1. Theoretical framework

Preventive care is related to primary and secondary health prevention. For ^{Stanhope et al. (2011}), in primary prevention, interventions are oriented toward health promotion and disease prevention, using actions that enable people to act and manage health determinants, either in the field of environmental protection, or in the specific protection, while secondary prevention aims at interventions that increase the probability of an early diagnosis of diseases, using, for example, screening.

Health intervention, especially at the primary prevention level, is not exclusive to health services and professionals, although they have increased responsibility.

Health is essential to human life, giving rise to well-being, ability to work and personal happiness (^{Ferreira & Gonçalves 2015}). The “Ordem dos Enfermeiros” (OE) also advocates that health is a state, but also the mental representation that each person has of their condition, associated with the control of suffering, the perception of physical well-being and emotional and spiritual comfort. Being a dynamic and continuous process, everyone wants to reach a state of balance in these different domains (^{OE, 2002}).

Vaccination is one of the most effective health promotion and disease prevention measures, either by controlling or eliminating diseases at a low cost, overcoming the costs associated with treatment and complications related to the disease is a right of citizens in Portugal. The flu vaccination is recommended for people aged ≥ 65 years and other vulnerable groups and should be administered in the autumn or until the end of each calendar year (^{Direção Geral da Saúde [ DGS, 2019]}).

Screening has also low costs, being mainly recommended for diseases with a high prevalence and subject to early detection and appropriate treatment, with guidelines for the ages/groups in which they are most recommended (^{Stanhope & Lancanter, 2011}). In Portugal, the DGS (²⁰¹¹, ²⁰¹⁴, ²⁰¹⁵, ²⁰¹⁷) issued guidelines for screenings associated to preventing arterial hypertension, diabetes, dyslipidemia in adults and oncological diseases.

Analyzing the data for the triennium 2012-2014, we found out that found that the proportional mortality by large groups of death causes, both at the national level and the level of ARS Norte, for all ages and both sexes, showed decreasing rates in diseases of the circulatory and digestive system, in malignant tumours and endocrine diseases, among others with less expressiveness (^{ARS Norte, 2018}).

In this context, the interest came up in this study, which aims to analyze how this population adheres to a health surveillance program, namely through vaccination, blood pressure (BP) and blood glucose and screening for breast, colon and prostate and cervix.

2. Methods

The present study is part of the descriptive, observational and transversal type quantitative paradigm. Concerning the sample, and given the impossibility of studying the entire population of a municipality in the district of Viana do Castelo, due to limited time for the study and difficulty inaccessibility to the participants, a partnership was established between the Escola Superior de Saúde de Viana do Castelo and the municipality, selected by the autarchy, representative parishes of the geographic diversity and also of demographic characteristics. The sample size was calculated for a prevalence study, assuming a tolerable error of 4% and a confidence interval of 95%. The initial sample was stratified, proportionally, by parish, according to the resident population, an option that could not be ensured during data collection, as it was not possible to maintain the number of surveys foreseen by the parish, leading to underrepresentation in some parishes and an over-representation in others.

The Kish method was supposed to be used for the selection of sampling units. However, it was impossible to apply the surveys to households, as these are predominantly rural parishes with dispersed dwellings, and data collection was carried out at the headquarters of parish councils and other places with concentration of people, having to opt for an accidental sampling technique. For the recruitment of the people to be surveyed, we counted with the collaboration of elements of the parish councils, who were asked to select according to the number of inquiries per parish, by sex and by age. However, it was observed that the distribution was not proportional according to sex and age group, and the sample was weighted according to these variables.

Thus, the sample consisted of 567 participants, 311 females and 256 males, aged between 15 and 94 years.

We used a questionnaire adapted from the IV National Health Survey (NHS), (^{Instituto Nacional de Estatística, Dr. Ricardo Jorge [INE, 2016]}) for data collection. The data from this study refer to Section 7 of the questionnaire - Preventive Care - consisting of 24 questions with several response options that aim to assess people's adherence to preventive care, encompassing not only its practice but also the frequency and reason by which they perform.

Each group of questions had specific inclusion criteria. For this study, we considered an inclusion criteria, to be the participant to answer all questions. Thus, the first eleven questions and the last two were intended for all people aged ≥15 years. Questions regarding mammography and cervical-vaginal cytology were addressed to women aged ≥20 years. The colon and rectal cancer screening questions were aimed at men and women aged ≥50 years. The prostate cancer screening questions were only asked for men aged 50 and over. General questions were addressed to all participants.

The survey was carried on by a group of 4th year Nursing degree students, by interview, in an average time of 30 minutes, during November 2019.

The ethical principles and rights of the participants were safeguarded either through the guarantee of anonymity and confidentiality of the data or the freedom to accept or not to collaborate in the study without any prejudice to the non-acceptance. In order to guarantee the principle of free and informed consent, the objective and purposes of the study were also explained, validating together with the participants if they had understood everything or if there was any doubt.

Descriptive statistics were used to process the data, with distribution, location, and dispersion measures. The Statistical Package for the Social Sciences (SPSS) version 20 was used.

