The use of simulated patients (SPs) in medical education has been described as early as 1968 and a number of advantages have been identified, over the use of real patients . Currently more than 80% of medical schools use SPs for training and assessing the competency of health professionals . The advantages in using SPs in training and assessments of medical students are presented in a detailed overview by Barrows . In the educational setting, when SPs are used for training of health professionals, they offer students the opportunity to learn and practice communication skills, history taking and examination techniques in a supportive, low risk (in relation to the well being of patients) and authentic environment. Trained SPs, in addition, are able to provide feedback on students' skills on building rapport with patients, manner of speech and language, interview structure and style etc.
When SPs are used for role playing clinical scenarios during examinations, the emphasis is on standardization of the SPs to ensure consistent role play as this is important for creating fair and equal circumstances for examinees. This is particularly relevant during high-stakes examinations. However, when viewed in the context of medical education, authenticity of role play and ability to provide the students with useful feedback are important, in terms of the quality of learning during SP contact learning sessions. Therefore, training of SPs in these areas is of paramount importance prior to using them in medical education.
A variety of methods for training SPs have been described such as demonstrations and video-clips on role play for orientation on SP technique, observation of real patients being interviewed and examined by physicians, coaching by experienced SPs or professional actors/actresses, and feedback by students and teaching faculty on SP performance . A recently published concise text further provides detailed instructions on the training of SPs for teaching and assessments 
Current status of SP training at the International Medical University
The International Medical University (IMU) has an integrated system-based curriculum for medical undergraduates in the pre-clinical phase which runs over five semesters (two and a half years). During this phase of the curriculum, SPs are used in both teaching and assessments and the use of real patients is minimal. The SP related teaching and learning activities are conducted with small groups of 5–6 students. The SPs enact or role play clinical scenarios relevant to different organ systems with individual students and in addition provide feedback on their performance during the history taking and physical examination learning sessions. The feedback provided by the SPs mainly focus on communication skills and patient etiquette. The tutors provide feedback on specific content knowledge and clinical skills during these supervised learning sessions, although not all learning sessions are supervised by tutors.
Currently IMU has a pool of 70 SPs and they undergo conventional small group training using video clips and group practice sessions etc. following recruitment, prior to participating in teaching. Case scenarios and videotapes are used for training over a day long workshop, delivered once a year. Experienced SPs, enact case scenarios during these demonstration sessions in the training programme. In addition, at the beginning of each organ system module in the curriculum, the SPs receive a short briefing of 30 minutes on the cases that they are expected to role play during the clinical skills teaching programme related to each system. Although SPs have been used for over 10 years in clinical skills teaching at IMU, the performance of these SPs has not been reviewed on a regular basis or in a structured manner either by students, tutors or curriculum managers. Thus it was important to measure and improve their current performance. In view of this lack of information, an evaluation of SP performance at teaching sessions was conducted. This identified some deficiencies in role play of the SPs and effectiveness of providing feedback to the students. Based on this information, retraining of SPs using an innovative approach based on self and peer assessment and feedback was designed.