1 Volume 21 2022 e227259 Original Article Braz J Oral Sci. 2022;21: e227259http://dx.doi.org/10.20396/bjos.v21i00.8667259 1 Department of Health Sciences and Children’s Dentistry, School of Dentistry of Piracicaba, University of Campinas, Piracicaba, São Paulo, Brazil. 2 Teacher at the Faculty of Dentistry of the State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil. 3 University of Zaragoza, Spain. 4 Faculty of Medicine of Jundiaí, Jundiaí, São Paulo, Brazil. Corresponding author: Dr Marília Jesus Batista Department of Health Sciences and Children’s Dentistry, Piracicaba Dental School – University of Campinas. Avenida Limeira, 901 – Piracicaba, SP – Brazil. Zip Code: 13414-018. P.O. Box 52. Phone: 55 (19) 2106 5209; Fax: 55 (19) 2106 5218. Cell phone: 55 (11)94449 1191. E-mail: mariliajbatista@yahoo.com.br, mariliamota@g.fmj.br Editor: Altair A. Del Bel Cury Received: October 13, 2021 Accepted: May 25, 2022 Health literacy dimensions among public health service users with chronic diseases in Piracicaba, Brazil, 2019 Carla Fabiana Tenani1 , Manoelito Ferreira Silva Junior2 , Maria da Luz Rosário de Sousa1,3 , Marilia Jesus Batista1,4,* Aim: This study analyzes factors associated with dimensions of health literacy (HL) functional, communicative and critical among public health service users with chronic non-communicable diseases. Methods: A cross-sectional analytical research was carried out in Piracicaba, São Paulo, Brazil, with adults and older adults attending Family Health Units (FHU). Data were collected by oral exam (CPOD and CPI) and a questionnaire on systemic conditions, sociodemographic factors, health behaviors and HLS (HLS-14). The outcomes consisted of functional, communicative, and critical HL dimensions dichotomized by median (high and low), which were analyzed by chi-square test (p<0.05) to find associations with the variables studied. Results: The study sample comprised 238 FHU users with 62.7 (± 10.55) mean age, of which 47.5% (n=113) showed high functional HL, 50.0% (n=119) high communicative HL, and 46.2% (n=110) high critical HL. High functional HL was associated with men (p<0.05). Functional and communicative HL were associated with having higher education (p<0.001 and p=0.018, respectively). High communicative and critical HL were associated with regular use of dental and medical services (p<0.05). Individuals with low functional HL were more likely to present poor tooth brushing (p=0.020). High HL (in all three dimensions) was associated with regular flossing and having more teeth (p<0.05). Conclusion: Functional, communicative and critical HL were associated with health behaviors and clinical outcomes, whereas the functional dimension was also associated with sociodemographic factors. HL dimensions allowed to differentiate health-related factors. Keywords: Health literacy. Oral health. Chronic disease. Health policy. National health programs. Public health. https://orcid.org/0000-0001-7203-2763 https://orcid.org/0000-0001-8837-5912 https://orcid.org/0000-0002-0346-5060 https://orcid.org/0000-0002-0379-3742 2 Tenani et al. Braz J Oral Sci. 2022;21: e227259 Introduction The demographic and epidemiological transition has widened the age pyramid and increased the prevalence of chronic non-communicable diseases (NCD) in the world population and, subsequently, in the Brazilian population1. Of strong behavioral char- acter, these morbidities require co-responsibility between health professionals and patients to control their consequences. In this regard, health literacy (HL) has been considered a key to health promotion and to improve health decision-making2. Health Literacy refers to personal knowledge, motivation, and skills to make health decisions throughout life2. According to Nutbeam’s concept, HL comprises three dimensions: functional, communicative, and critical literacy3. Functional HL consists of sufficient basic reading and writing skills to be used in everyday situations. In this dimension, one’s role is passive. In the communicative dimension, one seeks informa- tion through direct communication with reliable sources, such as health professionals, thus playing an active role. The critical dimension requires more advanced cognitive skills, such as critical analysis to judge whether a health information is appropriate and represents a greater control over one’s own health, requiring