| Participants |
(child or infant or toddler) AND (parent or mother or caregiver) |
Participants younger than 6 y |
Mean age of participants older than 6 y (or mean age reported plus 1 SD was >6 y) |
| Intervention |
AND (interactio* OR synchron* OR sensitiv* OR responsiv* OR facilitation OR input OR strategy OR communicative behavior OR parent behavior OR caregiver behavior OR mother behavior OR interaction) |
Parent training in language or related behaviors; parent was primary implementer |
Pharmaceutical interventions; therapist-implemented treatments in which parent training occurs in <50% of total intervention time |
| Comparison |
AND (language OR communicat* OR vocabulary OR joint attention or joint engagement OR verbal behavior). |
No treatment; business-as-usual control group; minimal treatment (<1 h of training per month) |
Parent training in language strategies; language intervention delivered by research staff |
| Outcome |
AND (language OR communicat* OR vocabulary OR joint attention OR joint engagement OR verbal behavior) |
Any measure of language, communication, speech, engagement, play, or verbal skills |
Social behavior with peers, complex or social play skills, brain-based measures, biological measures |
| Study design |
Search criteria were not restricted for design |
Treatment-control design |
Single case; group design with <10 participants per group at baseline; treatment-treatment comparison |
