Table 1 Summary results of the included studies
1st author, year | Country | Design | Sample size | Estimate | Adjustment | Age range (year)/mean | Autism criteria |
|---|---|---|---|---|---|---|---|
Brumbaugh, 2020 | USA | Cohort | 7876 | Hazard ratio | Adjusted/crude | 3–21 | DSM-IV |
Leavy, 2012 | Canada | Cohort | 218110 | Odds ratio | Crude | No data | ICD-9 |
Martini, 2022 | Netherland | Case–control | 1199 | Odds ratio | Crude | 14.01 | DSM-IV/ DSM-5 |
Xie, 2017 | Sweden | Cohort | 480728 | Odds ratio | Crude | No data | ICD-9/ICD10 |
Atladottir, 2016 | Denmark | Cohort | 519692 | Odds ratio | Crude | 1–33 | ICD-8/ICD-10 |
Persson, 2020 | Sweden/Finland/ Norway | Cohort | 50816 | Relative risk | Adjusted | 2 years until diagnosis | ICD-10 |
Sugie, 2005 | Japan | Case–control | 1805 | Odds ratio | Crude | 3 years or older | DSM-IV |
Tawfeeq, 2016 | Iraq | Case–control | 200 | Odds ratio | Crude | 3–15 | No data |
Zhang, 2010 | China | Case–control | 190 | Odds ratio | Crude | 3–21 | ICD-10/CARS |
Fernandes, 2016 | India | Cross-sectional | 184 | Odds ratio | Crude | No data | No data |
Al-Ali, 2021 | Iraq | Case–control | 276 | Odds ratio | Crude | 1–20 | No data |
Hisle-Gorman, 2018 | USA | Case–control | 35040 | Odds ratio | Crude | 2–8 | ICD-9 |
Laxer, 1988 | USA | Case–control | 38182 | Odds ratio | Crude | No data | DSM-III |
Rolschau, 2020 | Denmark | Cohort | 57888 | Odds ratio | Crude | No data | ICD-10 |
Cryan, 1996 | Ireland | Case–control | 98 | Odds ratio | Crude | 4–35 | DSM-III |
Lord, 1989 | USA | Case–control | 100 | Odds ratio | Crude | 3–8 | CARS |
Gillberg, 1983 | USA | Case–control | 50 | Odds ratio | Crude | 7 years or older | No data |