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Scottish Prisons' Dental Health Survey 2002

1. INTRODUCTION

1.1 Background

The Scottish Executive Health Department commissioned the Scottish Consultants in Dental Public Health to undertake a dental survey of the prison population.

The aim of the survey is to provide accurate and up-to-date information on the condition of people's teeth in the Scottish prison population. The findings of the survey will help to plan appropriate & effective oral health services in prisons.

Four previous surveys of the dental health of adults have been carried out: in 1968 England & Wales (Gray et al 1970); in 1972 Scotland (Todd and Whitworth 1974); in 1978, the UK (Todd and Walker 1980); in 1988, the UK (Todd and Lader 1991); in 1998, the UK (Kelly et al 2000). The sample frames for each of these surveys excluded the prison population.

A review of the literature reveals that there have been few studies or reports on the dental health of prisoners and thus, their oral health needs and attitudes are largely unknown.

1.2 Aims of the survey

The survey aims were to:

• investigate by questionnaire reported dental experiences, attitudes and knowledge, availability of dental care and oral hygiene;

• identify, by questionnaire, those who have total loss of natural teeth and investigate their reported use of complete denture(s);

• establish, by clinical examination, the condition of the natural teeth;

• establish, by clinical examination and interview, the prevalence of denture(s) worn in conjunction with natural teeth.

The study was designed so that the results could be compared with corresponding data from the 1998 Office for National Statistics (ONS) UK Adult Dental Health Survey of individuals resident in private households. (Kelly et al 2000). Diagnostic dental criteria of oral health included in this survey were identical to those used in the 1998 National Adult Health Survey.

2. THE SURVEY TIMETABLE

Preparation/pilot study: Winter 2001

Main study: April / May 2002

3. PROJECT MANAGEMENT ARRANGEMENTS

3.1 The Survey Team

The Scottish Consultants in Dental Public Health co-ordinated the study. Three dentists experienced in dental epidemiology were recruited for the survey.

3.2 Experience

The Scottish Consultants in Dental Public Health Group has wide experience in dental epidemiological surveys. The dental examiners and their recorders had extensive experience of carrying out large-scale dental surveys, including the 1978, 1988 and 1998 UK Surveys of Adult Dental Health.

3.3 Coverage

The survey covered the whole of Scotland. Recorders and the dentist used the same protocols and questionnaires, with appropriate modifications, as used in the ONS UK Adult Dental Health Survey in 1998. (Kelly et al 2000).

3.4 Key Staff

3.4.1 The Scottish Consultants in Dental Public Health

Mr C Jones, Consultant in Dental Public Health for Highland Health Board and Mrs M McCann, Deputy Chief Dental Officer were the principal research managers for the survey. Highland Health Board is registered under the Data Protection Act.

4. SURVEY COMPONENTS

The survey fieldwork consisted of two elements; a face-to-face questionnaire interview and a clinical oral examination using standardised methods and equipment.

4.1 Location of fieldwork

All the interviews and dental examinations were carried out in the prisons selected for the survey.

4.2 Field visits

Two recorders administered the questionnaires and accompanied a dentist, to act as recorder for the dental examination. The examination took place on the same day that the questionnaires were administered.

4.3 Recruitment of the dental examiners

The dental examiners were recruited from the Dental Public Health and Community Dental Service through the Scottish contact for the British Association for the Study of Community Dentistry (BASCD) co-ordinated NHS epidemiology programme. The examiners had experience of epidemiological fieldwork through involvement in previous national studies, local oral health surveys co-ordinated by BASCD and the 1998 Adult Dental Health Survey.

4.4 Funding

The Scottish Consultants in Dental Public Health received funding from the Scottish Executive Health Department Primary Care Development Fund. The study involved no direct cost to the Prison Service.

5. CONFIDENTIALITY

Strict confidentiality was maintained whereby no information about an identifiable individual was passed outside the National Health Service.

The main steps to preserve confidentiality and security during fieldwork and afterwards were:

• data on the portable computers used by recorders were at all times stored in password-protected form;

• names and other similar information which could give clues to a person's identity, did not form part of datafiles available to anyone outside the NHS. NB The NHS does not include the Prison Medical or Dental Service.

6. ETHICAL ISSUES

6.1 Types of research

The research is non-therapeutic. The survey was carried out in order to gain further knowledge of the dental health and dental health related to behaviour of the prison population. Although the survey does involve "interference with the subject", the procedures involve less than "minimal risk" falling within the category defined as "risk so small that it can be ignored" outlined in the ethical guidelines produced by the Royal College of Physicians (1990).

