Doctor's use of medical terms is generally considered to be one of the reasons for patients' poor comprehension of medical information. However, little research has been done on the effects of Chinese medical terms, which are constructed rather differently compared to English medical terms. This study manipulated the use of Chinese medical terms in a simulated clinical consultation, to investigate its effects on patients’ comprehension of medical information and their confidence for seeking further information. One hundred and eighty one eligible Hong Kong laypersons were randomly assigned to watch one of three video clips, which differed in the use of words explaining the underlying pathological changes and the treatment of prolapsed intervertebral disc: one with lay terms only (group 1), another with medical terms alone (group 2), and another one with medical terms supplemented with lay terms (group 3). After that, a computer-based questionnaire was used to assess the participants' comprehension of the information and confidence for seeking further information, followed by a semi-structured face-to-face interview on their perceptions of the utility of Chinese medical terms. Results suggested that although Chinese medical terms were perceived to be useful in assisting patients to look for further information on their diseases, the use of Chinese medical terms, either used with or without the supplements of lay terms, did not add to patients' comprehension of medical information and confidence for seeking further information. Regression models showed a significant trend of decreasing comprehension of the cause of the disease (β = -0.241, P = 0.002) and knowledge test scores (β = -0.214, P = 0.006) with increasing age of the participant. However, older persons had better comprehension of the word used (β = 0.238, P = 0.001). Participants' educational level was the most important determinant of knowledge test scores (β = 0.364, P < 0.001). In addition, persons with higher education (β = 0.207, P = 0.024), professional occupation (β = 0.173, P = 0.015) had better comprehension of the cause of disease. The findings of the study have implications for doctor-patient communication as well as medical education. To improve the effectiveness of doctor-patient communication, it may be more rewarding to enhance doctors' overall communication skills, rather than simply advocating their use or not use of medical language. / published_or_final_version / Anatomy / Master / Master of Philosophy