Procedures

Eligible patients received an information letter to participate. Patients were invited based on the referral letter of the general practitioner or referring specialist, which was screened by a research assistant on confirmed diagnosis or suspicion of knee or hip OA. Patients willing to participate were asked to contact the involved researcher. After registering for the study, participants received information about the study by e-mail, along with a hyperlink to an online consent form and questionnaire for baseline assessment (T0). Once the questionnaire was completed, participants were allocated to the intervention or control group (concealed allocation ratio 1:1, stratified by main OA-location hip or knee, using randomly varied block sizes (4 to 8)). Randomization was performed using an electronic data capture and management program; Castor EDC (www.castoredc.com). Participants were informed of the allocation through email, intervention group participants also received access to the educational eHealth tool. One day after the consultation all participants received the second questionnaire (T1) through email. Non-responding participants received a reminder after 1 week. The timeline for participants is illustrated in Fig. 1. Participants who did not attend the consultation were excluded. Diagnosis of all participants was checked in the patient information system post-consultation. Directly following the consultation the orthopedic surgeon rated the degree of involvement of the patient. All data were collected or processed in Castor EDC.

Study protocol and timeline for participants