a proactive role3,4. A low HL can have an impact on people’s health5, representing difficulties in making health-related decisions. Studies suggest that adults and older individuals with low HL have less access to and understanding of health information, use medications inappropriately, have less disease prevention and control, with higher rates of morbid- ity and hospitalization3. Conversely, a high HL means being able to take responsibility for the collective health and one’s own6. Measuring health literacy remains a challenge for health professionals and manag- ers, especially regarding the elaboration of strategies for developing critical thinking6. Most of the existing instruments for HL measurement target specific health condi- tions such as oral health7 or diabetes8, and few of them take on a multidimensional approach9,10. Most measure only functional HL11 and one more dimension12. Using an instrument able to assess the three HL dimensions, as described by Nut- beam, would thus allow us to identify the different aspects that might interfere in how people manage their health. In a community approach, information on the associated factors of HL dimensions contribute to assist and to plan health strategies in differ- ent health contexts, health conditions and/or age groups13. The Health Literacy Scale (HLS-14)10, for example, is a validated instrument that presents three dimensions14. Given this context, this study sought to analyze the socio-demographic variables, health behaviors and clinical factors associated with HL dimensions among public health service users with chronic non-communicable diseases. Materials and methods Study design and location A cross-sectional analytical study was carried out with users of the Unified Health System (SUS), with follow up at Family Health Units (FHU) in the municipality of Pira- 3 Tenani et al. Braz J Oral Sci. 2022;21: e227259 cicaba, São Paulo, Brazil, using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines15. Location According to the last census (2010), Piracicaba has a population of 364,571 inhabi- tants in the urban area, with an adult and older population of 261,56716. In 2018, the municipality’s health network had 71 Basic Health Units, of which 51 were FHUs. This study included only adult and older adult hypertensive and/or dia- betic users. Sample We performed a sample calculation considering the prevalence of low HL as 50%, based on Puello (2018)17, with a margin of error of 0.1 and design effect (deff)=2. Pre- dicting probable losses, we added 20%, totaling 298 participants. Sample selection Selection took place in two stages: first, we chose the FHU and then the participants. We performed a probabilistic drawing of eight Family Health Units and then four alter- nates, considering the number of hypertensive and/or diabetic users in the population registered at the FHU, according to a study by Morgan (2013)18. After two FHU refused to participate, two of the alternates were included. We had to include the remaining two alternate FHU to reach the sample size, thus totaling a final sample of 10 partic- ipating FHU (Figure 1). Estimating possible losses and refusals, we added 10 partici- pants for each selected FHU, with 40 users taken from the list of hypertensive and/or diabetic patients registered at each health unit. 8 FHU n = 240 C al cu la te d S am pl e USF 1 n = 40 USF 2 n = 40 USF 33 n = 40 USF 4 n = 40 USF 5 n = 40 USF 6 n = 40 USF alternate 1 USF alternate 2 USF alternate 3 USF alternate 4 USF 7 n = 40 USF 8 n = 40 alternates Figure 1. Distribution of the sample of NCD patients (type 2 diabetes and hypertension) and the FHUs selected for the study, adapted from Morgan (2013). 4 Tenani et al. Braz J Oral Sci. 2022;21: e227259 The health teams of each selected FHU randomly distributed 40 invitations to regis- tered users with type 2 diabetes and/or SAH in attendance on the scheduled dates to participate in the study. Data collection took place at the FHU during its opening hours. Inclusion criteria consisted of patients registered and monitored at the FHU in Pira- cicaba for type 2 diabetes and/or SAH, who attend the FHU on the scheduled day and time. Exclusion criteria included presence of abscesses or emergency oral health care on the day of collection, refusal to undergo clinical dental examination, and being unable to answer the questionnaire