3. Results

The sample was mostly female (n= 349; 54.7%), predominantly aged 25-64 years (61.6%). About half of them had completed basic education (50.8%), 97.9% had a family doctor, and 67.7% had had a health surveillance consultation in the last year. Regarding access to health services, 92.6% of the interviewees said they did not experience any difficulties; the constraints pointed out by the others were related to distance, waiting time, the transport network and timetable. It should be noted that the transport network was most mentioned by the elderly while waiting time and distance were the constraints most mentioned by all participants.

The influenza vaccine is administered annually, considering the variability of strains (DGS, 2019). As shown in Table 1, most respondents reported never having been vaccinated against influenza (64.6%). Of the people who claimed to have been vaccinated, it was in 2019 that the highest percentage (57.3%) was aged 65 years or over. A medical indication was the most mentioned reason for vaccination (64.2%), followed by advice from nurses (26%).

It was found (Table 2) that almost all people have evaluated the ED at some point in their lives (96.1%), and most have evaluated the ED for less than three months (68.6%). Concerning the cholesterol assessment, most had already performed the analysis (92.9%). Furthermore, their assessment prevails for less than a year in 74.4% of the participants and less than three months for 40.8%. Regarding blood glucose monitoring, 85.6% of them had already evaluated it, and the majority (45.2%) reported having evaluated it less than three months ago.

The most common reason for evaluating these three parameters was routine (TA 75.2% and cholesterol 82.7%) and glycemia for presenting complaints (84.7%). It was also found that the assessment of BP and cholesterol were more frequent among adults and the elderly.

One of the most frequent screenings is for breast cancer, using mammography, and for cervical cancer, using cervical-vaginal cytology. For this evaluation, women aged between 20 and 94 years were included, with an average of 53.88 years.

Regarding mammography, the age variable was operationalized according to the recommendations of DGS Norm 051/2011. The results revealed that in all women (n=311), 69.5% had already had a mammogram. It should be noted that 30.5% had never taken this exam. The majority of women who underwent this examination were aged from 50 to 69 years, and 81.4% of women underwent it two or less years ago. Cervicovaginal cytology was performed by most women (82.8%), mainly between 30 and 65 years old (81.6%). Of the total number of women (n=311), 75.3% underwent the examination less than three years ago, and 92% were less than 30 years old. Of the women over 30 years old, 82.7% had this screening for less than five years. The scaling of ages was operationalized according to the Portuguese Society of Gynecology (2014) recommendations.

These two screenings were mainly routine (mammography 82.4%; cytology 87.3%); the second reason was screening for disease (mammography 12.9% and cytology 10.6%) (Table 3).

Two tests perform colon cancer screening: colonoscopy and faecal occult blood test, recommended for both sexes, from 50 on. Thus, 295 people of both sexes were surveyed, aged between 50 and 94 years (DGS, Norm nº 003/2014), with an average age of 66.5 years. The occult blood test was the most frequent method, being mentioned by 60.4% of respondents, and of these, 79.6% mentioned having performed the test 2 years ago or less, with the predominant age group being between 50 and 74 years (84%). Colonoscopy was performed by 55.9%, with a predominance in the group from 50 to 74 years old (77%), in which 94.5% of them said they had performed this exam ten or less years ago. 75.3 % of the reasons for carrying it out were routine, while 19% for disease screening and 3.2% for disease control.

Prostate cancer screening is performed by prostatic examination, digital rectal examination, and Prostate Specific Antigen (PSA) test is indicated from 50 on, so the questions were addressed to men aged 50 and over (DGS, 2017). PSA was evaluated by 65.9% of men and prostate examination by 56.8 %, with a higher prevalence from 50 to 75 years old (86.9%), and of these, 57.1% performed this screening for less than two years.

Regarding the need for prostate examination, the majority reported it routinely (78.5%), followed by screening for the disease (15.1%), with 5.4% still reporting disease control, similar to the reasons for PSA assessment (Table 3).

4. Discussion

Based on the results obtained, the sample is predominantly female, with low education and ages between 25-64 years, in line with the data from the last Census (2021).

The surveyed population revealed excellent accessibility to health services. The majority reported having a health surveillance consultation in 2019, which may imply that they are aware of the importance of self-responsibility in preventing, protecting, and promoting their own health. Several factors may contribute to these results, such as the educational interventions of health professionals from local and other units, as well as the media, social networks, and informal support.

Difficulties in accessing care are few relate mostly to waiting time service and distance. Older people probably use the public transport network the most, and refer its inadequate adaptation to their needs. Accessibility could be optimized, for example, by creating mobile units. However, operationally, there is a need for better knowledge of the available human and material resources and a cost-benefit assessment.

