Preparation of the study

4.2.3.1. Questionnaire development and validation

The questionnaires and information sheets used for this study were prepared to meet the objectives of the study. The information and invitation leaflet and consent form were prepared based on the requirement of the Central Office for Research Ethics Committee (www.corec.org.uk/applicants/apply/safety.htm) for the City and East London Ethics Committee (CELEC) (Appendix 4.1 and 4.2). A pictorial leaflet was also provided with the written information and invitation leaflet for those who were unable to follow the written information and invitation. The questionnaires to be completed by the participants were translated into Bengali by the researcher and translated back into English by a second translator, which was then compared with the original questionnaire prepared for this study (Part b of the Appendix 4.1 and 4.2).

The questionnaire used for the demographics and tobacco use by the participants was previously prepared and validated for a survey on the oral health status of the residents in the borough of Tower Hamlets, London (Pearson et al., 1999). This questionnaire was restructured by the exclusion of sections considered inappropriate for the current study such as artificial denture use and its repair (Appendix 4.3). Data on the presence, intensity, and nature of oral pain of the participants at baseline was collected using the oral pain questionnaire that was previously validated and used for oral pain assessment amongst adult female Bangladeshis living in the borough of Tower Hamlets London. This questionnaire contained fourteen questions that needed to be answered (Pau et al., 2005) (Appendix 4.4). The question number one of the questionnaire was on the presence or absence of oral pain that had two responses ‘yes’ or ‘no’ only. The

other questions were to identify sites, nature, and association of oral pain with other exogenous substances such as food, hot and cold drinks. Each question had multiple options to answer. The Visual Analogue Scale (VAS) was used to identify the intensity of oral pain which was in the same questionnaire (Appendix 4.4). The smokeless tobacco dependence of the participants was assessed using a questionnaire measuring dependence on smokeless tobacco (Severson, et al.

2004) (Appendix 4.5 and 4.5b). The measures of this questionnaire were prepared in conjunction with the Fagerstrom Test for Nicotine Dependence-Smokeless Tobacco tolerance questionnaire (FTQ) (Ebbert, et al. 2006) which was used by Ebbert et al. (2009). The questionnaire was modified according to the current study protocol and used in this study.

Psychological distress of the participants was assessed using a previously validated Hospital Anxiety and Depression Scale (HADS) questionnaire (Zigmond and Snaith, 1983) (Appendix 4.6 and 4.6b). The association of social determinants namely social capital, neighbourhood status, daily household deprivation, and socio-economic status (SES) namely employment status, level of formal education and nature of occupation with paan tobacco chewing were assessed by using the questionnaire prepared and validated for a community study in the UK (Cooper et al., 2000) (Appendix 4.7). This questionnaire was suitable for both self-completion and completion by the researcher in the face-to-face interview.

General and oral health information was collected by face to face interview of the participants. A mouth examination of the participants was carried out at the start of participation of each volunteer. Mouth examination was carried out from February 2005 to January 2007 to check their oral and dental diseases associated with

teeth, gum, periodontal ligament and oral soft tissue and the findings were recorded using the questionnaire prepared, validated and previously used for the residents in the borough of Tower Hamlets, London (Pearson et al., 1999) (Appendix 4.8). The mouth examination was performed based on the diagnostic criteria of World Health Organization in International Classification of Diseases in Dentistry and Stomatology (WHO, 1998) and studies published by Pindborg et al., (1968) and Pindborg and Sirsat, (1966) for oral submucous fibrosis (Appendix 4.9).

4.2.3.2. Ethical considerations

The protocol adopted for this study was ethically approved by the following authorities: the local ethics committee; City and East London Ethics Committee (CELEC) and the Research and Development Office, Barts and The London NHS Trust. The application was made for the local ethics committee approval based on the application form published on their website, www.corec.org.uk/applicants/apply/safety.htm (reference no. 05/Q0603/3 dated 28 February 2005) (Appendix 4.10). The study protocol was peer reviewed by a subject specialist in this subject prior to the submission of application to CELEC, which was a pre-requirement for the approval of the study by the CELEC (Appendix 4.11). The Research and Development Office, Barts and the London NHS Trust approved and offered full support for indemnity of the research, if any during the period of research (Appendix 4.12).

The General Medical Practitioners (GMP) of all the participants were informed and permission was sought for the recruitment of their patients who had a history of chewing paan tobacco for the paan tobacco cessation programme offered by the

Bangladeshi Stop Tobacco Project (BSTP), and to examine their mouth for identification of mouth diseases. Permission was sought to refer them to specialist clinicians if further investigation and treatment was needed (Appendix 4.13).

4.2.3.3. Training and calibration exercise

The researcher was trained and calibrated for the diagnosis of oral and dental diseases such as dental caries, tooth wear, gingival and periodontal disease, and OML by looking at slides under microscope, microphotographs and attending clinics with the consultant of the Centre for Clinical and Diagnostic Oral Sciences, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London. A calibration exercise was performed for oral, dental and mucosal lesions, and demonstrated almost perfect agreement between the consultant and the researcher. The Kappa test results for dental caries and tooth wear, and oral mucosal lesion diagnoses were 0.86 and 0.88 respectively.

4.2.3.4. Pilot study

A pilot study was conducted on 15 potential participants to test the possible length of use of 50gm of smokeless tobacco product (Tin of zarda shown in the information leaflet, Appendix 4.1) or equivalent amount of tobacco leaf in paan.

The median of the pilot study was seven days; eight participants reported chewing this amount of ST in seven days and seven in more than seven days. Hence, the median of this pilot survey and 50gm of ST product zarda / tobacco leaf was used to assess the tobacco dependence in these study participants.

A pilot study was conducted to test the suitability of all the questionnaires used in the study in order to make adjustments if required and also of mouth examination

criteria. A total of 15 volunteers different from the first pilot study were invited to participate in the study. The order of the questions, level of understanding and length of the questions and questionnaires were tested. During the interview, it was found that there was no difficulty in filling in the questionnaire by the researcher or by the participants.

4.2.3.5. Study location

The study was conducted at the Centre for Clinical and Diagnostic Oral Sciences, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London. Data was collected through: 1) referrals from four general medical practitioners in London borough of Tower Hamlets, (2) outpatients of the department of Oral and Maxillofacial Surgery and Oral Medicine, Institute of Dentistry, London Hospital NHS Trust, Whitechapel, London. (3) Clients of Majlish Homecare Services, a non-government charity organisation based locally.