Table 3—

Increase in variation in CHD mortality explained by blood glucose

ModelTerms in fitted modelLikelihood ratio statistic (degrees of freedom); P value*
Compared with age-only modelCompared with model indicated
Overall variation between blood glucose groups
A    Age + BG (groups)47.0 (20); P < 0.001
Linear and quadratic effects using blood glucose
B    Age + blood glucose (linear)13.3 (1); P < 0.001
C    Age + blood glucose (Linear) + blood glucose (quadratic)22.5 (2); P < 0.0019.25 (1); P = 0.002 vs. model B
Linear effect above threshold value (no effect below threshold)
Age + blood glucose ≥3.8 (linear)16.7 (1); P < 0.001
Age + blood glucose ≥4.0 (linear)18.5 (1); P < 0.001
Age + blood glucose ≥4.2 (linear)21.9 (1); P < 0.001
Age + blood glucose ≥4.4 (linear)25.9 (1); P < 0.001
D    Age + blood glucose ≥4.6 (linear)28.4 (1); P < 0.0015.46§ vs. model B
Age + blood glucose ≥4.8 (linear)27.6 (1); P < 0.001
Age + blood glucose ≥5.0 (linear)25.5 (1); P < 0.001
Age + blood glucose ≥5.2 (linear)24.6 (1); P < 0.001
Age + blood glucose ≥5.4 (linear)22.3 (1); P < 0.001
Age + blood glucose ≥5.6 (linear)19.9 (1); P < 0.001
Linear effects above and below threshold value
E    Age + blood glucose ≥4.6 (linear) + blood glucose <4.6 (linear)29.4 (2); P < 0.0011.04 (1); P = 0.31 vs. model D
• Men with blood glucose ≥11.1 are excluded. Models compared using likelihood ratio statistics.

• * The likelihood ratio statistic is −2 (difference in log likelihood of two models). This estimates the increase in variation explained compared with the model specified.

• Degrees of freedom for test is equal to the difference in the number of parameters between two models being compared and is given in parentheses.

• In model A, blood glucose is grouped: <3.2; 0.2-mmol/l intervals from 3.2 to 6.3, 6.4 to 6.7, 6.8 to 7.5, 7.6 to 8.9, and 9.0 to 11.0.

• § Models D and C are not nested models so that the difference in the variation explained by these two models cannot be tested formally.