Determination of The Level of Knowledge About Hpv Among Adolescents and Improvement of Vaccinationapproval Through Health Education In The Area of Trikala, Central Greece

Background: The aim of this study is to assess the importance of the role of the Health Education among young adolescents, regarding the level of knowledge about the HPV and the acceptance of the HPV vaccination, in order to increase the vaccination coverage, both in young adolescents and young teenagers in the area of Trikala, in Central Greece. Methods: The methodological tools of the study were questionnaires. The completion of the questionnaires was gained after the informed and written consent of the parents – guardians. Ethical approval was obtained of the Ministry of Education, Research and Religions. Students of the 1st Gymnasium, randomly chosen by drawing among all school groups of the area. In the rst phase of the study, the questionnaires were completed by the entire study population. During the second and third phases, the completion of the questionnaires concerned the population under study, immediately after the interactive seminar and three months later, respectively. The IBM SPSS 20.0 statistical program was used for analyzing the data and extracting the results. Results: A total of 434 female students, who met the criteria for participation in the study, completed the questionnaire (response rate 76.26%). Most participants (66.6%) were girls. From the nal analysis of the results we observed a rapid change in the level of awareness about the HPV virus, between the three phases of the study. The percentage of the participants who stated that they "do not know" what HPV is, decreased from 44.4%, before the informative interactive intervention in students (rst phase), to1.6% and 8.1%immediately after the intervention (second phase) and 3 months later (third phase), respectively. Similarly, the willingness of young students to be vaccinated against the HPV was increased from 71% during the rst phase of the study, to 89.1% and 83.5% after the second and third phases, respectively. Conclusion: Young teens are poorly informed about the HPV and HPV vaccination. However, with the use of targeted interactive informational interventions in the school environment, a statistically signicant increase in both the level knowledge HPV recorded, well

protocol. The study included students from seven school complexes in the Prefecture of Trikala, distributed as follows: four schools selected from the city of Trikala (urban school complexes), two schools from the province of Kalambaka in the Prefecture of Trikala (rural school complexes) and the only private school existing in the prefecture. Out of 573 questionnaires given to students, 136 returned uncompleted (76.26% response rate).The largest response was observed in the Private High School (95%), while the 4thGymnasium of Trikala and the 1st Gymnasium of Kalampaka were those with the lowest participation rates, 68.1% and 68.1%, respectively (Table 1). Table 1 Response rate of the students of the 1st Grade of the school groups that were included in the study. The four urban school complexes were categorized into two groups (2schools in each group): one school was the interventional sample of the studied population and the other, in the same area of the city, was the control one (not the interventional sample of the studied population). Concerning the urban school group, the rst -grade students of the 1st and 3rd Gymnasium of Trikala, constituted the studied interventional population. The 4th and the 9th Gymnasium of Trikala were the control sample of the studied population. The selection of the school complexes that constituted the studied interventional population was made randomly by drawing lots. Similarly, in the rural school groupof the province of Kalambaka, the 1st Gymnasium of Kalampaka was the sample of intervention and the 2nd Gymnasium of Kalampaka was the sample of control of the studied population. Regarding, the Private Gymnasium, half of the 1st Grade students constituted the interventional sample and the other half were the noninterventional one (control sample) of the studied population (Table 2).

Questionnaire of the Study
The methodological tool of the study was a questionnaire. The questionnaire was chosen after a systematic bibliographic review of studies, with a similar research question. The questionnaire has been previously published and the license to use it was obtained after contacting the editorial team [15]. The editorial team approved the use of the English -language questionnaire. Subsequently, it was translated into Greek by two researchers, with an excellent knowledge of the English language and relevant knowledge of HPV vaccines and health education. Adopting the questionnaire in Greek Health Educational System some questions were removed while others were added. In order to test the clarity of the questions, a preliminary survey was initially conducted, based on the results of which the validity was fully checked and then the questionnaire received its nal form.
Criteria for selecting the questionnaire of the study were the limited possible number of questions and the focus on topics related to the HPV, HPV vaccination and cervical cancer. Its nal form consisted of 52 closed -ended questions, which were divided into four main sections. In the rst and second sections were included school data and student demographics, respectively. The third section included students' knowledge, attitude, and behavior toward HPV infection and the awareness of the relationship between the virus and cervical cancer. The fourth section included students' knowledge, attitude, and behavior toward HPV vaccination and cervical cancer. The data collected from the questionnaire were anonymized. No personal data was collected.

