ARTICLE IN PRESS          G Model          JVAC 12467 1–6                                                                 ...
ARTICLE IN PRESS      G Model      JVAC 12467 1–6      2                                                         K. Madden...
ARTICLE IN PRESS          G Model          JVAC 12467 1–6                                                                 ...
ARTICLE IN PRESS      G Model      JVAC 12467 1–6      4                                                                 K...
ARTICLE IN PRESS      G Model      JVAC 12467 1–6                                                             K. Madden et...
ARTICLE IN PRESS           G Model           JVAC 12467 1–6           6                                                   ...
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A content analysis of HPV vaccine information


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A content analysis of HPV vaccine information

  1. 1. ARTICLE IN PRESS G Model JVAC 12467 1–6 Vaccine xxx (2011) xxx–xxx Contents lists available at SciVerse ScienceDirect Vaccine journal homepage: 1 Sorting through search results: A content analysis of HPV vaccine information 2 online 3 Q1 Kelly Madden ∗ , Xiaoli Nan, Rowena Briones, Leah Waks 4 Q2 Department of Communication, University of Maryland, College Park, MD, United States 5 6 a r t i c l e i n f o a b s t r a c t 7 8 Article history: Introduction: Surveys have shown that many people now turn to the Internet for health information 9 Received 1 June 2011 when making health-related decisions. This study systematically analyzed the HPV vaccine information10 Received in revised form 17 August 2011 returned by online search engines. HPV is the most common sexually transmitted disease and is the11 Accepted 10 October 2011 leading cause of cervical cancers. Available online xxx Methods: We conducted a content analysis of 89 top search results from Google, Yahoo, Bing, and The websites were analyzed with respect to source, tone, information related to specific content analyzed13 Keywords: through the lens of the Health Belief Model, and in terms of two content themes (i.e., conspiracy theories14 HPV vaccine15 Internet and civil liberties). The relations among these aspects of the websites were also explored.16 Websites Results: Most websites were published by nonprofit or academic sources (34.8%) and governmental agen-17 Health belief model cies (27.4%) and were neutral in tone (57.3%), neither promoting nor opposing the HPV vaccine. Overall, the websites presented suboptimal or inaccurate information related to the five behavioral predictors stipulated in the Health Belief Model. Questions related to civil liberties were present on some websites. Conclusion: Health professionals designing online communication with the intent of increasing HPV vac- cine uptake should take care to include information about the risks of HPV, including susceptibility and severity. Additionally, websites should include information about the benefits of the vaccine (i.e., effec- tive against HPV), low side effects as a barrier that can be overcome, and ways in which to receive the vaccine to raise individual self-efficacy. © 2011 Published by Elsevier Ltd.18 1. Introduction To understand why people get or do not get the vaccine, it 34 is important to ascertain what information is available to them 3519 Genital human papillomavirus (HPV) is the most common sex- in decision-making. Approximately 80% of American adults are 3620 ually transmitted infection [1]. HPV is the leading cause of cervical searching for health information online, making it the third most 3721 cancers, a major health concern for women. Approximately 12,000 popular online activity [6]. People start with search engines when 3822 women are diagnosed with cervical cancer each year in the United looking for health information online rather than navigate directly 3923 States alone, with over a million afflicted with the disease world- to medical portals or sites of medical societies [7]. Additionally, 4024 wide [1]. Two vaccines have been approved to prevent the spread the Internet was named as one of the most preferred places to 4125 of HPV. Gardasil, licensed in 2006, and Cervarix, approved in 2009, get information about HPV vaccines [8]. This study then seeks 4226 are available for girls as young as 9, recommended for females ages to understand the nature of online messages people are exposed 4327 11 and 12, and encouraged for women ages 13–26 [2,3]. Gardasil to when they use search engines to find information about HPV 4428 is also available for males ages 9–26. Although HPV vaccines have vaccines. 