Background
The 2013 UK Children’s Dental Health Survey found that obvious decay experience (D
3MFT > 0) in the permanent teeth was evident in 34 % of 12-year-olds and 46 % of 15-year-olds [
1]. Some 58 % of children aged 12 and 45 % of those aged 15 reported that their daily life had been affected by problems with their teeth and mouth in the last three months [
2]. The 2002/03 Regional Dental Health Survey reported that 57 % of 14-year-olds in the North West of England had previous caries experience with active decay present in 33 % [
3]. Caries is a largely preventable disease but uptake of preventive practices are variable and affected by multidimensional aetiological factors acting at the psycho-social and environmental level [
4].
Adolescence represents a period of transition when children are establishing autonomy over their own behaviours [
5]. Social influences become increasingly important with an expectation that individuals will adopt the behaviours accepted as the social norm within their peer group, for example, with respect to smoking, eating the same foods, and other behaviours that can impact on oral health [
6‐
8]. However the personal views of adolescents about such influences have not been extensively explored.
The majority of studies exploring caries in adolescents are quantitative [
1,
2]. These studies provide useful descriptions of population trends in caries or uptake of preventive practice but not for exploring the reasons behind an individual’s actions [
9]. When a phenomenon is only partly understood, a qualitative design is preferable [
10]. However, few studies have used qualitative methodology to investigate oral health in adolescents, particularly within the United Kingdom [
8,
11].
A number of previous qualitative studies exploring the oral health influences and behaviours in adolescents used focus groups. However, adolescents can be strongly influenced by peer pressure and focus groups comprised of groups of children from the same peer group are noted to produce more critical comments about the effectiveness of oral health preventive practices [
12]. Other qualitative studies focused only on participants with specific characteristics e.g. pregnancy and orthodontic appliances that further limited the findings applicability to the wider population [
13‐
15]. Few studies exploring oral health were also able to describe the oral health of the participants and it is not clear how previous caries experience impacted on reported behaviours and attitudes.
The aim of this study was to explore the attitudes and beliefs of adolescents towards dental caries and their use or non-use of caries prevention regimens when caries status was known. It allowed adolescents views to be explored in an environment where they would not be directly influenced by their peers, in addition to providing a link to oral health -related characteristics of the participants.
Methods
Subjects
Participants were recruited through state-funded secondary schools (attended by students aged 11–16 years) in the North West of England. The inclusion criterion for schools was participation in the outcome component of the East Lancashire and Manchester Study (ELMS) (NIHR UK Clinical Research Network Study Portfolio, Ref: 10315). The study was a whole population prospective cohort study of children conducted in state-funded schools in the North West of England with data collected at four time points over seven years. Dental assessments were carried out at four time points supplemented at the last two time points with questionnaires about self-reported oral health behaviours and height and weight measures.
All students registered in secondary schools that took part in ELMS, who agreed to take part in the study and had the ability to consent, were eligible to participate. Subjects were excluded if they were not able to converse in English or unable to give consent. Six schools agreed to provide a list of potential participants. Caries status plus socio-demographic data was available for all participants from the ELMS dataset. The school provided individual level date of birth, gender, and home postcode data. A postcode is assigned to a geographical area usually comprising up to 25 houses. Postcodes were used to estimate small-area measure of socioeconomic status to participants based on national quintiles of the Lower Super Output Area (LSOA) Index of Material Deprivation 2010 (IMDQ, 2010) [
16,
17]. IMD Quintile 1 (IMDQ 1) was the least deprived and IMD Quintile 5 (IMDQ 5) the most deprived. For the purpose of this study, participants were recoded as IMDQ1-3 (less deprived) IMDQ 4–5 (more deprived). Ethnicity was reported by the parent according to nationally agreed categories and coded as white, Asian, black, Chinese, mixed or other [
18].
Purposive sampling was used to identify subjects with characteristics of relevance to the aim of the study and maximise variation within the sample. Criteria included caries status, gender and socio-economic status (Table
1). This non-probability approach is suitable for in-depth qualitative research in which the focus is to understand complex social phenomena [
19]. Planned number for recruitment was aligned with previous research [
8,
20‐
23] but actual recruitment was determined by theme saturation i.e. when no new information was generated from the analyses, no further interviews were conducted [
24].
