Abstract
Background:
Cervical cancer is the second most common female cancer in Ghana. Cervical cancer is preventable through knowledge, vaccination against the human papillomavirus (HPV), screening and treatment of precancerous lesions.
Objective:
This study aimed to assess the determinants of cervical cancer knowledge and barriers to HPV vaccine uptake among female university students in Ghana.
Design:
An anonymous, online cross-sectional study was conducted from 25 June to 22 September 2024.
Methods:
The survey contained questions on demographic characteristics, cervical cancer risk factors, symptoms, HPV vaccination and barriers to vaccine uptake. Binomial logistic regression analysis was performed to predict the factors associated with knowledge of cervical cancer. A p-value of less than 0.05 was considered statistically significant.
Results:
A total of 1662 female university students responded to the online survey. The mean age of the respondents was 21.5 ± 2.03 years. Overall, the prevalence of inadequate knowledge of cervical cancer was 60.2%. The least recognised cervical cancer symptom was blood in the stool or urine (58.4%). Respondents who had a steady partner and living together had 3.59 times higher odds of inadequate knowledge of cervical cancer compared to respondents who were not dating. Muslim respondents had 2.13 times higher odds of inadequate knowledge of cervical cancer compared to Christian. Unvaccinated respondents had 3.85 times higher odds of inadequate knowledge of cervical cancer compared to those who had received the HPV vaccine. More than four-fifths (87.0%) of the respondents indicated that they had not been vaccinated against HPV. The major barriers to HPV vaccine uptake included: inadequate knowledge of the vaccine, fear of side effects, lack of knowledge about the vaccination site, fear of injection and doubts regarding the vaccine’s efficacy.
Conclusion:
Improving access to cervical cancer awareness and HPV vaccination among university students is a critical public health goal to reduce the incidence of cervical cancer. It is important to promote a free national school-based HPV vaccination programme. Multi-component school-based educational interventions, including traditional methods such as lectures, group discussions and digital tools like web-based educational platforms should be implemented to improve cervical cancer knowledge among university students.
Introduction
Globally, cervical cancer is the fourth most common female cancer, with 662,301 new cases (annual age-standardised incidence rate of 14.12 per 100,000 women) and 348,874 deaths (age-standardised mortality rate of 7.08 per 100,000 women) in 2022. 1 Low- and middle-income countries (LMICs) face higher cervical cancer incidence and mortality rates, which is mainly due to lack of access to human papillomavirus (HPV) vaccination, screening, diagnostic and treatment services as well as other socio-economic determinants. 2 In Ghana, cervical cancer is the second most common cancer in women after breast cancer. In 2022, it was estimated that 3072 Ghanaian women were diagnosed with cervical cancer (annual age-standardised incidence rate of 29.3 per 100,000 women) and 1815 died from it (age-standardised mortality rate of 27.6 per 100,000 women). 1
In 2020, the World Health Organization developed the 90-70-90 global strategy to eliminate cervical cancer by 2030. This means that 90% of girls should be fully vaccinated with the HPV vaccine by the age of 15, 70% of women screened at ages 35 and 45, 90% of women with pre-cancer treated and 90% of women with invasive cancer managed. 3 Like many African countries, Ghana does not have national cervical cancer awareness, screening and HPV vaccination programmes. 4 Most cervical cancer screenings are opportunistic screenings. Also, few private and public hospitals have implemented HPV vaccination services in their reproductive health programmes. 5
Multiple epidemiological studies have identified several risk factors that contribute to the development of cervical cancer.6–9 These risk factors include HPV infection, weakened immune system, family history of cervical cancer, cigarette smoking, long-term use of oral contraceptives, sexual intercourse earlier than 18 years, multiple sexual partners, multiparity, menopause earlier than 45 years and low socio-economic status.8,10,11 Cervical cancer is preventable through HPV vaccination. However, several barriers to the uptake of the HPV vaccines in Africa have been reported in the literature, including high cost of vaccine procurement, misinformation about vaccine side effects and safety, inadequate infrastructure for vaccine cold chain storage and transport, limited access to vaccines in rural areas, fear of pain related to vaccine injections, lack of information on available vaccination services and mistrust in vaccination programmes.12,13 Additional barriers include cultural beliefs about sexual activity and limited knowledge of cervical cancer and HPV among women, including female students.12,14