4529 been shown to be highly effective [4], vaccine uptake rate among Research on vaccine information online in general has uncov- 4630 young females in the United States is still low. According to the ered a great deal of opposition to vaccines. The materials on 4731 2009 National Immunization Survey for Teens, approximately 44% anti-vaccine websites focused on the danger and ineffectiveness 4832 of adolescent females received the first dose of the HPV vaccine, of vaccines and also included information related to civil liberties 4933 with only 27% receiving all three doses [5]. (e.g., vaccination mandate violates parental rights) and conspir- 50 acy theories (e.g., vaccines are a hoax) [9]. Other misinformation 51 that exists on anti-vaccine websites includes incorrect interpreta- 52 ∗ Corresponding author at: Department of Communication, 2130 Skinner Build- tions of scientific reports [9,10]. Additionally, research has found 53 ing, University of Maryland, College Park, MD 20742-7635, United States. that using different keywords in online searches, such as vacci- 54 Tel.: +1 570 660 6743; fax: +1 301 314 9471. nation versus immunization, can result in dramatically different 55 E-mail addresses:, kkm (K. Madden). information about vaccines [11]. 56 0264-410X/$ – see front matter © 2011 Published by Elsevier Ltd. doi:10.1016/j.vaccine.2011.10.025 Please cite this article in press as: Madden K, et al. Sorting through search results: A content analysis of HPV vaccine information online. Vaccine (2011), doi:10.1016/j.vaccine.2011.10.025
  2. 2. ARTICLE IN PRESS G Model JVAC 12467 1–6 2 K. Madden et al. / Vaccine xxx (2011) xxx–xxx 57 Studies have also examined the nature of information specifi- were unavailable at the time of coding. The remaining 89 websites 119 58 cally related to the HPV vaccine presented in print news sources constituted the final working sample for the current study. 120 59 [12–14], Internet news articles [15], social networking sites or 60 blogs [16], and YouTube videos [17]. All these studies were con- 2.2. Coding scheme 121 61 ducted either before approval of the first HPV vaccine or within 62 two years after the first HPV vaccine was licensed, which limits The content analysis consisted of first coding for the source of 122 63 the generalizability of their results to the more recent online dis- the website (i.e., the individual or organization that published the 123 64 course surrounding the vaccines. More importantly, very few of website). Eight categories of source were included: governmental 124 65 the previous studies specifically investigated information about agencies, nonprofit/academic organizations, pharmaceutical/for- 125 66 the HPV vaccine contained in top ranked websites returned by profit companies, consumer generated content, news sources, 126 67 online searches through popular search engines, with the excep- advocacy groups or professional associations, medical cen- 127 68 tion of Habel et al. [15], who explored HPV vaccine information ters/hospitals, encyclopedic medical sites, and other. The tone of 128 69 from top online news search engines, and Tozzi et al. [18], who the website was categorized into neutral (i.e., does not approve or 129 70 investigated credibility, accessibility, design, and content cate- disapprove the HPV vaccine), negative (i.e., disapproves the vac- 130 71 gories related to information accuracy and currency. Neither of cine), positive (i.e., approves the vaccine), and ambiguous (i.e., 131 72 these studies provided a theoretical framework for the basis of their contains both disapproving and approving information). Addi- 132 73 analysis. We seek to improve on previous research by systemat- tionally, whether the website contained reference to conspiracy 133 74 ically analyzing websites in terms of the presence or absence of theories (e.g., government/companies/doctors are only out to make 134 75 information pertaining to important predictors of vaccine accep- money on the vaccine; vaccine is a hoax) or civil liberties (e.g., 135 76 tance within the framework of the Health Belief Model (HBM) [19]. government wants to mandate the vaccine and threatens citizens’ 136 77 The HBM specifically identifies five factors – susceptibility, severity, freedom) was coded. 137 78 benefits, barriers, and self-efficacy – that predict whether people Finally, we coded for HBM factors including (a) benefits, 138 79 will perform a particular health behavior. Perceived susceptibility specifically effectiveness of the vaccine (high effectiveness, low 139 80 addresses the extent to which the person perceives they are vul- effectiveness, or no information); (b) barriers, including phys- 140 81 nerable to the particular health problem. If people believe they are ical health risks (high risk, low risk, or no information) and 141 82 not vulnerable to a health problem, they are less likely to act to psychological risks, defined as the suffering of possible men- 142 83 prevent this problem [20]. Perceived severity refers to an individu- tal or emotional trauma or stress related to the vaccine, for 143 84 als’ belief that not