Table 1
Sampling framework and characteristics of participants recruited
Caries status | Caries free | 3 (0) | 3 (2) | 3 (1) | 3 (1) | 12 (4) |
Caries | 6 (1) | 6 (5) | 6 (4) | 6 (5) | 24 (15) |
Total | 9 (1) | 9 (7) | 9 (5) | 9 (6) | 36 (19) |
All parents and potential participants were informed of the study by participant information sheet (n = 41) and advised of how to opt-out. Adolescents who did not withdraw at this stage were invited to participate. Refusals were received from 18 potential participants and four failed to attend for interview. Formal written consent was obtained from participants. Theme saturation was reached when a total of 19 participants were recruited. The University of Manchester Ethics Committee granted ethical approval (Ref: 14106).
Procedure
The study was conducted in schools during June-July 2014. Interviews were conducted in small rooms at each participant’s school. The interviewer (EHS) attended sessions in collecting qualitative interview data provided by Academic and Researcher Development, University of Manchester. This included multi-disciplinary interactive sessions. A literature search was conducted to inform the theoretical framework within which our research questions lay; the development of the topic guide; and the range and depth of perspectives sought. [
8,
20,
25‐
30] Discussions were recorded digitally and transcribed verbatim. The length of interview was not fixed and determined in the field by the interviewer using participants’ verbal and non-verbal cues to revise the time. After each interview, field records were completed to capture the interviewer’s reflections on the process including non-verbal cues; the success or failure; information given after the interview and consideration of future modifications.
Interview schedule
A.
Perception
-
Tell me about what you think is a healthy mouth?
-
What do you think is meant by “tooth decay”?
-
Why do you think teenagers get tooth decay?
-
Why do you look after your teeth?
-
Tell me about people who could help you look after your teeth?
B.
Behaviour
-
What do you do to prevent tooth decay?
-
What do you do to take care of your healthy teeth?
-
What do you do to take care of tooth decay?
-
What is the role of diet in keeping your teeth healthy?
-
Who influences why you look after your teeth?
-
Where would you go for advice or information about looking after your teeth?
Data analysis
Transcripts and field records were uploaded into NVivo 10 software that supports the Framework approach that was used in analysis [
31]. This method was chosen because it supported exploration of specific a priori themes identified from the literature search and analyses of the outcomes of the preceding quantitative study; and facilitated an inductive approach to facilitate the emergence of new themes. A grounded theory (reference) approach was also considered, however we decided to pragmatically explore specific issues of interest, in addition to generating new, user generated themes. Grounded theory would have been more appropriate for the generation of a new, encompassing theory of oral health [
32].
After coding, the data was analysed by case and theme to identify variables (gender, previous caries status and socio-demographic status) associated with specific explanatory models, typologies or themes.
Two researchers (EHS and JG) analysed the transcripts. Codes were assigned to categories and sub-categories relating to the patterns or themes that emerged. This enabled questions to be refined and new avenues of inquiry to develop based on patterns of responses. Analysis produced a coding frame with 14 codes arranged within five overarching themes each with a description and example to ensure consistency of coding. When theme saturation was reached i.e. when no further themes were generated from the analyses, no further interviews were conducted [
24]. This was the point at which the collection of new data was deemed not to shed new light in the area under investigation.
This final analytical framework was applied to each transcript systematically. Interpretation was based on the original research objectives and new concepts generated inductively from the data. Agreement between researchers was reached by discussion and review of the transcripts.
The framework analysis produced a coding frame with 14 codes organised into five overarching themes. This paper presents the first two themes relating to participant’s definition and knowledge of oral health with an emphasis on caries. The third thematic discussion relates to the participants’ perception of influences (social, professional and external) on their oral health behaviours and attitudes. This focused primarily on the social support of their parents. The paper concludes with the reasons for oral health behaviour (habitual behaviour, delayed uptake and lifestyle choice) that participants expressed and how participants perceive their health behaviours will change in the future.
Reflexivity
The two data analysts were a health services researcher with a background in health psychology (JG) and a Specialty Registrar in Dental Public Health with a background in Paediatric and Special Care Dentistry (EHS). They reflected on their own assumptions before starting to identify potential sources of bias. JG had previous experience of analysing qualitative dental data and believed that there would be a gender difference in reported behaviours with males demonstrating less frequent oral hygiene behaviours. EHS had no previous experience of conducting qualitative research but received training. EHS’s view was that adolescents primarily viewed health as something that could be seen and that individuals were responsible for their own behaviours.
