Table 3. Proportion of Variability in Clinic-Level Percentages of Patients Provided Diabetes-Related Preventive Services Accounted for by Clinic-Level Patient Panel Characteristics

Clinic Patient Panel Characteristics	Full Patient Panel^*				Restricted Patient Panel^{^†}
Clinic Patient Panel Characteristics	LDL	FLU	Micro-Alb	HbA1c	LDL	FLU	Micro-Alb	HbA1c
Model r^{2^‡}
Mean age	0.21^{^§}	0.12	0.01	0.20^{^§}	0.22^{^§}	0.16	0.02	0.30^{^§}
Minority race^{^‖}	0.12	0.06	0.55^{^§}	0.08	0.12	0.06	0.51^{^§}	0.02
English-speaking	0.02	0.10	0.01	0.01	0.04	0.06	0.01	0.02
Spanish-speaking	0.03	0.03	0.08	<0.01	0.06	0.01	0.08	0.01
No insurance	0.25^{^§}	0.18^{^§}	<0.01	0.29^{^§}	0.25^{^§}	0.18^{^§}	<0.01	0.25^{^§}
Continuous insurance	0.26^{^§}	0.18^{^§}	<0.01	0.31^{^§}	0.25^{^§}	0.18^{^§}	<0.01	0.28^{^§}
Income <50% of FPL	0.04	0.15	0.02	0.06	0.03	0.15	0.01	0.08
Change in model r^{2^¶}
Mean age	0.01	<0.01	0.02	<0.01	0.02	0.02	0.03	0.05
Minority^{^‖}	0.13^{^§}	0.07	0.55^{^§}	0.10	0.12	0.06	0.48^{^§}	0.02
English-speaking	0.01	0.07	0.01	<0.01	0.01	0.11	0.01	<0.01
Spanish-speaking	0.01	0.08	0.09	0.01	0.01	0.07	0.05	0.02
Average income <50% of FPL	0.02	0.03	0.03	0.02	0.02	0.02	<0.01	0.03

Values were estimated using regression models of the logit transformation of the percentage of the patient panel receiving services.
↵* Includes all diabetic patients meeting inclusion criteria of at least 1 visit in 2006 and 2007; 425 patients were included in multiple clinic panels.
↵† Each patient was assigned to only one clinic denominator.
↵‡ Proportion of variability accounted for by clinic-level patient panel characteristics (unadjusted).
↵§ P < .05.
↵‖ Any patient with a race other than “white.” This includes black, Asian, Native American, Pacific Islander, nonwhite, and “other race.”
↵¶ The difference between the r² of a model containing the listed patient characteristic and the percentage of patients with continuous insurance and the r² of a model containing only the percentage of patients with continuous coverage. Changes in r² were not reported for the percentage of patients with no insurance because of the high correlation of the measure with the percentage of patients continuously insured.
FPL, Federal poverty level; FLU, influenza vaccination; HbA1c, hemoglobin A1c monitoring; LDL, low-density lipoprotein cholesterol screening; Micro-Alb, urine microalbumin screening.