Table 2 Outcome scoring instructions and management of missing item-level data

Screening questionnaires

 Preschool Anxiety Scale (PAS)

• 28 items

• Items scored 0–4

0= Not true at all

1=Seldom true

2=Sometimes true

3=Quite often true

4=Very often true

• Total score: sum of all items; range 0–112

• Screen positive: total score ≥34

No missing items allowed

 Approach subscale of the Short Temperament Scale for Children (STSC-A)

• 7 items

• Items scored 1–6

1=Almost never

2=Not often

3=Variable, usually does not

4=Variable, usually does

5=Frequently

6=Almost always

• Items 3–6 reverse scored

• Total score: sum of all items; range 7–42

• Screen positive: total score ≥30

No missing items allowed

 Generalised Anxiety Disorder Scale (GAD-7)

• 7 items

• Items scored 0 to 3

0= Not at all

1=Several days

2=More than half the days

3=Nearly every day

• Total score: sum of all items; range 0–21

Screen positive: total score ≥8

No missing items allowed

Questionnaire outcome measures

 Preschool Anxiety Scale (PAS)

As above

Where ≥ 75% items completed (≥21 items), calculate prorated total score using completed items

Where ≥8 missing items, treat measure as missing

 Approach subscale of the Short Temperament Scale for Children (STSC-A)

As above

Where 6 items completed, calculate prorated total score using completed items

Where ≥2 missing items, treat measure as missing

 Generalised Anxiety Disorder Scale (GAD-7)

As above

Where 6 items completed, calculate prorated total score using completed items

Where ≥2 missing items, treat measure as missing

 Child Anxiety Life Interference Scale—Preschool version (CALIS-PV)

• 18 items

• Items scored 0–4

0=Not at all

1=Only a little

2=Sometimes

3=Quite a lot

4=A great deal

• Total score: sum of all items; range: 0–72

• Higher scores indicate greater interference

Where ≥ 75% items completed (≥14 items),

calculate prorated total score using completed items

Where ≥5 missing items, treat measure as missing

 Strengths and Difficulties-Externalising Scale (SDQ-E)

• 10 items (items 2, 5, 7, 10, 12, 15, 18, 21, 22, 25)

• Items scored 0–2

0=Not true

1=Somewhat true

2=Certainly true

• Items 7, 21 and 25 reverse scored

• Total score: sum of all items; range: 0–20

• Higher scores indicate a higher level of externalising symptoms

Where ≥3 items completed for each of the two 5-item subscales, calculate prorated subscale score using completed items before calculating the total score

Where ≥2 missing items on either subscale, treat measure as missing

 Parent Overprotection Scale (POS)

• 19 items

• Items scored 0–4

0=Not at all

1=A little

2=Somewhat

3=Quite often

4=Very often

• Total score: sum of all items; range: 0–76

• Higher scores indicate greater parental overprotection

Where ≥ 75% items completed (≥15 items),

calculate prorated total score using completed items

Where ≥5 missing items, treat measure as missing

 Parenting Sense of Competence Scale-self-efficacy scale (PSOC-SE)

• 7 items

• Items scored 1–6

1=Strongly disagree

2=Disagree

3=Somewhat disagree

4=Somewhat agree

5=Agree

6=Strongly agree

• Total score: sum of all items; range: 7–42

• Higher scores indicate greater parenting self-efficacy

Where 6 items completed,

calculate prorated total score using completed items

Where ≥2 missing items, treat measure as missing

 Child Avoidance Measure (CAMP)

• 8 items

• Items scored 0–3

0=Never, almost never or not an issue

1=Sometimes

2=Often

3=Almost always

• Total score: sum of all items; range: 0–24

• Higher scores indicate greater child avoidance

Where ≥6 items completed,

calculate prorated total score using completed items

Where ≥3 missing items, treat measure as missing

 Responses to Uncertainty and Low Environmental Structure (RULES)

• 17 items

• Items scored 1–5

1=Not at all

5=Very much

• Total score: sum of all items; range: 17–85

• Higher scores indicate higher greater intolerance of uncertainty

Where ≥ 75% items (≥ 13 items) completed,

calculate prorated total score using completed items

Where ≥5 missing items, treat measure as missing

 Coping Questionnaire (CQ-P)

• Up to 3 items

• Items scored 1–7

1= Not at all able to help themself

7 =Completely able to help themself

• Score: first item score; range 1–7

• Higher scores indicate a higher level of coping

Where the first item is missing, treat measure as missing

 Additional questionnaire measure

  Motivation questionnaire

• 6 items

• Items scored 1–5

1=Strongly disagree

2=Disagree

3=Neither agree nor disagree

4=Agree

5=Strongly agree

• Item 4 reverse scored

• Total score: sum of all items; range 6–30

• Total score 6–18 = ‘ambivalent’

Total score 19–23 = ‘partially motivated’

Total score 24–30 = ‘motivated’

Where at least 5 items are completed, calculate the prorated total score using completed items