Table 4. Factors associated with infant mortality (n = 1553).
| n | % | infant deaths (n) | Follow up (years) | Mortality rate (per 100 PY) | Unadjusted Hazard Ratio (95%CI) | Adjusted HR (95% CI) | |
|---|---|---|---|---|---|---|---|
| Maternal age | |||||||
| 15–20 | 144 | 9.3 | 7 | 172 | 4.1 | 1 | |
| 21–25 | 526 | 33.9 | 19 | 644 | 3.0 | 0.73 (0.39, 1.37) | |
| 26–30 | 507 | 32.7 | 18 | 591 | 3.0 | 0.73 (0.32, 1.64) | |
| 31–35 | 251 | 16.2 | 9 | 296 | 3.0 | 0.73 (0.36, 1.47) | |
| >35 | 125 | 8.1 | 1 | 148 | 0.7 | 0.16 (0.02, 1.24) | |
| Household registration | |||||||
| This county | 1311 | 84.4 | 46 | 1585 | 2.9 | 1 | |
| Other county in Yunnan | 200 | 12.9 | 6 | 228 | 2.6 | 0.86 (0.31, 2.39) | |
| Other province | 24 | 1.6 | 1 | 27 | 3.7 | 1.23 (0.19, 7.97) | |
| Other country | 18 | 1.2 | 1 | 9 | 11.1 | 2.27 (0.25, 21.1) | |
| Ethnicity | |||||||
| Hanzu | 749 | 48.2 | 13 | 908 | 1.4 | 1 | 1 |
| Non-Han minority | 804 | 51.8 | 41 | 945 | 4.3 | 2.99 (1.82, 4.91) | 2.68 (1.64, 4.38) |
| Occupation | |||||||
| Peasants | 1145 | 73.7 | 47 | 1387 | 3.4 | 1 | |
| Migrant workers | 96 | 6.2 | 0 | 104 | 0.0 | 0 | |
| Housework or unemployed | 217 | 14.0 | 5 | 250 | 2.0 | 0.58 (0.23, 1.45) | |
| Workers/white collar/other/unknown | 95 | 6.1 | 2 | 109 | 1.8 | 0.51 (0.13, 1.99) | |
| Highest education level* | |||||||
| No education | 188 | 12.1 | 6 | 201 | 3.0 | 1 | |
| Primary school | 552 | 35.6 | 26 | 676 | 3.8 | 1.40 (0.71, 2.74) | |
| Junior high | 643 | 41.5 | 20 | 765 | 2.6 | 0.97 (0.44, 2.15) | |
| Senior high/college | 168 | 10.8 | 1 | 209 | 0.5 | 0.17 (0.02, 1.50) | |
| Timing of PMTCT initiation | |||||||
| 1st/2nd trimester | 980 | 63.0 | 24 | 1179 | 2.0 | 1 | 1 |
| 3rd trimester | 265 | 17.1 | 14 | 321 | 4.4 | 2.18 (1.12, 4.24) | 2.23 (1.11, 4.38) |
| L&D or no ARV | 308 | 19.8 | 16 | 349 | 4.6 | 2.24 (1.37, 3.69) | 1.70 (0.87, 3.32) |
| Site of delivery | |||||||
| Municipal hospital | 294 | 18.9 | 12 | 333 | 3.6 | 1 | |
| County hospital | 1165 | 75.0 | 34 | 1405 | 2.4 | 0.70 (0.31, 1.61) | |
| Township hospital /home/other | 94 | 6.0 | 8 | 113 | 7.1 | 2.08 (0.80, 5.39) | |
| Mode of delivery | |||||||
| Emergency cesarean section | 255 | 16.4 | 10 | 297 | 3.4 | 1 | |
| Elective cesarean section | 435 | 28.0 | 7 | 554 | 1.3 | 0.40 (0.15, 1.06) | |
| Vaginal birth | 863 | 55.6 | 37 | 998 | 3.7 | 1.09 (0.64, 2.86) | |
| ARV regimen during pregnancy | |||||||
| HAART | 1045 | 67.3 | 33 | 1224 | 2.7 | 1 | |
| scAZT | 200 | 12.9 | 5 | 277 | 1.8 | 0.77 (0.28, 2.08) | |
| No ARV during pregnancy | 308 | 19.8 | 16 | 349 | 4.6 | 1.73 (1.09, 2.73) | |
| Baby sex | |||||||
| Male | 796 | 51.3 | 24 | 968 | 2.5 | 1 | |
| Female | 757 | 48.7 | 30 | 882 | 3.4 | 1.33 (0.78, 2.28) | |
| Feeding mode | |||||||
| Formula feeding | 1518 | 97.8 | 51 | 1806 | 2.8 | 1 | 1 |
| Mixed feeding | 35 | 2.3 | 3 | 43 | 7.0 | 2.63 (1.16, 5.95) | 1.47 (0.76, 2.84) |
| Birth weight | |||||||
| ≥2.5kg | 1364 | 87.9 | 39 | 1646 | 2.4 | 1 | 1 |
| <2.5kg | 188 | 12.1 | 15 | 204 | 7.4 | 2.97 (1.99, 4.42) | 2.53 (1.41, 4.55) |
| Gestational age at birth | |||||||
| ≥37 weeks | 1453 | 93.6 | 44 | 1750 | 2.5 | 1 | 1 |
| <37 weeks | 100 | 6.4 | 10 | 100 | 10.0 | 3.66 (1.95, 6.89) | 2.36 (1.1, 5.09) |
| Infant prophylaxis | |||||||
| Yes | 1537 | 99.0 | 50 | 1839 | 2.7 | 1 | 1 |
| No | 16 | 1.0 | 4 | 14 | 29.4 | 10.1 (3.58, 28.4) | 7.7 (2.17, 27.4) |
| HIV infection (among 1452 tested) | |||||||
| No | 1423 | 98.0 | 9 | 1776 | 0.5 | 1 | |
| Yes | 29 | 2.0 | 3 | 33 | 9.2 | 3.16 (0.97, 10.2) | |
| Total | 1553 | 100.0 | 54 | 1849 | 2.9 | (95% CI: 2.2, 3.8) | |
Notes: PMTCT prevention of mother-to-child transmission; L&D labor and delivery; CART combination antiretroviral therapy; ARV antiretrovirals; scAZT short course zidovudine; sdNVP single-dose nevirapine.