Table 2.

Intervention and outcome indicators for the quantitative studies

Indicators	Definition
Intervention type	Comprised of indicated prevention and treatment interventions
	Indicated prevention were those that recruited participants based on an elevated score on a symptom measure
	Treatment intervention were those that recruited participants based on meeting the clinical criteria on diagnostic measures or clinical threshold on symptom measures
Format and modality	Whether the intervention was delivered in (1) group or individual format, (2) face-to-face or digitally, (3) involved parents or not
Dosage of session	The number of sessions intended to be held for the index intervention
Frequency of sessions	Frequency with which sessions were held: daily, weekly, biweekly, semiweekly
Duration of intervention	The minimum and maximum length of time from pre- to post- intervention
Provider	Highest education qualification for the providers in the index group (doctoral or non-doctoral)
Trainability	Extent to which others can be trained in an intervention; rated as high if the manual was available and treatment was delivered by non-doctoral-level practitioners; as moderate if the manual was available or treatment was delivered by non-doctoral-level practitioners; and as low if no manual was available and treatment delivered by doctoral-level practitioners only
Outcome status	Superior was applied when an intervention performed better than one or more other study groups (a psychosocial intervention, medication, combined psychosocial and medication, placebo, waitlist, no treatment, or other control groups) in a randomized trial on the primary outcome measure in the target symptom domain
	Valid equivalent was applied when an intervention had a qualifying tie with one or more evidence-based protocol in a randomized trial on the primary outcome measure in the target symptom domain
	Non-superior was applied when an intervention (i) performed worse than comparison groups, or (ii) performed equally against a non-evidence-based comparison group in a randomized trial on the primary outcome measure in the target symptom domain