Characteristics of the included studies
| Study setting | Type and aim of study | Comparison group | (1) Who received intervention; (2) When? | Sample size (1) randomised; (2) In analysis (% of randomised) | Universal or geographically targeted? | Outcome domains measured* |
| Beeghly24 USA | Individual RCT to compare the effectiveness of two one-to-one clinic-based interventions (infant-centred vs mother centred) on motor and cognitive development post-intervention | Two interventions compared | (1) Mothers and infant; (2) When child was 3, 14 and 30 days of age | (1) 163; (2) 125 (77%) | Universal | Motor Cognitive |
| Chang et al
25 Antigua, Jamaica and St Lucia | Cluster RCT to examine the effectiveness of a group-based intervention on language and cognitive development post-intervention | Usual care | (1) Mothers; (2) When child was 3, 6, 9, 12 and 18 months | (1) 30 health centres randomised (501 women enrolled); (2) 426 (85%) | Geographically targeted | Motor Language Cognitive Overall |
| Cheng26 Japan | Individual RCT to examine the effectiveness of an individual home-based intervention on social and emotional well being postintervention | Usual care, with a counselling service made available to all | (1) Mothers; (2) When child was 5-9 months | (1) 95; (2) 85 (89%) | Universal | SEWB |
| Christakis27 USA | Individual RCT to examine the effectiveness of giving two sets of building blocks and a newsletter of activities to complete with them on language development and social and emotional well-being postintervention | Usual care | (1) Families; (2) When child was 18-30 months | (1) 175; (2) 140 (80%) | Universal | Language SEWB |
| Cupples28 UK (Northern Ireland) | Individual RCT to examine the effectiveness of one-to-one contact with trained peer mentors on motor, cognitive development and social and emotional well being post-intervention | Usual care | (1) Mothers; (2) From 20 weeks of pregnancy to 12 months postpartum | (1) 343; (2) 280 (82%) | Geographically targeted (First-time mothers only) | Motor Cognitive SEWB |
| Doyle30–35 Ireland | Individual RCT to compare the effectiveness of the ‘high support’ versus ‘low support’ versions of the multicomponent ‘Preparing for Life’ programme on motor, language and cognitive development and social and emotional well-being while intervention was ongoing | Two interventions compared | (1) Parents; (2) From pregnancy to school entry | (1) 233 (2) 173 (74% at 6 months) 165 (71% at 12 months) 154 (66% at 18 months) 166 (71% at 24 months) 151 (65% at 36 months) | Geographically targeted | Motor Language Cognitive SEWB Overall |
| Drotar36 USA | Individual RCT to examine the effectiveness of the multi-component ‘Born to Learn’ programme on language and cognitive development and social and emotional well-being while intervention was ongoing | Usual care, plus handouts and offer of a different group meeting | (1) Parents and child; (2) Recruited between birth and 9 months; programme continued to age 3 | (1) 527; (2) 410 (78%, although inconsistent numbers presented in tables) | Universal | Language Cognitive† SEWB |
| Feinberg37–40 USA | Individual RCT to examine the effectiveness of a group-based intervention (‘Family Foundations’) on social and emotional well-being postintervention | Usual care plus brochure on childcare options | (1) Parents; (2) Recruited during pregnancy, continued to age 4-6 months | (1) 169; (2) 152 (90% at 6 months); 154 (91% at 12 months); 137 (81% at 36 months) | Universal (First-time mothers only) | SEWB† |
| Griffith41 UK (Wales) | Individual RCT to examine the effectiveness of a group-based parenting intervention (‘Incredible Years Toddler Programme’) on social and emotional well-being and overall development postintervention | Usual care (waiting list control group) | (1) Parents; (2) Children 12-36 months at baseline (mean age 21 months) | (1) 89; (2) 89 (100%) | Geographically targeted | SEWB Overall |
| High44 USA | Individual RCT to examine the effectiveness of a one-to-one clinic-based intervention on language development postintervention | Usual care | (1) Parents; (2) Children 5-11 months at baseline | (1) 205; (2) 153 (75%) | Geographically targeted | Language |
| Hiscock23 45 46 Australia | Cluster RCT to examine the effectiveness of a group-based intervention (‘Toddlers Without Tears’) on social and emotional well-being postintervention | Usual care | (1) Parents; (2) When child was 8, 12 and 15 months | (1) 40 maternal and child health centres randomised (733 women enrolled); (2) 672 (92% at 18 months); 656 (89% at 24 months); 589 (80% at 36 months) | Universal | SEWB |
| Johnston47 USA | Individual RCT to compare the effectiveness of the multicomponent ‘Healthy Steps’ programme with ‘Healthy Steps’ plus ‘PrePare’ on language development and social and emotional well-being postintervention | Two interventions compared | (1) Mothers; (2) Recruited during pregnancy, continued to age 3 | (1) 303; (2) 239 (79%) | Universal | Language SEWB |