It is essential for female university students to receive quality information about cervical cancer, the role of screening, early detection, HPV and vaccination services for primary prevention to be realised through behavioural change. Studies from diverse countries have shown differences in female students’ levels of knowledge, awareness and attitudes towards cervical cancer and its prevention.15–19 For example, in a cross-sectional study among 667 female students in Ethiopia, 39.4% confirmed that they had not heard of cervical cancer, while 97.8% had never been screened for cervical cancer. 20 Another cross-sectional study conducted among 234 female undergraduate students in Nigeria revealed poor knowledge of cervical cancer and its prevention (77.4%). 21 A similar poor level of knowledge among 373 female university students towards cervical cancer, HPV and prevention in South Africa has been reported in a previous study. 22 Factors such as gender, religion, marital status, year of study, programme of study and HPV vaccination status have been identified as determinants of cervical cancer knowledge and uptake of screening.23–25
In Ghana, studies on female university students’ knowledge of cervical cancer and its determinants are limited.26–28 It is important to focus on university students because they represent the future workforce leaders, with knowledge and skills in technology, management and healthcare necessary for societal and economic growth. One cross-sectional study conducted in 2016 among 410 female university students revealed that 82.4% and 31% of the students were not familiar with cervical cancer symptoms and risk factors, respectively. 26 Almost a decade later, data related to cervical cancer knowledge remains scarce, reducing opportunities to develop evidence-based awareness activities. Therefore, the aim of this study was to assess the determinants of cervical cancer knowledge and barriers to HPV vaccine uptake among female university students in Ghana.
Methods
Study design
An anonymous, online cross-sectional study was conducted from 25 June to 22 September 2024. The study was reported in accordance with Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines (see Supplemental File 1). 29
Study setting
This study was carried out in one of the largest universities in Ghana located in Kumasi, which is the capital city of the Ashanti Region of Ghana. There are six colleges within the university, namely the College of Agriculture and Natural Resources, College of Art and Built Environment, College of Humanities and Social Sciences, College of Engineering, College of Health Sciences and College of Science. These colleges offer a range of undergraduate and graduate degree programmes. The student population of the university is estimated to be 85,276 with 34,421 females representing 40.36%. 30
Respondents and recruitment
The inclusion criteria for the study respondents were all female university students in their first, second, third and fourth year of study and those aged 18 years and above. Female university students who were not willing to provide consent to participate in the study were excluded. Purposive and snowball sampling strategies were adopted to maximise the recruitment of respondents and provide a more comprehensive approach to the study. Information about the study was shared on students’ social media platforms. Hence, recruitment started on social media platform and was followed by word of mouth.
Sample size
Slovin’s formula, n = N/(1 + Ne2), was used to estimate the sample size for the study, 31 where n represents the sample size, N is the total student female population of 34,421 and e is the margin of error, estimated at 5% for this study. The sample size for the study was estimated to be 395. After adjusting for a non-response rate, the final estimated sample size was 1662.
Variables
The main outcome variables were knowledge of cervical cancer risk factors, knowledge of cervical cancer symptoms, understanding of HPV and determinants of cervical cancer knowledge. The secondary outcome variables were the prevalence of HPV vaccine uptake and barriers to its uptake.
Covariates
To address the effect of potential confounding factors, considered covariates included age, religion, college and years of study, relationship status and sexual activity. Age was categorised as ‘18–22 years’, ‘23–27 years’ and ‘more than 28 years’. The age range ‘18–22 years’ was selected as the starting age group because it is generally defined as young adulthood. 32 The respondents in each selected age category share similar experiences, which allowed for comparable data analysis. Sexual activity was categorised as ‘no’, ‘yes’ and ‘prefer not to say’. Religion was categorised as ‘Christian’, ‘Muslim’ and ‘Traditional beliefs’. Years of study was categorised as ‘first year’, ‘second year’, ‘third year’ and ‘fourth year’. Relationship status was categorised as ‘dating with no steady partner’, ‘steady partner and living together’, ‘steady partner but not living together’ and ‘not dating’.
