A prospective observational study was conducted by the Puget Sound Pediatric Research Network (PSPRN) and Bastyr University. PSPRN is a regional practice-based research network of community pediatric practices in the Puget Sound area; for this project, seven offices participated. Bastyr University is an academic alternative medical school located in Kenmore, WA. At PSPRN practices, participating providers discussed the study with parents of potentially eligible children; if the parent was interested, contact information was sent to the research assistants who explained the study in detail and completed the enrollment procedures. Bastyr University used a generalized recruitment strategy to enroll patients by advertisements.