Human papillomavirus (HPV) vaccination is a safe and effective primary prevention strategy for cervical cancer.1 Two HPV vaccines have been approved for use in the United States: a quadrivalent vaccine (Gardasil; Merck, Whitehouse Station, NJ) that protects against HPV types 6, 11, 16, and 18 and a bivalent vaccine (Cervarix; GlaxoSmithKline, Middlesex, UK) that protects against types 16 and 18. Human papillomavirus types 16 and 18 cause more than 70% of all cervical cancer cases, whereas HPVs 6 and 11 cause 90% of all genital warts cases.1 Despite recommendations for routine vaccination,1,2 HPV vaccine uptake in the United States has been low. Only 48.7% and 20.7% of US girls aged 13 to 17 years and women aged 19 to 26 years, respectively, have received at least 1 dose of the 3-dose series.3,4 Series completion rates are even lower, particularly among black and Hispanic females and adolescent females living below the poverty level.3,5
Despite the need for effective HPV vaccination interventions, relatively few have been tested.6–9 Moreover, the standard approach used in most intervention studies has been simply to provide general information about HPV infection and vaccination.6–8,10 This one-size-fits-all approach fails to consider the following: knowledge alone may be insufficient for promoting behavior change11 and the persuasiveness of health communications is enhanced when messages are tailored to individual characteristics of the message recipient.12,13
Message tailoring is one intervention approach that successfully addresses both of these issues. Tailoring is a health communication strategy in which health messages are individualized based on preassessment of key individual difference variables from the underlying theory of health behavior change.12 Tailored messaging helps focus attention on information that individuals may find more personally relevant, thus providing an opportunity to directly address factors that might hinder or support the enactment of a prescribed health behavior. Various meta-analyses have found tailoring to have significant effects on health behaviors (e.g., smoking cessation and cancer screening) and other theoretically relevant predictors (e.g., self-efficacy and behavioral intentions).13–16
Perceived barriers are a key component of the Health Belief Model and one of the strongest psychosocial determinants of health behavior change,17 including HPV vaccine uptake.18–21 Perceived barriers to HPV vaccination fall into 5 broad domains: vaccine expense, logistical concerns (e.g., lack of time and limited access), concerns about adverse effects and vaccine safety, discomfort and/or pain from the injection, and low perceived need for the vaccine.22 Research suggests that the relative importance of these barriers varies considerably across individuals. Some women are primarily concerned about vaccine safety, whereas others cite perceived lack of need or practical concerns related to obtaining the vaccine (e.g., vaccine cost) as primary deterrents to vaccination.22 Because perceived barriers predict subsequent HPV vaccine uptake,18–21 reducing individual barriers may be an effective strategy for promoting HPV vaccination in this population.
This study investigated whether tailoring intervention materials to women’s perceived barriers would increase their interest in receiving the HPV vaccine. Unvaccinated female participants were randomly assigned to read a tailored or nontailored message about HPV vaccination. We hypothesized that relative to participants in the nontailored condition, participants in the tailored condition would report greater increases in their intentions to receive the HPV vaccine.
Women attending a southeastern university were recruited though the university’s Web-based course management system (Blackboard) and the psychology department subject pool. Eligibility criteria included being female, aged 18 to 26 years, not having received any doses of HPV vaccine, and not currently pregnant. Interested individuals recruited via Blackboard completed a brief online screening survey to determine their eligibility. Other related questions were also included in the survey (e.g., age of first period and receipt of Hepatitis vaccines) to mask the true nature of the study. Women in the subject pool were screened via a questionnaire administered at the beginning of the semester. Eligible participants were invited via e-mail to schedule their session. All participants were rescreened for eligibility upon arrival to the laboratory. Three participants were ineligible after rescreening because they had recently initiated the series. In all, 64 participants from the general student body and 30 participants from the subject pool took part in the study (N = 94; Table 1).
The study was approved by the University Human Subjects Committee. Data collection occurred from late January through early April 2011. Participants completed the study one at a time. After providing informed consent, participants were rescreened for eligibility. Next, the experimenter randomly assigned participants to the tailored (n = 45) or nontailored (n = 49) condition based on a random assignment list created with a random number generator. Participants began by reading a short paragraph about HPV vaccination and then completed a brief survey on their perceived barriers to HPV vaccination (assessed with a checklist; see Table 2). While the participant completed the remainder of the pretest questionnaire, the experimenter prepared an information binder that was either tailored or not tailored to the participant’s perceived barriers. Participants were given a minimum of at least 8 minutes to review the binder. Those participants in the tailored condition received 1 extra minute for each additional card in their binder (details later). Finally, participants completed a posttest questionnaire and were debriefed. General student body participants received $10 cash, and subject pool participants received course credit for participating.
