“…Studies used either validated questionnaires or designed study-specific questions, with some studies using more than one questionnaire. Twenty-four of the studies (67%) [13,39,41,42,[44][45][46][48][49][50][52][53][54]56,57,60,61,65,[67][68][69][70][71][72] used specifically designed study-specific questions to explore patients' perceptions of treatment including beliefs, behaviours and attitudes toward medications. The validated Beliefs about Medicines Questionnaire (BMQ), which measures patient treatment beliefs, was used in 12 (33%) studies [33,40,43,47,51,55,58,59,[62][63][64]66], whilst five (14%) used the validated Illness Perceptions Questionnaire [33,43,58,59,66] which elicits patient beliefs about their illness.…”