Table 2.

Multilevel logistic regression model estimates for the relationship between urban sprawl (population density) and outcomes (odds ratios are for a decrease in population density of 1,000 persons per square kilometer)

Outcome	Fixed and random effect terms	Model (covariates included in the model)
		1. (Null—no covariates)	2. (Individual covariatesb only)	3. (Population density only)	4. (Individual covariatesb + population density)	5. (Individual covariatesb + population density + area level covariatesc)
Overweight (N = 5,940)	Population density (OR (95% CI))	–	–	1.096 (1.043–1.149)***	1.084 (1.033–1.139)**	1.087 (1.035–1.141)**
	Area level variance	0.055**	0.035**	0.019	0.011	0.003
	ICCa	0.016	0.011	0.006	0.003	0.001
Obese (N = 4,878)	Population density (OR (95% CI))	–	–	1.183 (1.102–1.269)***	1.142 (1.067–1.223)***	1.150 (1.080–1.225)***
	Area level variance	0.187***	0.130**	0.097**	0.074**	0.033*
	ICCa	0.054	0.038	0.029	0.022	0.010
Inadequate physical activity (N = 7,290)	Population density (OR (95% CI))	–	–	1.111 (1.064–1.160)***	1.120 (1.068–1.174)***	1.123 (1.071–1.177)***
	Area level variance	0.100***	0.100***	0.066***	0.061**	0.044**
	ICCa	0.029	0.029	0.020	0.018	0.013
No walking (N = 7,290)	Population density (OR (95% CI))	–	–	1.175 (1.099–1.256)***	1.179 (1.095–1.271)***	1.179 (1.095–1.271)***
	Area level variance	0.153***	0.141**	0.060**	0.037*	0.016
	ICCa	0.044	0.041	0.018	0.011	0.005

*p < 0.05, **p < 0.01, ***p < 0.001

^aICC = (area level variance) / (area level variance + π² / 3)

^bIndividual covariates include: age, gender, household income, education, smoking status, adequate diet and years lived in local area for all outcomes; inadequate physical activity for the overweight and obese outcomes; and feel safe walking down street after dark for physical activity outcomes

^cThe area level covariate is the quintile of Index of Relative Socio-Economic Disadvantage of the local government area