Medical students’ knowledge about human papillomavirus (HPV), HPV vaccine and head and neck cancer

ABSTRACT

The Human Papillomavirus (HPV) is a sexually transmitted infection that significantly affects the population worldwide. HPV preventive methods include vaccination, prophylactics, and education. Different types of cancers associated with HPV usually take years or decades to develop after infections, such as Head and Neck Cancer(HNC). Therefore, HPV prevention can be considered cancer prevention. A sample of medical students in Puerto Rico was evaluated to assess their knowledge about HPV, HPV vaccine, and HNC through two previously validated online questionnaires composed of 38 dichotomized questions, we measured HPV, HPV vaccination(HPVK), and HNC knowledge (HNCK). Out of 104 students surveyed, the mean HPVK score obtained was 20.07/26, SD = 3.86, while the mean score for HNCK was 6.37/12, SD = 1.78. Bidirectional stepwise regression showed study year and HPV Vaccine name had been the most influential variables on HPVK and HNCK. MS1 participants scored lower than MS2-MS4 participants, with no significant difference between MS2-MS4 scores. The results reveal knowledge gaps in HPV/HPV Vaccine and HNC among surveyed medical students. Our findings also suggest an association between knowledge of personal vaccination status, self-perceived risk, and how uncertainty in these factors may affect the medical students’ understanding of HPV, HPV vaccination, and associated cancers.

KEYWORDS:

• Human Papillomavirus (HPV)
• HPV vaccine
• HPV knowledge
• Head and Neck Cancer (HNC)
• HNC knowledge
• medical students
• medical education

Introduction

The Human Papillomavirus (HPV) is a sexually transmitted infection that significantly affects the population worldwide.¹ It is also the most common sexually transmitted infection in the United States of America (USA), with 79 million infections and approximately 14 million new infections every year.² According to data reported from epidemiologic studies of HPV infection prevalence, Puerto Rico (P.R.) has rates up to 79%.³ The most common and recommended preventive methods against HPV are vaccination, prophylactics, and education.⁴

Some different types of cancers are associated with HPV, and some of them usually take years or even decades to develop after infection.⁵ According to Vokes,⁶ over the last two decades, it has been recognized that Head and Neck Cancer (HNC) is related to this virus. Oropharyngeal cancer is a type of HNC.^7,8 The American Cancer Society (ACS)⁹ estimates that in the USA, in 2023, about 54,540 new cases of oral cavity and oropharyngeal cancer will be diagnosed, and about 11,580 will die from these types of cancers. The P.R. Central Cancer Registry¹⁰ indicates that oral cavity and pharynx cancer was the sixth most diagnosed among men from 2015–2019, accounting for 3.6% of all cancer incident cases and less than 1.0% of mortality cases. The P.R. Central Cancer Registry (2016–2020) reports that cervical carcinoma (11.4), oropharyngeal squamous cell carcinoma (2.7), and penile squamous cell carcinoma (2.3) are the top three incident HPV-related cancers, with rates per 100,000 and age-adjusted.¹¹

Primary care physicians are usually the first or only source of information most patients have to receive about HPV and its vaccine. In some medical schools, the curriculums are not up to date on the topic of HPV.¹² However, the extent to which the students are trained in this topic in their schools remains unclear.² In P.R., the physician training curriculum is structured in four years of study, which adheres to the same standards of medical curriculum in the United States. The curriculum of the San Juan Bautista School of Medicine (SJBSM) consists of two years dedicated to biomedical sciences followed by two years focused on clinical sciences. A recent study concluded that the overall knowledge that medical students had about HPV was low¹³ and another study had similar results in which students had a mean score of 19.4 out of a possible 24 on HPV & HPV Vaccine Knowledge and 7.2 out of a possible 12 on HPV-associated HNC.¹⁴

Previous studies have identified knowledge gaps regarding HPV, HPV Vaccine Knowledge, and HPV-associated HNC in medical students (M.D. students).^13–17 Therefore, it is of public health and clinical interest to assess these topics so M.D. student’s curriculum may be positively impacted. This project’s priority was to evaluate the sampled population’s readiness in addressing several topics, such as HPV, HPV vaccination, and the consequences of infection like HNC. This study’s specific aims are (1) Describe sociodemographic, HPV vaccination status, and lifestyle profiles for M.D. students. (2) Measure HPV/HPV vaccine and HPV-associated HNC knowledge among M.D. students. (3) Identify demographic and educational factors that are associated with the difference of knowledge among the students.

