Table 2.

Baseline Characteristics of Practices That Dropped Out of the NDP

Practice and Group	Dropout Date	Size, Location, Ownership	Practice Age, y	Reason for Dropout
D-1: Self-directed	October 2006	Large, metropolitan, system owned	17	Restructuring within system closed the original family medicine practice that applied to the NDP
D-2: Self-directed	March 2007	Medium, suburban, physician owned	25	Practice said they had too many competing demands to participate in NDP data collection
D-3: Self-directed	April 2007	Solo, rural, physician owned	2	Local hospital closed, forcing close of practice; physician joined practice in another town
D-4: Facilitated	March 2008	Solo, suburban, physician owned	<1	Physician owner closed original practice and joined another

IRB = institutional review board; NDP = National Demonstration Project.

Note: One facilitated practice dropped out of the NDP when the health system IRB did not approve inclusion in the study. All data related to this practice were expunged.