ABSTRACT

OBJECTIVE

The objective was to analyze the role of health literacy (HL) as a factor associated with tooth loss among users of the Brazilian Health System with chronic non-communicable diseases.

METHODS

The cross-sectional analytical study was conducted with adult and elderly users chosen at ten Family Health Clinics in a draw in the town of Piracicaba, São Paulo State, Brazil. A questionnaire was applied with sociodemographic data (sex, age, skin color and education), behavioral data (brushing and flossing), determinants in health (type of dental health services and how often) and clinical data (pain). Mouth conditions were collected by intraoral examination of visible dental biofilm and community Pediodontal Index. The systemic clinical conditions (blood glucose, glycated hemoglobin and blood pressure) were extracted from the medical records. The explanatory variable was HL (low, medium and high), measured with the Health Literacy Scale (HLS-14).

RESULTS

The outcome was tooth loss measured by the index of decayed, missing and filled teeth. Logistic regression was performed using a conceptual model for HL (p < 0.05). For the 238 subjects, the mean age was 62.7 years (± 10.55). Tooth loss was associated with HL in regression models adjusted by type of dental service, dental frequency, and dental floss. In the final model, the factors associated with tooth loss are older age (OR = 1,12; 95%CI: 1,07–1,17), a lower education (OR = 3,43; 95%CI: 1,17–10,10), irregular use of dental floss (OR = 4,58; 95%CI: 1.75 in–7,31), irregular use of dental services (n = 2,60; 95% 1,32–5,12), periodontal pocket (> 4 mm) (n = 0,31; 95%CI: 0,01–0,08), having visible dental biofilm (OR = 7,23; 95%CI: 3,19–16,41) and a higher level of blood sugar (glucose) (n = 1,98; 95%CI: 1.00–3,92).

CONCLUSIONS

tooth loss was associated with HL when adjusted by health behaviors; when sociodemographic variables and clinical conditions were included, it was less significant. In the final model, behaviors, determinants in health and clinical conditions were risk indicators of tooth loss, showing the multifactorial nature of this phenomenon.

Oral Health; DMF Index; Health Knowledge, Attitudes, Practice; Health Education, Dental

INTRODUCTION

Chronic Non-Communicable Diseases (NCDs) are characterized by their multifactorial etiology and are associated with several risk factors¹1. Malta DC, Andrade SSCA, Oliveira TP, Moura L, Prado RR, Souza MFM. Probabilidade de morte prematura por doenças crônicas não transmissíveis, Brasil e regiões, projeções para 2025. Rev Bras Epidemiol. 2019;22:E190030. https://doi.org/10.1590/1980-549720190030
https://doi.org/10.1590/1980-54972019003... . It is estimated that in 2020, 61 million people had diabetes in the Americas alone, and 70.9 million people died worldwide in 2019 as a result of diabetes mellitus³3. Institute for Health Metrics and Evaluation. GBD 2019 Cause and Risk Summaries. Diabetes mellitus — Level 3 cause. Seattle, WA: University of Washington, IHME; c2020 [cited 2020 Nov 6]. Available from: http://www.healthdata.org/results/gbd_summaries/2019/diabetes-mellitus-level-3-cause
http://www.healthdata.org/results/gbd_su... . Another important risk factor is hypertension, which affected more than a billion people in the American continent alone⁴4. Organização Pan-Americana da Saúde. COVID-19 afeta funcionamento de serviços de saúde para doenças crônicas não transmissíveis nas Américas. Brasília, DF: OPAS Brasil; 2020. [cited 2020 Oct 3]. Available from: https://www.paho.org/pt/noticias/17-6-2020-covid-19-afeta-funcionamento-servicos-saude-para-doencas-cronicas-nao
https://www.paho.org/pt/noticias/17-6-20... , in 2019, systolic blood pressure was the main global factor of deaths among individuals over 50 years of age²2. GBD 2019 Risk Factors Collaborators. Global burden of 87 risk factors in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet. 2020;396(10258):1223-49. https://doi.org/10.1016/S0140-6736(20)30752-2
https://doi.org/10.1016/S0140-6736(20)30... . These numbers lead to the conclusion that strategies to fight and prevent these conditions are urgently needed.

Currently in the Americas, 81% of deaths occur from NCDs⁴4. Organização Pan-Americana da Saúde. COVID-19 afeta funcionamento de serviços de saúde para doenças crônicas não transmissíveis nas Américas. Brasília, DF: OPAS Brasil; 2020. [cited 2020 Oct 3]. Available from: https://www.paho.org/pt/noticias/17-6-2020-covid-19-afeta-funcionamento-servicos-saude-para-doencas-cronicas-nao
https://www.paho.org/pt/noticias/17-6-20... ; in Brazil, in 2016, it is estimated that 74% of deaths were caused by the same reason⁵5. World Health Organization. Noncommunicable Diseases (NCD) Country Profiles 2018. Geneva (CH): WHO; 2018 [cited 2020 Oct 29]. Available from: https://apps.who.int/iris/handle/10665/274512
https://apps.who.int/iris/handle/10665/2... . In São Paulo State alone, in 2017, 65% of deaths were due to NCDs⁶6. Secretaria de Estado da Saúde de São Paulo, Coordenadoria de Controle de Doenças, Centro de Vigilância Epidemiológica, Divisãode Doenças Crônicas Não Transmissíveis. Painel Mortalidade DCNT Estado de São Paulo 1980-2018. São Paulo: CVE; 2019 [cited 2020 Mar 16]. Available from: https://docs.bvsalud.org/biblioref/2020/08/972096/dcnt_painel_esp_19802018.pdf
https://docs.bvsalud.org/biblioref/2020/... , and several other studies show that patients with chronic diseases also demand emergency services and hospitalizations⁷7. Hirschman KB, Shaid E, McCauley K, Pauly MV, Naylor MD. Continuity of care: the Transitional Care Model. Online J Issues Nurs. 2015;20(3):1. https://doi.org/10.3912/OJIN.Vol20No03Man01
https://doi.org/10.3912/OJIN.Vol20No03Ma... ,⁸8. Malta DC, Bernal RTI, Lima MG, Araújo SSC, Silva MMA, Freitas MIF, et al. Noncommunicable diseases and the use of health services: analysis of the National Health Survey in Brazil. Rev Saude Pública. 2017;51 Suppl 1:4s. https://doi.org/10.1590/s1518-8787.2017051000090
https://doi.org/10.1590/s1518-8787.20170... .