Study Schedule
The survey was conducted during the academic year 2018-2019. The time period for the study was from January 2019 to May of the same year. The completion of the questionnaires and the informational lectures to the students, were taking place during the working days and hours. The duration of the students' brie ng did not exceed forty -ve minutes -that is of, -one teaching hour. The research was divided into three phases ( Table 2). During the rst phase, the questionnaire was completed by the entire study population (intervention group and control group). Two weeks later (second phase), the information of the students included in the studied interventional population have been taken place, concerning the HPV and the value of the vaccination against it. The informational lectures that took place in the school amphitheater included the electronic presentation of the knowledge about the HPV, the HPV vaccination and their importance nowadays. The completion of the questionnaire by the students who constituted the studied interventional population, took place at the end of the seminar. Three months after the end of the seminars, the study was accomplished with the completion of the questionnaire, for the third time (third phase), by the students of the interventional group.

Data collection
The collection of the questionnaires, as well as the informative sessions, have been carried out by the author of the study. Principal of the schools gave permission to offer the seminar without compromising the operation of the school curriculum. The data collection was performed in conjunction with the method of recording information by the participants. Prior to the completion of the questionnaire, the written consent of the parents and guardians was obtained, after explaining the purpose and process of the research study, which allowed the voluntary participation of young students in the research.

Data Statistics
The IBM SPSS (Statistical Package for the Social Sciences) 20.0 statistical program, acquired by IBM, was used to analyze the sample data. Using the descriptive methods, we analyzed the sample by taking measurements of the frequency of responses to all questions. Through this process we received information about demographic characteristics, awareness about the HPV and its vaccination, as well as the willingness or unwillingness of participants to be vaccinated against the HPV.
Pearson X 2 statistical test, evaluated the possible dependence between questionnaire variables and students' knowledge status and behavior towards the HPV. The results between the three phases of the study were compared, both with the analysis of the tables obtained from the extraction of descriptive measures, and with the use of the statistical Paired t -test for dependent samples, in the 95% con dence interval. Through these we received the necessary information to enhance students' awareness and behavior about the HPV and the vaccination against cervical cancer. Statistically signi cant was considered the sample with p -value = 0.005.

General characteristics
A number of 434 students who met the criteria for participation in the study, lled the questionnaire, 289 (66.6%) of which were girls and 145 (33.4%) were boys. The vast majority of participants (95.6%) were of Greek nationality. 3% were Albanian, while only 1.4% of the participants were of another nationality.
Similarly, almost all of the participants (97.2%) were Orthodox Christians, 0.9% were Catholics, while 1.8% were of another religion. Of the 434 students surveyed, regarding their place of residence, 181 (41.7%) were living in a large city, 185 (42.6%) in a small town and the remaining 68 (15.7%) had a permanent residence in a village. Regarding the marital status of the parents of the participants, the vast majority of the sample (94.9%) indicated that their parents were married.12.2% of the sample had a low monthly family income, while 64.7% of the participants stated that the monthly family income was medium and the remaining 90 (22.8%) responded that the monthly family income was high. Overall, the general demographic characteristics of the study population are summarized in Table 3. In the main part of our research study we analyzed the data only from the students of the schools in which the informative actions took place -intervention schools (n = 248). In the studied interventional population, a number of two informative seminars have been carried out, which followed the rst grant of the questionnaire. In this process, we tried to assess whether Health Education through informative interactive intervention in the school community, in uenced the young adolescent students' knowledge about the HPV and their views on whether or not they were willing to accept a vaccination against the cervical cancer.