Participants in both conditions received basic information about HPV infection and vaccination adapted from the Centers for Disease Control and Prevention Web site. Information was presented in a “Question and Answer” format (e.g., How do people get HPV? Genital HPV is spread from one person to another by sexual contact…) printed on 6 cards in a binder (see Table 3). Participants in the tailored condition received the same basic information plus additional information tailored to their perceived barriers. Separate cards were developed to address 10 common perceived barriers to HPV vaccination, which matched the barriers assessed on the pretest. For example, participants concerned about vaccine safety were provided with information about the comprehensive Food and Drug Administration approval process for new vaccines. Tailored information binders included cards for every perceived barrier identified by individual participants. Tailored cards were not included for the following 2 perceived barriers—“I don’t know enough about the HPV vaccine” or “I just haven’t gotten around to getting the vaccine yet”—because these barriers were addressed indirectly in the basic information. Thus, participants in the tailored condition could potentially receive up to 8 additional cards in their set.
Perceived Barriers to HPV Vaccination
Perceived barriers were assessed using dichotomous and continuous measures on the pretest questionnaire (Table 2). For the dichotomous measure, participants were presented with a list of 10 reasons women may not have received the HPV vaccine and were asked to check all reasons, if any, that applied to them and then identify the primary reason they have not received the HPV vaccine. Barriers fell under 5 domains (cost, logistics, pain, safety, and perceived lack of need) derived from our previous work with this population.22 Two additional options were included on the checklist for women who (1) perceived themselves as having limited knowledge about HPV vaccines and/or (2) were intending to receive the vaccine but had not yet had a chance to do so. Participants also had the option to select “None of these reasons apply to me” and/or to enter any additional reason(s) not included on the list. To provide a continuous measure, participants rated the extent to which each barrier would prevent them from getting vaccinated for HPV in the next year (1 = not at all to 5 = a great deal).
Items were included on the pretest to assess sexual orientation, current relationship status, Papanicolaou testing history, and whether participants had previously engaged in vaginal intercourse and, if so, age of first intercourse and number of lifetime sexual partners.
HPV Awareness and Knowledge
Human papillomavirus and HPV vaccine awareness were assessed on the pretest using 2 items from previous research23: “Before you came here for this study today, had you ever heard of HPV and HPV vaccines (also known as Gardasil, Cervarix, the cervical cancer vaccine, or the HPV shot?)” Knowledge about HPV was assessed with 10 true-false items at pretest and posttest. A “don’t know” option was included to discourage guessing. Participants received 1 point for each correct response and 0 points for incorrect and “don’t know” responses. Points were summed to create pretest and posttest scores.
HPV Vaccination Intentions
Intentions to receive the HPV vaccine in the next year were assessed at pretest and posttest, with 5 items used in previous research20,24,25: “In the next year, how likely is it that you will: try to get more information about, consider getting, try to get, and actually get the HPV vaccine?” Participants also rated the likelihood they will get the HPV vaccine if a health care provider offered it to them in the next year (1 = very unlikely to 7 = very likely). Items were averaged to create a pretest (α = 0.95) and posttest score (α = 0.96).
Evaluations of the Health Information
Participants used a 5-point scale (1 = disagree strongly to 5 = agree strongly) to rate the extent to which information in the binder was informative, convincing, and difficult to understand (reverse scored) and the extent to which the binder discussed important health information for students. As a tailoring manipulation check, participants rated the extent to which the information “seemed personalized for me” and “was relevant to me.”
We used t tests and χ 2 analyses to compare participants in the tailored versus nontailored conditions on demographics, sexual history variables, awareness, perceived barriers, evaluations of the information, and the tailoring manipulation check items. We used a mixed (between-within)-factor-design analysis of variance to examine effects of the intervention on change in HPV knowledge over time (from pretest to posttest). For our primary analysis, we used a mixed-factor-design analysis of variance to examine the effects of the intervention on change in HPV vaccination intentions from pretest to posttest, controlling for baseline differences in “concern about possible adverse effects of the vaccine” and whether participants had ever engaged in vaginal intercourse. We report partial η 2 as a measure of effect size. We used SPSS version 19 (SPSS Inc., An IBM Company, Armonk, NY) to analyze the data. All statistical tests were 2 tailed.
Characteristics of Women Enrolled in the Study
Characteristics of enrolled women are provided in Table 1. Participants in the tailored and nontailored conditions were not significantly different in regard to demographic variables, sexual history variables, or HPV/HPV vaccine awareness (data not shown).
Perceived Barriers to HPV Vaccination
Descriptive data on perceived barriers to HPV vaccination are reported in Table 2. The mean (SD) number of barriers selected was 3.07 (1.28; range, 1–6). The most commonly selected barrier and primary reason for not getting vaccinated was concern about adverse effects. The next 2 most common barriers selected were concerns about the safety of the vaccine and limited knowledge about HPV vaccines. Fourteen percent entered other reasons for not getting vaccinated, with some providing specific examples of barriers already on the checklist and others providing additional reasons such as health insurance issues, concern that the vaccine provides only limited protection, parental opposition, and low perceived need.