due to physical and/or psychological status (informed by the respective FHU). Data collection Clinical data were collected by a dental surgeon (DS) after an 8-hour theoretical and practical training with an experienced examiner, with intra-examiner agreement which, considered within reliability standards, ranged from 90.6% to 100.0% for caries and periodontal disease19,20. Clinical oral examinations were performed by the examining board, properly dressed, and under World Health Organization (WHO) criteria, using a sterile peri- odontal probe and a clinical mirror, with the participant sitting in a chair, under nat- ural light21, at the FHU offices. The clinical conditions evaluated were visible dental biofilm22, index of decayed, lost and filled permanent teeth (DMFT) and Community Periodontal Index (CPI)21. Interviews were conducted with the participants following a questionnaire with 66 objective questions about behaviors, oral and general health determinants20,23. Subsequently, we applied the Health Literacy Scale (HLS-14)10 validated in Brazil- ian Portuguese14. This instrument presents 14 questions (5 for the functional and communicative dimensions and 4 for the critical dimension), answered by a 5-point Likert-type scale, with the following categories: “strongly disagree,” “disagree,” “nei- ther agree nor disagree,” “agree” and “strongly agree.” Total score ranges from 14 to 70 points, with higher scores indicating better HL. In the functional dimension (ques- tions 1 to 5) the score is reversed, where agreeing means having low HL, whereas the questions related to communicative (questions 6 to 10) and critical literacy (ques- tions 11 to 14) refer to high HL10. Data on blood pressure and glycemic indexes were collected from the current infor- mation in the medical records. Application of the questionnaire and HL instrument and the clinical oral examination were performed on the same day. Study variables Our variable of interested was HL, presented, in each dimension, at two levels: low and high, dichotomized by the median. Cutoff points for high and low levels were 11.0 for the functional dimension, 16.5 points for the communicative dimension, and 14.0 for critical literacy. Figure 2 summarizes the three dimensions3 and roles4, namely: functional HL – passive role, communicative HL – active role, and critical HL – proactive role. 5 Tenani et al. Braz J Oral Sci. 2022;21: e227259 Levels of Health Literacy FUNCTIONAL HL COMMUNICATION HL CRITICAL HL PASSIVE ACTIVE PROACTIVE Basic reading and writing knowledge that allows undestanding everyday health situations Empowerment and interaction: more advanced skills to actively participate in daily life, extract information and meaning from different forms of communication, and apply them to change circumstances Advanced knowledge in health analysis and critical thinking. Social and support networks, and skills to critically analyze information that allows for greater control over life events and situations Figure 2. Flowchart of the adapted health literacy dimensions (Kickbusch, 2004; Nutbeam, 2000). The study variables were grouped into sociodemographic, behavioral, and clinical data. Sociodemographic data consisted of age (considered continuously), gender (man or woman), and schooling level (less than 4 years, 4 full years, or 5 years or more), the cutoff point being elementary school20,23. Toothbrushing (up to 2 times/day, 3 or more times/day), flossing (daily use or no daily use), use of medical services (1 time/year [regular use], less than 1 time/year [irreg- ular use]), and use of dental services (1 time/year [regular use], less than 1 time/year [irregular use]) were the health behaviors analyzed20,23. Oral and systemic clinical conditions comprised: tooth loss, not considering third molars in calculation performed by codes 4 and 5 of the DMFT index (has 20 teeth or more, or has between 1 and 19 teeth, or edentulous) based on the reduced dental arch theory24; presence of periodontal pocket with code 3 or 4 per sextant in the CPI index (> 4mm) (yes or no); blood glucose (up to 126mg/dl, 127mg/dl or more); blood pressure considered normal (systolic [<130mmHg] and diastolic [85-89]); and hyper- tension (systolic [≥140mmHg] and diastolic [90mmHg or more])25,26. Data analysis We performed a descriptive analysis to obtain the frequency, mean, median and standard