acting to prevent the health problem will lead to example, the stigma associated with STIs or increased sexual activ- 144 85 severe consequences. Lower perceived severity reduces intentions ity/promiscuity (present or absent); (c) susceptibility, or likelihood 145 86 to enact a health behavior. In terms of perceived benefits, if indi- of contracting the HPV virus (high susceptibility, low susceptibility, 146 87 viduals believe that the health behavior will reduce the threat (thus or no information); (d) severity, or whether HPV is linked to cer- 147 88 providing benefits to the person), they are more likely to adopt the vical cancer (yes or no); and (e) self-efficacy, defined as steps one 148 89 behavior. Perceived barriers to performing the behavior also play could take to obtain the vaccine (present or absent). 149 90 into the decision, as those who believe the costs of adopting the 91 behavior are too high will not perform the behavior. Finally, per- 92 ceived self-efficacy refers to a person’s belief in his or her ability 2.3. Coding procedure 150 93 to perform the behavior, which will positively affect motivation to 94 perform the behavior. Using the HBM as a framework, we analyze The unit of analysis was the individual website. If little informa- 151 95 information available on the websites returned by an online search tion was presented on the initial page, coders were instructed to 152 96 in terms of the five predictors of vaccine acceptance. go one level down, or click only on links contained within the ini- 153 97 Additionally, we examine the sources of the websites, the tones tial page and internal to that page [22]. Coders were instructed not 154 98 of the websites, and possible associations between the type of to click on additional links on the subsequent page (i.e. go another 155 99 source and the tone of the website. We also investigate the pres- level down). This procedure was adopted because some websites 156100 ence of anti-vaccine themes related to conspiracy theories and civil contained very limited information on the opening page. To assess 157101 liberties and possible associations between the type of source and what information people would find, coders needed to explore ini- 158102 mention of either anti-vaccine theme. tial links. Two coders, who were blind to the research questions, 159 coded all of the websites about the HPV vaccines. The coders were 160 instructed on the definitions of the categories and their operational- 161103 2. Methods izations. A third coder (one of the authors) independently coded 162 15% of the websites in the sample (n = 14). Intercoder reliability 163104 2.1. Website sample was assessed with Krippendorff’s alpha, which was 0.95 overall. In 164 several categories, intercoder reliability was 1.00, including effec- 165105 The most frequently used online search engines are Google, tiveness, severity, psychological risks, self-efficacy, civil liberties, 166106 Yahoo, Bing, and [21]. We used these four search engines and conspiracy theories. Additional intercoder reliability scores 167107 on October 30, 2010 to locate websites related to the HPV vaccine. were 0.90 for source, 0.86 for susceptibility, 0.83 for tone, and 0.71 168108 The following search terms were used: HPV vaccine, HPV vacci- for health risks, all acceptable results considering the conservative 169109 nation, HPV immunization, human papillomavirus vaccine, human nature of Krippendorff’s alpha [23]. 170110 papillomavirus immunization, Gardasil, and Cervarix. Prior content111 analyses have used similar terms to locate information about vac- 2.4. Data analysis 171112 cination [9] and indicated the importance of using both vaccination113 and immunization as keywords [11]. Previous research found that Data were analyzed using SPSS for Windows (Version 16.0; SPSS, 172114 people choose to view one of the first 10 websites returned by a Inc., Chicago, IL). Descriptive statistics were run to assess the fre- 173115 search 97% of the time [7]. Therefore we retained the top 10 results quencies of source, tone, and the factors of the HBM. Additionally, 174116 from each search performed in our study. Duplicate websites were Chi-square analyses were performed to analyze relations between 175117 eliminated and sponsored links were not selected. As a result, a tone of the website and source of the website and between source 176118 total of 96 websites were retained. Of those 96 websites, seven of the website and HBM factors. 177 Please cite this article in press as: Madden K, et al. Sorting through search results: A content analysis of HPV vaccine information online. Vaccine (2011), doi:10.1016/j.vaccine.2011.10.025
