Table 3.

Results of Multilevel Logistic Regression

Predictor	Odds Ratio	95% CI
density	2.09a	[1.63, 2.69]
frequency	2.06b	[1.81, 2.36]
grade	2.48c	[1.89, 3.27]
interaction between density and frequency	0.45	[0.37, 0.55]
interaction between density and grade	0.85	[0.65, 1.10]
interaction between frequency and grade	0.69c	[0.58, 0.82]
three-way interaction between	1.35	[1.06, 1.73]
density, frequency, and grade
type of deletion	0.12c	[0.09, 0.16]
place of deletion	6.14c	[4.97, 7.60]

Note. 95% CI is the 95% confidence intervals. Confidence intervals containing 1 are nonsignificant.

^aodds ratio for z-score.

^bodds ratio for z-score of natural log transform.

^codds ratio for dummy variable d