Birnbrauer and Leach have presented a 10-year follow-up, showing that the few children who did well in their study (four of them, none of whom achieved "normal functioning") did not maintain these gains on follow-up (Birnbrauer and Leach, 2006). Sheinkopf and Siegel (1998), the retrospective study, features no autistics who achieved "normal functioning", and also shows no correlation between intensity of treatment and outcome measures. Lovaas (2002) forcefully criticizes this study, and does not accept its validity.
McEachin, Smith & Lovaas (1993): the follow-up into school ages of Lovaas (1987): See above. One of the "normal functioning" children loses this status.
Howard et al. (2005): This is also a one-year study that compares an ABA-based intensive intervention (for which there is no manual), to "eclectic" treatment (ABA of unknown quantity or quality, plus contradictory approaches), as well as to generic segregated special education. The groups aren't matched. None of the children achieve "normal functioning". The reported "effectiveness" of the ABA-based treatment does not take into account the total failure of two children, who could not continue in ABA, and whose data were discarded.