Table 1.

Summary of the rating scales used for the proposed study

Scale	Abbr	Description
Mental health
Kessler Psychological Distress Scale [34]	K10	This is a 10-item questionnaire intended to yield a global measure of distress based on questions about anxiety and depressive symptoms that a person has experienced in the most recent 4-week period [35, 36]
Patient Health Questionnaire [37]	PHQ-9	This screening tool is commonly used to screen for depression. The PHQ-9 has been shown to have 61% sensitivity and 94% specificity in adults [38–40]
General Anxiety Disorder Scale [41–43]	GAD-7	A self-report questionnaire with 7 items for screening and severity measuring of generalized anxiety disorder. Assessment is indicated by a total score, which is made up by adding together the scores for the scale of all seven items. The tools has been validated primarily in adults [41, 43, 44]
Beck Anxiety Inventory [45]	BAI	The BAI is a 21-item multiple-choice self-report inventory that measures the severity of an anxiety in adults and adolescents. The BAI items emotional, physiological, and cognitive symptoms of anxiety but not depression. The BAI has been used with young adults and can be completed in 5 min. The BAI has been shown to be psychometrically strong with high internal consistency (Cronback alphas ranging from 0.92 to 0.94) and test–retest reliability is 0.75. With youth, the BAI has also been shown to possess acceptable reliability and convergent and discriminant validity for both 14–18 year and inpatients and outpatients [46, 47]
Global Appraisal of Individual Needs– Short Screener [48]	GAIN-SS	The GAIN-SS is a short screening tool used in general populations to quickly identify people who would be flagged as having a behavioral health disorder. The measure has four subscales, each shown to work as a unidimensional measure [49]. We are unaware of any studies to date that have tested the GAIN-SS explicitly with young adults receiving community mental health services
Recovery
Canadian Personal Recovery Outcome Measure (PROM) [50]	C-PROM	New 30-item self-report scale to measure recovery in Canadians with mental illness. Measure has been shown to have high internal consistency, excellent face validity, and adequate test–retest repeatability with adults [51]. Has been tested with 200 young adults aged 18–30 years showing preliminary evidence to be fit for purpose for this population group. This study will provide further evidence to support the PROM’s utility and psychometric validity with youth
The Illness Management and Recovery Scale [52]	IMR	The IMR is a 13-item self-report measure of self-management and pursuit of recovery goals. Each item has a unique response set. The IMR has adequate internal reliability (α = 0.72) and good test-re-test reliability (α = 0.81) [52]
Quality of Life
EQ-5D [53]	EQ-5D	The EQ-5D measures health related quality of life (HRQL). It provides a utility between 0 and 1 representing the value placed on life lived in the current health state and is optimized for economic analyses and comparisons across health conditions. A youth version of the EQ-5D has been developed [54] and validated internationally [55]
Recovery Quality of Life Questionnaire-10 item version [56, 57]	ReQOL-10	The ReQOL is a newly developed measure of ReQoL-10 contains positively and negatively worded items covering seven themes: activity, hope, belonging and relationships, self-perception, well-being, autonomy, and physical health. The measure has been shown to have acceptable internal consistency, test–retest reliability (Cronbach alphas > 0.85), known-group differences, convergence with related measures, and were responsive over time (standardised response mean (SRM) > 0.4) [57]. The measure has not yet been validated with young adults receiving community mental health services