Questionnaire and data collection
A structured online questionnaire was used as the data collection tool for this study. The University College London Health Behaviour Research Centre, the Department of Health Cancer Team and the Eve Appeal validated cervical cancer awareness questionnaire was adapted for this study (see Supplemental File 2). 33 For example, the question ‘In the next year, who is most likely to develop cervical cancer in the UK?’ was removed from the final questionnaire. The psychometric evaluation of the cervical cancer awareness questionnaire indicates that it has satisfactory internal reliability with Cronbach’s alphas above 0.7 for all components. Test–retest reliability was found to be good, with all correlations above 0.7. 33 The questionnaire was developed and administered using Google Forms and was provided in English language. The questionnaire comprised of seven sections. Section A collected information on respondents’ demographic characteristics. Section B investigated students’ knowledge of the warning signs and symptoms of cervical cancer. Section C assessed students’ knowledge of the risk factors of cervical cancer. Section D probed students’ knowledge of HPV infection. Section E assessed students’ confidence in detecting cervical cancer symptoms. Section F identified students’ awareness of the HPV vaccination programme and their acceptance of the vaccine. Section G addressed barriers to the uptake of the HPV vaccine among female university students.
The data collection was conducted electronically. The survey was designed to be responsive and compatible with various devices, including smartphones, tablets and computers, to ensure ease of access for respondents. There was no financial compensation to participate in this study. The online survey was completed anonymously, with an electronic informed consent form signed by all respondents at the commencement of the electronic questionnaire. The first page of the online questionnaire included all required details regarding the study’s aim, confidentiality of information and the right to refuse or withdraw from the study. The link to the questionnaire was shared on students’ social media platforms. Reminder messages were sent after the first, second, third and fourth weeks of the initial invitation. The survey closed 2 weeks after the final reminder. It took 3–5 min to complete the online questionnaire. To maintain data security, the survey responses were stored on a password-protected Google Drive account accessible only to the research team. The study was approved by the Kwame Nkrumah University of Science and Technology Committee on Human Research, Publication and Ethics (CHRPE/AP/499/24).
Data analysis
Descriptive analyses were conducted to obtain the frequencies of respondents’ demographic and outcome variables. Knowledge of cervical cancer symptoms was assessed using a 10-point scale, with each incorrect response scored as 1 and correct as 2. Knowledge of cervical cancer risk factors was assessed by a 12-point scale. Similarly, each incorrect response was scored as 1 and correct as 2. A cut-off score of equal to or greater than 50% was considered adequate knowledge. 34 Binomial logistic regression analysis was performed to predict the association between outcome and demographic variables. The associations were reported as crude odds ratios (ORs) with a 95% confidence interval (CI). A p-value of less than 0.05 was considered statistically significant. Missing values were treated as truly missing. All statistical analyses were performed using Jamovi 2.5.6.
Results
Demographic characteristics of the respondents
Table 1 summarises the characteristics of the respondents. A total of 1662 female university students responded to the online survey. In total, 71% (n = 1180) of the respondents were less than 23 years old, with a mean age of 21.5 ± 2.03 years. Among the respondents, 84.4% (n = 1403) identified as Christians and 45.4% (n = 755) were sexually active; however, 49.6% (n = 824) were not in any serious relationship. Most of the respondents (n = 639, 38.4%) were from the College of Health Sciences. Overall, 32.8% (n = 545) of the respondents were in the fourth year.
Demographic characteristics of the respondents (n = 1662).
Knowledge of cervical cancer symptoms
In total, 50.7% (n = 843) of the respondents had inadequate knowledge of cervical cancer symptoms; however, there was no statistically significant difference between the respondents with adequate knowledge and those with inadequate knowledge of cervical cancer symptoms (p = 0.573). The median knowledge score on cervical cancer symptoms was 7 (interquartile range (IQR): 5–10). The least recognised cervical cancer symptom was blood in the stool or urine (n = 971, 58.4%), with a statistically significant difference observed between the responses (p < 0.001). The most commonly recognised cervical cancer symptoms were persistent pelvic pain (n = 861, 51.8%) as well as pain and bleeding during sex (n = 843, 50.7%) (see Table 2).
Recognition of cervical cancer symptoms by female university students in the southern part of Ghana based on the cervical cancer awareness questionnaire (n = 1662).
A p-value less than 0.05 was represented in bold.