Methods

A cross-sectional analytic methodology was employed since it provided the necessary means to assess knowledge among participants.¹⁸ The study was conducted between December 2022 and February 2023 with a study population consisting of M.D. students from SJBSM, one of the four medical schools in P.R. There were a total of 228 active M.D. students enrolled in the academic year 2022–2023, not on leave of absence (LOA), and in good standing. The 228 active M.D. students were distributed among academic years (MS1–4): MS1 = 61, MS2 = 62, MS3 = 69, MS4 = 36.

A target sample size of 144 was determined by considering the total count of active MD students, which amounted to 228. This calculation was guided by an anticipated frequency of 60%, extrapolated from mean scores in a prior study.¹⁴ This crucial data played a significant role in establishing a minimal sample size necessary for ensuring robust statistical validity, encompassing the entire potential sample pool. Notably, there was a greater emphasis placed on HNC knowledge scores for this purpose.

Out of 140 participants who accessed the online survey and met the inclusion criteria, 104 completed their responses, resulting in a response rate of 74%. Even though the proposed minimum sample size was not met, the measures attained statistical significance. A mean HPV Knowledge Score of 74.61% was expected at significance levels of .05 and 5% error margin, as stated in previous studies.¹⁴ The SJBSM Institutional Review Board (EMSJBIRB-13-22) approved the study prior to data collection.

A 35-minute online survey was developed based on survey items from previously validated questionnaires.¹⁴ The survey tool was distributed remotely and through in-person Q.R. codes, to be completed anonymously through an online survey tool (REDCap). These interventions promoted the project’s purpose, goals, and accessibility. Detailed informed consent was collected through the online platform. The survey consisted of 77 items divided into three sections that included: socio-demographic information, basic HPV and HPV vaccine knowledge, and HPV-related HNC knowledge. HPV and HPV Vaccine knowledge was collected in Section B through 26 dichotomized questions. Section C measured HPV-related HNC knowledge through 12 dichotomized questions. Both sections B and C were scored with 1 for correct answers, while incorrect and “I don’t know” were scored with 0. Section B’s HPV Knowledge score (H-Score) was calculated based on 26 possible points. Section C, HNC Score (C-Score) was calculated of 12 possible points. Independent variables included the year of study (first, second, third, or fourth year), age, sex (male, female), race (white, nonwhite [combining low-frequency responses]), marital status (married, single but dating, single, and not dating), and number of lifetime oral partners and number of lifetime vaginal partners (zero, one, ≥ two), physician recommendation of HPV vaccine (yes, no), HPV vaccine initiation (recipient of at least one dose), HPV vaccine completion (recipient of at least three doses), and specialty of interest (pediatrics, family medicine, internal medicine, surgery, other specialties).

Preliminary descriptive analysis was conducted using a combination of different software tools such as Excel, Tableau, and R. Non-parametric tests were utilized to further statistical analysis as data did not comply with normality standards. Both sociodemographic and risk factors were subjected to different comparisons with “Year of Study” by utilizing different sets of tests. Continuous variables were subjected to Shapiro Wilks tests to ascertain assumptions. On the other hand, categorical variables were compared with response variables using Kruskal Wallis chi-squared tests. Multiple linear regression models were conducted with the selected statistically significant variables of interest during bivariate analysis. Associations were observed between certain risk factors and variables such as year of study, the name of previously administered HPV vaccine, history of oral sexual activities, and different sources of HPVK when modeled with both outcome variables. All the statistical examinations utilized an alpha level of 0.05 to define statistical significance.

