. 2008 Jun 24;336(7659):1491–1494. doi: 10.1136/bmj.39570.749884.BE

Table 3.

Summary of effectiveness in nine controlled studies

Controlled studies (n=9)	Studies based on Breakthrough Series		Studies based on Vermont Oxford Network
Controlled studies (n=9)	Breakthrough Series	Breakthrough Series and chronic care model	Studies based on Vermont Oxford Network
Two randomised controlled trials		Homer et al^w64 (no effect)	Horbar et al^w71 (mixed effect)
Six controlled before and after studies	Landon et al^w63 (no effect), Baier et al^w61 (positive effect)	Benedetti et al^w62 (mixed effect), Mangione-Smith^w65/Schonlau et al^w66 (mixed effect), Asch^w67/Baker et al^w68 (mixed effect)	Horbar^w69/Rogowsi et al^w70 (mixed effect)
One interrupted time series	Pierce-Bulger et al^w72 (positive effect)