6.2 Recruitment to the survey and the dental examination

A letter, giving a brief outline of the nature and purpose of the survey, was given to all the sampled individuals in advance of the survey ( appendix 1). The survey was voluntary and the recorders were trained to give respondents a full explanation of the nature and purpose of the survey, including the voluntary nature of their participation. Individuals who agreed to participate still had the opportunity to refuse to answer any question, to opt out of the dental examination and to withdraw from either the questionnaire or examination at any time.

Individuals who reported that they had one or more natural teeth had the dental examination explained to them and they were asked if they would be willing to have their mouths examined by a dentist. Those who consented had the dental examination on the same day. The respondent signed a form giving their written consent before any examination was undertaken ( appendix 2).

6.3 Consent

Respondents were given clear explanations, both verbally and in writing of the purpose of the survey and the dental examination, and how information about them would be used. Express written consent was required before each dental examination ( appendix 2). The steps taken to ensure informed consent, without pressure or inducements, are described in 6.2 above. No incentive or reward was offered to participants.

Separate consent ( appendix 3) was sought from the respondents for information to be sent to the prison medical officer in the event of any serious oral pathology being identified (see 6.5).

6.4 Indemnity

The project is an epidemiological study of the prison population in Scotland. For the part of the study which involves a dental examination, NHS indemnity provided by the dentist's employing Trust applied to the examiners. The recorders were dental nurses who assist the dentists and are covered by the same NHS indemnity.

6.5 Handling professional questions during the dental examination and reporting pathology

The dental examiners did not make any comment about what was seen during the examination. If the participants asked about their dental health, and if questions related to the standard of previous dental care arose, the response was that the survey is not designed to collect the sort of information on which treatment can be planned, and that visiting a general dental practitioner or prison dentist is the best way of ensuring a thorough dental check-up.

The only exception to this was if the examining dentist noticed a lesion which he/she considered may be serious and potentially life-threatening (such as a suspected malignancy). Examiners were very unlikely to encounter such potentially serious pathology, as the incidence of these lesions is very low. The examination was not a screening exercise and did not involve examination of the oral soft tissues. However, it is possible that such a lesion may have been noticed and, as the implications are serious, a protocol to deal with this eventuality was in place.

6.6 Protocol for reporting serious pathology.

In the extremely unlikely event that such a lesion was noted, the examiner was obliged to follow a set protocol designed to make sure that the prison medical service was informed, whilst not causing the participant unnecessary worry.

The examiner should inform the participant using an appropriate form of words. As experienced clinicians, the examiners may wish to vary the approach or the tone they use to ensure good communication, but the basis of the wording should be the same in all cases. The dentist would usually want to introduce the subject, usually by asking whether or not the lesion causes any discomfort, and then state that "it is survey policy that a brief report of any ulcers or inflamed areas is passed to the Prison Medical Service. If the participant says that they will arrange to see the Prison Medical Service themselves then they should be encouraged to do this and it is left at that point. If the participant asks what the dentist thinks the lesion is, the dentist should answer honestly that they do not know, before re-iterating standard survey policy as above.

If the participant agreed to the dentist reporting their findings to the prison doctor, the dentist would record the site and nature of the suspect lesion and details of the nearest specialist unit where appropriate investigations could be undertaken ( appendix 3). This would be passed on immediately, along with the signed consent form, to the prison doctor.

It is most unlikely that any such lesions will be found and it is also unlikely that even those which are reported will turn out to be serious. It is the responsibility of the examiner not to alarm the participant unduly.

7. SAMPLING

7.1 The sample design

The survey covered all prisons in Scotland but only 8 prisons were visited.

The prisons were divided into three groups related to the majority of prisoners in three categories in each institution:

With the limited resources available, it was not be possible to visit every prison. The main female prison and the three Young Offender Institutions were sampled. A two stage sampling process was used to select the male sample; four prisons were selected from the fourteen male prisons (Dumfries and Glenochil also house young offenders). The unique status of Zeist prison excluded it from the sample

The sampling structure is shown in table 1 below. Please note that these figures were only used for planning the survey. The actual sample drawn for the survey was based on the day list of prisoners present on the survey days.

TABLE 1 - Sampling method of the prison population in Scotland

A random sample of 4 adult male prisons (2 days in each) should yield 320 subjects.

7.2 Power calculation and sample size

The UK adult dental health survey in 1998 found that 58% of Scottish adults had at least one decayed or unsound tooth.

