12.1 - Example

Example 12-1: Risk of heart disease Section

Risk of developing coronary heart disease (CHD) by age (<55 and 55+ years)

CHD 55+ (1) < 55 (0)
Present (1) 21 22
Absent (0) 6 51
  • Odds of disease among exposed = 21/6
  • Odds of disease among unexposed = 22/51
  • Odds ratio = 8.1

\(ln (P/(1 - P)) = \alpha + \beta_1 \times Age = -0.841 + 2.094 \times Age\)

  Coefficient SE Coeff/SE
Age 2.094 0.529 3.96
Constant -0.841 0.255 -3.30
  • \(OR= e^{2.094} = 8.1 \)
  • Wald Test = (3.96)2 with 1 df (p < 0.05)
  • 95% CI for \(\Theta = e^{(2.094 \pm 1.96 \times 0.529)} = (2.9, 22.9)\)