Results

Study participants characteristics

The statistical analysis of the data obtained from this study began with a univariate analysis to describe knowledge scores and sociodemographic characteristics (Table 1). In this study, several basic sociodemographic factors were considered to understand the profile of the population being studied. The survey was completed by 104 medical students, of whom 32.69% were first-year students, 23.08% were second-year students, 28.85% were third-year students, and 15.38% were fourth-year students. The mean (S.D.) age of participants was 25.9 (2.7). In the sample, 61 students (58.65%) identified as female, while 43 (41.35%) identified as male. In terms of race, more than half of the participants (64.42%) identified as Latin American. There were 38.83% (n = 40) of the sample who were single but in a committed relationship, 44.71% (n = 38) had two or more vaginal sexual partners, and 44.83% (n = 39) had multiple oral sexual partners during their lifetimes. Race and relationship status variables were considered for the project’s efforts to obtain a complete profile of the study population. However, they did not present statistical significance. In the study, 82 respondents had received the HPV vaccine, and 48 (58.54%) answered that they didn’t know the type of HPV vaccine they had received. The average score for HPVK was 20.07 ± 3.80, and the average score for HNCK was 6.37 ± 1.96 (Table 1). We observed trends in various sociodemographic variables such as “Which type of HPV Vaccine did you receive?” and “Have you ever had oral sex?.” The minimum required sample size was not reached. Nevertheless, of 140 participants who opened the online survey and met the inclusion criteria, 104 completed it for a 74% response rate. However, some measures obtained significance.

Table 1. Study participants characteristics.

Question	Mean or n	S.D. or %	H-Score	C-Score
			p-Value	p-Value
H-Score	20.07	3.80
C-Score	6.37	1.96
How old are you?	25.9	2.7	.020	.020
What year of study are you currently in?			<.001	.001
MS 1	34	32.69
MS 2	24	23.08
MS 3	30	28.85
MS 4	16	15.38
Sex at birth:			.300	.552
Female	61	58.65
Male	43	41.35
Have you ever had vaginal sexual intercourse?			.010	.104
Yes	86	83.5
No	17	16.5
Total = 103
Have you ever had oral sex?			.006	.028
Yes	87	86.14
No	14	13.86
Total = 101
Where have you heard about HPV? (Check all that apply)
Healthcare practitioner/hospital	86	82.69	.200	.003
Internet	64	61.54	.500	.631
Parents	32	30.77	.090	.008
Television/Radio/Magazines	30	28.85	.050	.450
Friends	29	27.88	.020	.251
Other	9	8.65	.005	.029
What stage of the HPV vaccination are you currently at?			.070	.633
I have had my 1st, 2nd and 3rd doses	60	57.69
I am yet to receive any HPV vaccination	14	13.46
I have had my 1st and 2nd doses	13	12.5
I have had my 1st dose	9	8.65
I have not been offered the vaccine	7	6.73
I do not wish to be vaccinated	1	0.96
Which of the HPV vaccines did you receive?			.001	.030
Gardasil (Quadrivalent)	22	26.83
Gardasil 9 (Nonavalent)	12	14.63
I don’t know/not sure	48	58.54
Total = 82
Do you think both males and females should be offered the vaccine?			.020	.223
Yes	101	97.12
I’m not sure/don’t know	3	2.88
Where have you seen/heard information on HPV vaccines?
T.V./Radio	29	27.88	.200	.535
Information leaflet	30	28.85	.400	.876
Poster in a pharmacy	23	22.12	.300	.2103
Internet	45	43.27	.600	.8059
School/College/University	52	50	.200	.0125
Physician/medical/nurse practitioner	64	61.54	.600	.222
I have not seen/heard anything	7	6.73	.040	.131
Other	4	3.85	.900	.700

HPV/HPV vaccine knowledge and HPV-associated HNC knowledge bivariate analysis

A Kruskal-Wallis test was used to compare HPV/HPV Vaccine Knowledge and HPV-associated HNCK according to sociodemographic and potential lifestyle risk factors (Table 1). The Kruskal-Wallis test showed that there was a statistically significant difference between HPV/HPV Vaccine knowledge and Year of Study (p-value < .01) and Type of vaccine received (p-value < .01). Similarly, a significant difference was found with some risk factors, such as: if they have had vaginal sexual intercourse (p-value: .02) and if they have ever had oral sex (p-value: .02). However, no difference was found between knowledge of HPV, HPV vaccine, future specialty, sex at birth, or race. H and C-Scores increased when comparing MS1 between MS2, MS3, and MS4, as seen in Table 2. However, no significant differences were observed between MS2, MS3 and MS4.