Quality
The semi-structured interview guide provided a clear set of instructions for the interviewer and a degree of comparison by standardising at least some of the questions. A verbal “debrief” conducted after every session with a member of the research team supported the reflective process. An audit trail of the process, field notes, memos and summaries of the data evidenced transparency of the process.
The transferability of semi-structured interviews depends on whether participants’ opinions are truly reflected and it cannot be guaranteed that participants will tell the truth. Threats to validity include the use of leading questions; the interviewer’s preconceived ideas influencing the discussion; and the participants’ perception of what the interviewer wants to hear. It was impossible to fully evaluate these effects but it was feasible to examine the internal consistency of what the participant said.
Data was transcribed verbatim and accuracy checked by reading the transcript while listening to the audio files. Two trained analysts conducted analysis as soon as possible after transcription [
33]. Adopting a participatory approach in which transcriptions are co-created and evaluated increased credibility. Credibility (internal validity) was assessed by prolonged and persistent observation until thematic saturation was reached. Commonalities and differences were identified before relationships based on participants’ characteristics and thematic similarities were considered.
Conclusions were both descriptive and explanatory. Deviant cases (outliers) were included in analysis. Comparison of outcomes was conducted and discussed to reach consensus, not about the codes applied but the reason for dissonance to reduce biased reporting. The output did not deliver a single definitive explanation for oral health attitudes and behaviours but generated a model for future research. The dependability (reliability) and consistency of data was considered by triangulation. Confirmatory evidence (objectivity) was sought by comparison across the transcripts, field notes and with the quantitative data (transferability). In future, member checks would be recommended (respondent validity). This was not logistically possible here as participants left their schools shortly after the research was conducted. The implications for policy i.e. transferability are discussed in the results.
Discussion
This is the first study in the United Kingdom using semi-structured interviews to explore what adolescents think causes caries, and why they adopt certain approaches to caries prevention. The use of face-to-face interviews rather than focus groups gave valuable insight into the personal experiences and day-to-day behaviours of individuals [
34]. The respondents represented a typical cross-section of the population in the area with high numbers of respondents from the white and Asian communities and higher representation from more deprived groups than the national averages [
35]. Respondents presented with high levels of caries reflecting the high prevalence and severity in this region reported previously [
36,
37].
It was anticipated that those with caries would report more dental problems and less uptake of caries preventive regimens [
1,
2] but there was no apparent difference between those with and without caries. Nor did those with high caries report the feelings of inadequacy voiced by similar adolescents in Hattne [
20]. This may be due to report bias or due to participants’ lack of perception about their actual behaviours. Theme saturation was reached before a high number of caries-free or affluent individuals were interviewed. Increasing the variation of participants may have revealed different patterns of behaviours. This could be addressed in future research.
There was also no evidence of the differences in behaviour related to gender reported previously [
12,
14]. Whether this reflected report bias, genuine changes in gender norms or was due to previous participants’ conforming to expectations of behaviour in focus groups was unclear. Triangulation through discourse with other members of the research team, revisiting the transcript and comparing findings with other published studies helped to ensure that the findings had validity.
The dominant influence on participants’ caries preventive regimens was the habitual preventive behaviour reinforced by parents from early childhood. The link between parents and the oral health of children has been previously reported [
20,
38]. This suggests that to improve adolescent health, oral health strategy should engage with parents [
39‐
41]. A life-course approach from early childhood would encourage development of and support on-going practice. It was clear that during this transitional developmental period, parental influence was waning and external factors, including peer pressure, and popular media became increasingly relevant. Hedman [
42] found that the desire to conform with peers was strong [
14,
38], particularly in older adolescents as anticipated by Stokes [
8]. The participant suggestion that “lifestyle” plays a role in behavioural choices suggests that, as in Trulsson [
14], adolescents may not be fully conscious of the impact of external influences. This endorses the provision of supporting environments to encourage uptake of positive oral health behaviours [
8].
This group perceived that the advice provide by professionals in school and at the dentist about oral health was inadequate and not tailored to the needs of the individual [
22]. Despite the support for school-based delivery of oral health promotion [
43] it seemed limited to the National Healthy Schools Programme (NHSP). As reported by Stokes [
44], this programme uses a Common Risk Factor Approach (dietary modification) [
45] to address a range of non-communicable diseases and does not specifically promote oral health behaviours such as tooth-brushing. Its purpose is to facilitate supportive environments in schools “making healthy choices easier” i.e. by restricting unhealthy foods in schools, children must choose healthier options. Evaluation of the NHSP has not demonstrated significant changes in pupil health-related behaviours following engagement with the NHSP [
46]. Its focus on diet modification to address the overweight/obesity epidemic has also led to misunderstandings of the role of different food groups in health.
