Results of all 35 questionnaire items. Statements about potential recruitment barriers were assigned to 7 categories. Physicians were asked to express their agreement with these statements on a Likert-type scale from 1 to 7. Box plots with medians and interquartile ranges summarize the answers of the physicians. For each category a summary plot of the answers is presented. Because of limited space some of the questions are slightly shortened. For the original question, please see the appended questionnaire.