Pragmatic Cluster Randomized Trials Using Covariate Constrained Randomization: A Method for Practice-based Research Networks (PBRNs)

From the Department of Family Medicine, University of Colorado, Denver (LMD, WP, WPD, CE); the Adult and Child Center for Outcomes Research and Delivery Science (ACCORDS), University of Colorado, Denver (LMD, BB, AK); the American Academy of Family Physicians National Research Network, Leawood, KS (LMD, WP); the DARTNet Institute, Aurora, CO (CH, WP); Department of Family Medicine, the State University of New York, Buffalo (CF); the Department of Pediatrics, University of Colorado, Denver (AK); and the Children's Hospital Colorado, Aurora, CO (AK).

From the Department of Family Medicine, University of Colorado, Denver (LMD, WP, WPD, CE); the Adult and Child Center for Outcomes Research and Delivery Science (ACCORDS), University of Colorado, Denver (LMD, BB, AK); the American Academy of Family Physicians National Research Network, Leawood, KS (LMD, WP); the DARTNet Institute, Aurora, CO (CH, WP); Department of Family Medicine, the State University of New York, Buffalo (CF); the Department of Pediatrics, University of Colorado, Denver (AK); and the Children's Hospital Colorado, Aurora, CO (AK).

From the Department of Family Medicine, University of Colorado, Denver (LMD, WP, WPD, CE); the Adult and Child Center for Outcomes Research and Delivery Science (ACCORDS), University of Colorado, Denver (LMD, BB, AK); the American Academy of Family Physicians National Research Network, Leawood, KS (LMD, WP); the DARTNet Institute, Aurora, CO (CH, WP); Department of Family Medicine, the State University of New York, Buffalo (CF); the Department of Pediatrics, University of Colorado, Denver (AK); and the Children's Hospital Colorado, Aurora, CO (AK).

From the Department of Family Medicine, University of Colorado, Denver (LMD, WP, WPD, CE); the Adult and Child Center for Outcomes Research and Delivery Science (ACCORDS), University of Colorado, Denver (LMD, BB, AK); the American Academy of Family Physicians National Research Network, Leawood, KS (LMD, WP); the DARTNet Institute, Aurora, CO (CH, WP); Department of Family Medicine, the State University of New York, Buffalo (CF); the Department of Pediatrics, University of Colorado, Denver (AK); and the Children's Hospital Colorado, Aurora, CO (AK).

From the Department of Family Medicine, University of Colorado, Denver (LMD, WP, WPD, CE); the Adult and Child Center for Outcomes Research and Delivery Science (ACCORDS), University of Colorado, Denver (LMD, BB, AK); the American Academy of Family Physicians National Research Network, Leawood, KS (LMD, WP); the DARTNet Institute, Aurora, CO (CH, WP); Department of Family Medicine, the State University of New York, Buffalo (CF); the Department of Pediatrics, University of Colorado, Denver (AK); and the Children's Hospital Colorado, Aurora, CO (AK).

From the Department of Family Medicine, University of Colorado, Denver (LMD, WP, WPD, CE); the Adult and Child Center for Outcomes Research and Delivery Science (ACCORDS), University of Colorado, Denver (LMD, BB, AK); the American Academy of Family Physicians National Research Network, Leawood, KS (LMD, WP); the DARTNet Institute, Aurora, CO (CH, WP); Department of Family Medicine, the State University of New York, Buffalo (CF); the Department of Pediatrics, University of Colorado, Denver (AK); and the Children's Hospital Colorado, Aurora, CO (AK).

From the Department of Family Medicine, University of Colorado, Denver (LMD, WP, WPD, CE); the Adult and Child Center for Outcomes Research and Delivery Science (ACCORDS), University of Colorado, Denver (LMD, BB, AK); the American Academy of Family Physicians National Research Network, Leawood, KS (LMD, WP); the DARTNet Institute, Aurora, CO (CH, WP); Department of Family Medicine, the State University of New York, Buffalo (CF); the Department of Pediatrics, University of Colorado, Denver (AK); and the Children's Hospital Colorado, Aurora, CO (AK).