deviation, using the Statistical Package for the Social Sciences (SPSS) software version 20.0. Chi-square tests were performed comparing the HL dimen- 6 Tenani et al. Braz J Oral Sci. 2022;21: e227259 sions with the variables studied (p<0.05). Internal consistence was estimated by Cronbach’s α (>0.70). Ethical aspects Study submitted and approved by the Research Ethics Committee under CAAE 94104618.7.0000.5418. The research started after approval and signing of the Informed Consent Form by the research participants. Results A total of 238 users with chronic diseases participated in the six-month data collec- tion period. Two users refused to undergo clinical oral examination, and a sample loss characterized by the non-attendance of 162 invited users, which was expected and calculated in the sample size and selection method. Mean age was 62.7 (±10.55) years old, and 78.5% (n=187) had lower schooling level. Regarding health behaviors, 68.1% (n=162) of the patients flossed regularly, and 74.8% (n=172) made irregular use of dental services (+1 year). As for the oral clinical exams, 57.6% (n=147) of participants presented a periodontal pocket > 4mm (Table 1). Table 1. Characteristics of sociodemographic variables, access, health behavior and health conditions among patients with chronic non-communicable diseases (n=238), users of Primary Health Care in Piracicaba, SP, Brazil, 2019. VARIABLES SOCIODEMOGRAPHIC n (%) Age (years) Mean 62.7(±10.55) Gender Women 165 (69.3) Men 73 (30.7) Schooling level 4 years 86 (36.1) 4 complete years 101 (42.4) 5 years or over 51 (21.4) HEALTH BEHAVIORS Toothbrushing Up to 2 times/day 103 (43.3) 3 or more times/day 135 (56.7) Flossing Daily use 76 (31.9) No daily use 162 (68.1) Medical service frequency Regular use (+ 1 time/year) 181 (76.1) Irregular use (- 1 time/year) 57 (23;9) Dental service frequency Regular use (up to 1 time/year) 58 (25.2) Irregular use (+ 1 time/ year) 172 (74.8) CLINICAL CONDITIONS (1)Dental loss Have 20 teeth or more 75 (31.5) Between 20 and 27 teeth 86 (36.1) Edentulous 77 (32.4) Continue 7 Tenani et al. Braz J Oral Sci. 2022;21: e227259 Continuation Periodontal pocket (> 4mm) Yes 137 (57.6) No 101 (42.4) Glycemia Up to 126 mg/dl 113 (47.5) 127 mg/dl or more 125 (52.5) Systolic Blood Pressure Up to 139 mmHg 174 (73.1) 140 mmHg or over 64 (26.9) Diastolic Blood Pressure Up to 89 mmHg 210 (88.2) 90 mmHg or over 28 (11.8) Source: Prepared by the authors (2020). Note: (1) Reduced dental arch theory (Armellini and Fraunhofer, 2002). Regarding health literacy (HL), total mean was 40.4 (± 9.3) points and the median 42.0 points. Analyzed by dimensions, the mean and standard deviation found were 11.0 (±4.4) for functional HL, 16.5 (±4.5) for communicative HL, and 14.0 (±3.4) for critical literacy. Among users, 47.5% (n=113) showed high functional HL, 50% (n=119) high communicative HL and 46.2% (n=110) high critical literacy. Table 2 presents the distribution of the HL dimensions for each question of the HLS-14 instrument. Most patients showed low HL for all three dimensions: functional (questions 1 to 4) had a higher percentages of agreement; communicative (questions 7 to 10) and critical (questions 11 to 14) had higher percentages of disagreement. Table 2. Distribution of Health Literacy for each question of the HLS-14 instrument among individuals with chronic non-communicable diseases (n=238), users of Primary Health Care in Piracicaba, SP, Brazil, 2019. QUESTIONS ACCORDING TO THE HEALTH LITERACY DIMENSIONS* ANSWERS Strongly agree Agree Neither agree nor disagree Disagree Strongly disagree n (%) n (%) n (%) n (%) n (%) FUNCTIONAL 1. I find words I cannot read 88 (37.0) 82 (34.5) 39 (16.4) 23 (9.7) 6 (2.5) 2. The print is too small for me 82 (42.0) 90 (37.8) 22 (9.2) 22 (9.2) 4 (1.7) 3. The content is very difficult to understand 88 (37.0) 89 (37.4) 35 (14.7) 20 (8.4) 6 (2.5) 4. It takes me a long time to read (the instructions) 72 (30.3) 75 (31.5) 39 (16.4) 48 (20.2) 4 (1.7) 5. I need someone to help me read 65 (27.3) 45 (18.9) 27 (11.3) 91 (38.2) 10 (4.2) COMMUNICATIVE 6. I look for information in several places 31 (13.0) 76 (31.9) 31 (13.0) 69 (29.0) 31 (13.0) 7. I find the information I need 28 (11.8) 70 (29.4) 36 (15.1) 83 (34.9) 21 (8.8) 8. I understand the information found 26 (10.9) 70 (29.4) 45 (18.9) 80 (33.6) 17 (7.1) 9. I tell my opinion about the disease to my