Group characteristics
There were no statistically significant differences between the study arms regarding the characteristics of practices (number of patients per quarter, number of GPs working in the practice, locality of the practice), GPs (sex, age, specialization for natural medicine, activity in undergraduate medical education), and patients (sex, age, degree of education, number of persons in the household, and number of persons under 18 years in the household).The GPs were on average 50 years old, and 66% male. 65% were active in undergraduate medical education, and 12% had a specialization for natural medicine. 56% of the practices (34/61) recruited the maximally allowed number of 11 patients. Patients were on average 33 years old (modal 20, median 30), and 64% female (Table Selected characteristics of practices, GPs and patientsFigures are numbers (percentages), unless stated otherwise. SD standard deviation; *Chi