Knowledge of cervical cancer risk factors
Overall, 57.9% (n = 963) of the respondents had inadequate knowledge of cervical cancer risk factors. There was a statistically significant difference between the respondents with inadequate knowledge and those with adequate knowledge of cervical cancer risk factors (p < 0.001). The median knowledge score on cervical cancer risk factors was 9 (IQR: 6–12). Having sex at a young age was the least recognised cervical cancer risk factor (n = 1092, 65.7%), with a statistically significant difference found between the responses (p < 0.001). The most common cervical cancer risk factors recognised by the respondents were HPV infection (n = 1013, 61.0%), having multiple sexual partners (n = 897, 54.0%) and infection with Chlamydia (n = 875; 52.6%) (see Table 3).
Recognition of cervical cancer risk factors by female university students in the southern part of Ghana based on the cervical cancer awareness questionnaire (n = 1662).
HPV: human papillomavirus.
A p-value less than 0.05 was represented in bold.
Determinants of cervical cancer knowledge
Table 4 shows the binomial logistic regression results of the factors associated with respondents’ knowledge of cervical cancer. Overall, the prevalence of inadequate knowledge of cervical cancer was 60.2% ([95% CI: 57.8–62.5]; p < 0.001). Muslim respondents had 2.13 times higher odds of inadequate knowledge of cervical cancer compared to Christian respondents (OR = 2.13 [95% CI: 1.55–2.91]; p < 0.001). Sexually active respondents had 1.78 times higher odds of inadequate knowledge of cervical cancer compared to those who preferred not to disclose their sexual activity status (OR = 1.78 [95% CI: 1.28–2.46]; p < 0.001). Also, respondents who were in the first, second and third years of their studies had increased odds of inadequate knowledge of cervical cancer compared to fourth-year respondents. Respondents studying in the Colleges of Humanities and Social Sciences, Engineering and Health Sciences had statistically significant increased odds of inadequate knowledge compared to respondents from the College of Agriculture and Natural Resources (p < 0.001). It was not clear why respondents from the College of Agriculture and Natural Resources had adequate knowledge of cervical cancer. Similarly, respondents who had a steady partner and living together had 3.59 times higher odds of inadequate knowledge of cervical cancer compared to respondents who were not dating (OR = 3.59 [95% CI: 2.29–5.64]; p < 0.001). In addition, unvaccinated respondents had 3.85 times higher odds of inadequate knowledge of cervical cancer compared to those who had received the HPV vaccine (OR = 3.85 [95% CI: 2.84–5.23]; p < 0.001).
Binomial logistic regression analysis of determinants of cervical cancer knowledge.
OR: odds ratio; CI: confidence interval; HPV: human papillomavirus.
A p-value less than 0.05 was represented in bold.
Knowledge of HPV
The median knowledge score on HPV was 10 (IQR: 6–12). There was a statistically significant difference between the respondents with inadequate knowledge and those with adequate knowledge of HPV (p < 0.001). Over two-thirds of the respondents (n = 1128, 67.9%) did not know that men could be infected with HPV (p < 0.001). However, more than half of the respondents (n = 928, 55.8%) knew that a person could have HPV for many years without knowing it (see Figure 1).

Understanding of HPV among female university students in the southern part of Ghana based on the cervical cancer awareness questionnaire (n = 1662).
HPV vaccination and barriers to the vaccine uptake
Overall, 63.9% (n = 1062) of the respondents did not know about the availability of HPV vaccine to prevent cervical cancer. More than four-fifths (n = 1446; 87.0%) of the respondents indicated that they had not been vaccinated against HPV, but 68.7% (n = 1142) reported that they will consider vaccination in the future. The five major barriers to HPV vaccine uptake included: lack of enough knowledge on the vaccine (n = 979, 58.9%), fear of side effects (n = 785, 45.6%), lack of knowledge about the vaccination site (n = 706, 42.5%), fear of injection (n = 554, 33.3%) and doubts regarding the efficacy of the vaccine (n = 526, 31.6%) (see Table 5).
Barriers to HPV vaccine uptake among female university students in the southern part of Ghana based on the cervical cancer awareness questionnaire (n = 1662). Respondents selected multiple options.
HPV: human papillomavirus.
