Table 4

Ridge regression coefficients between monthly climatic variables and logarithmic incidence of bacillary dysentery (with k = 0.5, 1950–1996, Shenyang, China)

Duration

R²

Minimum temperature

Average temperature

Maximum temperature

Air pressure

Relative humidity

Precipitation

Evaporation

Long-term Effect

Season

1950–1966, Jan – Jul

0.718

0.079*

0.072*

0.051*

-0.042

0.053

0.156*

0.032

0.458*

0.110*

1950–1966, Aug – Dec

0.818

0.109*

0.075*

0.067*

-0.093*

-0.047

0.068

0.148*

0.442*

-0.084*

1967–1976, Jan – Jul

0.653

0.138*

0.115*

0.106*

-0.097*

0.149*

0.096

-0.009

0.142*

0.106*

1967–1976, Aug – Dec

0.768

0.101*

0.092*

0.076*

-0.156*

0.103

0.013

0.073*

0.338*

-0.101*

1977–1986, Jan – Jul

0.490

0.072*

0.046

0.063*

-0.033

0.222*

0.119

0.114*

0.111

0.052

1977–1986, Aug – Dec

0.822

0.113*

0.127*

0.153*

-0.118*

-0.041

0.065

0.189*

-0.094*

-0.125*

1987–1996, Jan – Jul

0.822

0.131*

0.115*

0.100*

-0.069*

0.148*

0.207*

-0.017

-0.140*

-0.154*

1987–1996, Aug – Dec

0.892

0.154*

0.144*

0.142*

-0.101*

0.048

0.058

0.125*

-0.132*

-0.135*

1950–1996, Jan – Jul

0.306

0.107*

0.082*

0.080*

-0.030

0.018

0.131*

-0.027

0.045

0.111*

1950–1996, Aug – Dec

0.430

0.134*

0.105*

0.094*

-0.110*

-0.116*

0.062

0.071*

0.016

-0.116*

* P < 0.05

Huang et al. BMC Infectious Diseases 2008 8:130   doi:10.1186/1471-2334-8-130