| Landry48 USA | Individual RCT to compare the effectiveness of two different models of home visits on language and cognitive development and social and emotional well-being postintervention | Two interventions compared | (1) Mothers; (2) When child was 6-10 months | (1) 264; (2) 240 (91%) | Geographically targeted | Language‡ Cognitive‡ SEWB‡ |
| Lobo49 USA | Individual RCT to compare the effectiveness of a ‘handling and positioning’ intervention with a ‘social interaction’ intervention on motor development while the intervention was ongoing and postintervention | Two interventions compared | (1) Parents; (2) For 3 weeks, from when child was 2 months of age | (1) 28; (2) 28 (100%) | Universal | Motor |
| Miller50 Ireland | Individual RCT to examine the effectiveness of the multi-component ‘Lifestart’ programme on cognitive development and social and emotional well being whilst intervention was ongoing | Usual care | (1) Parents; (2) Recruited when child < 12 months, continued to age 5 | (1) 435; (2) 347 (80% at 36 months) | Universal (although parents self-referred) | Cognitive SEWB |
| Minkovitz51–53 USA | Individual RCT to examine the effectiveness of the multi-component ‘Healthy Steps’ programme on social and emotional well-being in the long-term while intervention was ongoing | Usual care | (1) Families; (2) Recruited at birth or first well-child visit, continued to age 3 | (1) 2235; (2) 1593 (71%) | Universal | SEWB |
| Niccols54 Canada | Individual RCT to examine the effectiveness of a group-based intervention (‘Right from the Start’) on social and emotional well-being postintervention | Usual care | (1) Mothers; (2) Children 1-24 months at baseline | (1) 76; (2) 73 (96% immediately postintervention) 64 (84% at 6 months) | Universal (although parents self-referred) | SEWB |
| Niccols55 Canada | Individual RCT to examine the effectiveness of a group-based intervention (‘COPEing with Toddler Behaviour’) on social and emotional well-being postintervention | Usual care (waiting list control group) | (1) Mothers; (2) Children 12-36 months at baseline (mean age 24 months) | (1) 79; (2) 74 (94% immediately postintervention) 71 (90% at 1 month) | Universal (although parents self-referred) | SEWB† |
| Santelices56 Chile | Individual RCT to examine the efficacy of a multicomponent intervention (‘Promoting Secure Attachment’) on social and emotional well-being postintervention | Usual care, plus one lecture by a psychologist | (1) Mothers; (2) Recruited during late pregnancy, continued to age 1 | (1) 100; (2) 72 (72%) | Universal (First-time mothers only) | SEWB |
| Tsiantis57 58 Cyprus, Greece, Portugal, Yugoslavia | Cluster RCT to examine the effectiveness of training primary healthcare workers to use semistructured interviews to promote language development and social and emotional well-being while intervention is ongoing | Usual care (healthcare workers in this group received one lecture) | (1) Mothers; (2) Recruited during pregnancy, continued to age 2 | (1) 80 primary healthcare workers (number of women randomised not reported, ‘recruitment did not achieve target figures’); (2) Not reported | Universal | Language SEWB† |
| Wagner59 60 USA | Individual RCT to examine the effectiveness of a multicomponent intervention (‘Parents as Teachers’) on motor, language and cognitive development and social and emotional well-being while intervention is ongoing | Usual care, plus age-appropriate toys ‘at regular intervals’ and an annual child assessment | (1) Mothers; (2) Recruited during pregnancy, continued to age 2 | (1) 665; (2) 266 (40%) | Geographically targeted | Motor Language Cognitive SEWB |
| Wiggins61 62 UK (England) | Individual RCT to examine the effectiveness of two postnatal social support interventions (SHV and CGS) on language development, social and emotional well-being overall development postintervention | Both interventions compared with usual care | (1) Mothers; (2) Recruited when child was ~10 weeks, continued to age 1 | (1) 731 (SHV 183, CGS 184, control 364); ii) SHV comparison: 493 (91% at 12 months); 443 (81% at 18 months). CGS comparison: 492 (90% at 12 months); 456 (83% at 18 months). | Geographically targeted | Language§ SEWB§ Overall§ |
*Used a validated questionnaire for measuring outcome unless indicated otherwise (although the use of the instrument may not always have been validated in the target population).
†Used a combination of validated questionnaires and coding of videotaped activities and behaviours (no validated coding framework described).
‡Used coding of videotaped activities and behaviours (no validated coding framework described).
§No validated measure used; asked parents whether they perceived their child’s development to be normal and whether they had worries about specific areas of development (including speech and behaviour).
CGS, Community Group Support; RCT, randomised controlled trial; SEWB,social and emotional well-being; SHV, Support Health Visitors.