Early intervention in 208 Swedish preschoolers with autism spectrum disorder. A prospective naturalistic study.
Two years of full-time ABA gave Swedish preschoolers no extra adaptive boost over lighter, targeted lessons.
01Research in Context
What this study did
Fernell et al. (2011) watched 208 Swedish preschoolers with autism for two years.
Kids got either intensive ABA (20-plus hours a week) or lighter targeted ABA lessons.
The team tracked daily-living skills with the Vineland test every six months.
What they found
Both groups gained a few Vineland points, but the jump was tiny.
Only the kids who already had near-average IQ drove the small bump.
More hours did not give more progress — the score lines stayed on top of each other.
How this fits with other research
Kotsopoulos et al. (2021) followed Swedish kids for three years and saw big adaptive gains.
The difference: they used a data-driven plan that flexed hours each month, not a fixed high dose.
Lotfizadeh et al. (2020) in the UK also found no extra adaptive benefit when they doubled weekly hours.
Together the three studies say: clever individual planning beats simply piling on hours.
Why it matters
You can stop selling families on “more is always better.”
Check the child’s profile instead — kids with stronger IQ scores respond to any steady ABA dose.
Try adjusting goals and teaching style before you raise the weekly calendar.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Review your highest-hour cases — if Vineland is flat, cut two hours and add parent coaching instead.
02At a glance
03Original abstract
Early intervention has been reported to improve outcome in children with autism spectrum disorders (ASDs). Several studies in the field have been randomized controlled trials (RCTs). The aim of this study was to assess ASD outcome in a large naturalistic study. Two hundred and eight children, aged 20-54 months, with a clinical diagnosis of ASD were given intervention and monitored prospectively in a naturalistic fashion over a period of 2 years. The toddlers were considered representative of all but the most severely multiple disabled preschool children with ASD in Stockholm county. They fell into three cognitive subgroups: one with learning disability, one with developmental delay, and one with normal intellectual functioning. Data on intervention type and intensity were gathered prospectively in a systematic fashion. Intervention was classified into intensive applied behaviour analysis (ABA) and non-intensive, targeted interventions, also based on ABA principles. Children were comprehensively assessed by a research team before the onset of intervention, and then, again, 2 years later. Change in Vineland adaptive behaviour scales composite scores from intake (T1) to leaving the study (T2) was set as the primary outcome variable. The research team remained blind to the type and intensity of interventions provided. One hundred and ninety-eight (95%) of the original samples stayed in the study throughout the whole 2-year period and 192 children had a complete Vineland composite score results both at T1 and T2. Vineland composite scores increased over the 2-year period. This increase was accounted for by the subgroup with normal cognitive functioning. There was no significant difference between the intensive and non-intensive groups. Individual variation was considerable, but no child in the study was "problem-free" at follow-up. Our data do not support that children with ASD generally benefit more from the most intensive ABA intervention programs than from less intensive interventions or targeted interventions based on ABA.
Research in developmental disabilities, 2011 · doi:10.1016/j.ridd.2011.08.002