Ethical approval was provided by the participating institutions,and self-administered questionnaires were distributed to students during the last 5–10 minutes of their lectures. Participating students did not receive incentives, an information sheet accompanied each questionnaire outlining the research aims and objectives,and all students were informed that participation was voluntary and anonymous. All data were confidential and data protection was observed at all stages of the study. A representative sample of students was sought at all participating universities, and students were informed that by completing the questionnaire, they agree to participate in the study. All data were entered into the computer centrally at one site using the software Teleform®; this maximised the quality assurance and minimised any data entry errors.