(a)
| Studies | Participant characteristics | Methods | Control condition (if applicable) | ||
|---|---|---|---|---|---|
| n total (intervention group) | Age (months) mean (min–max) | Diagnosis | |||
| Drew et al., 2002 [38] | 24 (intervention = 12) | 22.5 | Childhood autism (ICD-10) | Randomized controlled trial | Local services: mixture of services |
| Mahoney and Perales, 2003 [36] | 20 | 32.1 | Autistic disorder or PDD | Preexperimental design: pre/postintervention | n/a |
| Mahoney and Perales, 2005 [37] | 20 | 32.6 | ASD | Preexperimental design: pre/postintervention | n/a |
| Wetherby and Woods, 2006 [39] | 17 | 18.2 (12–24) | Provisional clinical diagnosis of ASD | Quasi-experimental design: pre/postintervention | Contrast group: no treatment |
| Rocha et al., 2007 [40] | 3 | 31.7 (26–42) | Autistic disorder | Single subject multiple baseline across pairs of participants | n/a |
| Schertz and Odom, 2007 [41] | 3 | 26.3 (22–33) | Strong early markers of ASD | Mixed methods: multiple-baseline design | n/a |
| Vismara et al., 2009 [34] | 8 | 27.5 (10–36) | Autistic disorder (DSM-IV) | Case study: nonconcurrent multiple-baseline design | n/a |
| Gulsrud et al., 2010 [42] | 34 | 30.6 (21–36) | ASD | Quasi-experimental design | n/a |
| Kasari et al., 2010 [43] | 38 (intervention = 19) | 30.8 (21–36) | Autistic disorder (DSM-IV) | Randomized waitlist control design | Waitlist: mixture of services |
| Oosterling et al., 2010 [44] | 67 (intervention = 36) | 32.9 | Autistic disorder or PDD | Randomized controlled trial | Care-as-usual: daycare with speech and language therapy, motor therapy, music therapy, play therapy, and support for parents |
| Wong and Kwan, 2010 [45] | 17 (intervention = 9) | 26.5 (17–30) | ASD (DMS-IV) | Randomized waitlist control design | Waitlist: no intervention |
| Carter et al., 2011 [46] | 55 (intervention = 29) | 20.3 (15–25) | At risk of ASD | Randomized controlled trial | Control group: business as usual |
| Rogers et al., 2012 [10] | 98 (intervention = 49) | 21.0 (14–24) | At risk of ASD | Randomized controlled trial | Community group; mixture of services |
| Green et al., 2013 [47] | 77 (intervention = 7) | 8.4 (8–10) | Infant siblings of autistic probands | Case series with comparison groups; high risk (n = 37) and low risk (n = 33) | Comparison groups: no intervention |
| Steiner et al., 2013 [48] | 3 | 12 | Infant siblings of probands with ASD | Case series | n/a |