Table 3 Hypertension prevalence and risks of three exposed cohorts in severely and less severely affected areas compared with non-exposed cohort

  Prevalence (%)

19.4

20.8

30.5

25.6

  P^a

0.998

0.011

0.059

  Odds ratio (95 % CI)^a

Ref.

1.00(0.39–2.57)

2.12(1.19–3.79)

1.73(0.98–4.06)

  P^b

0.989

0.012

0.069

  Odds ratio (95 % CI)^b

Ref.

0.99(0.39–2.56)

2.11(1.18–3.77)

1.70(0.96–3.01)

  Prevalence (%)

18.3

20.6

26.8

20.8

  P^a

0.743

0.261

0.796

  Odds ratio (95 % CI)^a

Ref.

0.88(0.37–2.03)

1.38(0.79–2.41)

1.17(0.74–1.84)

  P^b

0.763

0.248

0.906

  Odds ratio (95 % CI)^b

Ref.

0.88(0.37–2.06)

1.40(0.79–2.46)

0.97(0.54–1.72)

 P for interaction between area and cohort^a

Ref.

0.459

0.001

0.144

 P for interaction between area and cohort^b

Ref.

0.901

0.009

0.062