According to the results of the survey, vaccination rate was low, which may be explained by the time of data collection (1st fortnight of November) and the predominance of people aged between 25 and 64 in the sample, with the vaccine, recommended mainly in priority groups, aged 65 years or older, chronically ill, and immunocompromised and other at-risk groups (Portugal, 2019). During data collection, it was also possible to perceive that the advantages of this vaccine are still not very clear to most respondents, which, in turn, may affect adherence to it. Thus, a more significant investment is required of health professionals in terms of health promotion and education regarding the importance of this prophylatic for influenza, as well as the risk that the disease entails. Tones and Tilford (1994), cited by ^{Carvalho & Carvalho (2006}), refer to health education as a planned professional activity that facilitates learning related to health and illness, and which is expected to produce changes in knowledge understanding and ways of thinking about others.

Considering the chronic illnesses, with the highest prevalence at the national level which include those, associated with Arterial Hypertension (HTA), hypercholesterolemia (DGS, 2015) and hyperglycemia high adherence was observed, in the assessment/monitoring of BP, cholesterol and blood glucose, and this level was higher than that observed at the national level (INE, 2016), with health surveillance being the main rationale given. It should be noted that hypertension is the most closely monitored risk factor, as shown by the percentage presented. The greater adherence to the assessment of AT may result from the fact that it is a non-invasive measure and performed routinely in health consultations, at the pharmacy or even at home, while other monitoring implies more invasive procedures, such as clinical analyzes and other screenings. It should be noted that the percentage of people who evaluated the AT in the last year is higher than that presented in the National Health Survey (NHS) of 2014 (^{INE, 2016}) by around 10%. According to this survey, 2.2 million people (25.3%) reported having hypertension, which represents an increase of 23.4% compared to 2005/2006. The portrait of Health (Portugal, 2018) confirms this trend, noting that hypertension affects 36% of the Portuguese from the age of 25 to 74, and cerebrovascular diseases accounted for 29.7% of deaths in 2015 in Portugal.

Hyperglycemia is one of the leading causes of diabetes which, according to data published in 2018, affected 10% of the Portuguese population aged from to 74, especially in older age groups (Portugal, 2018). The concern of individuals and health professionals is related to the fact that this disease has a growing prevalence. According to the Portuguese Society of Diabetology (2016), by 2040, one in 10 adults will have diabetes. For these same reasons, it is essential to invest in the prevention of modifiable risk factors to reverse the increasing trend of this health problem that causes high morbidity and mortality. On the one hand, in people with diabetes, the blood glucose assessment is a means of monitoring the disease, allowing the analysis of the variation in blood glucose levels, also understanding whether they adopt healthier lifestyle habits and/or if changes in pharmacological treatment are required. On the other hand, even in people without this pathology, periodic monitoring is essential since changes in glucose metabolism, or other factors may increase the levels in the blood.

It should be noted that 17.2%, 10.1% and 9.3% of respondents monitored, respectively, BP, cholesterol and blood glucose for disease control. In this sense, it is essential, in addition to pharmacological measures, health promotion and educational interventions aimed at physical activity, healthy eating and obesity prevention.

Cancer is one of the leading causes of death, representing the second leading cause in Portugal (Portugal, 2018). In oncological disease screenings, the analysis followed national and international recommendations regarding the age when the respective screening exams began, with high adherence to cervical-vaginal cytology (82.8%), higher than the one observed in the NHS, which was 70.7% (INE, 2016), and lower concerning mammography (69.5%), being lower than the national results of 2014 (84.2%). It should be noted that the majority of women who underwent mammography were in the 50 to 69 age group, strongly recommended, having performed the exam less than two years ago, data overlapping with those of the NHS, reporting that 84.2% of women, in this age group, they underwent a mammogram in the two years prior to the interview (INE, 2016). Given that there are still no effective measures to prevent or cure breast cancer and that more than 90% of women with this pathology can be cured if diagnosed at an early stage, this screening can be a very effective measure (DGS, 2011). A significant part of this sample (n=96; 31%) underwent mammography before the age of 50, age and younger than that recommended by the DGS, probably due to morphological changes and/or presenting symptoms (DGS, 2011). It is also crucial to mention that a significant percentage of the sample has never undergone this test (29.1%), which may correspond to women with ages marginal to those recommended to undergo the test.

In colorectal cancer screening, faecal occult blood tests and a colonoscopy were performed by more than half of the respondents and for the majority, two years or less than ten years before, respectively, mainly for routine examination. The rate of adherence to colonoscopy in the ten years prior to the survey is higher than the national results of the NHS (INE, 2016), which was 35.1%.

Regarding screening for prostate cancer, the percentage of PSA tests was higher than that of digital rectal examination. This discrepancy may be related to the fact that the latter is a more invasive test, physically and psychologically than the PSA test based on blood analysis. Digital rectal examination is still a taboo subject for some men, which was also observed during the surveys due to the discomfort caused by the questions in some interviewees. More than half had a digital rectal screening; however, only about 1/3 of men had it less than three years ago. Compared to the results obtained in the NHS 2014, the percentage of completion of the PSA is similar (66.6%). However, comparing the rate of digital rectal examination in the present study (57.1%) it appears to be higher than that observed in the NHS 2014, which was 32.1% (INE, 2016).