  3. 3. ARTICLE IN PRESS G Model JVAC 12467 1–6 K. Madden et al. / Vaccine xxx (2011) xxx–xxx 3 Fig. 1. Source and tone of websites.178 3. Results Many leading health authorities, including the Centers for Disease 199 Control and Prevention (CDC), support cervical cancer vaccination 200179 Of the 89 websites coded, 31 (34.8%) websites were from for girls and young women.” An example of negative tone is this 201180 nonprofit or academic organizations. The second largest source excerpt from a blog: “The truths about Gardasil® and cervical can- 202181 category was governmental agencies, with 22 websites (24.7%). cer are suppressed. I am not just talking about the controversial 203182 Additionally, 14 websites (15.7%) were developed by pharmaceu- adverse reports of embolisms, strokes, motor neuron degeneration, 204183 tical companies, 11 (12.4%) website pages were published by news numbness, muscle weakness, paralysis, heart disorders, skin disor- 205184 organizations, five (5.6%) were consumer generated, three (3.4%) ders, extreme fatigue, debilitating headaches, recurring dizziness, 206185 fell under the category of encyclopedic medical websites, 2 (2.2%) seizures, and death. I am talking about the plain, unequivocal truth 207186 were published by professional organizations, and one website was about cervical cancer and Gardasil.” The blog goes on to provide 208187 Q3 developed by a medical center or hospital (see Fig. 1). information dismissing Gardasil’s effectiveness and the prevalence 209188 The website’s tone was also recorded. The majority of the web- of cervical cancer. 210189 sites were neutral in tone, as 51 (57.3%) of the websites were neutral We examined whether there was a relation between tone 211190 toward the HPV vaccines. Additionally, 25 (28.1%) of the websites of the website and source of the website. We excluded four 212191 were positive in tone, or supportive of the HPV vaccines, 7 (7.9%) source categories that had five or fewer websites (consumer gen- 213192 were negative in tone, or disapproving of the HPV vaccines, and erated information, nongovernmental advocacy groups, medical 214193 6 (6.7%) websites were ambiguous in tone, indicating that the site centers/hospitals, and encyclopedic medical sites). The remaining 215194 provided information both positive and negative in tone (see Fig. 2). four source categories were submitted to a series of Chi-square 216195 An example of positive tone is demonstrated on a webpage from tests. A significant relation was found between tone of the website 217196 the pharmaceutical manufacturer GlaxoSmithKline: “Vaccination and source of the website ( 2 (9, N = 78) = 27.970, p < 0.01). Although 218197 with CERVARIX can help stop cervical cancer before it starts. Really! the majority of news sources were coded as neutral (45.5%), 27.3% 219198 CERVARIX is your shot at stopping cervical cancer before it starts. of news sources were coded as negative, and 18.2% were positive 220 in tone. In comparison, none of the governmental agencies’ web- 221 sites or the pharmaceutical websites was negative in tone, and 222 two (6.5%) websites posted by nonprofit or academic organizations 223 were negative in tone. Information related to tone of website by 224 source is also included in Fig. 1. 225 Content of the websites was assessed with respect to mentions 226 of conspiracy theories and civil liberties and the five factors of the 227 Health Belief Model. Two websites (2%) made reference to possible 228 conspiracy theories and eight sites (9%) mentioned civil liberties 229 associated with HPV vaccination. Arguments for a conspiracy the- 230 ory were evident on a webpage from Natural News: “If true, this 231 information reveals details of an enormous public health fraud 232 being perpetrated on the American people, involving FDA officials, 233 Big Pharma promoters, and even the governors of states like Texas.” 234 An example of a reference to civil liberties includes this excerpt 235 from a webpage published by the National Conference of State Leg- 236 islatures: “Some people who support availability of the vaccine do 237 not support a school mandate, citing concerns about the drug’s cost, 238 Fig. 2. Tone of websites overall. safety, and parents’ rights to refuse.” 239 Please cite this article in press as: Madden K, et al. Sorting through search results: A content analysis of HPV vaccine information online. Vaccine (2011), doi:10.1016/j.vaccine.2011.10.025
