Table 1.

Study Codes with Definitions, Levels, and Inter-Rater Reliability

Research Question	Codes	Code Definitions	Code Levels	Kappa
2	Availability	Availability of measure for use beyond the original research study setting	Available in the public domain with no associated cost; Available with associated cost; Unavailable	.84
2	Psychometric Indicator	Was at least one psychometric indicator reported for measure?	Yes; No	.98
3	Information Source	Source providing information / completing the measure	Service Records/Setting; Youth; Caregiver; Provider; Research Staff/Observer	.89
3	Target	Individual about whom the measure was completed	Youth; Caregiver; Family; Provider	.76
4	Administration Count	Number of times measure was completed over course of study	Count	1.00
4	Timing	The timing of measurement within the course of treatment	Before treatment; during/after 1st treatment session; repeatedly (measured multiple times over course of treatment); pre/post (measured before treatment and after conclusion of treatment); after conclusion of treatment; other	.78
4	Purpose	The purpose for which the measure was collected in the study	Initial evaluation (completed prior to engagement intervention); Progress Monitoring (to evaluate change in an engagement domain over the course of an intervention); Outcome Measure (dependent variable to determine intervention efficacy); Other	.57
4	Informed Treatment	Were measure data used in treatment planning, intervention selection, intervention adaptation, or another component of treatment/intervention delivery?	Yes; No	1.00

Note. “Engagement Domain” was coded for 48 studies in (Becker et al. (2018)). For the additional four studies coded in the current study, the kappa value for engagement domain was 1.00.