The prevalence of decay in the Scottish prison population is unknown. Using preliminary results for a survey carried out in the North West of England, they found that 75% of their prison population had untreated decay. We can use this estimate as the likely prevalence of untreated decay in the Scottish prison population. Using the known disease prevalence in the Scottish adult population (58%) and the estimated prevalence in the Scottish prison population (75%) at an alpha level of 5% and a power of 90% to detect a significant difference in prevalence, the sample size is 172 in each group using the method described in the text book; Medical Statistics by Armitage, Berry and Matthews(2002). With three groups the final sample size needed was 516 completed dental examinations.

The survey took place over 4 weeks, taking 20 working days. It was anticipated that there was 4 hours maximum survey time in each day (10.00am - noon and 2.00pm - 4.00pm). The questionnaire was completed in less than ten minutes and the dental examination was completed in less than five minutes. With two recorders, it was estimated that 10 subjects would be seen in an hour. This gave a daily rate of 40 interviews and dental examinations.

7.2.1 Female Prisons

The female prison, Cornton Vale, was surveyed over four days, which should have allowed a full sample (circa 232 less refusals etc.). The other three prisons housing a minority of female inmates were only included in the sample if they arose by chance (Aberdeen, Dumfries & Inverness). The day list of prisoners, produced by the prison, was used to obtain the sample of prisoners.

7.2.2 Young Offenders Institutions (male)

The three Young Offenders Institutions were surveyed for two days each, which provided a sample of 80 from each prison (240 in total). The sample drawn was boosted by 25% to allow for refusals. The day list of prisoners, produced by the prison, was used to obtain the sample of prisoners. The subjects were selected using random numbers. The proportion required to produce the sample for each particular prison was applied, e.g. if the proportion required was 1 in 3, then starting from a random number between 1 and 3, every 3rd prisoner was selected until the sample size in the prison was reached.

7.2.3 Male

Four prisons were selected from the twelve adult male prisons. These prisons were surveyed for two days each, which should have provided a sample of 80 from each prison. The samples drawn were boosted by 25% to allow for refusals. The day list of prisoners, produced by the prison, was used to obtain the sample of prisoners. The subjects were selected systematically. The proportion required to produce the sample for each particular prison was applied, e.g. if the proportion required was 1 in 20, then starting from a random number between 1 and 20, every 20 ^th prisoner was selected until the sample size in the prison has been reached. Table 1 (above) summarised the sample design and expected sample sizes in each prison.

Where possible, the survey team tried to achieve 40 dental examinations per day. Table 2 shows the sample frame and planned sample numbers.

TABLE 2 - Summary of sample frame and sample sizes. Please note that these figures were only used for planning.

From Statistical Bulletin Criminal Justice Series (CrJ/2000/7) November 2000 (Table 4, average daily population)

8. THE QUESTIONNAIRE

One of the main survey aims was to produce data comparable to that collected in the Office for National Statistics 1998 UK Adult Dental Health Survey. The modified questionnaire is attached at appendix 5. The interview was expected to take no more than 10 minutes for each participant. The interview included questions on current dental health and hygiene, experience of treatment, dentures, and possible barriers to seeking treatment.

9. THE DENTAL EXAMINATION

Clinical criteria

There was a requirement to ensure that the clinical criteria were the same as those used for the 1998 UK Adult Dental Health Survey. As with the questionnaire, the examination was kept consistent. The protocol for the Clinical Criteria is attached at appendix 4. The clinical examination was only carried out on people who reported they had some natural teeth.

The following data was collected.

• The number of natural teeth present and the condition of their crown surfaces. This included an assessment of arrested and both cavitated and non-cavitated lesions, type of restorative materials used & the presence of any crowns and/or bridges and spaces.

• A record of dentures currently worn.

• Any significant conditions with treatment implications not covered elsewhere, for example, hypodontia, developmental anomalies of hard tissues, clefts of the lip and/or palate, trauma, soft tissue pathology.

The procedures and precautions taken for the clinical examination are described in the Clinical Criteria at appendix 4.

10. THE TRAINING AND ORGANISATION OF THE DENTAL TEAM

The Scottish Consultants in Dental Public Health took the lead in questionnaire design, training interviewers, carrying out fieldwork and analysis. The training of the dentists was undertaken by the Dental Schools of Birmingham, Dundee, Newcastle and Wales, as part of the 1998 UK Adult Dental Health Survey.

Equipment

Each survey dentist required the following equipment:

• Purpose-built (Daray) lamp plus protective foam for G-clamp, incorporating standard safety features

• No. 4 plane mouth mirrors

• Straight probes (blunted to 0.3 mm diameter)

• Rubber gloves

• Cotton buds / sterile wipes

• Yellow bags for disposal of waste

• Extension lead & circuit breaker

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