Background
Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States [
1]. The link between HPV viruses and malignancies in both men and women is well established with HPV genotypes 16 and 18 being responsible for nearly all cervical cancers [
2]. HPV is also responsible for 91% of anal cancers, 75% of vaginal cancers, 63% of penile cancers, 69% of vulvar cancers and 60% of oropharyngeal cancers in the US [
2,
3]. Three HPV vaccines are currently licensed in the United States for the prevention of infection due to HPV infection: Gardasil and Cervarix that offer protection against oncogenic genotypes 16 and 18 and the new Gardasil 9, which has the potential to prevent approximately 90% of cervical, vulvar, vaginal, and anal cancers caused by HPV types 16, 18, 31, 33, 45, 52, and 58 [
4].
The United States Advisory Committee on Immunization Practices recommends vaccination for all girls and boys starting at 11 or 12 years of age, with catch up vaccination between ages 13–26 in women and 13–21 in men [
5]. Even though it has been a decade since the HPV vaccine was approved in June 2006, there is still a lack of widespread uptake of this cancer-preventing vaccine. In 2014, only 40% of adolescent girls (age 13–17) and 22% of adolescent boys in the US received all 3 doses of the vaccine [
6]. Due to the under-utilization of the HPV vaccination, 69 National Cancer Institute-designated Cancer Centers jointly issued a call to action to increase HPV vaccination rates in early 2016 [
7].
Although well studied internationally [
8,
9], very little is known about US medical students’ knowledge and attitudes about the HPV vaccine. This is especially important as US millennial medical students will be the first generation of providers who may have received the vaccine beginning in 2006; the same vaccine that they will now be expected to recommend to their patients. A 2016 study surveyed high school to health care professional students (including medical students) in New York State [
10]. The authors partly conclude that this is related to health care professional students being less likely to have been recommended the vaccine by a health care provider than their younger counterparts - high school and college students [
10]. Students who reported that their HPV vaccine information source was the doctor had a higher vaccine completion rate when compared to students whose information source was family and friends. However, one major limitation of this study was that data was not separated by type of health profession student, so prevailing attitudes of US medical students remains unclear. In their educational intervention for physicians, medical students, and non-physicians, Berenson et al. [
11] found medical students had inadequate baseline knowledge of HPV epidemiology and the HPV vaccine, but after attending a brief, 30 minutes lecture increased their knowledge scores significantly. This demonstrates the potential for using educational interventions to increase HPV vaccine knowledge in this population.
Objectives
The primary aims of this pilot study were to examine HPV vaccination rates among medical students and survey their knowledge and attitudes toward vaccination. Additionally, comparisons were sought between vaccinated versus non-vaccinated students. A secondary aim was to evaluate students’ perceived levels of comfort in counseling patients about HPV vaccine. This data will be used to develop and tailor educational interventions on the HPV vaccine at our medical school.
Methods
Participants
Participants included all 390 medical students enrolled at a single US Midwest allopathic medical school in October 2015. Participation in the study was voluntary with no compensation provided.
Measurements
Participants were invited via email to complete an anonymous online survey on HPV. No signed consent was required since the survey was distributed via an online platform. An information sheet was emailed to the student to let them know about the study and that their computer IP address would not be collected. Participants could access the survey at a time and location of their choosing to optimize privacy while completing the survey. Completion of the survey indicated consent. The University’s Institutional Review Board approved the study protocol.
The email contained a link to an anonymous, 20-question online survey and an information sheet about the study. Two email reminders were sent 1 week apart. The survey included a mix of 5-point Likert scale, categorical (yes/no), and free text completion items. Items included: 1) demographic information; 2) vaccination status for HPV; 3) motivating factors for accepting or rejecting the vaccine; and 4) basic knowledge about HPV and the HPV vaccine. Attitude questions about HPV vaccination included: beliefs about the safety and efficacy of the vaccine, views on mandatory vaccination, comfort in providing counseling about vaccination, and intention to recommend vaccination to friends and family. Participants were also invited to comment on their views about the vaccine. Previous research on HPV and influenza vaccination uptake assisted in formulating the content of this pilot questionnaire [
12‐
14].
Qualitative analysis
Analysis of answers to the open-ended questions followed the grounded theory methodology [
15]. A sub-group of investigators (JMS, TW and NMA) independently developed initial coding themes and then met to discuss and agree on a common coding approach and code definitions. Discrepancies were discussed and resolved. Responses were grouped under the key themes identified.
Statistical analysis
Likert scale items were coded such that higher values corresponded to stronger agreement (1 = strongly disagree and 5 = strongly agree). Additionally, Likert scale items were collapsed to reflect overall agreement (by combining scores of 4 (agree) and 5 (strongly agree)). Categorical variables are reported as counts and percentage frequencies. They were examined using Fisher’s Exact test.
Sub-analyses were conducted based on gender and vaccination status. Students who had completed all 3 doses of the vaccine were considered fully vaccinated. Students who did not receive any doses of the vaccine were considered non-vaccinated. Partially vaccinated students (completed 1 or 2 doses of the vaccine) were excluded from the sub-analyses, as we did not have background information on the reasons for not completing all doses of the vaccine, which may introduce bias into the attitudes regarding the vaccine. All analyses used The SAS® System for Windows version 9.3, Cary, NC.