Another major challenge to the health of the population are mouth conditions⁹9. Peres MA, Macpherson LMD, Weyant RJ, Daly B, Venturelli R, Mathur MR, et al. Oral diseases: a global public health challenge. Lancet. 2019;394(10194):249-60. https://doi.org/10.1016/S0140-6736(19)31146-8
https://doi.org/10.1016/S0140-6736(19)31... , especially tooth loss, which ranked in 2019 as the 22^nd largest cause of health deficiency, 31^st in prevalence and 56^th in incidence¹⁰10. Institute for Health Metrics and Evaluation. GBD 2019 Cause and Risk Summaries. Edentulism and severe tooth loss - Level 4 cause. Seattle, WA: University of Washington, IHME; c2020 [cited 2020 Nov 6]. Available from: http://www.healthdata.org/results/gbd_summaries/2019/edentulism-and-severe-tooth-loss-level-4-cause
http://www.healthdata.org/results/gbd_su... . Caries and periodontal disease, in addition to other health behaviors, are the main known risk factors for tooth loss,¹¹11. Silva Junior MF, Batista MJ, Sousa MLR. Risk factors for tooth loss in adults: a population-based prospective cohort study. PLoS One. 2019;14(7):e0226794. https://doi.org/10.1371/journal.pone.0219240
https://doi.org/10.1371/journal.pone.021... but studies show that tooth loss has been associated with systemic changes such as cardiac risk, for example, showing the need for strategies with integral approaches to care.¹²12. Tsakos G, Quiñonez C. A sober look at the links between oral and general health [editorial]. J Epidemiol Community Health. 2013;67(5):381-2. https://doi.org/10.1136/jech-2013-202481
https://doi.org/10.1136/jech-2013-202481... In this sense, the World Health Organization (WHO) has placed emphasis on health literacy (HL) as an important key to health promotion, as it is considered a measurable and modifiable factor.

Unlike HL, the structural determinants of health are more difficult to modify, literacy can be changed through health promotion interventions, group education, motivational interviews and counseling, thereby increasing autonomy in decision-making. Changes in literacy levels can be measured by using validated instruments of easy application to approach patients, either individually or collectively¹³13. Dennis S, Williams A, Taggart J, Newall A, Denney-Wilson E, Zwar N, et al. Which providers can bridge the health literacy gap in lifestyle risk factor modification education: a systematic review and narrative synthesis. BMC Fam Pract. 2012;13:44. https://doi.org/10.1186/1471-2296-13-44
https://doi.org/10.1186/1471-2296-13-44... ,¹⁴14. Silva-Júnior MF, Sousa MLR, Batista MJ. Health literacy on oral health practice and condition in a adult and elderly population. Health Promot Int. 2020:daaa135. https://doi.org/10.1093/heapro/daaa135
https://doi.org/10.1093/heapro/daaa135... .

Health literacy is the ability to obtain and understand basic information necessary for making health decisions, covering crucial components for seeking well-being and health promotion. For this reason, it is an important marker of inequality¹⁵15. Kickbusch I, Pelikan JM, Apfel F, Tsouros AD, editors. Health literacy: the solid facts. Copenhagen (DK): WHO Regional Office for Europe; 2013 [cited 2020 Feb 1]. Available from: https://apps.who.int/iris/bitstream/handle/10665/128703/e96854.pdf
https://apps.who.int/iris/bitstream/hand... ,¹⁶16. World Health Organization. World report on ageing and health. Geneva (CH): WHO; 2015 [cited 2020 Oct 7]. Available from: http://apps.who.int/iris/bitstream/10665/186463/1/9789240694811_eng.pdf?ua=1
http://apps.who.int/iris/bitstream/10665... . Asa research field, HL has been gaining prominence both as an interference factor in health behaviors and conditions¹⁷17. World Health Organization. Shanghai Declaration on promoting health in the 2030 Agenda for Sustainable Development. In: 9. Global Conference on Health Promotion; 2016 Nov 21-24; Shanghai, China. Geneva; WHO; 2016 [cited 2020 Oct 7]. Available from: https://www.who.int/healthpromotion/conferences/9gchp/shanghai-declaration.pdf
https://www.who.int/healthpromotion/conf... ,¹⁸18. Firmino RT, Martins CC, Faria LS, Paiva SM, Granville-Garcia AF, Fraiz FC, et al. Association of oral health literacy with oral health behaviors, perception, knowledge, and dental treatment related outcomes: a systematic review and meta-analysis. J Public Health Dent. 2018;78(3):231-45. https://doi.org/10.1111/jphd.12266
https://doi.org/10.1111/jphd.12266... ,¹⁹19. Batista MJ, Marques ACP, Silva Junior MF, Alencar GP, Sousa MLR. Translation, cross-cultural adaptation and psychometric evaluation of Brazilian Portuguese version of the 14-item Health Literacy Scale. Cienc Saude Coletiva. 2020;25(7):2847-57. https://doi.org/10.1590/1413-81232020257.22282018
https://doi.org/10.1590/1413-81232020257... and in the epidemiological transition with increased NCDs. It is currently very easy to obtain health information, mainly on the internet; however, much of this information is inaccurate, especially because of the indiscriminate spread of fake news, which promote misinformation and affect the health of the population, even threatening lives²⁰20. Wang Y, McKee M, Torbica A, Stuckler D. Systematic literature review on the spread of health-related misinformation on social media. Soc Sci Med. 2019;240:112552. https://doi.org/10.1016/j.socscimed.2019.112552
https://doi.org/10.1016/j.socscimed.2019... . In this sense, HL can be of great relevance for determine decision-making in healthcare¹⁵15. Kickbusch I, Pelikan JM, Apfel F, Tsouros AD, editors. Health literacy: the solid facts. Copenhagen (DK): WHO Regional Office for Europe; 2013 [cited 2020 Feb 1]. Available from: https://apps.who.int/iris/bitstream/handle/10665/128703/e96854.pdf
https://apps.who.int/iris/bitstream/hand... , even more so when controlled and directed by factors such as age, income, employment, education and skin color. Recent literature shows that individuals with low levels of HL have shorter lifespans, more diseases, cannot use health services and generate more costs to the services²¹21. Ho TG, Hosseinzadeh H, Rahman B, Sheikh M. Health literacy and health-promoting behaviours among Australian-Singaporean communities living in Sydney metropolitan area. Proc Singap Healthc. 2018;27(2):125-31. https://doi.org/10.1177/2010105817741906
https://doi.org/10.1177/2010105817741906... .

