Measures of adverse health conditions and their derivation (N=11 399)
| Condition | Method of measurement | Variable label (coding) |
|---|---|---|
| Wheeze | Main respondent report whether child had wheezing or whistling in the chest in the last 12 months. | Yes (1) or no (0) |
| Eczema | Main respondent report whether child had ever had eczema. | Yes (1) or no (0) |
| Long-standing illness | Main respondent report that child has a long-standing illness (eg, epilepsy, hearing or sight conditions, cancer). Conditions measured in separate indicators (wheeze, eczema, injury, overweight/obesity and conduct/emotional/social disorders) were excluded. | Yes (1) or no (0) |
| Injury | Main respondent report of an unintentional injury for which medical attention was sought between MCS Sweep 4 (age 7) and Sweep 5 (age 11). | Yes (1) or no (0) |
| Unfavourable weight | Objective BMI (weight/height2) derived from heights and weights measured by trained interviewers; age and sex standardised BMI z-scores derived. BMI z-score classified according to the IOTF published cut-offs: thin35 (≤grade 1), overweight (excluding obesity) and obesity35 combined into unfavourable weight category. | Index: Unfavourable weight (thin, overweight or obese) (1) Normal (0) LCA analysis: Categories: thin, normal BMI, overweight, or obese |
| Socioemotional difficulties | Main respondent completed the SDQ questionnaire about the child. Sum of ‘emotional’, ‘peer’, ‘conduct’ and ‘hyperactivity’ SDQ subscales dichotomised based on published recommendations.34 | Borderline/abnormal (≥14; 1) Normal (0–13; 0) |
BMI, body mass index; SDQ, Strengths and Difficulties Questionnaire.