Table 1 Descriptive statistics of the participants
From: The association between air pollution and preterm birth and low birth weight in Guangdong, China
Experimental group | Control group | χ 2 | p | |||
|---|---|---|---|---|---|---|
N | % | N | % | |||
Agea | 912.29 | 0.38 | ||||
20~25 | 350 | 25.38 | 368 | 26.82 | ||
26~30 | 690 | 50.04 | 674 | 49.13 | ||
31~35 | 237 | 17.19 | 239 | 17.42 | ||
36~40 | 73 | 5.29 | 60 | 4.37 | ||
41~49 | 29 | 2.10 | 31 | 2.26 | ||
Educationa | 13.67 | 0.85 | ||||
Primary school and below | 20 | 1.71 | 18 | 1.59 | ||
Junior high school | 271 | 23.20 | 319 | 28.21 | ||
Senior high school | 286 | 24.49 | 283 | 25.02 | ||
College | 526 | 45.03 | 473 | 41.82 | ||
Postgraduate and above | 65 | 5.57 | 38 | 3.36 | ||
Occupationa | 39.95 | 0.52 | ||||
Farmer | 249 | 22.02 | 266 | 24.01 | ||
Worker | 223 | 19.72 | 259 | 23.38 | ||
Service industry | 111 | 9.81 | 102 | 9.21 | ||
Business | 41 | 3.63 | 47 | 4.24 | ||
Housework | 33 | 2.92 | 23 | 2.08 | ||
Teacher/Civil servant | 395 | 34.92 | 323 | 29.18 | ||
Others | 79 | 6.98 | 88 | 7.94 | ||
Registered residencea | 1.19 | 0.28 | ||||
Rural | 845 | 60.97 | 912 | 66.23 | ||
Urban | 541 | 39.03 | 465 | 33.77 | ||