Table 2

Incidence ratios with their 95% CIs: index period (January and February 2007) versus control periods

Incidence ratio (95% CI)
Control period I: December 2004 to March 2005 and December 2005 to March 2006Control period II: December 2006 and March 2007Control period I and II
Crude model1.37 (1.12 to 1.67)1.37 (1.06 to 1.79)1.37 (1.13 to 1.66)
Model 1*1.43 (1.12 to 1.83)1.49 (1.03 to 2.15)1.53 (1.11 to 2.11)
Model 21.05 (0.57 to 1.94)1.49 (1.03 to 2.15)1.44 (1.02 to 2.02)
Model 30.92 (0.27 to 3.11)1.49 (1.03 to 2.15)1.44 (1.02 to 2.03)
  • * Adjusted for weekday, season, month.

  • Adjusted for weekday, season, month, temperature.

  • Adjusted for weekday, season, month, temperature, unemployment rate.