Abstract
We aimed to determine whether the type of outcome expectation, stemming from HPV vaccination, would have any effect on young men's HPV vaccine intent. We recruited young men (18–24 years of age) from two university campuses (n = 150). After answering a series of questions they were randomly assigned to one of three information conditions (all delivered by computer): (1) how women may benefit from men's HPV vaccination, (2) preventing genital warts and (3) preventing head and neck cancers. Intent to be vaccinated against HPV in the next 12 months was assessed before and after receiving the informational session corresponding to the assigned condition. A repeated-measures t-test indicated that a significant increase in young men's intent to be vaccinated after they received the assigned information (t = 9.48, [147], P = 0.0001). However, the increase in intent to be vaccinated did not vary by group assignment as there were no significant differences in mean intent scores between the three groups (F = 0.59, [2/144], (P = 0.56). Information that promotes the outcome expectations of protecting women from cervical cancer, preventing genital warts for men and preventing head and neck cancers for men may be equally effective in promoting increased intent for HPV vaccine acceptance among young university men.
Introduction
In the USA, the recent Food and Drug Administration (FDA) approval of Gardasil® for males aged 9–26 years raises important questions for promotion efforts to enhance acceptance and uptake of Gardasil§ by young men. One question that is unique to men's acceptance of the vaccine is, what information enhances uptake? Although the Advisory Committee on Immunization Practices (ACIP) made their ‘permissive recommendation’ based on the vaccine's protective value against genital warts, 1 it is plausible that reducing incidence and prevalence of types 16 and 18 HPV infection in male subjects could also result in a corresponding drop in HPV incidence among their female sexual partners. Further, it is conceivable that some men may benefit from the vaccine based on its hypothesized protective value against head and neck cancers. 2 Thus, three very different reasons for being vaccinated can be offered to young men.
Social cognitive theory (SCT) offers a useful construct that can be used to conceptualize the question of how to best promote the HPV vaccine for male subjects. SCT suggests that before effort is expended there must be a sufficiently strong belief that the health behaviour will ‘pay off’ in either a short-term or long-term time frame. 3 These beliefs are termed ‘outcome expectations’. In the context of vaccinating men with a quadravalent vaccine (Gardasil®) these expectations can reasonably be grouped into altruism (i.e. protecting female sexual partners via immunity conferred against types 16 and 18), averting genital warts (via immunity conferred against types 6 and 11) and averting potential risk of some head and neck cancers.
Unfortunately, only a handful of studies have begun to investigate this research question. A study published in 2003, of 127 university men, found that 74% would accept a hypothetical HPV vaccine and this finding was not significantly related to whether men had been randomized to receive a message describing the benefits as a form of sexually transmitted infection (STI) prevention (averting genital warts), a form of reproductive health (averting warts and protecting female sex partners from cervical cancer) or both the ‘STI prevention’ and ‘reproductive health’ messages combined. 4 A similar study, published in 2009, randomized USA university-based men to receive one of two prevention messages - one about self-protection (averting warts) and the other about self and sexual partner protection (averting warts and cervical cancer risk among female sexual partners). 5 Potential acceptance of the vaccine did not vary by group assignment. Finally, in an observational study, 138 university-based men responded to an HPV vaccine acceptance question framed as averting cervical cancer and another question framed as averting warts and preventing cervical cancer. 6 The percentage of men indicating ‘extremely likely’ regarding vaccine acceptance was much greater (78%) in response to the latter question compared with the former (38%). Unfortunately, none of these studies included the outcome expectation of averting head and neck cancer. Also, each of these previous studies was conducted prior to USA FDA approval of Gardasil® for male subjects and therefore the research was conducted in the context of a hypothetical vaccine. To address more precisely the effect of different messages on the acceptance of Gardasil®, we used an experimental trial design, randomizing university-based men to three conditions in a study following FDA approval of Gardasil® for male subjects. Given the current emphasis on the averting the outcome expectation of averting genital warts, this condition can be considered as a control for two other conditions: averting head and neck cancers and averting cervical cancers. We tested the null hypothesis that differences between the three conditions would not be found.
Methods
Recruitment
The study recruited 150 university-based men between October 2009 (following FDA approval of Gardasil® for male subjects) and December 2009. Young men were recruited from two universities (75 at each) located in southern USA. Recruitment occurred primarily by flyers posted on campus. Flyers advertised the study as being about ‘attitudes toward the HPV vaccine.’ Men (aged 18–24 years) contacted project staff if they were interested in volunteering and were screened for eligibility. Participants were given a compensation of US$30 for their participation in the study, which took approximately 30 minutes to complete. The Institutional Review Boards at Emory University and Morehouse University each approved the study protocol prior to implementation.
