Comprehensive synthesis of early intensive behavioral interventions for young children with autism based on the UCLA young autism project model.

Reichow et al. (2009) pooled every published trial that copied the UCLA Young Autism Project.

They asked: does 25-40 hours a week of one-to-one ABA raise IQ and daily-living scores for preschoolers with autism?

The team used meta-analysis to average results across all qualifying studies.

The overall answer was yes — EIBI produced meaningful gains on average.

Kids varied widely: some shot up 30 points, some barely budged.

The paper warns that you must watch each child and adjust the program.

Rodgers et al. (2021) updated the same question with finer data. Their 2021 individual-kid meta-analysis shows smaller, but still real, IQ and adaptive gains.

Reichow (2012) looked at five later meta-analyses and found the same medium effect — the signal holds.

Kovshoff et al. (2011) extends the story: without a maintenance plan, most gains fade within two years after EIBI stops.

Start EIBI early, but do not treat it as a one-time fix. Use the first six months to test if the child is moving; if not, tweak intensity, goals, or parent training. Build a hand-off plan before you fade hours so skills stick.