Selection bias on intellectual ability in autism research: a cross-sectional review and meta-analysis

Table 1 Descriptive statistics for studies and participant groups by field

Field	Studies, N (%)	Total number of participants		Number with ASD		Characteristics of ASD population
Field		Median	IQR	Median	IQR	Mean % male	Mean age (years)
Interventions	35 (11)	33	70	30	48	82	11
Biology—neuroimaging, neuropathology, genetics and omics	38 (13)	51	69	26	41	83	17
Epidemiology	22 (7)	10,197	54,362	457	1623	72	8
Psychology and cognitive neuroscience	126 (42)	54	49	24	25	82	17
Social, school, education and family circumstances	45 (15)	97	198	74	123	78	14
Diagnostics, diagnostic scales, identification, screening and scale development	35 (12)	162	298	103	197	79	15
All	301 (100)	62	116	32	67	80	15