In light of that, it is relevant to verify the role of HL in tooth loss from a theoretical conceptual model, in the context of NCDs. Thus, the objective of this study was to analyze the role of HL as a factor associated with tooth loss among users of the Brazilian Health System (SUS) with NCDs.

METHODS

Study Design and Site

This is a cross-sectional analytical study conducted under the Strengthening the Reporting of Observational Studies in Epidemiology (Strobe) for cross-sectional studies²²22. Malta M, Cardoso LO, Bastos FI, Magnanini MMF, Silva CMFP. Iniciativa STROBE: subsídios para a comunicação de estudos observacionais. Rev Saude Publica. 2010;44(3):559-65. https://doi.org/10.1590/S0034-89102010000300021
https://doi.org/10.1590/S0034-8910201000... , in the town of Piracicaba, São Paulo State, Brazil, with a random sample among users of Family Health Clinics (FHC) in Primary Health Care (PHC) of the Brazilian Health System (SUS).

Universe and Sample

According to the 2010 Census, the estimated population of Piracicaba was 364,571 residents in the urban area, and the adult and elderly population was 261,567²³23. Instituto Brasileiro de Geografia e Estatística. Censo demográfico 2010 - Cidades: panorama: Piracicaba. Rio de Janeiro: IBGE; 2010 [cited 2019 Mar 15]. Available from: https://cidades.ibge.gov.br/brasil/sp/piracicaba/panorama
https://cidades.ibge.gov.br/brasil/sp/pi... . The town’s healthcare network had 71 basic health clinics, 51 of which were FHCs²⁴24. Secretaria Municipal de Saúde de Piracicaba. Plano Municipal de Saúde 2018-2021. Piracicaba, SP: SMS; 2017 [cited 2018 Mar 23]. Available from: http://saude.piracicaba.sp.gov.br/institucional/ppa-plano-plurianual/
http://saude.piracicaba.sp.gov.br/instit... .

For the Health Clinics, Morgan’s study (2013) was considered²⁶26. Morgan BS. Avaliação do monitoramento telefônico na promoção do autocuidado em diabetes na atenção primária em saúde [dissertação]. Belo Horizonte, MG: Universidade Federal de Minas Gerais, Escola de Enfermagem; 2013. and out of the 51 FHCs in Piracicaba, the determined number was eight FHCs and four substitute clinics.

For the individuals, the sample size was calculated considering the prevalence of high HL as 50%²⁵25. Perez Puello SC. Avaliação da literacia em saúde [dissertação]. Piracicaba, SP: Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba; 2018., 10% error and two delineation effect. The final sample estimated for the study was 238 individuals. Estimating a probable loss, 20% was added, thus totaling 298 individuals.

Sample Selection

For the selection of Health Clinics, a draw was held of 8 units and 4 more substitutes²⁶26. Morgan BS. Avaliação do monitoramento telefônico na promoção do autocuidado em diabetes na atenção primária em saúde [dissertação]. Belo Horizonte, MG: Universidade Federal de Minas Gerais, Escola de Enfermagem; 2013. in a probabilistic way, considering the number of hypertensive and diabetic patients registered per clinic in the town’s computer system. After two refusals, two substitute FHCs were included, but due to the difficulty in reaching the number of users in some FHCs, another 2 substitutes were included to reach the proposed sample size, totaling at the end 10 FHCs for selection of participants.

When selecting the sample, to compensate for losses, 10 more participants in each of the ten FHCs were added to the sample size through an invitation to participate in the study. Thus, 400 users were selected so that the mininum number (n = 238) could be reached.

The inclusion criteria in the study were: being an adult user (≥ 20 years) registered in the selected FHC; a diagnosis of NCDs (type 2 diabetes and/or systemic arterial hypertension) followed by the clinic; being available to come to the clinic. The exclusion criteria were: exhibit mouth pain or abscess on the day of the interview; refusal to undergo oral clinical examination; having a physical and psychological state (informed by the FHC) that prevented the completion of the examinations and understanding of the questionnaire.

The users were invited to participate in the study by Community Health Agents (personally, during home visits, when coming to the clinic for an appointment or in the HiperDia group). The evaluations took place during the FHC work hours at dates, times and places chosen by the manager himself.

Data Collection

Data collection was undertaken from July to December 2019 by a dentist who had been previously trained, between May and June 2019, by a “gold standard” Examiner, including theoretical and practical discussions for eight hours, in order to obtain at least 90% agreement for caries, presence of visible dental biofilm and periodontal pocket²⁷27. Ainamo J, Bay I. Problems and proposals for recording gingivitis and plaque. Int Dent J. 1975;25 (4):229-35.,²⁸28. Organização Mundial da Saúde; Faculdade de Odontologia da Universidade de São Paulo. Levantamentos em Saúde Bucal: métodos Básicos. 5. ed. São Paulo: FOUSP; 2017 [cited 2019 Jan 7]. Available from: http://www.fo.usp.br/wp-content/uploads/2011/06/Levantamentos-Saude-Bucal_5ed_Nov2017.pdf
http://www.fo.usp.br/wp-content/uploads/... . Intraobserver agreement varied from 90.6% to 100% for dental conditions and periodontal disease, which places it within the reliability standards²⁹29. Frias AC. Estudo de confiabilidade do Levantamento Epidemiológico de Saúde Bucal – Estado de São Paulo 1998 [dissertação]. São Paulo: Universidade de São Paulo, Faculdade de Saúde Pública; 2000..

Initially, a pilot collection was performed with users (n = 18) in one of the selected FHCs. When considering that there was no need to change the collection pattern or to adapt the questionnaire, the participants of the pilot study were included in the final sample.