In-depth exploration identified significant knowledge gaps and misinterpretation similar to those identified by Ostberg [
25]. There was marked confusion about what constituted a cariogenic or cariostatic diet. As in Murphey [
13] and Hedman [
42] participants underplayed the role of sugar ingestion, and were unclear of the role of tooth-brushing in prevention. There was no quality element to participants understanding of tooth-brushing beyond the requirement to perform it twice daily [
42]. This lack of understanding had a negative impact on the efficacy of their oral health behaviours. Mouthwash was considered an effective alternative to tooth-brushing because participants did not understand the anti-cariogenic properties of fluoride toothpaste. Mouth cleaning (either with a tooth-brush or mouthwash) after ingesting sugar-rich food was understood to prevent caries; similarly to cleaning a wound would prevent infection by removing bacteria.
The participants had a holistic view of oral health and cited criteria from both the biomedical and psycho-social models [
22]. This aligned with the views of adolescents in earlier studies, although previous participants gave greater primacy to aesthetics over oral health [
20,
22]. Consideration was given to oral health as the absence of disease and freedom from pain, but they also acknowledged the social impact of an aesthetic smile [
14]. Participants recognised that pleasing oral aesthetics did not equate with good oral health.
Previously, the attainment of general health was more valued than oral health [
13]. Here, parity was given to both and attainment linked. This was related to participants’ superficial understanding of the role of diet in a multiplicity of illnesses including obesity and caries. Although all parties desired the aesthetic ideal, it was accepted that this did not always equate with health. This synergy could be utilised in future preventive strategy development. For example, an integrated health promotion strategy to improve oral and general health would tie-in with these participants’ holistic understanding of health. Promotion of body image could be used as a motivator [
15]. Oral and general health were seen as equally important and closely interlinked.
In contrast to Ostberg, this group recognised that they could influence their own oral health [
47]. This may reflect their holistic view of health beyond the bio-medical model. However, if participants practice behaviours they expect to be effective but still get caries long-term practice will be negatively impacted [
20]. This has particular relevance as adolescents assume increasing responsibility for their oral health. It is important that they internalise cues for oral health behaviours to promote long-term effective self-care as parental influence wanes [
48]. Those with more favourable dental health beliefs have better oral health when older [
49].
Respondents were conscious of external influences beyond the education and health sectors. For example, Fitzgerald [
22] found that participants used media adverts, especially as they grew older, to inform their knowledge about oral health [
50]. In our study the veracity of information was improved by delivery by “dentists” or “scientists”. Unfortunately, this was evidenced by the erroneous use of mouthwash as an alternative to tooth brushing. This suggests that this age group does value the expertise and authority of professionals in the popular media, which could be utilised in the real world [
20,
25].
In the future, participants expect that the loss of parental and environmental support as they leave school will coincide with a withdrawal from professional dental service and maintaining oral health will be more difficult [
22]. Emphasising general health benefits could be used to motivate uptake as respondents highlighted the holistic model of health and the importance of aesthetics.
Acknowledgements
The authors would like to acknowledge Paul Brocklehurst and Hilary Whitehead at the University of Manchester for their advice in drafting the paper; and the staff and students at participating schools in North West England.
The University of Manchester funded this study.
For the ELMS: The staff at Cumbria and Lancashire Comprehensive Local Research Network and Research and Development at Lancashire Care NHS Foundation Trust provided support and assistance throughout recruitment; the research team at Salaried Dental Services, Lancashire Care National Health Service (NHS) Foundation Trust including Catherine Morley; Joe Fielding, Uriana Boye, Angela Willasey and Sarah Proctor who acted as Gold Standard examiners for the calibration and training events. Funding was received from Colgate-Palmolive. Support cost funding was obtained from Cumbria and Lancashire Comprehensive Local Research Network (CLCLRN).
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
EHS, MT and KM made substantial contributions to conception and design. EHS performed the interviews. EHS and JG analysed and interpreted the data. All authors contributed to drafting the article or revising it critically for important intellectual content; and had final approval of the version to be published.