The percentage of participants endorsing each perceived barrier was equivalent across the 2 experimental conditions, with one exception. A larger proportion of participants in the nontailored condition (74%) reported that they were “concerned about possible adverse effects of the vaccine” relative to participants in the tailored condition (36%): χ 2 (1, N = 94) = 13.64, P < 0.001. Likewise, further analysis of the continuous perceived barrier items showed that participants in the nontailored condition were more concerned about adverse effects (mean [SD], 3.78 [1.20]) than participants in the tailored condition (mean [SD], 3.16 [1.48]; t 92 = 2.45; P = 0.027). No differences in the primary barrier selected were observed across the 2 conditions.
Evaluations of the Health Information
Individuals in the nontailored and tailored conditions did not differ in their evaluations of the health information (all P values > 0.55). The tailoring manipulation check revealed that participants in the tailored condition perceived the information to be more personalized (mean [SD], 3.96 [0.88]) and relevant (mean [SD]. 4.40 [0.75]) than participants in the nontailored condition (mean [SD], 3.39 [1.10; t 92 = −2.76; P = 0.007] and 4.04 [0.91; t 92 = −2.07, P = 0.041], respectively).
We observed a significant increase in HPV knowledge from pretest (mean [SD], 4.99 [2.22]) to posttest (mean [SD], 8.23 [1.20]; F 1, 92 = 216.71; P < 0.001; partial η 2 = 0.702); however, no main effect of condition or condition by time interaction was observed.
HPV Vaccination Intentions
Participants who previously had sex indicated greater intentions to receive the HPV vaccine compared with participants who had never had sex (F 1, 90 = 4.86, P = 0.030, partial η 2 = 0.051). We also observed a significant effect of time such that intentions to receive the HPV vaccine increased from pretest to posttest (F 1, 90 = 54.63, P < 0.001, partial η 2 = 0.378). Most important, we observed the predicted condition by time interaction such that the increase in HPV vaccination intentions from pretest to posttest was larger for participants in the tailored condition relative to the nontailored condition (F 1, 90 = 4.02, P = 0.048, partial η 2 = 0.043; Fig. 1). No other effects were observed. Simple main effects tests confirmed that the increase in vaccination intentions from pretest to posttest was significantly greater within the tailored condition (P < 0.001, partial η 2 = 0.316) than the nontailored condition (P < 0.001, partial η 2 = 0.138).
This study provides encouraging evidence that tailoring intervention materials to women’s perceived barriers to HPV vaccination may be an effective strategy for increasing HPV vaccine uptake. Participants’ intentions to receive the vaccine increased from baseline to follow-up in both the tailored and nontailored conditions, yet this increase was significantly greater for women who received information that specifically addressed their perceived barriers to receiving the vaccine. These findings support previous research demonstrating the positive effects of tailoring on known psychosocial predictors of health behavior.13–16,26
In this trial, tailored messaging directly addressed one of the primary predictors of HPV vaccination uptake—perceived barriers. Results show that although the barriers to HPV vaccination endorsed by participants were largely consistent with those observed in previous studies,22,27 they were highly individualized, with participants citing anywhere between 1 to 6 barriers each. Some women qualified their responses by providing specific examples, whereas others noted other barriers not included in the original checklist. This further suggests the importance of providing individualized messages rather than generic, one-size-fits-all information.16,26,28
We manually evaluated women’s pretest responses to create a tailored information binder using print-based cards. As such, experimenters were not blind to condition. Future HPV vaccination interventions could remedy this issue and achieve more sophisticated levels of tailoring through the use of computer algorithms. Tailoring on multiple demographic, psychosocial, and behavioral variables could also possibly lead to larger effects than those observed in the present study because we only tailored on one psychosocial predictor of HPV vaccine uptake. Access to and engagement in these tailored interventions could likewise be enhanced through interactive, Web-based, and mobile technologies. Various meta-analyses have found computer-tailored, Web-delivered interventions to be effective for other health behaviors,14–16 but there are limited efficacy studies for HPV prevention.
Limitations of this study reveal important directions and considerations for future research. First, the small sample size precluded us from examining whether the tailoring intervention significantly reduced those perceived barriers selected by individual women. Because some barriers may be more resistant to change than others, it will be important for future research to investigate this issue more thoroughly. Second, participants were recruited from a convenience sample of women attending college; thus, findings may have limited generalizability. Additional research should extend recruitment to community samples that may be more representative of the population of unvaccinated young adult women. Third, our primary outcome variable was HPV vaccination intentions instead of behavior. Future studies should assess the effects of a tailored approach on both uptake and series completion. Exploring the feasibility of implementing the present tailored messaging intervention in a doctor’s office or clinic waiting room is another interesting direction for future research.
In closing, findings provide promising evidence of the effectiveness of tailoring for increasing HPV vaccination in young adult women. Given the relatively low rates of HPV vaccine uptake in the United States, innovative and effective strategies will be critical to promoting large-scale acceptance of the vaccine. Because few interventions have been rigorously tested, these findings represent an important step forward for efforts aimed at reducing cervical cancer and other HPV-related disease.
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