doctor, family, or friends 10 (4.2) 52 (21.8) 37 (15.5) 115 (48.3) 24 (10.1) Continue 8 Tenani et al. Braz J Oral Sci. 2022;21: e227259 Continuation 10. I put the information found into practice in my daily life 7 (2.9) 19 (8.0) 47 (19.7) 139 (58.4) 26 (10.9) CRITICAL 11. I know when the information is good for my case 10 (4.2) 37 (15.5) 52 (28.1) 110 (46.2) 29 (12.2) 12. I consider whether the information is true 6 (2.5) 27 (11.3) 35 (14.7) 143 (60.1) 27 (11.3) 13. I have knowledge to judge whether the information is reliable 17 (7.1) 72 (30.3) 57 (23;9) 78 (32.8) 14 (5.9) 14. I get information that helps me make decisions about how to improve my health 10 (4.2) 61 (25.6) 29 (12.2) 112 (47.1) 26 (10.9) Source: Prepared by the authors (2020). Note: *HLS-14 instrument (Suka et al., 2013), validated in Brazil by Batista et al. (2020). HL dimensions were associated with the sociodemographic, behavioral, and clinical variables. The bivariate analysis showed that having more than 20 teeth and regular flossing were associated with high HL in all three dimensions (Table 3). Confirmatory analysis obtained a Cronbach’s α = 0.87. Table 3. Sociodemographic factors, access, health behaviors, and clinical conditions associated with health literacy dimensions among patients with chronic non-communicable diseases (n=238), users of Primary Health Care in Piracicaba, SP, Brazil, 2019. VARIABLES HEALTH LITERACY DIMENSIONS (HL) FUNCTIONAL HL COMMUNICATIVE HL CRITICAL HL < HL > HL p-value < HL > HL p-value < HL > HL p-value n (%) n (%) n (%) n (%) n (%) n (%) SOCIODEMOGRAPHIC Gender Women 95 (57.6) 70 (42.4) 0.019 79 (47.9) 86 (52.1) 0.325 86 (52.1) 79 (47.9) 0.440 Men 30 (41.1) 43 (58.9) 40 (54.8) 33 (45.2) 42 (57.5) 31 (42.5) Schooling level 4 years 54 (62.8) 32 (37.2) <0.001 50 (58.1) 36 (41.9) 0.018 48 (55.8) 38 (44.2) 0.056 4 complete years 57 (56.4) 44 (43.6) 52 (51.5) 49 (48.5) 60 (59.4) 41 (40.6) 5 years or over 14 (27.5) 37 (72.5) 17 (33.3) 34 (66.7) 20 (39.2) 31 (60.8) HEALTH BEHAVIORS Toothbrushing Up to 2 times/day 63 (61.2) 40 (38.8) 0.020 46 (44.7) 57 (55.3) 0.150 58 (56.3) 45 (43.7) 0.494 3 or more times/day 62 (45.9) 73 (54.1) 62 (45.9) 73 (54.1) 70 (51.9) 65 (48.1) Flossing Daily use 32 (42.1) 44 (57.9) 0.028 24 (31.6) 52 (68.4) <0.001 28 (36.8) 48 (63.2) <0.001 No daily use 93 (57.4) 69 (42.6) 95 (58.6) 67 (41.4) 100 (61.7) 62 (38.3) Continue 9 Tenani et al. Braz J Oral Sci. 2022;21: e227259 Continuation Medical service frequency Regular use (+ 1 time/year) 98 (54.1) 83 (45.9) 0.372 101 (55.8) 80 (44.2) <0.001 107 (59.1) 74 (40.9) 0.003 Irregular use (- 1 time/year) 27 (47.4) 30 (52.6) 39 (68.4) 18 (31.6) 21 (36.8) 36 (63.2) Dental service frequency Regular (up to 1 year since last time) 25 (43.1) 33 (56.9) 0.094 15 (25.9) 43 (74.1) <0.001 20 (34.5) 38 (65.5) <0.001 Irregular (+ than 1 year since last time) 96 (55.8) 76 (44.2) 102 (59.3) 70 (40.7) 105 (61.0) 67 (39.0) CLINICAL CONDITIONS Dental loss Have 20 teeth or more 29 (38.7) 46 (61.3) 0.013 25 (33.3) 50 (66.7) 27 (36.0) 48 (64.0) <0.001 Between 20 and 27 teeth 49 (57.0) 37 (43.0) 48 (55.8) 38 (44.2) 0.002 47 (54.7) 39 (45.3) Edentulous 47 (61.0) 30 (39.0) 46 (59.7) 31 (40.3) 54 (70.1) 23 (29.9) Periodontal pocket (> 4mm) Yes 51 (50.5) 50 (49.5) 0.591 45 (44.6) 56 (55.4) 0.149 88 (64.2) 49 (35.8) <0.0001 No 74 (54.0) 63 (46.0) 74 (54.0) 63 (46.0) 40 (39.6) 61 (60.4) Glycemia Up to 126 mg/dl 61 (54,0) 52 (46,0) 0,668 50 (44,2) 63 (55,8) 0,092 60 (53,1) 53 (46,9) 0,840 127 mg/dl or over 64 (51,2) 61 (48,8) 69 (55,2) 56 (44,8) 68 (54,4) 57 (45,6) Systolic Blood Pressure Up to 139 mmHg 92 (52.9) 82 (47.1) 0.857 95 (54.6) 79 (45.4) 0.019 103 (59.2) 71 (40.8) 0.006 140 mmHg or over 33 (51.6) 31 (48.4) 24 (37.5) 40 (62.5) 25 (39.1) 39 (60.9) Diastolic Blood Pressure Up to 89 mmHg 112 (53.3) 98 (46.7) 0.492 105 (50.0) 105 (50.0) 1.000 112 (53.3) 98 (46.7) 0.704 90 mmHg or over 13 (46.4) 15 (53.6) 14 (50.0) 14 (50.0) 16 (57.1) 12 (42.9) Source: Prepared by the authors (2019). Note: *Reduced dental arch theory (Armellini and Fraunhofer, 2002) Discussion Our study highlighted different associations between the dimensions of health lit- eracy (HL) and sociodemographic factors, health behaviors, and clinical outcomes. A multidimensional evaluation of HL provides a broader approach that can deepen our understanding regarding HL levels and enhance one’s health autonomy. Hence, the differential of a multidimensional instrument used to increase measurement sensitivity is evident, allowing more variables associated with the construct to be identified. Despite the research on validated HL tools, few studies have assessed HL dimensions and associated factors27. The Health Literacy Scale (HLS-14), validated in Brazilian Portuguese, showed good internal consistency, which is considered adequate when greater than or equal to 0.70. Its psychometrics properties were satisfactory to evaluate health literacy, as showed by Batista et al.14. 