Discussion
This cross-sectional survey provides insights into the determinants of cervical cancer knowledge and barriers to HPV vaccine uptake among female university students in Ghana. The study results revealed that more than half of the respondents had inadequate knowledge of cervical cancer risks, symptoms and the availability of the HPV vaccine to prevent cervical cancer. These results are similar to those reported in a previous study from Ethiopia, which indicated that 59.6% of female university students had inadequate knowledge of cervical cancer and its risk factors. 35 This inadequate knowledge may stem from limited community and school-based interventions aimed at promoting cervical cancer awareness and education in Ghana. 36 A recent systematic review and meta-analysis has demonstrated that school-based cervical cancer education through an active learning approach has the potential to increase knowledge of cervical cancer, HPV infection and vaccination among female students. 37
The results showed that the three least recognised symptoms of cervical cancer were: blood in the stool or urine (58.4%), persistent vaginal discharge with unpleasant smell (53.7%) and vaginal bleeding between periods (52.9%). The results are consistent with those reported in previous studies conducted in countries such as Bangladesh, Ethiopia and Saudi Arabia.38–40 The ability to recognise symptoms of cervical cancer is critical for early diagnosis when the cancer is localised and has a higher potential for cure. 41 Studies have demonstrated that individuals who are unable to recognise symptoms of cancer are more likely to delay seeking medical help.42,43 Delayed medical care is a major public health problem in most LMICs, including Ghana. Community members, including female university students, ought to be empowered to take control of their health. By providing evidence-based interventions tailored to cultural context, students can learn about early warning signs and symptoms of cervical cancer, diagnosis, treatment options and survivorship.44–46
The study revealed that almost 60% of female university students had inadequate knowledge of cervical cancer risk factors. However, the level of inadequate knowledge of cervical cancer risk factors was lower than that reported in many other studies conducted in Ethiopia, Saudi Arabia and Uganda.20,47,48 Concerning knowledge of HPV, almost 70% of female university students did not know that men could be infected with HPV. Similarly, the results showed that 63.9% of female university students were unaware of the availability of the HPV vaccine to prevent cervical cancer. A previous study from Malaysia has also reported that over 90% of students held the misconception that only girls can be infected with HPV and were unaware that vaccinating boys protects both sexes. 49 In a study from India, while the majority of female students knew cervical cancer is preventable through vaccination, their knowledge of the age to be vaccinated, types of vaccines and number of doses were low. 50
An important result from this study was that 87% of female university students had not been vaccinated against HPV. However, 68.7% reported that they would consider vaccination in the future if they satisfied the eligibility criteria. This result is consistent with those of previous studies conducted in Brazil and Jordan.51,52 The HPV vaccine is recommended for everyone beginning at age 9 and up to age 26. Vaccination is less beneficial for adults older than 26 years because most individuals in this age range have already been exposed to HPV. 53 Ghana does not have a national HPV vaccination programme. 5 HPV vaccines are only available at some selected health facilities, costing between $17 and $34 per dose. The majority of Ghanaian women make less than $63 per month, which would prevent them from affording the HPV vaccine. 54 Key barriers to HPV vaccine uptake identified in this study included: lack of sufficient knowledge about the vaccine, fear of side effects, lack of knowledge about the vaccination site, fear of injection and doubts regarding the efficacy of the vaccine. Other identified barriers were high cost of the HPV vaccine, vaccination not deemed necessary and busy schedule. These results are comparable to those of previous studies from other LMICs.55,56 Identified strategies to increase HPV vaccine uptake included: financial incentives, reminders, one-dose HPV schedule, school-based interventions, education, information and communication campaigns.57,58
Contextual factors such as religion, sexual lifestyle, year of study, colleges within the university, relationship status and HPV vaccination status emerged as important determinants of cervical cancer knowledge in this study. For example, Muslim female students were two times more likely to have inadequate knowledge of cervical cancer compared to Christian female students. This underscores the need to target Muslim female students in cervical cancer educational interventions. The result is consistent with a previous study reporting that religious beliefs and their related practices constitute major barriers to health education and healthcare utilisation. 59 Sexual lifestyle was also a significant determinant, with sexually active female students being more likely to have inadequate knowledge of cervical cancer compared to those who preferred not to disclose their sexual activity status. Furthermore, female students who had a steady partner and were living together had almost four times higher odds of inadequate knowledge of cervical cancer compared to those who were not dating. We are unable to postulate if this was due to embarrassment related to talking about cervical cancer and sex. Equally, unvaccinated female students were more likely to have inadequate knowledge of cervical cancer compared to those who had received the HPV vaccine (OR = 3.85 [95% CI: 2.84–5.23]; p < 0.001). These results are corroborated by a previous study that reported that 96.7% of vaccinated adolescents had heard of cervical cancer, compared to 50.8% of unvaccinated women in Kenya. 60
The results from this study could help design and implement a multi-component educational intervention consisting of lectures, video and web-based health education to increase HPV vaccine uptake and cervical cancer knowledge among university students. The educational intervention could cover themes such as: (1) basic information on cervical cancer (anatomy and function of the cervix, epidemiology and disease burden, signs, symptoms and risk factors); (2) the importance of early detection, recommended screening methods (Pap smear and HPV test) and guidelines for Pap smear screening; (3) information on HPV infection and role of HPV vaccine in preventing cervical cancer; (4) social strategies for HPV vaccination, including information on the accessibility and price of HPV vaccine; (5) case study showing the prognosis of Ghanaian women with advanced cervical cancer and (6) treatment options, survivorship and palliative care for cervical cancer patients.
