1. Institute for Health Research, Kaiser Permanente Colorado, Denver, Colorado;
2. Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado;
3. Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota;
4. HealthPartners Institute for Education and Research, Minneapolis, Minnesota;
5. Division of Research, Kaiser Permanente Northern California, Oakland, California
6. Kaiser Permanente San Francisco Medical Center, San Francisco, California; and