Data collection took place inside the FHC facilities, with questionnaire application, oral clinical examination and collection in clinical records.

A questionnaire was applied with 66 adapted³⁰30. Silva-Junior MF, Sousa MR, Batista MJ. Prospective cohort of adult oral health in Piracicaba, SP, Brazil. BMC Res Notes. 2019;12:221. https://doi.org/10.1186/s13104-019-4243-y
https://doi.org/10.1186/s13104-019-4243-... objective questions in order to obtain data on sociodemographic factors, behavior and determinants in health, HL evaluated using the following data: 14-Item Health Literacy Scale (HLS-14)³¹31. Suka M, Odajima T, Kasai M, Igarashi A, Ishikawa H, Kusama M, et al. The 14-item health literacy scale for Japanese adults (HLS-14). Environ Health Prev Med. 2013;18:407-15. https://doi.org/10.1007/s12199-013-0340-z
https://doi.org/10.1007/s12199-013-0340-... , translated and validated in Brazil by Batista et al¹⁹19. Batista MJ, Marques ACP, Silva Junior MF, Alencar GP, Sousa MLR. Translation, cross-cultural adaptation and psychometric evaluation of Brazilian Portuguese version of the 14-item Health Literacy Scale. Cienc Saude Coletiva. 2020;25(7):2847-57. https://doi.org/10.1590/1413-81232020257.22282018
https://doi.org/10.1590/1413-81232020257... , with 14 questions on a Likert scale (5 points), with the following categories: “strongly disagree”, “disagree”, “neither agree nor disagree”, “agree” and “strongly agree”; and total score from 14 and 70 points, in which higher scores indicate better HL. Questions 1 to 5 are related to the functional dimension and have their score inverted, that is, agreeing with affirmations means having low LS, and the other issues related to communicative literacy (6 to 10) and critical (11 to 14).

The clinical conditions evaluated were the existence of visible dental biofilm (on at least one surface) according to Ainamo and Bay (1975)²⁷27. Ainamo J, Bay I. Problems and proposals for recording gingivitis and plaque. Int Dent J. 1975;25 (4):229-35., index of decayed, lost and filled permanent teeth (CPOD) and community Periodontal Index (CPI)²⁸28. Organização Mundial da Saúde; Faculdade de Odontologia da Universidade de São Paulo. Levantamentos em Saúde Bucal: métodos Básicos. 5. ed. São Paulo: FOUSP; 2017 [cited 2019 Jan 7]. Available from: http://www.fo.usp.br/wp-content/uploads/2011/06/Levantamentos-Saude-Bucal_5ed_Nov2017.pdf
http://www.fo.usp.br/wp-content/uploads/... . The participants were examined in the premises of the FHC while seated in chairs, with the aid of natural light, using a Ball Point probe and a sterilized clinical mouth mirror, following the criteria set by the WHO²⁸28. Organização Mundial da Saúde; Faculdade de Odontologia da Universidade de São Paulo. Levantamentos em Saúde Bucal: métodos Básicos. 5. ed. São Paulo: FOUSP; 2017 [cited 2019 Jan 7]. Available from: http://www.fo.usp.br/wp-content/uploads/2011/06/Levantamentos-Saude-Bucal_5ed_Nov2017.pdf
http://www.fo.usp.br/wp-content/uploads/... . The latest clinical data regarding diabetes and systemic blood pressure were extracted from the medical records of the participants at the FHC.

Study Variables

Health Literacy was considered as an explanatory variable (Figure 1) and was evaluated through the HLS-14 in which the sum of score varies from 14 to 70 points, with higher scores indicating higher HL. After the descriptive analysis, HL was divided into thirds: low (0 to 33 points), medium (from 34 to 46 points), and high (> 46 points)³⁴34. Queres JFM, Lima BA, Camara MPM, Santos MCC, Taboada GF. Avaliação do conhecimento e atitudes e sua relação com parâmetros de controle do diabetes mellitus. J Health Connec. 2018;2(1):21-9..

The variables were selected according to the theoretical conceptual model adapted for the study (Figure 1), categorized as:

Exogenous: age (continuous), sex (female and male) and skin color (white and other “yellow, black or brown”);

Primary determinants in health: personal income (up to one minimum salary, and above one minimum salary) and education (less than 4 years, or up to 4 full years, and 5 years or more – elementary school 1 and 2), with the inclusion of illiterate persons and considering elementary school as a cut-off point for age, in this sample;

Intermediate determinants in health: health-related behaviors, such as tooth brushing (3 or more times a day, and up to 2 times a day), flossing (uses daily, and does not use daily), frequency/use of medical and dental services (once a year or more, and less than once a year);

Access to health services: type of medical or dental service (public or private), time of last medical consultation (less than one year, and more than one year) and reason for dental consultation (routine, pain or need) adapted³⁰30. Silva-Junior MF, Sousa MR, Batista MJ. Prospective cohort of adult oral health in Piracicaba, SP, Brazil. BMC Res Notes. 2019;12:221. https://doi.org/10.1186/s13104-019-4243-y
https://doi.org/10.1186/s13104-019-4243-... ,³³33. Ministério da Saúde (BR), Seretaria de Atenção à Saúde, Secretaria de Vigilância em Saúde. SB Brasil 2010: Pesquisa Nacional de Saúde Bucal: resultados principais. Brasília, DF; 2012 [cited 2019 Apr 29]. Available from: https://bvsms.saude.gov.br/bvs/publicacoes/pesquisa_nacional_saude_bucal.pdf
https://bvsms.saude.gov.br/bvs/publicaco... ;

