Table 2.

Correlation Coefficients for Hospital-Level Random Effects in Logistic Mixed Regression Models of Intensive Care Use across 90 Hospitals

	Empty Model	Model with Patient Factors	Model with Patient and Hospital Factors
	Model 1	Model 2	Model 3
Random effects variance*
Hospital-level variance (95% CI)	0.38 (0.06, 0.28)	0.81 (0.60, 1.1)	0.57 (0.42, 0.76)
Intraclass correlations**(%)
Hospital (95% CI)	10.3 (7.6, 13)	19.7 (15.1, 24.4)	14.6 (11, 18.3)
Residual	89.7	80.3	85.4
Observations	1,011,363	1,011,354	1,011,354

^*The residual (patient) variance in a mixed logistic regression model is fixed at π^(2/3).

^**ICC calculated as proportion of hospital variance divided by total variance where total variance is the sum of hospital variance and residual variance π^(2/3).

CI, confidence interval.