  4. 4. ARTICLE IN PRESS G Model JVAC 12467 1–6 4 K. Madden et al. / Vaccine xxx (2011) xxx–xxx or gave ways in which to obtain the vaccine and 44 (49.4%) did not 264 provide such information (see Fig. 4). 265 We also examined if there was any association between the type 266 of source and specific website content through Chi-square tests. 267 A significant relation was found between source and self-efficacy, 268 ( 2 (3, N = 78) = 12.913, p < 0.01). Governmental sources were the 269 most likely to report steps to get the vaccine with 72.7% provid- 270 ing this information. News sources were the least likely to provide 271 self-efficacy information, with only one of the 11 news websites 272 providing information about steps to get the vaccine. 273 4. Discussion 274 As young women and even young men and their caregivers con- 275 sider whether or not to receive the HPV vaccine, it is important 276 Fig. 3. HBM content on websites. Notes: effectiveness – how did the website describe to understand the information available for them to make such a 277 the effectiveness of the HPV vaccine; health risks – how did the website describe the level of physical health risks associated with receiving the vaccine; susceptibility – decision. An increasing number of people turn to the Internet for 278 how did the website describe one’s susceptibility to HPV infection. health information, and most visit top search engine sites to begin 279 their research. The current study investigated the nature of HPV 280 vaccine information on websites returned by searching Google, 281240 In terms of the five factors of the HBM, 52 (58.4%) websites indi- Yahoo, Bing, and through a systematic content analy- 282241 cated that the HPV vaccine was highly effective, six (6.7%) indicated sis of 89 websites, specifically in the context of the Health Belief 283242 low effectiveness of the vaccine, and 31 (34.8%) did not mention Model. Although past research has failed to provide significant 284243 effectiveness. For health risks, 11 (12.4%) indicated high health risks evidence of the impact of online information on health behavior 285244 associated with the HPV vaccine, 32 (36%) reported low risks, and [24,25], several recent studies have suggested or shown that expo- 286245 46 (51.7%) did not mention any risks. For susceptibility, 53 (59.6%) sure to online health information can affect behavioral intentions 287246 reported high susceptibility, six (6.7%) reported low susceptibil- and actions specifically in the context of vaccination [26,27], mak- 288247 ity, and 30 (33.7%) did not report susceptibility (see Fig. 3). For ing it important to explore how websites may be used as a tool to 289248 psychological risks, six (6.7%) of the websites relayed information facilitate decision-making by those considering HPV vaccination. 290249 about psychological risks, while 83 (93.3%) did not describe any Web-based interventions pose a series of advantages compared to 291250 psychological risks. One example of a psychological risk was from offline communication programs, including increased interactivity, 292251 a nursing center resource page: “Will the HPV vaccine encourage more flexibility, and reduced costs [28,29]. Search engine results 293252 sexual activity among teenagers? Concerned Women for America may also provide individuals with information opposed to as well 294253 (CWFA) states, ‘Giving the vaccine to young girls before they are as similar to their previously held views [30], which increases the 295254 sexually active provides them with a false sense of security, possi- chance for attitude change. On the other hand, the web also makes 296255 bly leading to risky sexual behavior that would not have occurred it easier for negative vaccine information to circulate and under- 297256 had the threat of cervical cancer been present.’ A quote by 17-year- mine vaccination attitudes and behaviors, and perceptions of risks 298257 old Simmone Leslie in the New York Amsterdam News suggests that related to vaccines. Therefore, efforts need to be undertaken to 299258 this concern may be valid: ‘Hopefully, it will be available [Gardasil] counteract such negative information online. 300259 so you won’t need parental consent because not every teenager Overall, we found that the majority of websites were neutral or 301260 would want their parents to know whether or not they are sex- positive in tone, supporting the HPV vaccine, and few websites were 302261 ually active.”’ In terms of severity, 66 (74.2%) described the link negative in tone or in opposition to people receiving the vaccine. 303262 between HPV and cervical cancer and 23 (25.8%) failed to describe This finding may appear encouraging considering prior content 304263 the connection. Additionally, 45 (50.6%) encouraged self-efficacy analyses [9,10] have demonstrated that online searches for the term 305 Fig. 4. Additional HBM content on websites. Notes: psychological risks – whether the website discussed any psychological risk associated with receiving the vaccine; severity – whether the website reported the link between HPV infection and cervical cancer; self-efficacy – whether the website discussed steps to get the vaccine. Please cite this article in press as: Madden K, et al. Sorting through search results: A content analysis of HPV vaccine information online. Vaccine (2011), doi:10.1016/j.vaccine.2011.10.025