Clinical conditions: pain (teeth and/or gums; no pain, and some pain) adapted³⁰30. Silva-Junior MF, Sousa MR, Batista MJ. Prospective cohort of adult oral health in Piracicaba, SP, Brazil. BMC Res Notes. 2019;12:221. https://doi.org/10.1186/s13104-019-4243-y
https://doi.org/10.1186/s13104-019-4243-... , visible dental biofilm (yes for at least one surface with biofilm, or not) and periodontal pocket (CPI Code 3 or 4, pouch > 4mm) (yes or not)²⁸28. Organização Mundial da Saúde; Faculdade de Odontologia da Universidade de São Paulo. Levantamentos em Saúde Bucal: métodos Básicos. 5. ed. São Paulo: FOUSP; 2017 [cited 2019 Jan 7]. Available from: http://www.fo.usp.br/wp-content/uploads/2011/06/Levantamentos-Saude-Bucal_5ed_Nov2017.pdf
http://www.fo.usp.br/wp-content/uploads/... ,³³33. Ministério da Saúde (BR), Seretaria de Atenção à Saúde, Secretaria de Vigilância em Saúde. SB Brasil 2010: Pesquisa Nacional de Saúde Bucal: resultados principais. Brasília, DF; 2012 [cited 2019 Apr 29]. Available from: https://bvsms.saude.gov.br/bvs/publicacoes/pesquisa_nacional_saude_bucal.pdf
https://bvsms.saude.gov.br/bvs/publicaco... . Glycemic control monitored by fasting blood glucose (altered < 126mg / dl), diabetes mellitus (127 mg/dl or more), glycated hemoglobin (HbA1c) (up to 7.0% and 7.1% or more)³⁴34. Queres JFM, Lima BA, Camara MPM, Santos MCC, Taboada GF. Avaliação do conhecimento e atitudes e sua relação com parâmetros de controle do diabetes mellitus. J Health Connec. 2018;2(1):21-9.,³⁵35. Ministério da Saúde (BR), Secretaria de Atenção à Saúde, Departamento de Atenção Básica. Estratégias para o cuidado da pessoa com doença crônica: diabetes mellitus. Brasília, DF; 2013 [cited 2019 Apr 29]. (Cadernos de Atenção Básica; nº 36). Available from: https://bvsms.saude.gov.br/bvs/publicacoes/estrategias_cuidado_pessoa_diabetes_mellitus_cab36.pdf
https://bvsms.saude.gov.br/bvs/publicaco... , and SAH whereas normal (systolic [< 130 mmHg] and diastolic [85–89]), and hypertensive patients with (systolic [≥ 140/90mmHg] and diastolic [90–99mmHg or more]), or taking antihypertensive drugs³⁶36. Ministério da Saúde (BR). Secretaria de Atenção à Saúde, Departamento de Atenção Básica. Estratégias para o cuidado da pessoa com doença crônica: hipertensão arterial sistêmica. Brasília, DF; 2013 [cited 2019 Apr 29]. (Cadernos de Atenção Básica; nº 37). Available from: https://bvsms.saude.gov.br/bvs/publicacoes/estrategias_cuidado_pessoa_doenca_cronica.pdf
https://bvsms.saude.gov.br/bvs/publicaco... .

The outcome of the study (dependent variable) was tooth loss, with a cutoff point based on the theory of the shortened dental arch, which considers satisfactory the existence of ten pairs of occlusive teeth without aesthetic gaps.³⁷37. Armellini D, Fraunhofer JA. The shortened dental arch: a review of the literature. J Prosthet Dent. 2002;92(6):531-5. https://doi.org/10.1016/j.prosdent.2004.08.013
https://doi.org/10.1016/j.prosdent.2004.... The calculation of missing teeth was performed by codes 4 (tooth missing due to caries) and 5 (tooth missing due to other reasons) of the DMFT index, and the variable tooth loss was categorized into: has 20 or more teeth, has between 19 and 1 tooth, and edental (has no teeth). The third molars were excluded from the examination, so the total tooth loss was having lost 28 teeth.

As shown in Figure 1, a conceptual theoretical model of determinants in health based on Nutbeam was built for the study³⁸38. Nutbeam D. Health literacy as a public health goal: a challenge for contemporary health education and communication strategies into the 21st century. Health Promot Int. 2000;15(3):259-67. https://doi.org/10.1093/heapro/15.3.259
https://doi.org/10.1093/heapro/15.3.259... , considering health literacy, the adapted model of Sørensen³⁹39. Sørensen K, Van den Broucke S, Fullam J, Doyle G, Pelikan J, Slonska Z, et al. Health literacy and public health: a systematic review and integration of definitions and models. BMC Public Health. 2012;12:80. https://doi.org/10.1186/1471-2458-12-80
https://doi.org/10.1186/1471-2458-12-80... et al. and Martins⁴⁰40. Martins AMEBL, Almeida ER, Oliveira CC, Oliveira RCN, Pelino JEP, Santos ASF, et al. Alfabetização em saúde bucal: uma revisão da literatura. Rev Assoc Paul Cir Dent. 2015;69(4):328-34. et al., for analyzing oral health conditions under the primary determinants and health behaviors⁴¹41. Andersen RM, Davidson PL. Ethnicity, aging, and oral health outcomes: a conceptual framework. Adv Dent Res. 1997;11(2):203-9. https://doi.org/10.1177/08959374970110020201
https://doi.org/10.1177/0895937497011002... .

Data Analysis

The analysis was carried out on the software Statistical Package for the Social Sciences (SPSS), version 20.0. First, descriptive analyses were performed to obtain the frequency, mean, median, standard deviation and Chi-Square test of the variables collected, based on the theoretical model (Figure 1), with a significance level of 5%.

Then, ordinal logistic regression models were analyzed for the tooth loss condition (3 categories). Logistic regression analysis was performed with a hierarchical approach, according to the model shown in Figure 1. For inclusion in the model, in each block the cut was considered to be p < 0.20 and the significance in the final model was p < 0.05.

The adjustments were: Model 1: regression model with age and education; Model 2: adjusted by type of dental service and HL; Model 3: adjustment for periodontal pocket, tooth/gum pain, visible dental biofilm and blood glucose; Model 4: adjustments of Models 1 and 2 with education, HL and age; Model 5: adjustments of Models 1, 2 and 3, education, HL, age, frequency/dental use and flossing; Model 6: adjustments of Models 1, 2, 4 and 5 with education, HL, age, frequency/dental use, flossing, periodontal pocket, visible dental biofilm and blood glucose.

Ethical Aspects

The study protocol was submitted and approved by the Research Ethics Committee under CAAE 94104618.7.0000.5418. The Informed Consent Form was previously signed by all participants.

