Table 2 Generalized estimating equation (GEE) results showing the association between PM_2.5 pollution and ARI in children

PM_2.5(every 10 µg increase/m³)

1.222*** (1.018, 1.0261)

1.231*** (1.192, 1.270)

-

PM_2.5Quartiles

Q1 (2.5–34.4 µg/m³)

1 (1, 1)

-

1 (1, 1)

Q2 (34.5–51.5 µg/m³)

1.12 (0.900, 1.404)

-

1.131 (0.904, 1.415)

Q3 (51.6–78.2 µg/m³)

1.989*** (1.544, 2.563)

-

2.067*** (1.604, 2.662)

Q4 (78.3–128.9 µg/m³)

4.219*** (3.202, 5.560)

-

4.450*** (3.374, 5.870)

Current age of child

0.991 (0.971, 1.012)

0.99 (0.970, 1.011)

Sex of child

Male

1 (1, 1)

1 (1, 1)

Female

0.925** (0.871, 0.981)

0.925* (0.872, 0.982)

Mother’s highest educational level

No education

1 (1, 1)

1 (1, 1)

Primary

1.236* (1.042, 1.465)

1.246* (1.050, 1.479)

Secondary

1.036 (0.894, 1.200)

1.039 (0.897, 1.203)

Higher

0.946 (0.777, 1.152)

0.933 (0.767, 1.134)

Wealth quintile

Poorest

1 (1, 1)

1 (1, 1)

Poorer

1.099 (0.952, 1.269)

1.089 (0.944, 1.258)

Middle

0.961 (0.800, 1.154)

0.953 (0.793, 1.144)

Richer

0.811 (0.653, 1.007)

0.806 (0.649, 1.001)

Richest

0.745* (0.573, 0.969)

0.764* (0.589, 0.990)

Type of place of residence

Urban

1 (1, 1)

1 (1, 1)

Rural

1.311* (1.031, 1.667)

1.284* (1.009, 1.633)

Mother’s smoking habit

Smokes cigarettes/tobacco

1 (1, 1)

1 (1, 1)

Does not smoke

0.484*** (0.367, 0.638)

0.487*** (0.369, 0.642)

Type of cooking fuel used in the HH

Clean fuel

1 (1, 1)

1 (1, 1)

Unclean fuel

0.807** (0.702, 0.926)

0.813** (0.709, 0.933)

Cons.

4.400*** (3.559, 5.439)

8.157*** (5.268, 12.631)

16.9*** (10.942, 26.104)