Table 1.

Overview of secondary outcomes

Outcome	Survey measure	Response	Scoring	Psychometrics
Outcomes completed by both parents and adolescents
Social Distance [23]	5 questions assessing desire for social distance from the person in the psychosis vignette. E.g. Would you be happy for your child / Would you be happy … to develop a close friendship with X?	4-point Likert scale 1 = Yes definitely 2 = Yes, probably 3 = Probably not 4 = Definitely not	Mean score of 5 questions, range 1–4.	Parent ω = .90 Adolescent ω = .88
Stigma: Weak-not-sick [23]	4 questions assessing that the person in the psychosis vignette is weak not sick. E.g. X could snap out of it if (he/she) wanted	5-point Likert scale 1 = Strongly disagree 2 = Disagree 3 = Neither agree nor disagree 4 = Agree 5 = Strongly agree	Mean score of 4 questions, range 1–5, dichotomized to low stigma (=1) or not (> 1).	Parent ω = .81 Adolescent ω = .56
Stigma: Dangerous/Unpredictable [23]	4 questions* assessing that the person in the psychosis vignette is dangerous or unpredictable. E.g. X’s problem makes (him/her) unpredictable	5-point Likert scale 1 = Strongly disagree 2 = Disagree 3 = Neither agree nor disagree 4 = Agree 5 = Strongly agree	Mean score of 4 questions, range 1–5.	Parent ω = .46 Adolescent ω = .45
K6 psychological distress (12-month version) [24]	6 questions assessing the frequency of psychological distress in the worst month during the past 12 months	5-point Likert scale 1 = None of the time 2 = A little of the time 3 = Some of the time 4 = Most of the time 5 = All of the time	Total scores of 19 or above indicate a high level of psychological distress	Parent ω = .91 Adolescent ω = .93
Outcomes completed by parents only
Problem recognition	What, if anything, do you think is wrong with X? Question in response to each of 4 vignettes: depression, social phobia, EDNOS, psychosis	Verbatim responses were scored for correct/incorrect, blinded to group allocation and timepoint.	1 point for correct recognition if the following were mentioned: Depression (depression, depressed), social phobia (anxiety/anxious, social anxiety, social phobia, anxiety disorder, performance anxiety), EDNOS (Eating disorder, EDNOS, bulimia/bulimic/bulimia nervosa/mia, binge eating/loss of control eating, binge eating disorder, anorexia/anorexia nervosa/anorexic/ana, disordered eating), psychosis (schizophrenia/paranoid schizophrenia, psychosis/psychotic, schizophrenic, schizoaffective disorder, precursor to schizophrenia). Mean score of 4 responses, range 0–1.	ω = 0.82
Quality of MHFA intentions	Imagine X is your child. You want to help (him/her). What would you do? Question in response to each of 4 vignettes: depression, social phobia, EDNOS, psychosis	Verbatim responses were scored for consistency with the MHFA Action Plan in the Youth MHFA manual, [17] blinded to group allocation.	Mean score of 4 responses, range 0–12.	Inter-rater reliability (ICC) for 4 vignettes ranged from 0.74–0.84. ω = 0.56
Confidence to help	How confident would you be in your ability to help X? Question in response to each of 4 vignettes: depression, social phobia, EDNOS, psychosis	4-point Likert scale 1 = Very confident 2 = Fairly confident 3 = Slightly confident 4 = Not confident at all	Mean score of 4 responses, range 1–4.	ω = 0.84
Knowledge about youth mental health problems	18 questions on knowledge about mental health problems, derived from the Youth MHFA manual [17]. E.g. If a teenager has a traumatic experience, it is best to make them talk about it as soon as possible	Agree, Disagree, Don’t know	1 point for a correct response to each question, range 0–18.	Test-retest r = 0.67 (PFA group)
Quality of MHFA support towards other person	Over the last 12 months, has anyone else you know had any sort of mental health problem?...Have you done anything to help the person with this problem?...What did you do?	Verbatim responses were scored for consistency with the MHFA Action Plan, blinded to group allocation.	Scores range 0–12.	Inter-rater reliability ICC = 0.76
Appropriate help-seeking for mental health problem	Over the last 12 months, have you yourself had any sort of mental health problem?...Have you done anything to deal with this mental health problem?...What did you do?	Verbatim responses were scored for the presence of an appropriate source of help.	Scored a 1 if mentioned any of the following professionals or treatments: taking medication, antidepressant, anxiolytic, counselling, counsellor, GP, psychologist, psychiatrist, CBT, hospital, other medical (mental health practitioner or specialist, professional for alcohol misuse, maternal & child health nurse), professional organization (Centre Against Sexual Assault, Drummond Family Services).
Outcomes completed by adolescents only
Perceived general social support from parent [25]	Communication subscale of Parent Attachment from the People in My Life Questionnaire (5 questions). E.g. My parents can tell when I am upset about something.	4-point Likert scale 1 = Almost never or never true 2 = Sometimes true 3 = Often true 4 = Almost always or always true	Scores range 5–20.	ω = 0.82
Intended help-seeking from parent	If you had a problem right now like X would you ask for help?...Where would you go? Question in response to each of 4 vignettes: depression, social phobia, EDNOS, psychosis	Verbatim responses.	Scored 1 point per vignette if mentioned seeking help from a parent. Sum score of 4 responses, range 0–4.	ω = 0.71
Actual help-seeking from parent	Over the last 12 months, have you had any sort of mental health problem?... Did you get help from family?... Who in the family?	Verbatim responses.	Scored a 1 if adolescent reported seeking help from either or both parents.
Help-seeking from a health professional	Over the last 12 months, have you had any sort of mental health problem?... Did you get help from a health professional or counsellor?	Verbatim responses.	Scored a 1 if adolescent responded with yes.

Note: ω was calculated as Revelle’s omega total for total scores

*3 questions only for adolescents, see Yap et al. 2014 [23]