Demographic characteristics
Age group assessed by the question “what is your age” response options recoded into (0) “< 40 years”, (1) “≥ 40 years”.
Education level assessed by the question “what is your education level” using response options (1) “primary level”; (2) “secondary level”; (3) “university”; (4) “post-graduate”. The original categories recoded into (0) basic education (includes responses 1, 2); (1) “university and post-university education” (includes responses 3, 4).
Employment was assessed via the question “what is your occupation” using response options (1) “students”; (2) “labor”; (3) “employee”; (4) “unemployed”; (5) “professional”; (6) “retired”. The original categories recoded into (0) unemployed (including original categories 4, 6); (1) employed (including original categories 1, 2, 3, 5).
Residence was assessed via the question “where is your residence” using response options (1) “suburban”; (2) “urban”; (3) “city”. The original categories recoded into (0) suburban (including the original categories 1); (1) urban (including the original categories 2, 3).
Sources of information was assessed via the question; “from where did you get this information” using response options (1) “general media (TV, radio)”, (2) “internet (social media)”, (3) “health workers”, (4) “news- paper and magazine”, (5) “other people”. The original categories recoded into (0) from media (includes original response 1, 2, 4); (1) from direct contact (includes 3, 5, 6).
Heard of oral cancer was assessed via the question; “have you heard of oral cancer”; using response options (1) “yes”; (2) “no”; (3) “I don’t know”. The original categories recoded into (0) no (includes original response 2, 3); (1) yes (includes original response 1).
Believes about oral cancer was assessed via four questions; “Does the risk factors of oral cancer increase with age”; “is oral cancer a preventable disease”;; using response options (1) “yes”; (2) “no”; (3) “I don’t know”. The original responses recoded into (0) false beliefs (includes original response 2, 3); (1) correct beliefs (includes original response 1); “is oral cancer is contagious”; using response options (1) “yes”; (2) “no”; (3) “I don’t know”. The original categories recoded into (0) false beliefs (includes original response 1); (1) correct beliefs (includes original response 2, 3); “is treatment of oral cancer possible”; using response options (1) “yes”; (2) “no”; (3) “I don’t know”. The original categories recoded into (0) false beliefs (includes original response 2, 3); (1) correct beliefs (includes original response 1). The sum variable “believes about oral cancer” (Cronbach’s alpha α = .30) was constructed from the questions (0–4), with median split (Median 3, IQR 1), (0) false beliefs (includes original categories 0, 1, 2); (1) correct beliefs (includes original category 3, 4).
Knowledge of signs and symptoms was assessed via thirteen questions; “do you think loss of taste is a sign of oral cancer”; “do you think dry mouth is a sign of oral cancer”; “do you think bleeding from the gum is a sign of oral cancer”; “do you think burning sensation is a sign of oral cancer”; “do you think numbness of the tongue or other area of the mouth is a sign of oral cancer”; “do you think difficulty in chewing or swallowing is a sign of oral cancer”; “do you think an abnormal swelling is a sign of oral cancer”; “do you think soreness in the mouth that bleed easily and doesn’t heal is a sign of oral cancer”; “do you think undue falling or loosing of teeth is a sign of oral cancer”; “do you think continues pain in the jaw is a sign of oral cancer”; “do you think white/red patch on the gum is a sign of oral cancer”; “do you think lump or thickening in the neck is a sign of oral cancer”; “do you think color change is a sign of oral cancer” using response options (1) “yes”; (2) “no”; (3) “i don’t know”. The original categories recoded into (0) poor knowledge (includes original response 2, 3); (1) good knowledge (includes original response 1). The sum variable “knowledge of signs and symptoms” (Cronbach’s alpha α = .90) was constructed from the 13 questions (0–13) with median split (median7,IQR 6); (0) poor knowledge (includes original categories 0,1,2,3,4,5,6,); (1) good knowledge (includes 7, 8,9,10,11,12,13).
Knowledge of risk factors of oral cancer was assessed via eleven questions; “do you think smokeless tobacco (Toombak) is a risk factor”; “do you think (smoking (cigarette/shisha) is a risk factor”; “do you think alcohol is a risk factor”; “do you think family history of oral cancer is a risk factor”; “do you think exposure to sunlight is a risk factor”; “do you think old age is a risk factor”; “do you think poor oral hygiene is a risk factor”; “do you think chronic trauma is a risk factor”; “do you think sedentary life style is a risk factor”; “do you think hot and spicy food is a risk factor”; “do you think spiritual/demonic attack is a risk factor”. Using response options (1) “strongly agree”, (2) “agree”, (3) “undecided/neutral”, (4) disagree, (5) “strongly disagree”. The original categories recoded into (0) poor knowledge of risk factors (includes 3, 4, 5); (1) good knowledge of risk factors (includes original response 1, 2). The sum variable “knowledge of risk factor” (Cronbach’s alpha α = .65), was constructed from 11 questions (0–11) with median split (median 5, IQR 2); (0) poor knowledge includes original categories 0, 1, 2, 3, 4); (1) good knowledge (includes original categories 5, 6, 7, 8, 9, 10, 11).
Attitude towards oral cancer screening was assessed via the questions; “do you think oral cancer screening should be mandatory”; using response options (1) “yes”, (2) “no”, (3) “i don’t know”. The original categories recoded into (0) negative attitude (includes original responses 1, 2); (1) positive attitude (original responses 1).
Ever screened for oral cancer was assessed via the question; “have you ever gone to oral cancer examination (screening)”; using response options (1) “yes”, (2) “no”, (3) “i don’t know”. The original categories recoded into (0) not screened (includes original responses 2, 3); (1) ever screened (original responses 1).