Table 1.
Description of the variables measured for the jth individual belonging to the ith school at wave k in the analysis model
| Variable | Type | Grouping /Range | Label |
|---|---|---|---|
| Child’s sex | Categorical | 0 = Female 1 = Male | sexij |
| Child’s age (wave 1) | Continuous | Range [7–11] | ageij1 |
| SES measured by the SEIFA IRSAD quintile (wave 1) | Categorical | 0 = 1st quintile (most disadvantaged) | SESij1 |
| 1 = 2nd quintile | |||
| 2 = 3rd quintile | |||
| 3 = 4th quintile | |||
| 4 = 5th quintile (most advantaged) | |||
| Standardized NAPLAN numeracy score (wave 1) | Continuous | z-score | NAPLAN _ zij1 |
| Standardized NAPLAN numeracy score (waves 3,5 and 7) | Continuous | z-score | NAPLAN _ zijk |
| a Depressive symptoms (waves 2,4 and 6) | Continuous | Range [0,8] | depressionij(k − 1) |
| b Overall child behaviour reported by SDQ (waves 2,4 and 6) | Continuous | Range[0,40] | SDQij(k − 1) |
IRSAD Index of Relative Socio-Economic Advantage and Disadvantage, NAPLAN National Assessment Program - Literacy and Numeracy, SDQ Strengths and Difficulties Questionnaire, SEIFA Socioeconomic Index for Areas, SES Socio-Economic Status
aA subset of 4 items (each ranging from 0 to 2) from the Short Mood and Feelings Questionnaire (SMFQ) was used to measure the depressive symptoms at each wave in the CATS study [3, 38]. Depressive symptoms at each wave in our study is the total summary score of these four items
b For measuring the overall child behaviour, a total difficulties score is derived from the first 4 subscales of the Strengths and Difficulties Questionnaire (SDQ): emotional symptoms, conduct problems, hyperactivity/inattention, peer relationship problems (each ranging from 0 to 10) [39]. This variable is not included in the analysis but is included in the imputation model as an auxiliary variable to improve its performance