Description of study variables (omitting simple ‘Yes or No’ data items)
| Construct | Measurement items | Interpretation |
|---|---|---|
| Mental health competence (outcome measure) | Overall social competence | Eg, plays and works cooperatively with other children |
| Responsibility and respect | Eg, demonstrates self-control | |
| Approaches to learning | Eg, is able to solve problems by himself/herself | |
| Readiness to explore new things | Eg, is eager to play a new game | |
| Prosocial and helping behaviour | Eg, comforts another child who is upset | |
| Child characteristics | Gender | 0=female, 1=male |
| Family resources | Family hardship | Yes to any of eight questions about financial difficulty eg, being unable to pay bills on time |
| Total yearly income before tax | Income before tax, superannuation or health insurance (including pensions and allowances) | |
| Family stability | Family structure | Child lives with both biological parents; child lives in reconstituted family; Other (single mother) |
| Co-parenting scale | Three items measuring frequency of supportive behaviour between parents; 1 (Never) to 5 (Always) | |
| Hendrick relationship quality score | Six items from the Relationship Assessment Scale;33 higher scores indicate higher relationship quality | |
| Parent mental health | Any stressful life events | Yes to any of 12 items, eg, serious illness, injury or assault in the last 12 months |
| Maternal psychological distress score | K6 psychological distress scale,34 reverse scored so that a higher score indicates a relative lack of psychological distress | |
| History of postnatal depression | Yes or no | |
| Mother's parenting style | Warmth | Six items examining the regularity of warm parenting behaviours, eg, expressing affection by hugging, kissing and holding child |
| Use of inductive reasoning | Three questions examining reasoning with study child. Higher scores indicate more frequent use | |
| Consistent parenting | Five items, eg, ensuring completion of behaviour requests | |
| Anger | Five items, eg, feeling angry when punishing the child | |
| Observed to praise child | Parent was observed praising child at least twice during the visit from researcher; Yes or No |