10 Tenani et al. Braz J Oral Sci. 2022;21: e227259 Recent studies using HL instruments associated with NCDs, including oral diseases27, have assessed mainly reading and writing skills28, that is, only the functional dimen- sion, disregarding communication and/or broad interaction with health care systems. In our study, therefore, we chose to use the HLS-14 instrument, a pioneering tool for measuring the three HL dimensions (functional, communicative, and criti- cal), according to Nutbeam (2000)3. Rapidly applicable, with reliable psychomet- ric indexes not restricted to a specific area or health condition10, it can serve both to define clinical protocols more consistent with reality, thus improving people’s level of understanding of health information, and to carry out interventions capable of improving health literacy29. The questions with the greatest impact on literacy inquired about the difficulty in reading and finding information when needed, and in communicating one’s opinion about a health condition and being able to judge whether the information is reliable. Regarding sociodemographic factors, men showed greater functional literacy, result not found in other studies30. Gender inequity is an important social marker in Bra- zil, especially in a sample of predominantly older adults. This finding may indicate a lack of study opportunities in a generation where these opportunities, including decision-making, were restricted for women. Today, as observed in the 2010 census, women have a high level of schooling, with female school attendance increasing 9.8% in high school compared to men16. Studies also highlight that older adults may have limited understanding of health information31 and greater participation of women due to the feminization of the aging process32. But even with this limited functional liter- acy, the literature points to greater self-care among women, including regular use of health services33. Consequently, HL needs to go beyond the functional level. Our findings showed that high functional and communicative HL were associated with high schooling level. These HL dimensions are related to passive and more active attitudes, such as communication. However, we must consider the cogni- tive differences, skills, and roles between people with the same educational level34. As such, research that exclude illiterate individuals from its sample30 may lose het- erogeneity of results and restrict the understanding of literacy dimensions after all, literacy is one of and not the only aspect analyzed by HL dimensions. Studies show that functional literacy focuses on reading skills, in which the people act more pas- sively in health-related issues4. Better reading and comprehension skills are asso- ciated with better formative education, which is related to schooling level, a marker and social determinant of health35. HL is thus related to one’s schooling, reflect- ing on their health behaviors; consequently, developing health literacy can reduce health inequalities36. Regarding oral health behaviors, our results revealed that regular flossing was asso- ciated with high levels of all HL dimensions. Lower frequency of tooth brushing was associated with low functional HL, corroborating a recent study37. Oral health care and use of dental services can have an impact on clinical health conditions13. In our study, regular use of dental services was also associated with communicative and critical HL. The literature points out that, besides greater use of services, indi- viduals with higher HL seek preventive consultations, showing a more active role in 11 Tenani et al. Braz J Oral Sci. 2022;21: e227259 the pursuit of health4. An unexpected finding in the present research was the associ- ation between low communicative and high critical HL and irregular use of medical