Table 1. Distribution of sample by key social and demographic indicators.
| Indicator | Distribution (%)a according to year of survey |
P-valueb | ||||
|---|---|---|---|---|---|---|
| 1991 |
1994 |
1997 |
2002 |
|||
| (n = 15 594) | (n = 18 059) | (n = 17 302) | (n = 15 772) | |||
| Residence | ||||||
| Rural | 71 | 73 | 73 | 53 | ||
| Urban | 29 | 27 | 27 | 47 | 0.0000 | |
| Woman’s education | ||||||
| No education | 15 | 12 | 9 | 5 | ||
| Some primary education | 64 | 60 | 57 | 48 | ||
| Some secondary education | 20 | 25 | 30 | 41 | ||
| Some higher education | 2 | 3 | 4 | 6 | 0.0000 | |
| Husband’s education | ||||||
| No education | 9 | 8 | 5 | 3 | ||
| Some primary education | 61 | 57 | 53 | 45 | ||
| Some secondary education | 26 | 30 | 36 | 44 | ||
| Some higher education | 4 | 5 | 5 | 7 | 0.0000 | |
| Pooled wealth quintile | ||||||
| Quintile 1 (lowest SES) | 35 | 27 | 17 | 9 | ||
| Quintile 2 | 24 | 22 | 20 | 15 | ||
| Quintile 3 | 17 | 17 | 24 | 18 | ||
| Quintile 4 | 13 | 18 | 24 | 24 | ||
| Quintile 5 (highest SES) | 10 | 15 | 15 | 33 | 0.0000 | |
| Woman’s age at delivery (years) | ||||||
| < 20 | 15 | 14 | 14 | 12 | ||
| 20–29 | 58 | 56 | 55 | 56 | ||
| 30–39 | 24 | 27 | 28 | 28 | ||
| ≥ 40 | 2 | 3 | 3 | 3 | 0.0000 | |
| Parity at delivery | ||||||
| 1 | 29 | 29 | 33 | 35 | ||
| 2–5 | 59 | 57 | 57 | 57 | ||
| ≥ 6 | 13 | 14 | 10 | 8 | 0.0000 | |
| Total | 100 | 100 | 100 | 100 | ||
SES, socioeconomic status. a All percentages were calculated using sample weights. The unit of analysis was live births in the past 5 years. b P-values are from χ² tests for differences by survey, adjusted for survey clustering.