Strengths and limitations
The validated questionnaire used was in English, and all the respondents could speak and read English; therefore, the questions were well understood by the respondents. The results reflect the true cervical cancer knowledge among female university students because of the large sample size. The use of an online, anonymous survey facilitated the efficient collection of data from students across different colleges, ensuring broad representation. Nevertheless, the study has some limitations. Firstly, this was a cross-sectional study that depended on self-reporting, with no attempt to independently verify respondents’ information. Therefore, reporting bias could have affected the study, potentially introducing social desirability bias. The use of Slovin’s formula could have resulted in an underestimation of the required sample size. Additionally, this study focused solely on female students, although HPV infection can occur in both males and females. Hence, we may have lost valuable male perspectives and insights on cervical cancer and HPV.
Conclusion
Improving access to cervical cancer awareness and HPV vaccination among university students is a critical public health goal to reduce the incidence of cervical cancer. Barriers to HPV vaccine uptake identified in this study included: lack of sufficient knowledge about the vaccine, fear of side effects, lack of knowledge about the vaccination site, fear of injection, doubts regarding the vaccine’s efficacy and high cost of the HPV vaccine. It is important to promote a free national school-based HPV vaccination programme. Multi-component school-based educational interventions, including traditional methods such as lectures, group discussions, awareness campaigns, leaflets, videos and digital tools like social media and interactive web-based educational platforms should be implemented to improve cervical cancer knowledge among university students.
Supplemental Material
sj-doc-1-whe-10.1177_17455057251335446 – Supplemental material for Determinants of cervical cancer knowledge and barriers to human papillomavirus vaccine uptake among female university students: A cross-sectional study
Supplemental material, sj-doc-1-whe-10.1177_17455057251335446 for Determinants of cervical cancer knowledge and barriers to human papillomavirus vaccine uptake among female university students: A cross-sectional study by Andrew Donkor, Loretta Pokua Osei, Ewura Adwoa Kwafoa Acquaah-Arhin, Pamela Deladem Suka, Doris Kitson-Mills, Alberta Naa Afia Adjei, Evans Ohemeng, Samiratou Ouedraogo and Veronica Millicent Dzomeku in Women’s Health
Supplemental Material
sj-docx-2-whe-10.1177_17455057251335446 – Supplemental material for Determinants of cervical cancer knowledge and barriers to human papillomavirus vaccine uptake among female university students: A cross-sectional study
Supplemental material, sj-docx-2-whe-10.1177_17455057251335446 for Determinants of cervical cancer knowledge and barriers to human papillomavirus vaccine uptake among female university students: A cross-sectional study by Andrew Donkor, Loretta Pokua Osei, Ewura Adwoa Kwafoa Acquaah-Arhin, Pamela Deladem Suka, Doris Kitson-Mills, Alberta Naa Afia Adjei, Evans Ohemeng, Samiratou Ouedraogo and Veronica Millicent Dzomeku in Women’s Health
Footnotes
Ethics approval and consent to participate
The study was approved by the Kwame Nkrumah University of Science and Technology Committee on Human Research, Publication and Ethics (CHRPE/AP/499/24). All subjects in this study signed informed consent forms after being properly informed about the study’s aims, methods and ethical issues, such as voluntary participation, confidentiality and the right to withdraw at any time of the study without giving justifications.
Author contributions
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Data Availability Statement
All data generated or analysed during this study are attached to this published article.
Supplemental material
Supplemental material for this article is available online.
References
Supplementary Material
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