Participants were English speaking adults over 18 years of age, with no previous history of oral cancer. Participants were invited to take part from two General Dental Practices in two boroughs in South East London. The two boroughs were selected because each of the boroughs had an estimated adult smoking prevalence for 2006–08 that was higher (27%) than the regional average for London (21%). The Dental Practices were approached based on their practice location, size and on previous working relationships with the department conducting the research. A total of ten dentists work across both practices from which patients were recruited.
The questionnaire was piloted for face validity by staff and patients at the King's College London Dental Institute, which has a patient population similar to the study sample. No major amendments were required following feedback from the pilot. Initial patient contact was made by sending an invitation letter from the principal dentist and a detailed information sheet to all patients who had appointments during the study period. The information sheet included the purpose of the study which was to know the current levels of patient knowledge and awareness as well as what was required of participants. The survey was self-administered, voluntary and anonymous. All patients had the option to either complete the questionnaire at the surgery and return it immediately or take the questionnaire home to complete at their own convenience. Participants who chose the latter option were given a freepost envelope with which to return the completed questionnaire. Reminder letters including new copies of the questionnaire and return envelopes were sent to all respondents whose completed questionnaires had not been received within four weeks. It was clearly stated in the information sheet that returning a completed questionnaire implied consent. All data was collected over a period of ten days between April and June 2011.
Ethical approval for this study was received from London – Bloomsbury National Research Ethics Service Committee. It is possible that if Dentists at participating practices were informed that patients will be asked if they are aware that the Dentist checked their mouth for any signs of oral cancer and if the results of this screening were discussed with them, the Dentists may have altered their own behaviour in consultations. The British Psychological Society has guidelines which allow for the withholding of some of the details of study if such knowledge of these details is likely to lead to a modification of behaviour although debriefing should occur as soon as possible after data has been collected. Following these guidelines, Dentists in this study were informed that there was a survey of their patients' knowledge and awareness about oral cancer but they were not made aware of the aspect of the questionnaire on oral cancer screening experience until after all data had been collected.
The questionnaire was based on the validated measures developed and used in a similar study in the United States as well as those used in the United Kingdom. It was divided into five sections and collected data on key information about participant's knowledge, experience and awareness about early detection of oral cancer along with health-related behaviours (particularly risk factors for oral cancer), and socio-demographic details, including age, gender, ethnicity, education, marital status and socio-economic status. An additional file shows the full questionnaire [see Additional file 1]. The entire questionnaire took about fifteen minutes to complete.
Healthcare Use. The questionnaire also asked respondents asked about their use of healthcare services. There were questions enquiring about when they last visited their GP as well as how much time had passed between their previous visit to the Dentist and the current appointment. Their reasons for visiting the Dentist were also explored.
Health-related Behaviours: Risk Factors. Alcohol Use: The 3-item Alcohol Use Disorders Identification Test Consumption (AUDIT-C) was used to assess alcohol use. This is a short-form version of the Alcohol Use Disorders Identification Test (AUDIT), a screening tool which was developed by the World Health Organization. The AUDIT-C is used worldwide for identification of alcohol misuse and has been validated. The questions asked include how often alcohol is consumed and the quantity consumed. Total Audit-C scores are calculated with a score of five or more indicating high risk.
Tobacco Use: Using items from the questionnaire by the Office for National Statistics in conjunction with the Department of Health and the NHS Information Centre for Health and Social care, respondents were asked if they smoke at all nowadays or if they did so in the past. There were also questions regarding quantity of cigarettes smoked and other tobacco use like chewing tobacco.
Knowledge and Experience of Oral Cancer and Screening. Participants' self-reported knowledge and awareness of oral cancer was elicited by asking if they had heard of the disease and how much they knew about it, ranging from a lot to nothing at all. Participants' awareness was probed further by asking whether or not they knew if their mouths had ever been screened for oral cancer, if this was done by their Dentist and when. There was also one question regarding their awareness of any extra oral examination of lymph nodes. There were three possible answers to these questions, 'Yes', 'No' and 'Don't Know/Not sure'. For some of the analysis, respondents answering 'No' or 'Don't Know/Not Sure' were grouped together as unaware while those answering 'Yes' were aware. Additionally, two subscales from the Humphris Oral Cancer Knowledge Scale explored respondents' knowledge of risk factors for oral cancer as well as their knowledge of what screening for oral cancer entails.
Attitudes and Emotion Towards Screening for Oral Cancer. Attitudes Towards Oral Cancer 'Screening': Patients' attitude towards having an oral cancer screening was also investigated using four items from the Humphris Oral Cancer Knowledge Scale. A 'total' score for attitude was derived by summing the individual scores for each question. The lowest possible score (0) means a very negative attitude to screening and the highest possible score is 16 reflecting a very positive attitude to screening.
Emotion Towards Oral Cancer 'Screening': A subscale describing respondents' feeling towards having a check up for mouth cancer was included. Participants were asked to rate how anxious, concerned and worried they would be on a likert scale ranging from 'not anxious' to 'extremely anxious'. Scores range from 0 (low emotion) to the highest score of 12 (high emotion).
Patients' Desire to Know if Screening is Taking Place and Need for Support to Reduce Risk. Two questions were asked specifically to determine patients' desire for information and communication about oral cancer screening and risk management. The first question was 'Would you want your dentist to tell you if they were checking your mouth for signs of mouth cancer?' and the second was 'Would you want your dentist to help you reduce your risk of getting mouth cancer'. Responses were 'Yes', 'No' and 'Don't know/Not sure'.
Anticipated Help-seeking Behaviour. In order to ascertain respondents' intentions to seek help for possible signs of oral cancer, they were asked if they would seek help for a list of twelve signs assuming these signs had persisted for three weeks or more. These signs included five signs (a red patch, a white patch, a painful ulcer, swelling in the mouth and pain in the mouth) commonly associated with oral cancer. They were also asked to choose which health care professional they would go to for help concerning these signs should it persist for more than three weeks. The questions used in this section are a modification of a questionnaire that was developed by Scott et al.. The term 'Anticipated delay' is used to refer to a situation wherein respondents do not intend to visit a Doctor or Dentist for signs associated with oral cancer that had lasted for three weeks.
Descriptive statistics were used to describe the sample, their knowledge and experiences. Inferential statistics were then used to check for relationships between outcome measures and risk factors (e.g. alcohol use and smoking status), sociodemographics (borough, gender, age, marital status, ethnicity, educational qualification and socioeconomic classification) as well as health behaviours (e.g. visiting the GP, visiting the Dentist and the reason for Dental visit).
Sample size was calculated by conducting power analysis using the statistical software G Power version 3.0.5. The sample size was based on providing sufficient power for t-tests, Chi-square tests for 1 degree of freedom and Pearson correlation analysis. To compensate for missing data, recruitment continued until 186 participants returned their questionnaires. The software used for analyzing the data was the Statistical Package for Social Sciences version 19.
BMC Oral Health. 2012;12(55) © 2012 BioMed Central, Ltd.