Table 1.
All-cause univariate risk factor analysis for infant mortality in the Agincourt sub-district, 1992-2007
| Factor | n | IRR | p-value | signif |
|---|---|---|---|---|
| Temporal | ||||
| 1 year continuous | 31,804 | 1.23 | <0.001 | * |
| 5 year period | 31,804 | |||
| 1992-1996 | 10,744 | 1.00 | ||
| 1997-2001 | 10,624 | 4.61 | <0.001 | * |
| 2002-2006 | 10,436 | 10.76 | <0.001 | * |
| Demographic | ||||
| Male gender | 31,804 | 1.86 | 0.006 | * |
| Mother refugee status | 29,068 | |||
| South African citizen | 18,746 | 1.00 | ||
| Mozambican origin | 10,322 | 1.12 | 0.638 | |
| Breast feeding and birth weight | ||||
| Breast fed | 23,890/25,697 | 0.21 | <0.001 | * |
| Breast fed (diarrhoea & malnutrition) | 23,890/25,697 | 0.38 | 0.001 | * |
| Increasing birth weight (kilograms) | 15,235β | 0.42 | <0.001 | * |
| Maternal | ||||
| Mother Mozambican in-migrated post 1992 α | 10,322 | 4.89 | 0.004 | * |
| Mother status | 31,041 | |||
| Mother in same household | 27,076 | 1.00 | ||
| Mother not in household | 2,488 | 0.01 | <0.001 | * |
| Mother death | 1,477 | 5.79 | <0.001 | * |
| Mother residency status | ||||
| Permanent (> = 6 months in site) | 28,852 | 1.00 | ||
| Migrant | 25,200 | 0.45 | 0.059 | # |
| Other | 2,035 | 0.36 | 0.067 | # |
| Increasing number of months resident during the previous 12 months | 28,962 | 1.11 | 0.001 | * |
| Mother died in child's first year | 91/31,804 | 65.72 | <0.001 | * |
| Mother age at pregnancy | 27,981 | 0.99 | 0.595 | |
| Mother education | 16,971 | |||
| None or primary | 6511 | 1.00 | ||
| Secondary | 9561 | 0.90 | 0.677 | |
| Tertiary | 899 | 0.13 | <0.001 | * |
| Paternal | ||||
| Father died in child's first year | 59/31,804 | 0.69 | 0.834 | |
| Father died before birth | 57/31,804 | 0.98 | 0.993 | |
| Household head | 26,034 | |||
| Male gender | 16,625 | 0.86 | 0.331 | |
| Mozambican origin | 9,972 | 1.04 | 0.808 | |
| Age (years) | 25,660 | |||
| 18-29 | 2,995 | 1.00 | ||
| 30-49 | 13,143 | 0.93 | 0.785 | |
| 50-64 | 6,486 | 1.39 | 0.243 | |
| 65+ | 3,036 | 1.43 | 0.272 | |
| Household morbidity and mortality | ||||
| Cumulative number of household deaths in year of birth (continuous) | 31,804 | 14.64 | <0.001 | * |
| None | 26,444 | 1.00 | ||
| 1 | 4,048 | 35.51 | <0.001 | * |
| 2-3 | 1,232 | 109.34 | <0.001 | * |
| 4+ | 80 | 131.47 | <0.001 | * |
| Number of household admissions in year of birth (continuous) | 2,895 | 1.55 | 0.093 | # |
| None | 2,392 | 1.00 | ||
| 1-2 | 402 | 1.51 | 0.464 | |
| 3+ | 101 | 17.80 | 0.041 | * |
| Fertility | ||||
| Birth parity (continuous) | 25,083 | 1.22 | 0.170 | |
| 1 | 25,083 | 1.00 | ||
| 2-3 | 16,526 | 2.32 | 0.001 | * |
| 4+ | 7,663 | 0.55 | 0.313 | |
| Preceding birth interval | 8,421 | 1.05 | 0.001 | * |
| Post birth interval | 7,199 | 0.51 | <0.001 | * |
| Previous birth stillborn | 318/27,981 | 16.71 | <0.001 | * |
| Previous sibling died | 945/27,981 | 7.48 | 0.001 | * |
| Preceding interval sibling death | 413 | 1.23 | 0.413 | |
| Mother attended antenatal clinic | 24,928 | 0.06 | <0.001 | * |
| Number of antenatal clinic visits | 17,305 | 0.84 | <0.001 | * |
| Socio-economic status of household | ||||
| SES absolute score (quintiles) | 9,397 | |||
| Most poor | 1,584 | 1.00 | ||
| Very poor | 1,801 | 0.81 | 0.540 | |
| Poor | 1,971 | 0.91 | 0.780 | |
| Less poor | 2,019 | 0.91 | 0.780 | |
| Least poor | 2,022 | 0.98 | 0.940 | |
| Food security status of household | ||||
| Predicted food shortage in coming year | 3,481 | |||
| Same amount of food | 1,122 | 1.00 | ||
| More food | 377 | 0.31 | 0.091 | # |
| Less food | 1,982 | 1.24 | 0.597 | |
| Distance to nearest health facility | ||||
| Minimum distance to health facility (straight-line) from household | 25,749 | |||
| < 5 km | 24,023 | 1.00 | ||
| > = 5 km | 1,726 | 1.18 | 0.607 | |
| Minimum distance to health facility (network) from village centroid | 31,804 | |||
| < 5 km | 1,220 | 1.00 | ||
| > = 5 km | 30,584 | 1.28 | 0.684 | |
| Climatic | ||||
| Elevation (meters) - rainfall proxy | 30,583 | |||
| 350-399 | 2,554 | 1.00 | ||
| 400-449 | 14,202 | 0.43 | 0.072 | # |
| 450-499 | 4,120 | 0.25 | 0.009 | * |
| 500-549 | 7,202 | 0.17 | <0.001 | * |
| 550-599 | 2,505 | 0.46 | 0.226 |
Total sample size (n = 31,804)
α: infectious and parasitic deaths only
β: birth weight data only available for this number of infants
* significant at the 5% level; # significant at the 10% level