RESULTS

A total of 238 users with chronic oral diseases followed at ten FHCs participated in this study. Of those, 7.2% (n = 17) of the users had diabetes, 46.6% (n = 111) of them had SAH, and 46.2% (n = 110) had diabetes and SAH. Two users refused to undergo the clinical examination and there was loss of sample due to 162 users not showing up. The response rate was 59.5%, but the desired minimum was achieved.

The mean age of the participants was 62.7 (± 10.55) years, and the majority were women, 69.3% (n = 165). They had lower education 78.5% (n = 187) among the participants and the level of low HL occurred in 33.8% (n = 84), the average level in 36.8% (n = 85) and high level in 29.3% (n = 69).

Low HL was associated with the lower frequency of brushing, irregular use of dental services, irregular flossing, higher prevalence of edentulism, presence of some kind of pain (gum/teeth), systolic blood pressure, periodontal pocket (> 4mm) and visible dental biofilm (Table 1).

The mean missing teeth in the sample was 14.63 (± 9.36). Figure 2 shows the gradients of tooth loss in relation to the gradients of health literacy: the higher the literacy gradient, the lower the prevalence of edentulism, and the higher prevalence of the presence of 20 or more teeth.

Tooth loss was associated with literacy in Model 2 by mean HL (OR = 2.80; 95%CI: 1.50–5.20) and low HL (OR = 4.70; 95%CI: 2.50–8.82), when adjusted by type of dental service. However, the HL became less significant when other variables were included from Model 3, adjusted for visible periodontal pocket, pain (teeth/gums), visible dental biofilm and blood glucose (Table 3).

In the final model, tooth loss was associated with older age(OR = 1,12; 95%CI: 1,07–1,17), lower education level (OR = 3,43; 95%CI: 1,17–10,10), a higher level of blood sugar (glucose) (OR = 1,98; 95%CI: 1,00–3,92), no dental floss use (OR = 4,58; 95%CI: 1,75–7,31), irregular use of dental services (OR = 2,60; 95%CI: 1,32–5,12), periodontal pocket > 4mm (OR = 0,31; 95%CI: 0,01–0,08) and visible dental biofilm (OR = 7,23; 95%CI: 3,19–16,41) (Table 3).

DISCUSSION

Health Literacy was a significant factor associated for tooth loss, even with intermediate determinants in health, access to service and health behaviors, but when adjusted for sociodemographic factors and clinical conditions, it became no statistically significant. It was found that as health literacy gradients increase, edentulism decreases. However, it is known that tooth loss is influenced by multiple factors, therefore, as demonstrated in the final model of this analysis, it was associated with age, education, not flossing, irregular use of dental services, existence of periodontal pocket, visible dental biofilm and glycemic index. It is noteworthy that these same factors, with the exception of glycemic index, were also the factors associated with HL in the bivariate analysis.

Health Literacy has been regarded as an intermediate determinant factor in health behaviors and outcomes¹⁷17. World Health Organization. Shanghai Declaration on promoting health in the 2030 Agenda for Sustainable Development. In: 9. Global Conference on Health Promotion; 2016 Nov 21-24; Shanghai, China. Geneva; WHO; 2016 [cited 2020 Oct 7]. Available from: https://www.who.int/healthpromotion/conferences/9gchp/shanghai-declaration.pdf
https://www.who.int/healthpromotion/conf... and a crucial factor for understanding health information nowadays, leading to health maintenance and recovery¹⁵15. Kickbusch I, Pelikan JM, Apfel F, Tsouros AD, editors. Health literacy: the solid facts. Copenhagen (DK): WHO Regional Office for Europe; 2013 [cited 2020 Feb 1]. Available from: https://apps.who.int/iris/bitstream/handle/10665/128703/e96854.pdf
https://apps.who.int/iris/bitstream/hand... , as shown by recent studies¹⁸18. Firmino RT, Martins CC, Faria LS, Paiva SM, Granville-Garcia AF, Fraiz FC, et al. Association of oral health literacy with oral health behaviors, perception, knowledge, and dental treatment related outcomes: a systematic review and meta-analysis. J Public Health Dent. 2018;78(3):231-45. https://doi.org/10.1111/jphd.12266
https://doi.org/10.1111/jphd.12266... ,⁴²42. Yadav UN, Hosseinzadeh H, Lloyd J, Harris MF. How health literacy and patient activation play their own unique role in self-management of chronic obstructive pulmonary disease (COPD)? Chron Respir Dis. 2019;16:1479973118816418. https://doi.org/10.1177/1479973118816418
https://doi.org/10.1177/1479973118816418... . The association with intermediate behavioral factors, such as regular flossing, access to services, frequency and type of dental services, has also been observed in the literature¹¹11. Silva Junior MF, Batista MJ, Sousa MLR. Risk factors for tooth loss in adults: a population-based prospective cohort study. PLoS One. 2019;14(7):e0226794. https://doi.org/10.1371/journal.pone.0219240
https://doi.org/10.1371/journal.pone.021... ,⁴³43. Henderson E, Dalawari P, Fitzgerald J, Hinyard L. Association of oral health literacy and dental visitation in an inner-city emergency department population. Int J Environ Res Public Health. 2018;15(8):1748. https://doi.org/10.3390/ijerph15081748
https://doi.org/10.3390/ijerph15081748... ,⁴⁴44. Batista MJ, Lawrence HP, Sousa MRL. Oral health literacy and oral health outcomes in an adult population in Brazil. BMC Public Health. 2018;18(1):60. https://doi.org/10.1186/s12889-017-4443-0
https://doi.org/10.1186/s12889-017-4443-... , ratifying the role of HL in health decision-making. Thus, it is evident that HL is an important social determinant to be considered as a strategy for on promoting health and well-being.

The use of model adjustment in this study might indicate that the main outcome in oral health, namely tooth loss, is caused by several risk factors accumulated throughout the individual’s history, therefore health behaviors, tooth brushing, flossing and clinical conditions, such as oral and general diseases, more proximal conditions, end up reducing the impact of HL in this outcome, when these aspects are considered. However, it is observed that, as the health literacy gradient increases, so does edentulism.

