Pretest: Participants were informed about the aims of the study and filled in a consent form. A paper version of the German translation of the Injustice Experience Questionnaire was completed in presence of the interviewer. The structure of the standardized interview followed the recommendations for pretesting transcultural translations of questionnaires. Patients were asked if there were any items difficult to understand, unacceptable or offending them. Subsequently they had to answer questions about the content and meaning of the IEQ-items. The interviewer asked all questions and entered the responses. All data were directly stored in a MySQL database at a Swiss commercial web-server (www.scientific-affairs.ch).~Validation Study: Participants are informed about the aims of the study and fill in a consent sheet. By e-mail they receive an access link to the online survey which can be completed at home. The survey includes the following questionnaires: Injustice Experience Questionnaire (IEQ), Depression subscale of the Depression, Anxiety and Stress Scale (DASS), Tampa Scale for Kinesiophobia (TSK), McGill Pain Questionnaire (MPQ), Pain Catastrophizing Scale (PCS), Pain Disability Index (PDI) and part concerning causes of pain of the German Pain Questionnaire (DSF). About 20 minutes is needed to answer the 80 questions of the survey. After completing the survey participant can choose if they would like to be informed about the results of the filled in questionnaires. All data is saved anonymously during the survey and stored in a MySQL database at a Swiss commercial web-server (www.scientific-affairs.ch).
Purpose of the study is the validation of the German version of the Injustice Experience Questionnaire.~Pretest: Participants were informed about the aims of the study and fill in a consent form. They filled in a paper version of the German translation of the Injustice Experience Questionnaire. In a structured interview patients were asked if there were any items difficult to understand, unacceptable or offending them. Subsequently they had to answer questions about the content and meaning of the IEQ-items.~Validation Study: Participants were informed about the aims of the study and filled in a consent form. By e-mail they received an access link to the online survey. The questionnaires of the survey could be filled in at home. The survey could be interrupted and terminated later. About 20 minutes were needed to answer the 80 questions of the survey. All data was saved anonymously during the survey.