Discussion
The HPV vaccine was introduced in 2006 for girls and added to the list of approved vaccines for boys in 2011. Although several studies have examined vaccination practices and attitudes toward HPV vaccination in practicing physicians [
14,
16‐
18] and in international medical students and residents [
8,
9,
11‐
13,
19], the authors only found one study reporting HPV vaccination rates in US medical students [
10]. However, in that study all health care professional students were lumped into a single student category so there was no way to separate out medical student data [
10]. Assessing medical student knowledge and attitudes about the HPV vaccine is vital since many in this group were likely to be the initial recipients of the HPV vaccine that was first offered in 2006. When these students become physicians they will carry with them this unique personal experience not found in other older health care providers. The current study represents the first report of HPV vaccination rates, knowledge, and attitudes among these US medical students.
In the under 25 age group, we found HPV vaccination rates for female and male medical students who had received at least one dose to be 72.3% and 19.3% respectively, a markedly higher coverage rate than the most recently reported national figures of 40.2% for females and 8.2% for males in a similar age group in 2014 [
20]. Similar to other college students, the higher overall vaccination rates among medical students may be the result of better knowledge, motivation, and better access to vaccinations and healthcare [
21‐
23]. The majority of the students who were vaccinated appeared to have a better understanding of HPV pathogenesis and the safety and efficacy of the HPV vaccine. It is additionally interesting to note that 73% of vaccinated students felt that vaccination should be mandatory as compared to 38% of non-vaccinated students. Although the authors are aware of no data on HPV vaccine receipt by health care providers, we believe that positive attitudinal differences in medical students who are HPV vaccine recipients, are similar to other vaccine studies, which show previous vaccination tends to impart a positive influence [
13,
24]. Similar to our previous work on influenza vaccine, the current study showed a significantly higher likelihood of previously vaccinated students recommending influenza vaccination to friends and family [
13].
The current study strongly supports the assertion that provider recommendation is a consistent and powerful predictor of vaccination, as evidenced by the large proportion of vaccinated students citing provider recommendation as a reason they received it. Gilkey et al. [
16] found that participants who received a provider recommendation were 35 times more likely to receive HPV vaccination [
25]. Gilkey et al. [
16] also found that vaccine uptake was adversely affected if health providers introduced the topic of HPV vaccination without expressly recommending it. Again, when comparing health professions students to high school and college level, Suryadevara et al. [
10] found that most health professions students had not been counseled about the HPV vaccine and attributed this to lower uptake of the vaccine by this population.
Our survey also revealed deficits in student knowledge and misperceptions about HPV. Although a majority of the students were well informed about HPV transmission (93.4%), cervical cancer (91.1%), and vaccine safety (90.1%), there was lack of knowledge about the protective effect of the HPV vaccine in cancers other than cervical (49.5%) as well as the duration of immunity provided by the vaccine. (56.3%) There was also the perception among the non-vaccinated students that they were not at risk for HPV. Greater emphasis, therefore, needs to be placed in teaching about the importance of HPV in disease etiology and the causal role of HPV in a variety of cancers [
2,
3]. Initiatives geared toward educating medical students about HPV vaccine should focus on cancer prevention and include data on safety and efficacy and strategies for positively framing counseling messages to patients.
Our previous experience illustrates the effectiveness of an early intervention coupled with experiential learning when teaching about influenza vaccination [
13]. Guided by this assessment, beginning this academic year, we have developed and integrated multi-faceted educational interventions aimed at improving knowledge of HPV, cancer and vaccines, as well as providing students hands on experience practicing vaccine counseling with standardized patients. We anticipate these will play a pivotal role in the endorsement of this vaccine by our future physicians. In the short term these skills will also assist students in discussing the importance of this vaccine during their community engagement activities. Further studies to evaluate the impact of these teaching strategies aimed at millennial medical students are currently being planned.
Limitations of the study
This study has several limitations. First, this study was conducted at a single medical school on a relatively small sample size that may limit generalizability. Although national survey data may have revealed regional variations, there are no indications that this institution’s students are noticeably different from those in other US allopathic medical schools. Self-reported data made it difficult to verify the accuracy of respondents’ vaccination status and we did not assess age at initiation of the vaccine. Also, this study did not seek to compare medical student attitudes between HPV and other vaccines. The survey was not designed to assess where the students obtained their knowledge and how it may have impacted their beliefs. Finally, the survey may have been influenced by a response bias – between those who responded to the email survey and those who opted not to participate, which prevented us from identifying possible patterns of characteristics among non-respondents.
Conclusions
Medical students are a key audience for HPV-related communication and training not only because of their impending role as healthcare providers, but also as future policy makers. We believe a particularly important contribution made by this study is the perspective of millennial medical students as a unique group of future healthcare providers, who will be the first to have had a personal experience with the vaccine. This study also highlights a pervasive lack of understanding regarding the protection against cancer other than cervical, conferred by the HPV vaccine. Although students acknowledge the importance of the vaccine and the need for patient education and counseling to prevent HPV-related cancers through vaccine compliance, they nonetheless feel ill prepared to provide that counseling. Students should be taught age-relevant approaches to counseling parents, adolescents, and young adults about this cancer-preventing vaccine that could save the lives of millions.
It is hoped that medical student personal experiences with the vaccine, supplemented by medical school education about HPV and appropriate vaccine-counseling skills, will allow them to share information with patients and parents in a clear, reassuring way, devoid of stigma. We anticipate they will be healthcare providers who play a critical role in recommending the HPV vaccine and help protect young people from life threatening cancers.
Acknowledgements
We are grateful to Ms. Michelle Jankowski for her assistance with the statistical analysis. We also appreciate the critical review of Leon Pedell, MD and his editorial assistance in preparing this manuscript.