Therefore, it is necessary to demonstrate the intermediate role of HL in reducing tooth loss, which is the main result of oral health seen as a global challenge, and in periodontal diseases which, associated with NCDs, can have serious consequences and impact the individual’s quality of life⁹9. Peres MA, Macpherson LMD, Weyant RJ, Daly B, Venturelli R, Mathur MR, et al. Oral diseases: a global public health challenge. Lancet. 2019;394(10194):249-60. https://doi.org/10.1016/S0140-6736(19)31146-8
https://doi.org/10.1016/S0140-6736(19)31... , although the association between tooth loss and HL is still inconclusive in the literature¹⁸18. Firmino RT, Martins CC, Faria LS, Paiva SM, Granville-Garcia AF, Fraiz FC, et al. Association of oral health literacy with oral health behaviors, perception, knowledge, and dental treatment related outcomes: a systematic review and meta-analysis. J Public Health Dent. 2018;78(3):231-45. https://doi.org/10.1111/jphd.12266
https://doi.org/10.1111/jphd.12266... ,⁴⁵45. Firmino RT, Ferreira FM. Paiva SM, Granville-Garcia AF, Fraiz FC, Martins CC. Oral health literacy and associated oral conditions: a systematic review. J Am Dent Assoc. 2017;148(8):604-13. https://doi.org/10.1016/j.adaj.2017.04.012
https://doi.org/10.1016/j.adaj.2017.04.0... .

In this study, tooth loss showed associations with older age due to a cutting effect, that is, related to the historic outcome of Brazil’s public policies in oral health and their impact on the population¹⁴14. Silva-Júnior MF, Sousa MLR, Batista MJ. Health literacy on oral health practice and condition in a adult and elderly population. Health Promot Int. 2020:daaa135. https://doi.org/10.1093/heapro/daaa135
https://doi.org/10.1093/heapro/daaa135... . Education, another primary health determinant, was also associated with tooth loss, corroborating other findings in which lower education is associated with higher prevalence of tooth loss⁴⁶46. Gomes Filho VV, Gondinho BVC, Silva-Junior MF, Cavalcante DFB, Bulgareli JV, Sousa MRL, et al. Tooth loss in adults: factors associated with the position and number of lost teeth. Rev Saude Publica. 2019;53:105. https://doi.org/10.11606/S1518-8787.2019053001318
https://doi.org/10.11606/S1518-8787.2019... ,⁴⁷47. Helal O, Göstemeyer G, Krois J, El Sayed KF, Graetz C, Schwendicke F. Predictors for tooth loss in periodontitis patients: systematic review and meta-analysis. J Clin Periodontol. 2019;46(7):699-712. https://doi.org/10.1111/jcpe.13118
https://doi.org/10.1111/jcpe.13118... , and established as an indicator of health risk⁴⁸48. Watt RG. From victim blaming to upstream action: tackling the social determinants of oral health inequalities. Community Dent Oral Epidemiol. 2007;35(1):1-11. https://doi.org/10.1111/j.1600-0528.2007.00348.x
https://doi.org/10.1111/j.1600-0528.2007... . Sociodemographic, economic and age factors, also found in other studies, are structural factors, therefore difficult to modify⁴⁹49. Solar O, Irwin A. A conceptual framework for action on the social determinants of health. Geneva (CH): WHO; 2010. (Social Determinants of Health Discussion Paper; nº 2: Policy and Practice).,⁵⁰50. Cabellos-García AC, Castro-Sánchez E, Martínez-Sabater A, Díaz-Herrera MA, Ocaña-Ortiz A, Juárez-Vela R, et al. Relationship between determinants of health, equity, and dimensions of health literacy in patients with cardiovascular disease. Int J Environ Res Public Health. 2020;17(6):2082. https://doi.org/10.3390/ijerph17062082
https://doi.org/10.3390/ijerph17062082... . Health Literacy is a modifiable factor and is strongly associated with behaviors and aspects associated with tooth loss, although other studies are needed to clarify the association with health outcomes. The WHO highlights that HL is key to the development of health promotion¹⁵15. Kickbusch I, Pelikan JM, Apfel F, Tsouros AD, editors. Health literacy: the solid facts. Copenhagen (DK): WHO Regional Office for Europe; 2013 [cited 2020 Feb 1]. Available from: https://apps.who.int/iris/bitstream/handle/10665/128703/e96854.pdf
https://apps.who.int/iris/bitstream/hand... and an important indicator of social disparities¹⁵15. Kickbusch I, Pelikan JM, Apfel F, Tsouros AD, editors. Health literacy: the solid facts. Copenhagen (DK): WHO Regional Office for Europe; 2013 [cited 2020 Feb 1]. Available from: https://apps.who.int/iris/bitstream/handle/10665/128703/e96854.pdf
https://apps.who.int/iris/bitstream/hand... .

The income variable was associated with tooth loss in the univariate analysis; however, when adjusting for education and age, it becomes less significant (it was not associated with HL). This may have occurred due to the collinearity with education and/or the homogeneity of the sample in the socioeconomic aspect, where most earn a minimum salary or more and have up to four years of schooling.

This sample showed associations of tooth loss were found with behaviors such as irregular flossing and use of dental services, variables that impact the increase in the prevalence of tooth loss in individuals with chronic diseases, according to a study conducted in Santa Rita, Paraíba State, Brazil⁵¹51. Maia FBM, Sousa ET, Sampaio FCS, Freitas CHSM, Forte FDS. Tooth loss in middle-aged adults with diabetes and hypertension: social determinants, health perceptions, oral impact on daily performance (OIDP) and treatment need. Med Oral Patol Oral Cir Bucal. 2018;23(2):e203-10. https://doi.org/10.4317/medoral.22176
https://doi.org/10.4317/medoral.22176... . Regarding clinical conditions, existence of dental biofilm and periodontal pocket, associations were also found in other studies, reinforcing the influence of NCDs on periodontal disease, tooth loss and systemic consequences⁵²52. Kocher T, König J, Borgnakke WS, Pink C, Meisel P. Periodontal complications of hyperglycemia/diabetes mellitus: epidemiologic complexity and clinical challenge. Periodontology. 2000;78(1):59-97. https://doi.org/10.1111/prd.12235
https://doi.org/10.1111/prd.12235... ,⁴⁷47. Helal O, Göstemeyer G, Krois J, El Sayed KF, Graetz C, Schwendicke F. Predictors for tooth loss in periodontitis patients: systematic review and meta-analysis. J Clin Periodontol. 2019;46(7):699-712. https://doi.org/10.1111/jcpe.13118
https://doi.org/10.1111/jcpe.13118... . In this study, individuals who had more teeth present in their mouths had more periodontal pockets, considering the large number of individuals who were edental.