Measures
Data were collected using audio computer-assisted self-interview (ACASI). The single item assessing intent to be vaccinated read as follows: ‘because the HPV vaccine is now available for use in men, how likely would you get the HPV vaccine within the next year?’ The item was scored using a 6-point Likert-type scale with a response format ranging from (1) ‘very unlikely’ to (6) ‘very likely.’
Procedures
Eligible and willing men completed written informed consent and the ACASI assessment process. They were subsequently randomized to one of three trial conditions corresponding to each of three outcome expectations: (1) altruism condition (averting cervical cancer); (2) personal sexual protection condition (averting genital warts) or (3) personal cancer protection condition (averting head and neck cancers). Each informational session was presented on the laptop computer and involved a very brief (6 slides and a photo) PowerPoint presentation. The six slides shown in the altruism condition provided basic information about the cause, prevalence and prevention of cervical cancer; the photo was of a cancerous cervix. In the genital warts condition, men were informed that genital warts are the most common STI in the USA. They were also instructed that treatment of warts is not always successful and they learned about the causative role of HPV types 6 and 11 as well as the efficacy of the vaccine (Gardasil
Data analysis
A repeated-measures t-test was conducted to determine whether, overall, men's intent to be vaccinated against HPV increased between the pretest and post-test. A one-way analysis of covariance (ANCOVA) (controlling for pretest scores and African American/black versus non-African American/black race) was then used to determine whether mean post-test scores were significantly different among the three randomly assigned groups.
Results
Characteristics of the sample
The average age was 20.2 years (SD = 1.5). The majority (53.3%) identified as African American or black, with 19.3% identifying as white, 21.3% identifying as Asian or Pacific Islanders and the remainder identifying as ‘mixed’ or members of ‘other races.’
Changes between assessments
The overall mean pretest intent score observed was 3.19 (SD = 1.33) whereas the overall mean post-test intent score was 3.91 (SD = 1.34). This increase of 0.72 on the 6-point scale was significant (t = 9.48 [147], P = 0.0001).
Differences among groups
The one-way ANCOVA was non-significant, suggesting no difference in the mean post-test measures of intent among the three groups (F = 0.59 [2/144], P = 0.56). This did not change when entering only the pretest scores as a covariate and the F-value decreased somewhat when entering only the variable comparing African American/black men to the remainder (F = 0.33 [2/144], P = 0.72).
Discussion
These exploratory findings suggest that an informational session meant to enhance specific outcome expectations with HPV vaccination of young men may significantly increase intent to be vaccinated within the next 12 months. The null hypothesis was retained however, suggesting that it is not necessarily the type of information provided, which in this instance was either altruism-focused (i.e. reduce risk of HPV infection for female sexual partners), for personal prevention of genital warts or for personal prevention of head and neck cancers, but rather that providing young men with any of these types of information promotes their intent to be vaccinated. This finding, importantly, suggests that all three types of information are valuable approaches in promoting the sexual health of young university men.
Findings are limited by several factors. Most importantly it is quite likely that costs associated with the vaccine may not have been as highly influential for these college men compared with similar age men who could not afford to attend college. Thus, the intentions assessed in this study may be overly optimistic in other populations. It is also quite noteworthy that intentions do not always translate into behaviour and thus the findings may overestimate actual vaccine-seeking behaviours of these men in the future. The findings are also inherently limited by the possibility of demand characteristics operating between assessments. Further research may benefit men by testing messages involving the outcome expectation of averting penile cancer and anal cancer (particularly for men who have sex with men). Further research should also investigate whether presenting young men with multiple outcome expectations will produce more favourable attitudes towards the vaccine.
Conclusion
Although the findings are limited by the use of a convenience sample of USA university-based students, this is the first study to use a randomized trial design to evaluate differences in young men's intentions to be vaccinated as a function of their exposure to three different types of information corresponding to distinct outcome expectations related to receiving Gardasil®. Moreover, this study was conducted immediately following FDA approval of Gardasil® for male subjects. Of interest, we found that information alone can significantly increase young men's willingness to be vaccinated with Gardasil®. Equally important, this increase occurred irrespective of whether the information was tailored to address men's altruism to prevent HPV among female sexual partners, genital wart prevention or prevention of head and neck cancers. Thus, the findings suggest that all three types of information should be used to develop optimally effective HPV vaccine promotion programmes targeting USA university-based men. Ideally, messages will need to be tailored for various populations.
Footnotes
Acknowledgements
Funding was provided by a grant from Merck Pharmaceuticals to Dr Di demente.