title: Investigating the effects of climate variations on bacillary dysentery incidence in northeast China using ridge regression and hierarchical cluster analysis.
abstract: BACKGROUND
  The effects of climate variations on bacillary dysentery incidence have gained more recent concern. However, the multi-collinearity among meteorological factors affects the accuracy of correlation with bacillary dysentery incidence.
  
  
  METHODS
  As a remedy, a modified method to combine ridge regression and hierarchical cluster analysis was proposed for investigating the effects of climate variations on bacillary dysentery incidence in northeast China.
  
  
  RESULTS
  All weather indicators, temperatures, precipitation, evaporation and relative humidity have shown positive correlation with the monthly incidence of bacillary dysentery, while air pressure had a negative correlation with the incidence. Ridge regression and hierarchical cluster analysis showed that during 1987-1996, relative humidity, temperatures and air pressure affected the transmission of the bacillary dysentery. During this period, all meteorological factors were divided into three categories. Relative humidity and precipitation belonged to one class, temperature indexes and evaporation belonged to another class, and air pressure was the third class.
  
  
  CONCLUSIONS
  Meteorological factors have affected the transmission of bacillary dysentery in northeast China. Bacillary dysentery prevention and control would benefit from by giving more consideration to local climate variations.
authors.affiliation: Department of Epidemiology, School of Public Health, China Medical University, Shenyang 110001, PR China. dshuang@mail.cmu.edu.cn
authors.forename: Desheng
authors.initials: D
authors.lastname: Huang
authors.forename: Peng
authors.initials: P
authors.lastname: Guan
authors.forename: Junqiao
authors.initials: J
authors.lastname: Guo
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Baosen
authors.initials: B
authors.lastname: Zhou
mesh_terms: D000399:Air Pressure; D002681:China / Q000453:epidemiology; D002980:Climate; D016000:Cluster Analysis; D004405:Dysentery, Bacillary / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D015994:Incidence; D016018:Least-Squares Analysis; D014887:Weather