Table 2. Average H-Score and C-Score by year of study.

	H-Scores		C-Scores
	Mean	sd (σ)	Mean	sd (σ)
MS1	17.18	4.49	5.29	1.87
MS2	20.54	2.75	6.58	1.68
MS3	21.77	1.99	7.00	1.50
MS4	19.62	1.96	6.33	2.22

HPV/HPV vaccine knowledge and HPV-associated HNC knowledge multivariate analysis

Stepwise regression using MS1 as the intercept yielded the best predictive model, as seen in Table 3, for both H and C Scores. The model included the variables “Study Year” and “Which HPV Vaccine did you receive” with an adjusted R² of 0.3906 and 0.17, respectively. The results between study years were: MS 1 (β = 15.90, 95% CI: 15.24, 16.57), MS 2 (β = 4.07, 95% CI: 3.09, 5.04), MS 3 (β = 4.82, 95% CI: 3.90, 5.73), MS 4 (β = 3.73, 3.73, 5.93). The results of C-Score were MS1(β = 5.03, 95% CI: 4.64, 5.41) with MS2 (β = 1.33, 95% CI: 0.76, 1.89), MS3 (β = 1.92, 95% CI: 0.86, 1.92) and MS4 (β = 2.03, 95% CI: 1.39, 2.66). An interaction plot including both categorical variables can be observed in Figure 1 for each knowledge score in order to observe the effect of each variable.

Figure 1. Interaction plots for respective knowledge score linear models adjusted for “year of study” and “vaccine name”.

Table 3. Linear regression model for H-Score and C-Score adjusted for “year of study” and “Which of the HPV vaccines did you receive?”.

Linear Model of M.S. Status by Vaccine Name VS K Scores	Adjusted β (95% CI)
	H-Score	P Value	C-Score	P Value
Intercept	15.9 (15.23, 16.57)	<.001	5.03 (4.64, 5.42)	<.001
MS2	4.07 (3.1, 5.04)	<.001	1.33 (0.77, 1.89)	.02115
MS3	4.82 (3.9, 5.74)	<.001	1.39 (0.86, 1.92)	.01033
MS4	4.83 (3.73, 5.93)	<.001	2.03 (1.39, 2.67)	.00216
Quadrivalent	2.75 (1.91, 3.59)	.00161	1.2 (0.71, 1.69)	.01548
Nonavalent	1.83 (0.79, 2.87)	.08299	0.18 (−0.42, 0.78)	.76817

Potential confounding variables were analyzed from the linear regression models. We found that variables: “Have you ever had oral sex?” and “Do you think both males and females should be offered the vaccine?” had a potential confounding impact on H-Scores when evaluated against the study year. Likewise, a potential confounding effect for C-Score was obtained from variables: “Age,” “If they heard about HPV from their parents,” and “If they have seen or heard about HPV Vaccine from their school” when compared against the study year. However, when included in the stepwise regression, these variables did not have a strong enough effect on the model and were not considered at the moment of reporting the best fitting model.

Discussion

This project aimed to evaluate the readiness of M.D. students throughout the four years of medical school in addressing several topics, such as HPV, HPV vaccination, and the consequences of infection like HNC. The curriculum in SJBSM, includes HPV topics from the first to third year. The first-year curriculum discusses the topic of the HPV vaccine and HNC from a molecular perspective. Meanwhile, these topics are discussed in greater depth during the second year in microbiology and pathophysiology classes. Third-year curriculum (clerkships) included topics related to HPV, HPV vaccine, HNC, and other related issues. These clerkships include Internal Medicine, Obstetrics and Gynecology (Ob-Gyn), Pediatrics, and Family Medicine. Similarly, the fourth-year clerkships that cover these topics are in Hematology/Oncology and Ob-Gyn. According to our knowledge, this is the first study conducted in P.R. that uses medical students as the study population to assess knowledge of HPV, HPV vaccination, and HPV-related HNC.

