Table 1 Geographic and sociodemographic characteristics of the study population

Sex^a,*

 Male

28 (65.1)

279 638 (51.3)

-

 Female

15 (34.9)

265 717 (48.7)

-

Month of Birth

 January – April

19 (44.2)

177 918 (32.6)

142 (33.8)

 May – August

8 (18.6)

192 896 (35.4)

134 (31.9)

 Sept – December

16 (37.2)

174 541 (32.0)

144 (34.3)

Birth weight^**

 < 2500 g

6 (14.0)

33 027 (6.1)

28 (6.7)

 ≥ 2500 g

37 (86.0)

508 466 (93.2)

390 (92.9)

Gestational age^***

 < 37 weeks

11 (25.6)

42 235 (7.7)

34 (8.1)

 ≥ 37 weeks

32 (74.4)

489 232 (89.7)

373 (88.8)

Relative income^a

 ‘Lower’

21 (48.8)

232 269 (42.6)

-

 ‘Higher’

21 (48.8)

310 003 (56.8)

-

Urban–rural status^a,b

 Rural

< 6 (≤ 11.6)

34 111 (6.3)

-

 Urban

38–43 (≥ 88.4)

505 236 (92.6)

-