Table 2.

Participant characteristics

Study	Country	Risk	Mother mean age at start, in years	Child age at start, in months	Primiparous %	Intervention, n	Control, n
Ammaniti et al 56	Italy	Depressive or psychosocial risk	33	Third trimester	Not reported	47	44
Baggett et al 43	USA	Low income	Intervention: 25; control: 27	~4	Mean number of children: 1.75	20	20
Barlow et al 59	UK	Vulnerable	<17 years: intervention—17.9%; control—22.2%	Second trimester	Not reported	68	63
Bridgeman et al 47	USA	Low income	17–35	2	Not reported		Unclear*
Cassidy et al 44	USA	NBAS or low income	24	6.5–9	100	85	84
Fergusson et al 57 58	New Zealand	Two or more risk factors present	Mother: intervention—24; control—24 Father: intervention—27; control—27	Not reported (recruited within 3 months of birth)	Not reported	206	221
Høivik et al 45	Norway	Interactional problems	30	7.3	72	88	70
Kaminski et al 36	USA	Low income	24	Prenatally (LA), at birth (Miami)	Not reported	338	236
Katz et al 46	USA	African–American with inadequate prenatal care	25	0	Mean number of children: 2.9	146	140
Mendelsohn et al 48	USA	Low-educated Latina mothers	Intervention: 30; control: 30	0.5	Intervention: 21.2; control: 36.2	77	73
Salomonsson et al 52 53 54	Sweden	Worried mothers	Intervention: ~34; control: ~32	Intervention: 4.4; control: 5.9	Intervention: 81; control: 78	40	40
Sierau et al 55	Germany	Economic and social risk factors	Intervention: 21; control: 22	Third trimester	100	394	361
Taylor et al 42	USA	Poverty, single marital status, low education, age <20, previous substance abuse or a history of abuse	Intervention (n): <20: 44; 20–30: 122; >30: 34; control: <20: 58; 20–30: 108; >30: 34	3	Not reported	50	50
van den Boom et al 49 50	The Netherlands	Lower class mothers with irritable infants	Mother: 25 Father: intervention—28; control—29	6	100	50	50
Klein Velderman et al 51	The Netherlands	Insecure attachment	28	~7	100	54	27

*The study only reported number of participants in each analysis.

NBAS, Neonatal Behavioural Assessment Scale.