|  |  | Multiple linear regression analysisd | |
---|---|---|---|---|
Characteristics | n (%) | Mean ± s.d. (95% CI) of Hb (g/L) | Coeff (95% CI) | P-value |
Gestational agea | Â | Â | -0.25 (-0.44, -0.05) | 0.012 |
   1st trimester | 49 (12.9) | 135.8 ± 20.9 (132.2, 143.8) |  |  |
   2nd trimester | 119 (31.3) | 128.0 ± 21.0 (124.4, 132.2) |  |  |
   3rd trimester | 212 (55.8) | 125.6 ± 18.3 (123.3, 128.5) |  |  |
Age | Â | Â | -0.14 (-0.59, 0.30) | 0.524 |
   <25 | 123 (32.4) | 128.6 ± 20.0 (125.4, 132.9) |  |  |
   25-30 | 163 (42.9) | 128.0 ± 19.1 (125.4, 131.5) |  |  |
   30+ | 93 (24.5) | 125.7 ± 20.7 (122.3, 130.9) |  |  |
Ethnicity | Â | Â | 8.09 (1.68, 14.50) | 0.013 |
   Tibetan | 330 (86.8) | 126.6 ± 20.2 (124.9, 129.4) |  |  |
   Non-Tibetanb | 50 (13.2) | 134.6 ± 15.1 (130.8, 139.5) |  |  |
Residence | Â | Â | 5.66 (1.03, 10.30) | 0.017 |
   Urban | 234 (61.6) | 125.9 ± 18.9 (124.1, 129.1) |  |  |
   Ruralc | 146 (38.4) | 130.4 ± 20.9 (127.3, 134.4) |  |  |
Parity | Â | Â | 1.23 (-1.72, 4.17) | 0.414 |
   0 | 173 (45.5) | 127.4 ± 19.1 (124.7, 130.6) |  |  |
   1 | 120 (31.6) | 126.4 ± 21.2 (123.0, 130.9) |  |  |
   2+ | 87 (22.9) | 130.5 ± 18.9 (126.8, 135.2) |  |  |
Annual income ($) | Â | Â | 10.65 (3.04, 18.25) | 0.006 |
   <264 | 49 (12.9) | 119.8 ± 22.6 (111.0, 128.5) |  |  |
   264+ | 331(87.1) | 128.8 ± 19.5 (126.8, 131.0) |  |  |
Total | 380 (100.0) | 127.6 ± 19.8 (125.7, 129.6) |  |  |