Table 2.

Sample characteristics of the included studies.

Study, year	Country	Service setting	Income level	Study design	Population	Participant mean age	Method of recruitment	Total number of participants	Intervention length	Theoretical orientation (if stated)	Delivery type
Entenberg et al [45,46], 2023	Argentina	Not included	High-income setting	Randomized controlled trial	Parents in Argentina with at least 1 child aged 2 to 11 years	35.85 (SD 5.77)	Facebook posts and email list advertisements	170 (intervention group: 89; control group: 81)	15 minutes	Incredible Years Parenting Programme; behavior change techniques	Facebook Messenger
Fletcher et al [43], 2017	Australia	Not included	High-income setting	Pilot feasibility and acceptability study	Fathers expecting a child within 6 months or fathers with infants younger than 3 months	33.7 (range 21-59)	Advertisement posters in community centers, through Facebook forums, and at the hospital neonatal intensive care unit via trained staff	46	6 weeks	Psychoeducation, mood monitoring, and awareness	SMS text messaging
Fletcher et al [44], 2020	Australia	Not included	High-income setting	Pilot feasibility and acceptability study (no effectiveness)	Partners of mothers diagnosed with perinatal mental illness	29.3	Partners were invited after clinical interview at regional health centers	23	44 weeks	Psychoeducation, mood monitoring, and awareness	SMS text messaging
Mason et al [49], 2021	United States	Health care clinic	High-income setting	Randomized controlled trial	Parents of adolescents (aged 13 to 18 years) participating in the substance abuse prevention program	Parent mean age not reported	Community partner advertisement	52 (parents); 69 (adolescents)	4 weeks	Behavioral-skill framework (Dishion et al [54])	SMS text messaging
Entenberg et al [48], 2021	Argentina	Not included	High-income setting	Randomized controlled trial	Parents aged ≥18 with at least 1 child aged 2 to 10 years; not seeking psychological treatment	33.3% (n=11) of the participants were aged between 30 and 33 years, 30.3% (n=10) aged between 34 and 37 years, and 36.4% (n=12) were aged ≥38 years	Facebook posts	33	20 minutes	Incredible Years Parenting Programme	Facebook Messenger
Barreto et al [52], 2021	Brazil	Hospital	High-income setting	Intervention development and acceptability evaluation	New mothers aged >18 years with newborns of at least 24 hours old	24.4	Approached by research team in hospital and asked to participate	142	No time limit	Not stated	Within app
Downing et al [47], 2018	Australia	University (for initial onboarding)	High-income setting	Randomized controlled trial	Parents of children aged 2 to 4 years	Intervention group: 36.1 (3.9); control group: 34.1 (3.7)	Snowball method through community outreach and advertising	57 (Intervention group=30, control group =27)	6 weeks	Behavior change (CALO-RE)	Text messaging
Yu et al [50], 2023	Taiwan	Not reported	High-income setting	Intervention development and acceptability evaluation	Parents with childrearing difficulties	NRa	NR	58	12 weeks	Behavior change	Within app
Chua et al [51], 2023	Singapore	Tertiary public hospital	High-income setting	Intervention development and acceptability evaluation	Men and women of childbearing age; 10 with no children, single	26.7	Convenience sampling	11	28 weeks	Bandura self-efficacy theory, positive psychology, and psychoeducation	Within app
Jäggi et al [53], 2023	Peru	In home for onboarding and baseline interviews	Low-income setting	Pilot feasibility and acceptability study	Pregnant women and mothers with children aged 0 to 6 years	29	Convenience sampling	180	20 weeks	NR	Facebook Messenger

^aNR: not reported.