Behaviors are influenced by the determinants and have an impact on chronic diseases, therefore paying attention to the types of determinants of inequities⁵³53. Marmot M, Allen J, Bell R, Bloomer E, Goldblatt P, et al. WHO European review of social determinants of health and the health divide. Lancet. 2012;380(9846):1011-29. https://doi.org/10.1016/S0140-6736(12)61228-8
https://doi.org/10.1016/S0140-6736(12)61... can determine improvements in health. In this case, HL can be a modifying agent empowering individuals and placing them as a protagonist of their health. In short, understanding HL associated with health behaviors becomes a considerable predictor.

The association between high blood glucose and tooth loss pointed out in this study proves that tooth loss is an important indicator of systemic health, as other studies have also pointed out⁵⁴54. Michaud DS, Fu Z, Shi J, Chung M. Periodontal disease, tooth loss, and cancer risk. Epidemiol Rev. 2017;39(1):49-58. https://doi.org/10.1093/epirev/mxx006
https://doi.org/10.1093/epirev/mxx006... ,⁵⁵55. Dörfer C, Benz C, Aida J, Campard G. The relationship of oral health with general health and NCDs: a brief review. Int Dent J. 2017;67 Suppl 2:14-8. https://doi.org/10.1111/idj.12360
https://doi.org/10.1111/idj.12360... . It is even considered as a risk factor for heart disease¹²12. Tsakos G, Quiñonez C. A sober look at the links between oral and general health [editorial]. J Epidemiol Community Health. 2013;67(5):381-2. https://doi.org/10.1136/jech-2013-202481
https://doi.org/10.1136/jech-2013-202481... ,⁵⁶56. Lee HJ, Choi EK, Park JB, Han KD, Oh S. Tooth loss predicts myocardial infarction, heart failure, stroke, and death. J Dent Res. 2019;98(2):64-70. https://doi.org/10.1177/0022034518814829
https://doi.org/10.1177/0022034518814829... and rheumatoid arthritis⁵⁷57. Genco RJ, Sanz M. Clinical and public health implications of periodontal and systemic diseases: an overview. Periodontology 2000;2020;83(1):7-13. https://doi.org/10.1111/prd.12344
https://doi.org/10.1111/prd.12344... . In addition to potentiating more serious health conditions, this condition can be a predictor of mortality⁵⁸58. Friedman PK, Lamster IB. Tooth loss as a predictor of shortened longevity: exploring the hypothesis. Periodontology 2000;2016;72(1):142-52. https://doi.org/10.1111/prd.12128
https://doi.org/10.1111/prd.12128... , an extremely relevant fact that reinforces the importance of an integral approach in healthcare⁵⁹59. Salci MA, Silva DMGV, Meirelles BHS, Rêgo AS, Radovanovic CAT, Carreira L, et al. Diabetes mellitus e saúde bucal: a complexa relação desta assistência na atenção primária à saúde. Saude Pesq. 2020;13(2):265-72. https://doi.org/10.1111/prd.12128
https://doi.org/10.1111/prd.12128... .

One limitation of this study was the cross-sectional approach, which did not allow a causal inference. Another aspect to be considered was the homogeneity of the sample, in which all individuals exhibit chronic diseases and the possibility of comorbidities. However, the sample is representative of this portion of the population that needs to be studied and inserted into the health services with a unique understanding and with greater consideration for integral health, since it is the age group in which the most severe oral diseases occur, especially tooth loss⁶⁰60. Kassebaum NJ, Smith AG, Bernabé E, Fleming TD, Reynolds AE, Vos T, et al. Global, regional, and national prevalence, incidence, and disability-adjusted life years for oral conditions for 195 countries, 1990-2015: a systematic analysis for the Global Burden of Diseases, injuries, and risk factors. J Dent Res. 2017;96(4):380-7. https://doi.org/10.1177/0022034517693566
https://doi.org/10.1177/0022034517693566... , its determinants can cause reflexes in systemic health, therefore requiring rapid attention.

Knowing and identifying associated risk factors can enable better management of health care for this population, and the development of health promotion strategies. Since many health systems in the world do not keep up with the increased burden of NCDs and The Associated health needs of the population⁶¹61. GBD 2019 Universal Health Coverage Collaborators. Measuring universal health coverage based on an index of effective coverage of health services in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet. 2020;396(10258):1250-84. https://doi.org/10.1016/S0140-6736(20)30750-9
https://doi.org/10.1016/S0140-6736(20)30... , this study is a relevant warning for managers to consider integrality in health, as well as LS, in multiprofessional team work⁶²62. Barreto ACO, Rebouças CBA, Aguiar MIF, Barbosa RB, Rocha SR, Cordeiro LM, et al. Perception of the Primary Care multiprofessional team on health education. Rev Bras Enferm. 2019;72 Suppl 1:266-73. https://doi.org/10.1590/0034-7167-2017-0702
https://doi.org/10.1590/0034-7167-2017-0... and in their public policy actions aimed at this population. To this end, this study also shows the use of a tool for measuring the HL that is easy to apply, so that health teams can act to control NCDs

When measurable through instruments used by health professionals (such as the one used in this study), HL will also be important for changing clinical outcomes, and it can be modified through interventions and health promotion actions that increase people’s autonomy in decision-making. Therefore, it is relevant to consider integral healthcare and HL in health promotion policies.

CONCLUSION

Tooth loss was associated with health literacy when adjusted for health behaviors; when sociodemographic variables and clinical conditions were included, health literacy became no significant. In the final model, behaviors, determinants in health and clinical conditions were risk indicators of tooth loss, which shows the multifactorial nature involved in this phenomenon. Therefore, future studies aimed at understanding tooth loss and approaching health literacy and integral healthcare are encouraged.

REFERENCES

Publication Dates

History