Table 1.
Summary statistics for the analytical sample† from the Birth to Twenty Plus (Bt20) cohort study of children born in April–June 1990 in Soweto-Johannesburg, South Africa
| Age collected | Mean or %‡ | sd | Range | |
|---|---|---|---|---|
| Dependent variable | ||||
| Stunting (HAZ <−2) (%) | 2 years | 23·15 | – | 0–1 |
| HAZ | 2 years | −1·28 | 1·15 | −6·15–2·91 |
| Maternal education | ||||
| Years of education completed | antenatal–2 years | 10·01 | 2·75 | 0–14 |
| Baseline | ||||
| Female (%) | 0 months | 52·53 | – | 0–1 |
| Birth weight | ||||
| Birth weight (g) | 0 months | 3103 | 491 | 1070–4800 |
| Birth weight Z-score | 0 months | −0·45 | 1·11 | −5·66–2·63 |
| Feeding | ||||
| Duration of breast-feeding (months) | 6 months, 1 year, 2 years | 13·05 | 8·99 | 0–25 |
| Food variety score | 1 year | 34·07 | 10·77 | 8–75 |
| Illness | ||||
| Respiratory symptoms | 6 months, 1 year, 2 years | 2·54 | 1·27 | 0–4 |
| PCA respiratory symptoms | 6 months, 1 year, 2 years | 0·49 | 1·32 | −2·20–1·94 |
| Eyes & ears symptoms | 6 months, 1 year, 2 years | 0·44 | 0·59 | 0–2 |
| PCA eyes & ears symptoms | 6 months, 1 year, 2 years | 0·21 | 1·17 | −0·61–3·63 |
| Gastrointestinal symptoms | 6 months, 1 year, 2 years | 0·87 | 0·91 | 0–3 |
| PCA gastrointestinal symptoms | 6 months, 1 year, 2 years | 0·27 | 1·29 | −0·96–3·34 |
| Caregiver | ||||
| Mother principal caregiver (%) | 2 years | 62·23 | – | 0–1 |
| Mother–child relationship | 2 years | 4·58 | 2·14 | 0–6 |
| PCA mother–child relationship | 2 years | −0·09 | 2·13 | −4·65–1·29 |
| Reproductive | ||||
| Mother’s age (years) | 0 months | 25·52 | 5·91 | 14–43 |
| Birth order | antenatal–2 years | 2·00 | 1·04 | 1–4 |
| Birth spacing (another child born within 24 months) (%) | 2 years | 5·35 | – | 0–1 |
| Attitudes | ||||
| Health utilisation score (based on vaccinations received) | 1 year | 1·20 | 0·65 | 0–2 |
| Services | ||||
| Services index | 0 months–2 years | 1·62 | 0·91 | 0–3 |
| PCA services index | 0 months–2 years | 0·09 | 1·31 | −1·74–2·11 |
| Socio-economic status | ||||
| Asset index (simple count) | 2 years | 3·16 | 1·61 | 0–6 |
| Crowding | antenatal–2 years | 3·30 | 1·67 | 0·50–19 |
| PCA asset index | 2 years | 0·08 | 1·55 | −3·90–2·95 |
| Parental occupation score | antenatal–2 years | 1·88 | 1·34 | 0–5 |
HAZ, height-for-age Z-score; PCA, principal components analysis.
†
The analytical sample consists of children with non-missing data on HAZ at 2 years and the covariates (n 691).
‡
The mean/percentage column shows the mean for continuous variables and the percentage for binary variables.