Data assessment
All oncology physicians were asked to answer questionnaires at multiple time points during the KOKON-KTO study. First, a web-based survey prior to e-learning was implemented (baseline MD). Second, paper–pencil questionnaires were distributed to the oncology physicians to provide information after each communication with their patients or provision of the information leaflet to their patients, respectively. Third, each oncology physician received a paper–pencil questionnaire after having conversations with as many patients as they were able to enroll in the study. For the physician–patient interaction level, a systematic external rating of a consultation of the participating oncology physicians was conducted by two experienced independent raters. For this, a consultation with a standardized patient was undertaken during the onsite skills-training workshop in the intervention and control groups.