childhood and adolescence (ns) | 8.0 (3.79) | 22.5% |
| Martins et al. (2008) | Australia | Cross‐sectional | NT, SIB | 41 AUT | Childhood (2–12 years) | ‐ | 17% AUT |
| 14 SIB | 50% SIB | ||||||
| 41 NT | 44% NT | ||||||
| Nadon et al. (2011) | Canada | Cross‐sectional | None | 95 | Childhood (3–10 years) | 7.3 (2.4) | 8.4% |
| Padmanabhan and Schroff (2020) | India | Cross‐sectional | None | 146 | Childhood (3–11 years) | 7.09 (2.55) | 19% |
| Panerai et al. (2020) | Italy | Cross‐sectional | None | 111 | Childhood (2–12 years) | Median, split into: | Split into: |
| 5.0 AUT | 18.9% AUT‐W | ||||||
| 5.3 NT | 24.3% aut‐wo | ||||||
| Pomoni (2016) | UK | Cross‐sectional | NT | 103 AUT | Childhood (2–14 years) | 7.32 (2.58) AUT only | 22.3% AUT |
| 151 NT | 51.0% NT | ||||||
| Riccio et al. (2018) | Italy | Cross‐sectional | Age‐matched NT | 43 AUT | Childhood (2–11 years) | 6.28 (2.3) AUT 7.2 NT | 30% AUT |
| 41 NT | |||||||
| Schnizler (2014) | US | Cross‐sectional | Age‐ and IQ‐matched NT | 28 AUT | Childhood and adolescence (2–18 years) | 12.75 (1.90) AUT | 21.4% AUT |
| 31 NT | 13.07 (2.92) NT | 45.2% NT | |||||
| Shamaya et al. (2017) | Israel | Cross‐sectional | Age‐ and gender‐matched NT, SIB | 50 AUT | Childhood (3–6 years) | In months: | 19.6% AUT |
| 12 SIB | 5.41 (11.1) AUT | 28.6% SIB | |||||
| 29 NT | 77 (32) SIB | 24.1% NT | |||||
| 51.6 (11.6) NT | |||||||
| Smith et al. (2020) | UK | Cross‐sectional | NT, TS, ADHD | 27 AUT | Childhood and adolescence (6–17 years) | ‐ | 40.7% AUT |
| 27 NT | 18.5% NT | ||||||
| 27 TD | 18.5% TS | ||||||
| 17 ADHD | 41.2% ADHD | ||||||
| Suarez et al. (2012, 2014) | US | 1. Cross‐sectional 2. Longitudinal | None | 1. 141 | Childhood (3–9 years) | 1. Split into: | 1. 5% |
| 2. 54 | 6.23 (1.85) severe | 2. 12% | |||||
| 6.24 (1.39) moderate | |||||||
| 6.88 (1.51) typical | |||||||
| 2. ‐ | |||||||
| Tanner et al. (2015) | US | Cross‐sectional | None | 35 | Childhood (4–10 years) | Split into: | Split into: |
| 6.5 (1.9) selective | 11.8% selective | ||||||
| 6.9 (2.0) nonselective | 5.6% nonselective | ||||||
| Trinh (2014) | US | Cross‐sectional | NT | 9 AUT | Childhood (5–12 years) | 9.11 (0.72) AUT | ‐ |
| 16 NT | 7.19 (0.53) NT | ||||||
| Wang et al. (2019) | China | Cross‐sectional | Age‐matched NT | 81 AUT | Childhood (3–7 years) | 5.18 (0.92) AUT | 17.3% AUT |
| 153 NT | 5.34 (1.14) NT | 16.8% NT | |||||
| Zickgraf and Mayes (2018) | US | Cross‐sectional | None | 1112 | Childhood and adolescence (1–17 years) | 6.4 (3.3) | 10.6% |
| Zickgraf et al. (2020) | US | Cross‐sectional b | None | 185 | Childhood, adolescence and young adulthood (4–17 years) | 8.65 (3.03) | 28% |
| Zobel‐Lachuisa et al. (2015) | US | Cross‐sectional | NT | 34 AUT | Childhood (5–12 years) | 8.61 (2.32) AUT | 3% AUT |
| 34 NT | 8.76 (2.23) NT | 20.6% NT |
Abbreviations: ADHD, attention deficit hyperactivity disorder; ASD, autism spectrum disorder; AUT, autism; AUT‐W, autism with feeding problems; AUT‐WO, autism without feeding problems; DD, developmental delay; ID, intellectual disability; NT, neurotypical; OCD, obsessive compulsive disorder; REP, representative sample; SIB, neurotypical siblings of an autistic child; TS, Tourette's syndrome; UG, undergraduate sample.
a
Total sample.
b
Secondary data analysis.