Knowledge about HPV
The analysis of the data revealed that no statistically signi cant difference was observed in the level of knowledge about the HPV, based on the sex of the participants ("I Don't Know" -Male 40.7%, Female 46.5%, p = 0.466). On the other hand, a statistically signi cant difference was observed between the levels of students' annual family income ("I Don't Know" -High 18.6%, Medium 40.4%, Low 93%, p = 0.00), their nationality ("I Don't Know" -Greek 43.3%, Albanian 0%, Another 100%, p = 0.00) and the different residential areas of the participants ("I Don't Know" -Big City 48.5%, Small Town 16.9%, Village 84.6%, p = 0.00).Typically, students who stated that they come from high-income families, have higher rates of knowledge about the HPV. Similarly, increased levels of knowledge about the virus were noticed among participants of Greek origin, compared to Albanians or other nationalities, as well as in those living in urban centers compared to those living in villages (Table 4).

Willingness for HPV vaccination
Analysis of the data of our research (Table 5) showed that there is a statistically signi cant difference in the rates of vaccination willingness against HPV, based on gender ("Willing" -Male 62.6%, Female 75.8%, p = 0.028), the annual family income ("Willing" -High 78%, Medium 82.2%, Low 23.3%, p = 0.00) and the place of residence ("Willing" -Big City 76.5%, Small Town 80.5%, Village 33.3%, p = 0.00). It is worth noting that a much higher rate of willingness to vaccinate was observed among girls than boys. At the same time, students who stated that they come from high -income families, are more likely to be vaccinated, as well as students living in -urban areas, where the rate is statistically signi cantly higher compared to the ones coming from rural areas. No statistically signi cant difference was observed in the willingness rates for vaccination based on the nationality of the participants ("Willing" -Greek 70.4%, Albanian 50%, Another 100%, p = 0.233). According the nal analysis of the results it is observed a rapid change regarding the level of knowledge about the HPV between the three phases of the study: Phase 1: The percentage of participants who stated that "I don't know" what HPV is, was 44.4% (n = 110), while 52.4% of young adolescent students (n = 130) replied that it was a virus. In addition, 38.3% (n = 95) answered that sexual intercourse is the most common mode of transmission.
Phase 2: After the intervention, participants who stated "I don't know" what HPV is, decreased to 1.6% (n = 4), while 95.6% (n = 237) of those responded it was a virus. At the same time, 95.6% (n = 237) of the participants answered that sexual intercourse is the most common mode of transmission.
Phase 3: Three months after the intervention, participants who replied "I don't know" what HPV is, had a percentage of 8.1% (n = 20), while 88.3% (n = 219) stated that it is a virus. Furthermore, 86.3% (n = 214) of the participants indicated that the most common way of viral transmission, is the sexual intercourse (Graph 1 and Graph 2).
Moreover, a change in the responses of the studied population was noticed, regarding the willingness for HPV vaccination among young adolescent students (Fig. 3), although this rate was quite high during the rst phase of the study. Speci cally, in phase 1, willing to be vaccinated was the 71% (n = 176) of the sample, in phase 2 (immediately after the informative intervention) this percentage was risen to 89.1% (n = 221) and nally, in phase 3 (three months after the informative intervention) the willingness rate for HPV vaccination was 83.5% (n = 207).

Discussion
In our study, we ecorded young adolescents' level of awareness on HPV and its vaccination, was a cornerstone for the organization, modernization and implementation of primary preventive programs, including the vaccination against cervical cancer. The vaccination against the HPV may be proven to be the best strategic option, the above reduces the risk of developing the disease in the long run, and in long term the cost effectiveness to the country's health system. In fact, vaccinating girls at a young age, before the initiation of sexual activity, is preferred nowadays mainly for 2 reasons: First of all, at that time the young body has not yet been exposed to the virus and secondly, the immune response with antibody production is much greater at younger ages [16].