services. This result can be explained by the sample characteristic of patients with chronic disease, who need continuous medical follow-up. The presence of a periodontal pocket was associated with a low critical HL. Oral hygiene is associated with HL and with the risk of developing periodontal disease38, which can lead to tooth loss. Tooth loss the worst oral health outcome was associated with all HL dimensions, but remains inconclusive13. When associated with risk behaviors for oral diseases, HL becomes relevant as a measure to reduce and control tooth loss, as it can help promote oral and general health, and studies exploring this topic have been per- formed39. Thus, an in-depth knowledge of one’s HL level can be an important differ- entiator in the health-disease process40. SAH was associated with communicative and critical HL, as shown by Borges et al. (2019)30. Considering that such dimensions of HL are associated with people’s proac- tive abilities4, blood pressure indices may, in this case, be influenced by aspects that interfere with their discharge, such as: frequency, type, and access to health services, interaction with health professionals, and others37. Since the outcomes of oral and general health diseases and aggravations, such as periodontal disease, tooth loss and SAH, are associated with more advanced dimensions of literacy, such as communicative and critical HL, it becomes clear that inequality negatively impacts health. As for the limitations, we can cite the restricted sample of the study. Nonetheless, it was representative of Unified Health System users with SAH and diabetes, where important associations between the HL dimensions and aspects involving the inte- gral health of these users, often neglected in research2, were contemplated. Measur- ing health literacy by a self-report instrument is always challenging, but using a vali- dated questionnaire and proper analysis can control bias, thus improving the quality of the study. Despite the limitations, our exploratory study presents unprecedent results that show a new perspective regarding the application and analysis of health literacy dimensions, reaffirming the need for greater research interest in exploring and improving on this topic in future studies. Improving population HL can reduce the prevalence of chronic health conditions and the individual and collective impacts of these morbidities. Our results showed that using instruments that cover only functional literacy may be insufficient to assess health literacy, and that the analyzes need to incorporate all three dimen- sions to formulate safer and more accurate strategies for professionals, managers, and users. The present work contributes to greater attention to the complexity and challenges involved in advancing the topic, serving as a starting point for future studies and as an aid to evidence-based public health policies that seek to improve the health of SUS users. Thus, future studies should consider HL using a multidimensional approach for public health policies and health promotion strategies. 12 Tenani et al. Braz J Oral Sci. 2022;21: e227259 In conclusion, functional, communicative, and critical HL dimensions were associ- ated with sociodemographic, behavioral and clinical factors among adults and older adults with NCDs, users of public health services in a different way. Declaration of Conflicting Interests The authors declare no potential conflicts of interest regarding the research, author- ship, and publication of this manuscript. Funding We thank the Coordination for the Improvement of Higher Education Personnel – CAPES (code 01) for funding this research. The authors thank Espaço da Escrita – Pró-Reitoria de Pesquisa – UNICAMP for the language services provided. Data availability Datasets related to this article will be available upon request to the corresponding author. Authors contribution It is stated that, for the conception of the manuscript, the authors Marilia Jesus Batista and Carla Fabiana Tenani made substantial contributions, such as the design and elaboration of the work. The author Carla Fabiana Tenani performed the data acquisition. The authors Carla Fabiana Tenani, Manoelito Ferreira Silva Junior, Maria da Luz Rosário de Sousa and Marilia Jesus Batista analyzed and interpreted the data for the study. 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