Table 1. Association between independent variables and the adjusted number of dialysis stations.

Predictors	Zero-order correlations	Standardized regression coefficients
		Model without region	Model with region
Population density	.06	**−.24	**−.23
Income	**.20	−.10	−.08
Physician-specialist	**.45	**.66	**.65
Population growth	−.02	*.13	.08
Medicare reimbursement per enrollee	**.18	.03	.04
Midwest	—	—	.03
South	—	—	.09
West	—	—	.07
R2	—	.27	.27
N = 408

^*Statistically significant at the p < .05 level.

^**Statistically significant at the p < .01 level.

NOTES: R² is percent of variance explained. N is the number of cases.

SOURCE: Cleary, P.D., Harvard Medical School; Schlesinger, M., John F. Kennedy School of Government; Blumenthal, D., Massachusetts General Hospital.