  5. 5. ARTICLE IN PRESS G Model JVAC 12467 1–6 K. Madden et al. / Vaccine xxx (2011) xxx–xxx 5306 vaccination tend to result in a fair amount of anti-vaccination infor- Internet searches in our content analysis did not provide readers 372307 mation. The difference in tone may be due to greater acceptance of with information about the connection. 373308 the vaccine or the waning of the initial worry about the untested The majority of the top websites returned by search engines 374309 nature of the vaccine. Differences in results of tone between this indicated a high level of susceptibility to HPV, but more than a third 375310 study and others could be due to procedural difference as well. We of the websites did not include information about susceptibility, 376311 attempted to include more search terms than were typically used despite the fact that HPV is the most common sexually transmitted 377312 in prior analyses and relied on multiple popular search engines disease. A survey study [34] found that nearly half of young women 378313 rather than a single search engine to arrive at the most compre- were unaware of the prevalence of HPV and considered themselves 379314 hensive evaluation. This qualification must then be applied to all not at risk to contract the virus. If a third of the websites returned by 380315 comparisons hereafter. top search engines fail to provide information about susceptibility, 381316 Some may suspect that those in vaccine critical communities young women may continue to be misinformed. 382317 have found alternative forums for criticism (new media channels Certain types of sources provided more information than other 383318 such as MySpace or YouTube). Some research exploring these out- types of sources in terms of self-efficacy. Governmental agency 384319 lets found coverage to be more positive than negative [16,17]. More websites, the second largest source category, were the most likely 385320 recent analyses, however, indicate a greater amount of negative to provide steps to get the HPV vaccine. This aligns with Tristram’s 386321 discourse [31]. Additional research is needed to examine social net- [35] recommendation for HPV vaccination programs to collaborate 387322 work platforms, where the individual layperson is able to engage with governmental organizations. News sources, however, con- 388323 freely in the conversation surrounding the HPV vaccine. tinue to provide little information related to self-efficacy. 389324 More than a quarter of news sources were negative in tone in It may also be important to note that few websites (5.6%) were 390325 contrast to websites in the other source categories, which were user generated. Among the five we located, two of the webpages 391326 overwhelmingly positive or neutral in tone toward the HPV vac- were blogs that negatively portrayed the HPV vaccine, two were 392327 cine. Although not surprising that the news media may take a users responding to other users’ questions in online forums, and 393328 more critical stance on the vaccine than governmental agencies or the fifth webpage was simply an informational blog about the 394329 pharmaceutical websites, this negative coverage may undermine HPV vaccine. The lack of user-generated sources in the top search 395330 governmental efforts aimed at increasing levels of vaccination. results was countered by the abundance of non-profit and academic 396331 Very few websites mentioned conspiracy theories related to sources, which, according to Tozzi et al. [18], provide more accu- 397332 governmental agencies or pharmaceutical companies, but nearly rate and clearly written content, as well as transparency for and 398333 one in ten websites did mention threats to civil liberties, indicating accountability to users. The superior quality of these sites may have 399334 that parents’ concern about mandating the HPV vaccine is a critical led them to be more frequently visited, more likely to appear in the 400335 issue alive in the HPV vaccine discussion. This has been a continuing top search results, and thus potentially more consequential in the 401336 debate, as Gostin and DeAngelis [32] found that legislation attempts decision to get vaccinated against HPV. 402337 to make HPV vaccinations mandatory in schools has undermined There are a few limitations of our study that might be addressed 403338 public confidence and created a backlash of concerned parents. or present opportunities for future research. First, although the use 404339 To deal with this particular issue, Charo [33] recommended opt- of a variety of search terms may be seen as a strength of the study, all 405340 out programs for parents, in which they can choose to have their search terms used by individuals to search for information related 406341 children vaccinated without interfering with their right to attend to HPV vaccination may not have been included in the list. Survey- 407342 school. ing individuals about which search terms they actually use is an 408343 For those making the decision of whether or not to get important step for future research. 