Ietje Perfors

137 Methods Design The GRIP study is a multicentre randomised controlled trial (RCT), of which the protocol paper has been published previously. 12 The Medical Ethical Committee of the University Medical Centre Utrecht considered the study protocol non-eligible for full ethical review according to Dutch law. Study population and setting Patients were recruited in four hospitals in the centre of the Netherlands, between April 2015 and May 2017. Patients were considered eligible if aged 18 or older, newly diagnosed with either breast cancer, colorectal cancer, gynaecological cancer, lung cancer or melanoma, and scheduled for treatment with curative intent. Patients were excluded if they were unable to fill in questionnaires, if they had a major psychiatric disease or personality disorder, if they already started cancer treatment or if the patient’s GP worked outside the study area or did not agree to participate. Recruitment and randomization After being diagnosed, patients were recruited by the treating specialist or oncology nurse. After consent, the researcher contacted the patient by phone the following (working) day to evaluate eligibility and to provide detailed study information. After signing the informed consent form, patients were randomised 1:1 to the usual care or intervention group. Randomisation was performed using an online computerised randomisation module provided by an independent data centre of the UMC Utrecht. Minimisation was applied to ensure balance between the two groups regarding treating hospital and cancer type. Blinding was not possible due to the nature of the intervention. 6