Sex
According the analysis of the data of the present study, it is indicated that the level of knowledge about the HPV and the vaccination against cervical cancer, is not statistically signi cant between the two genders. The hypothesis that girls are more aware on this issue than boys, is con rmed in most research studies. Durosoy et al attributed the fact that the majority of participants who were informed about the effects of HPV were women, to that the awareness campaigns were aimed mainly to girls and women and less to men and boys [17]. Similarly, Gerend and Magloire noticed that female students reported higher awareness and knowledge level about the HPV and its related diseases, than their classmates [18].
Furthermore, in a recent study, Tung and his colleagues revealed that female students had a higher level of knowledge and a more positive attitude towards the HPV, than male participants [19]. Similarly, Patel and his colleagues indicated that young adolescent women were more aware of the HPV and HPV vaccination than men. This nding probably re ects the fact that HPV is mainly considered a women's health issue and that most countries currently recommend the HPV vaccination only for women [14].
However, studies have shown that homosexual male adolescents have a higher level of knowledge about the HPV and the effects of HPV infection than the heterosexual ones, mainly attributed to the fact that the virus is also associated with the development of anal cancer [20,21].
Regarding the vaccination against the HPV, it is noticed that girls demonstrate a higher willingness on this matter than males. The above result is con rmed by many studies from the international literature. In 2015, Khurana and his colleagues indicated that the acceptance of cervical cancer vaccination among unvaccinated adolescent men, was much lower than in girls, emphasizing the importance of education in increasing the vaccination coverage among the male population [22]. Moreover, in a recently published systematic review, the increased acceptance of the HPV vaccines was mainly attributed to the greater willingness for vaccination against cervical cancer, by young adolescent women [23].

Place of residence
The present study revealed that the residence area of young adolescent students is strongly related to the level of knowledge about the HPV and their willingness to be vaccinated against cervical cancer. It is concluded that students living in urban centers, are more aware of the HPV and HPV vaccination than students living in rural areas. Students residing in a village tend to be unwilling to be vaccinated against cervical cancer.
The majority of scienti c studies that have investigated the HPV coincide with the above expected result, reinforcing the hypothesis that the level of knowledge about the virus and its vaccination, varies not only in different countries, but also among regions of the same country. Durusoy and his colleagues concluded that there is a wide range of behavioral approaches to the intention to vaccinate against the HPV among countries, with the Western ones demonstrating higher rates of acceptance of HPV vaccines, than the Easterns. The same study also indicated that participants from Turkey's western region, were more willing to be accepted and to be included in a preventive vaccination program, than the residents of the mainland [17].
Moreover, quite signi cant seems to be the variation in the level of knowledge about the HPV and HPV vaccination in European countries. A higher level of awareness is observed among Italian adolescence, approximately two years after the introduction of HPV vaccines [24], while the lowest level of knowledge is noticed in Sweden, three years before the implementation of the national vaccination program [25]. Studies from Hungary and the Netherlands have also been demonstrating a higher level of awareness about the HPV, compared to Germany, suggesting that the knowledge about the virus and HPV vaccination is a multifactorial issue, the solution of which seems not to be only the introduction of a national vaccination program, against cervical cancer [26,27,28,29,30].

Family income
According the results of our study, it is concluded that the annual family income is statistically signi cantly related to the level of knowledge about the HPV and the willingness to undergo vaccination.
It is noticed that the higher the family income, the higher the level of awareness about the HPV. Typically, students who state that their annual family income is low, are less likely to be vaccinated against the HPV virus.
The outcome of a study conducted by Durosoy and his colleagues is similar. The authors indicated that participants with a higher socioeconomic status were more likely to be vaccinated against the HPV, than the economically weaker counterparts [17]. Similarly, Mortensen in 2010 revealed that vaccination acceptance among adolescents, was associated with a higher level of education and higher socioeconomic status of their parents, without being able to pinpoint which of the two factors was the most important [31]. In 2016, Schülein and his colleagues found that the educational level of parents, was slightly most important factor than the socioeconomic level, in terms of acceptance of HPV vaccination [32].
In contrast, a recent study from Slovenia, aiming to determine the relationship between socioeconomic factors and cervical cancer vaccination, indicated that the lowest vaccination rates were not statistically signi cantly correlated with the lower average family income, nor was there any relationship between higher education ratios and the immunization rate of the participants in the study [33].

Family status
The marital status of the parents of the participants in this study was not statistically signi cantly related to the level of knowledge about the HPV and the willingness to be vaccinated against cervical cancer.
However, regardless of the marital status and the lack of correlation between the examined factors, a strong tendency to be vaccinated against the HPV among the participants was found.
Similarly, in a previous study aiming to determine whether parents would allow their children to be vaccinated against the HPV and which variables could in uence their decision, the authors concluded that marital status was not related statistically signi cantly with the acceptance of HPV vaccination [26]. In contrast, a recent study indicated that participants' family status, along with other socio-demographic factors, such as race, nationality, maternal education, health care provider composition, family income, and the age of the unvaccinated daughter, appear to be statistically signi cantly related to one or more factors identi ed as barriers to the decision to vaccinate against cervical cancer [34].