409344 themselves or their children vaccinated, complete and thorough Additionally, our data cannot provide an analysis of the way 410345 information about the vaccine seems imperative. HPV vaccines in which people may use websites from different sources and 411346 have been reported to be effective at preventing the virus and ultimately the way in which they are influenced by different 412347 subsequently cervical cancer. More than half of the websites in sources. An important direction for future research, therefore, is to 413348 our sample reported high effectiveness of the HPV vaccines and understand the impact of information source on how HPV vaccine 414349 a third of the websites did not mention effectiveness of the HPV information is perceived and utilized in decision-making. Further- 415350 vaccines. Only a few reported low effectiveness. From this analy- more, risk perceptions are key in predicting health behavior, more 416351 sis one might expect that people searching for information online so than an objective account of information. Our study could not 417352 about HPV vaccines would come to the conclusion that the vaccine provide answers to individual reception of the presented infor- 418353 is effective. However, people may interpret missing information mation. However, understanding the information available that 419354 about vaccine effectiveness to be as much of a cause for concern as may influence perceptions may be seen as an important formative 420355 information indicating low effectiveness. Habel et al. [15] lamented research step. 421356 the fact that media coverage of the HPV vaccine failed to pro- Another limitation of this research is the lack of information 422357 vide accurate information about the effectiveness of the vaccine on when the studied websites were last updated. This information 423358 and noted incorrect information about effectiveness might lead to would be crucial for determining whether the HPV vaccine infor- 424359 delays in immunization and fewer people choosing to receive the mation presented was reflective of an ongoing trend or simply a 425360 vaccine. residual from past debate. Because our study was conducted after 426361 Additionally, in our content analysis, we found 74% of websites the controversy over vaccine mandates had peaked, it is possible 427362 made the connection between HPV and cervical cancer, while 26% that some of the negative discourse we discovered was an artifact 428363 of websites failed to provide a link. The percentage of websites mak- from the previous debate. 429364 ing this connection is a slight increase from the percentage of online This study was limited to search results returned from search 430365 news articles (70%) establishing the link between HPV and cervi- engines within the United States. Other studies may seek to inves- 431366 cal cancer in 2006 [15], but a sharp decrease from the percentage tigate online information available about the HPV vaccine in other 432367 of offline news articles and broadcasts providing the connection countries, as Tozzi et al. have done [18]. 433368 (99%) in 2005 and 2006 [14]. Calloway et al. [12] argued that the In conclusion, our analysis showed that while most informa- 434369 failure to connect cervical cancer to HPV might influence the pub- tion available about the HPV vaccine online is positive or neutral, 435370 lic’s acceptance of the vaccine. Despite scientific research linking negative information exists as well. Health professionals need to 436371 HPV with cervical cancer, a quarter of the top websites returned by consider the potential impact of negative information and devise 437 Please cite this article in press as: Madden K, et al. Sorting through search results: A content analysis of HPV vaccine information online. Vaccine (2011), doi:10.1016/j.vaccine.2011.10.025
  6. 6. ARTICLE IN PRESS G Model JVAC 12467 1–6 6 K. Madden et al. / Vaccine xxx (2011) xxx–xxx438 ways to counteract false or negative statements, including infor- [14] Kelly BJ, Leader AE, Mittermaier DJ, Hornik RC, Cappella JN. The HPV vaccine and 483439 mation related to civil liberties. The negativity of news stories, the media: how has the topic been covered and what are the effects knowledge 484 about the virus and cervical cancer? Patient Educ Couns 2009;77:308–13. 485440 in particular, is a cause for concern and may indicate the need [15] Habel MA, Liddon N, Stryker JE. The HPV vaccine: a content analysis of online 486441 for better training of journalists in relaying vaccine information. news stories. J Womens Health 2009;18:401–7. 487442 Additionally, the websites we studied presented suboptimal or [16] Keelan J, Pavri V, Balakrishnan R, Wilson K. An analysis of the human papilloma 488 virus vaccine debate on MySpace blogs. 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