Table 1.

Characteristics of Physician Groups

	Responding groups	Non-responding groups	P value for difference
	Median (range)
Number of physicians	15 (3-244)	10 (2-46)	0.02*
Number of practice sites	2 (1-19)	1 (1-10)	0.30*
Organizational model	Number of groups (%)
Integrated medical group	46 (64)	NA
Independent practice association	16 (22)	NA
Mixed	10 (14)	NA
Majority of physicians employed by group	33 (51)	NA
Network-affiliated	45 (63)	32 (71)	0.42**
Group eligible for performance-based payment…
…based on patient experience	19 (28)	NA
…based on clinical quality (e.g., HEDIS measures)	55 (87)	NA

HEDIS, Healthcare Effectiveness Data and Information Set; NA, Not Available

*P value from Wilcoxon rank sum test

**P value from Fisher exact test