Nationality
The analysis of the data of our study revealed that nationality is statistically signi cantly related to the level of knowledge about the HPV and the willingness to vaccinate. Greeks appear to be much more informed about the virus, than students of Albanian or other nationalities. However, it is necessary to point out the observed disproportion of nationalities among the participants, as 95.6% are of Greek nationality, which does not allow us to assess the result excellently and with great accuracy.
Similarly, a study from Italy indicated lower vaccination coverage rates against the HPV in foreigners, compared to Italian citizens [35]. Furthermore, other studies involving female adolescents of national minorities from degraded areas, found that the rates of HPV vaccination were lower compared to those of privileged ones [36,37]. In contrast, a recent Canadian population study found that school vaccination programs can lead to higher vaccination coverage rates, even in areas inhabited by a larger percentage of national minorities [38].
Health Education as a means of improving the knowledge level about the HPV and the vaccination willingness.
In an effort to approach and interpret the main outcomes of this research study, it appears that through Health Education, using targeted informative intervention, a statistically signi cant increase in both the level of knowledge about the HPV and the infection caused by it, is recorded, as well as to the adolescents' willingness to be vaccinated against HPV and cervical cancer.
Furthermore, towards the same research axis and direction is the publication of a systematic bibliographic review by our research team. The conclusion we have drawn, is that adolescents are not su ciently informed about the HPV and the HPV preventive vaccination. In order to improve the level of knowledge about the virus and the consequences of HPV infection, is mandatory to provide information through the framework of compulsory education, primary health care and the development of informative interactive interventions. The knowledge and receptive susceptibility to HPV infection and to HPV-related health issues, demonstrate the urgent need for a well-designed training program nowadays, in order to bridge the gap between HPV awareness and vaccine acceptance [39].
Previous studies have also indicated that informing young women, is an important factor in shaping positive thinking and perception towards the vaccination against HPV [17,20,40]. In 2014, Lee and his colleagues highlighted the role of school environment, which should provide young teens with more information about the prevention of cervical cancer, while enhancing the health education. The purpose of the above is the proper information of the students, concerning the severity of the disease, in order to be achieved higher rates of participation in a vaccination program against cervical cancer [40].
On the other hand, it has beenindicatedby other studies, that the participation and completion of a preventive HPV vaccination program is not directly correlated to the level of awareness of vaccinated women. Based on the results of other studies, it was concluded that women who were vaccinated against cervical cancer did not have a higher level of knowledge about the HPV, than the non-vaccinated ones, although it would be expected that vaccinated women would have received at least basic information on the virus and its implications [41,42]. Similarly, Fishman and his colleagues noticed that neither parental nor adolescent HPV knowledge was related to future adolescent vaccination, as some participants with a low level of awareness about the HPV and its preventive vaccination, eventually completed the prophylactic vaccination program, whereas, in contrast, individuals who initially demonstrated high levels of knowledge, were eventually not vaccinated against HPV and cervical cancer [43].

Conclusions
Young adolescent students are poorly informed about the HPV and HPV vaccination, which can be a signi cant obstacle to the necessary increase in the vaccination coverage of the population. The use of interactive lecturing interventions to young adolescent students in the school environment, could contribute statistically signi cantly to the increase in both the level of knowledge about the HPV and the infection caused by it, as well as in the willingness of participants to be vaccinated against the HPV and cervical cancer.
At the same time, the implementation of Health Education programs in schools, under the responsibility of the State, can be an important measure in an effort to reduce the incidence of cervical cancer. Sex education of young girls and boys in order to gain a good amount of knowledge concerning issues such as sex life, family planning, proper use and effectiveness of contraceptive methods and good hygiene, reduces the exposure of the population to predisposing risk factors for developing HPV. the study was explained to the parents -guardians of the minor students, who were asked for the signed consent, in order for the students to participate in the study. The study participants were informed that they are free to participate. The collected data were kept con dential in compliance to established Human Subject Protection guidelines.

Consent for publication
Not applicable.