The findings of this study differ from the previous study conducted by Du et al.,¹⁴ first-year medical students had a greater participation rate, and second-year students had a lower participation rate. Regardless of the year of study, there was representative participation of both females and males in both studies.

Our results indicate that the study population possesses different levels of knowledge of HPV, HPV vaccination, and HNC. It also suggests that students’ H-Scores and C-Scores increased when comparing between first year and subsequent study years. However, MS 2, 3, and 4 results were relatively constant. In addition, there were special interests in variables of HPV source of information and current vaccination status as these variables speak to participants’ perceived risk and perceived role as future patient educators. The year of study was a particular variable of interest since it was expected to be positively correlated with higher Knowledge Scores in general.¹⁴

In line with the findings of the preceding study by Du et al., a directly proportional trend has been identified as score results increased in ascending order per year of study.¹⁴ In this current study, the average score for HPVK was 20.1 out of 26, and the average score for HPV associated with HNCK was 6.4 out of 12. These scores were consistent with comparable articles where students exhibited a mean score of 19.4 out of 26 on HPV & HPV Vaccine Knowledge and 7.2 out of 12 on HPV-associated HNCK.¹⁴ From these scores, a high yield of adequate responses originated from third- and fourth-year M.D. students. However, these results have ascertained gaps in knowledge among medical students in topics related to HPV and HNC. The knowledge gaps included a significant difference between HPV/HPV Vaccine knowledge and Year of Study, and the type of vaccine received, including knowledge about some risk factors, such as: if they have had vaginal sexual intercourse and if they have ever had oral sex. Consistent with findings and recommendations from Neeley et al.,¹⁹ our study also indicates that medical students perceive a lack of comprehensive coverage of oncology topics, emphasizing the need for curricular improvements. Neeley et al. ‘s identification of gaps in oncology education, such as the limited requirement for non-surgical oncologic clerkships, resonates with our findings. A higher level of proficiency was expected from this population compared to first- and second-year M.D. students due to their academic progress.²⁰ Other concerns that require consideration are some identified risk factors, such as sexual practices and alcohol use, that are directly related to the presented topics.

Exposure to the risk factors presented during this study can be factored as possible ongoing knowledge gaps. These results are similar to those from past studies that demonstrate a common tendency toward exposure to risk factors and lack of knowledge.^2,18 Other studies indicated a possible link in retrospective engagement in the improvement of HPV and HPV related HNCK adherence. An example of the following could be as simple as engaging M.D. students to inquire about their HPV vaccination status. Related studies have expressed the need to adjust teaching methods to improve knowledge assimilation and retention.^21,22 Another study conducted in a medical school obtained improvements in increasing knowledge retention among M.D. students as a result of adjusting traditional teaching methods.²⁰ The findings of related studies suggest that it may be possible to improve the curriculum of medical students regarding HPV, HPV vaccine, and the relationship between HPV and HNC.^2,23

The study by Thanasuwat et al.¹² underscores the effectiveness of online educational interventions in boosting knowledge and willingness to recommend the HPV vaccine among healthcare trainees. Their findings, which showed a significant increase in correct responses about HPV-related cancers post-intervention, align with the knowledge gaps identified in our research. This similarity suggests that similar online modules could enhance medical students’ understanding of HPV’s link to HNCs, potentially influencing their future clinical practices. Given that 68.5% of Thanasuwat et al.‘s participants reported an increased likelihood of recommending the HPV vaccine post-intervention, integrating comprehensive HPV education into medical curricula could be key in promoting vaccination advocacy among future physicians. This underscores the effectiveness of online educational interventions in boosting knowledge and willingness to recommend the HPV vaccine among healthcare trainees.

Linear regression models were constructed based on significant variable combinations to find a best-fitting model. Potential confounding variables such as age and sex at birth were also evaluated. Similar to a previous study, age was not considered for further analysis since collinearity was evidenced and reproduced during statistical analysis.¹⁴ Stepwise regression yielded a theoretical best model based on significant variables for HPV and C-Scores. Both models yielded the same variables for best fit: “Year of Study” and “What HPV Vaccine did you receive.” Due to study limitations and sample size, we did not expect models to show any correlations; however, a low correlation was found (R² = 0.3906) for the HPVK Score.

