Study participants
The present cross-sectional study was carried out in April–May 2007 among a census of dental students attending the 3rd, 4th and 5th study year in 6 dental faculties in Khartoum, the capital of Sudan. A list of all the dental faculties was obtained from the Ministry of Higher Education and lists of all registered students in the 3rd, 4th and 5th years were obtained from all faculties through the Dean's office. The faculties included in this study were publicly and privately funded. Moreover, they represent all available dental faculties in Sudan admitting clinical students and thus include students from all over the country. The total number of dental students registered by the time of the survey was 782 (3rd, 4th and 5th graders) out of which 642 students (response rate 82%, mean age 21.7, 82% girls) completed self-administered, anonymous questionnaires in supervised (by teaching assistants) class-room settings. The main reason for non-participation was absenteeism on the day of the data collection.
Written informed consent was obtained from all participants. A formal ethics waiver was received from the research committee at the University of Science and Technology. All included faculties provided approval letters before conducting the study. Before being used in the field, the questionnaire was reviewed by experienced local researchers, dental academics and health administrators.
Measures
The survey instrument, constructed and administered in English, contained 44 questions regarding HIV and AIDS related knowledge, sources of information and need for further education of dental students. This instrument has been employed previously among university students in East Africa [19].Sources of HIV and AIDS related information were assessed using 6 questions, "How much information about HIV and AIDS related issues have you received from-1) lectures-, 2) radio/TV-,3) internet-,4) reading materials-, 5) friends/relatives-,6) health care workers". Each question had response categories ranging from (1) "very much" to (5) "non at all". For cross tabulation each question was dichotomized into (0) "some/little information received" (original categories 3, 4, 5) and (1) "much/very much information received" (original categories 1, 2). Two formative sum scores were constructed yielding "Amount of information received from reading materials/media" (information received from Radio/TV, internet, reading materials, friends/relatives) and "Amount of information received from lectures/health care workers" (information received from lectures, health workers). For cross tabulation and logistic regression analysis the sum scores were dichotomized based on a median split yielding (1) "very much/much information received from reading materials/media and health care workers" and (0) "some/little/none information received from reading materials/media and health care workers".
Need for further education
6 questions were applied in terms of. "How do you rate your need for further education regarding 1) basic HIV/AIDS related topics, 2) patient management, 3) treatment recommendations, 4) advice on referrals, 5) clinical manifestations, 6) psycho-social complications". Each question had a response category in the range (1) "no need" to (4) "great need". For cross tabulation analysis each question was dichotomized into (1) "moderate/great need" (original categories 3, 4) and (0) "no need" (original categories 1, 2). A formative sum score was constructed based on the 6 questions and labelled "Need for further information on HIV and AIDS". The sum score was dichotomized based on a median split into (1) "moderate to great need" and (0) "slight need/no need" for use in cross tabulation and logistic regression analysis.
Knowledge about modes of HIV and AIDS transmission was assessed using the statements
"HIV and AIDS can be transmitted by 1) using contaminated sharp instruments-, 2)unsafe blood transfusion, 3) contaminated blood transfusion, 4) not transmitted through shaking hands-, 5) not transmitted through eating with infected people". In addition, the students replied to the statement "Condom use is safe prevention". Each statement had response category in the range from (1) "strongly agree" to (5) "strongly disagree". For cross-tabulation each statement was dichotomized yielding (1) = "correct knowledge" (original categories 1, 2) and (0) "incorrect knowledge" (original categories 3, 4, 5). Two sum scores were constructed from 5 variables yielding "Transmission through contaminated instruments"(unsafe blood transfusion, contaminated blood transfusion, contaminated sharp instruments) and "Transmission through shaking hands and eating" (shaking hands, eating). in addition to the one item assessing "Condoms are safe prevention". The two sum scores were dichotomized on a median split into (1) = "Correct overall knowledge" and (0) "Incorrect overall knowledge".
Knowledge of risk groups for HIV and AIDS, was assessed using 6 statements with response scale (1) "correct", (0) "incorrect". The students were asked "Is it correct or incorrect that university students, barbers, truck drivers, soldiers, teachers and health care workers are considered as high risk groups by profession"? One formative sum score was constructed from the 6 variables. For logistic regression analysis the sum score was dichotomized based on a median split into (1) "Correct knowledge on occupational risk groups", (0) "Incorrect knowledge on occupational risk groups"
Statistical procedure
Data were analyzed using the Statistical Packages for Social Sciences (SPSS), version 15. Differences between students from public and private institutions were analyzed using cross-tabulation and Pearson's chi-squared test. Multivariate analysis was conducted by multiple logistic regression analysis with odds ratio (OR) and 95% Confidence Interval (CI). P-value for statistical significance was set to 0.05.