biostudies-literatureMason DEconomic and Social Research CouncilKing's College LondonMedical Research Council3165-3179https://www.ebi.ac.uk/biostudies/studies/S-EPMC8349337biostudies-literatureUnknown51(9)Longitudinal studies have generally reported poor outcomes in adulthood for the majority of individuals (c.50-60%) with autism. Several factors putatively predict outcome (e.g. IQ), but findings remain mixed. This paper presents an updated meta-analysis of autism outcome studies and extends previous findings with additional analyses (including meta-regression). A total of 4088 records was screened and 18 studies, involving 1199 individuals, were included in the quantitative analysis. Estimated percentages indicated that 20.0% of participants were rated as having a good outcome, 26.6% a fair outcome, and 49.3% a poor outcome. Meta-regression indicated that lower IQ in adulthood was predictive of poor outcome; other meta-regression models did not survive correction for multiple comparisons. Journal of autism and developmental disordersA Meta-analysis of Outcome Studies of Autistic Adults: Quantifying Effect Size, Quality, and Meta-regression.PMC83493372106586Glaser KHappe FKempton MJStewart GRMason DCapp SJHowlin PfalseA Meta-analysis of Outcome Studies of Autistic Adults: Quantifying Effect Size, Quality, and Meta-regression.Longitudinal studies have generally reported poor outcomes in adulthood for the majority of individuals (c.50-60%) with autism. Several factors putatively predict outcome (e.g. IQ), but findings remain mixed. This paper presents an updated meta-analysis of autism outcome studies and extends previous findings with additional analyses (including meta-regression). A total of 4088 records was screened and 18 studies, involving 1199 individuals, were included in the quantitative analysis. Estimated percentages indicated that 20.0% of participants were rated as having a good outcome, 26.6% a fair outcome, and 49.3% a poor outcome. Meta-regression indicated that lower IQ in adulthood was predictive of poor outcome; other meta-regression models did not survive correction for multiple comparisons. 2021-01-01T00:00:00Z2021 Sep2026-07-16T09:13:20.864Z2026-07-09T10:52:12.694ZS-EPMC83493373320035210.1007/s10803-020-04763-2