Other studies conducted on HNCK have found similar results, where HPV related HNCK was lower than other HPV-related cancers, such as a 2018 survey aimed at medical students at ten medical schools in New York State.²⁴ In this study, where information was collected on HPV-positive cancer knowledge, HNCK was among the lowest Knowledge scores amongst the surveyed medical students across all years of study.²⁴ Our similar findings might suggest a more systemic problem creating these gaps in knowledge.¹⁷ However, a more comprehensive prospective study would be necessary to determine this.

Our models, as shown in Table 3 and Figure 1, also describe the role of perceived susceptibility in medical students, as students who self-reported not knowing their HPV vaccine name scored lower than students who reported knowing what HPV vaccine they received. Although the C-Score model does not represent this trend clearly, as seen in Figure 1, the HPVK model does show a clear trend indicating a difference in score between the first year and year 2,3,4. However, when adjusted for Vaccine name Knowledge, both HPVK and HNCK can be seen to lower slightly, but when comparing students who know what HPV Vaccine they have, the scores are significantly higher, indicating that uncertainty in this risk variable may play a role in predicting knowledge scores. Uncertainty has been shown to play a role in HPVK; however, the directionality of this association has yet to be determined.²²

Although vaccination status has been shown to be associated with HPVK in college students,²² in our case, we must consider our study population at a higher standard of scrutiny and explore how the effect of uncertainty vs. certainty in students’ own vaccination status better describes the knowledge and lack of knowledge when it comes to HPV and HPV associated Cancers.²² Therefore, medical schools can consider training for medical students to increase confidence in discussing these issues with their patients.^17,25

Ongoing endeavors for HPV vaccination public policy have been made since 2010 led by nonprofit, public, and private organizations. Since 2018, HPV vaccine was established as a school-entry requirement in P.R for students aged 11 and above.²⁶ Promotion of HPV vaccination to adolescents and adults up to 45 years of age who probably do not have the vaccination series up to date is a major public health recommendation.²⁷ It is also important to provide educational forums by scientists and health providers to cover the benefits of vaccination as a preventive method for HPV infection and the risks of developing cancer in the long term.^27–29

An identified limitation within this study includes the sample size of MS2 students due to their low participation rate. In addition, the duration and timing of data collection, as well as the length of the questionnaire, were also considered as limitations. The data collection period was conducted during the Christmas break, and the estimated time to complete the questionnaire was 35 minutes. Therefore, we believe these factors could be considered barriers for study participants. Nevertheless, this study is one of the first to address the topics of HPV/HPV Vaccine and HPV-associated HNC among medical students in P.R.

Conclusion

Our findings highlight gaps in HPV/HPV Vaccine and HNCK among the surveyed medical students. This study offers valuable insights into the involvement of medical students in cancer prevention and vaccination, encouraging medical students to self-identify lifestyle risk factors. Our findings also suggest the need to explore the association between knowledge of personal vaccination status, self-perceived risk, and how uncertainty in these factors plays a role in the medical students’ understanding of HPV, HPV vaccination, and associated cancers. Evaluating medical school curriculums to enhance discussion of these topics, alongside self-assessment of risk factors and vaccination status, should be considered when addressing these knowledge gaps.

Authors’ contribution

All authors included in this study, Isardo Braverman Diaz, Norangelys Solis Torres, Luis A. Rivera Morales, Jose J. Perez Sánchez, Valeria S. Perez Bravo, Angel J. Neris Sanchez, Alexis Vera, Yaritza Diaz-Algorri, participated in the conception, design, analysis, interpretation, drafting and review and have approved this version for publishing agreeing to be held accountable for all aspects of the work.

Acknowledgments

The authors thank Dr. Yocasta Brugal, President of San Juan Bautista School of Medicine, for her outstanding institutional support and Dr. Estela S. Estape, Research Center Director, for the scientific writing review.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors reported there is no funding associated with the work featured in this article.