Fig. 1

Flowchart for the study selection process. Reason 1: no secondary literature (e.g. primary or tertiary literature, editorial, letter); Reason 2: no systematic review, HTA report; meta-analysis; Reason 3: systematic review/ HTA report/ meta-analysis does not contain (separated) results from RCTs or controlled prospective trials; Reason 4: tasks or interventions are not done in primary care setting or no separated results for the primary care setting; Reason 5: the interventions assessed is not a medical intervention substituted by nurses (e.g. no medical intervention, traditional nursing intervention); Reason 6: intervention in the control group is not a medical intervention executed by doctors (services in the intervention and control group must be the same, no additional services); Reason 7: no patient-relevant outcomes (e.g. hospital admissions, patient satisfaction, mortality, morbidity), clinical surrogate parameters (e.g. blood pressure, HbA1c, …), health care system-relevant outcomes (e.g. costs) assessed/reported; Reason 8: language is not English or German; Reason 9: no full text publication in line with PRISMA statement, Reason 10: no human study; Reason 11: OQAQ (Overview Quality Assessment Questionnaire) rating < 5; Reason 12: duplicate, more recent version available