TABLE 2.

Summary of Intervention Design by Site

Site	Patient inclusion criteria	Outreach methodology	Randomization
1	Patients born between 1945 and 1965 who had previously visited a site 1 clinic and who had no prior evidence of HCV testing in their medical records	In-person recruitment by study coordinators at four internal medicine clinics	Cluster randomized crossover design: two intervention clinics and two control clinics which switched midway through the study (Rietbergen & Moerbeek, 2011)
2	Patients identified in the EHR system born between 1945 and 1965 who had made at least one primary care visit to a system-affiliated physician in the past year and who had no prior evidence of HCV testing in their medical records	Repeated mailing outreach at weeks 0, 1, 4, 8, and 12, based on a Dillman Total Design Survey Method (Hoddinott & Bass, 1986)	Stratified multiclinic, individually randomized—within each clinic, patients were randomized to intervention or control
3	Patients born between 1945 and 1965 and who had no prior evidence of HCV testing in their medical records	EHR best practice alert targeted to medical assistants indicating patients eligible for a test	Cluster randomized design among 10 semiautonomous primary care practices

NOTE: HCV = hepatitis C virus; EHR = electronic health record.