Abstract
Background
Beliefs are known to be a key determinant in vaccines’ uptake. However, little is known about beliefs surrounding the success of the human papillomavirus (HPV) vaccine in preventing cervical cancer in the United States.
Methods
Data from the Health Information National Trends Survey 5 Cycle 1 (2017) were analyzed for 1851 female respondents aged 18 years and older. Weighted multinomial logistic regression was employed to determine predictors of beliefs in the success of the HPV vaccine in preventing cervical cancer.
Results
Overall, 29.8% of women believed that HPV vaccine is successful in preventing cervical cancer, 6.6% believed it is not successful, and 63.6% did not know if the HPV vaccine is successful. Non-Hispanic blacks (adjusted odds ratio [aOR] = 1.80, 95% confidence interval [CI] = 1.16 to 2.79), women with no more than 12 years of education (aOR = 2.05, 95% CI = 1.17 to 3.60), those who did not know if they were advised by a health-care provider to get an HPV shot within the last 12 months (aOR = 4.19, 95% CI = 1.39 to 12.60), and those unaware of a family cancer history (aOR = 5.17, 95% CI = 1.48 to 18.21) were more likely to not know whether the HPV vaccine prevents cervical cancer. Women younger than 65 years were more likely than elderly to believe that the HPV vaccine is not successful at preventing cervical cancer.
Conclusions
A substantial proportion of US women are uninformed about the HPV vaccine. To accelerate progress in the HPV vaccine’s uptake, future interventions should incorporate educational programs, particularly targeting Non-Hispanic blacks, women with a lower level of education, and those younger than 65 years. Health-care providers’ participation in promotion of patient education about HPV vaccination should also be increased.
Human papillomavirus (HPV) is the most common sexually transmitted agent in the United States and is primarily known for the causal role it plays in the development of cervical cancer (1,2). Virtually all cervical cancers are caused by 14 strains of HPV, leading to about 13 240 new cases and 4170 deaths in the United States each year (3). Although population-level screening programs have substantially reduced the burden of cervical cancer, geographic, ethnic, and racial disparities in cervical cancer morbidity and mortality still exist in the United States (4). These disparities are indicative of inequities in access to preventive care, largely stemming from barriers such as access to health care, cultural influences, and education (5).
Despite documented benefits of HPV vaccination such as evidence of safety and high efficacy in preventing HPV-associated cancers, attaining high coverage has been a challenging task in the United States, with recent trends suggesting that the Healthy People 2020 goal of 80% HPV vaccination coverage will not be achieved. More than a decade since the introduction of the HPV vaccine in the United States (6), less than half of eligible adolescents are up to date with HPV vaccination (7). More so, inequities have been observed in HPV vaccination access and uptake. For example, fewer people receive the HPV vaccine in rural areas compared with urban dwellings (7), and blacks have been shown to be less likely to initiate or complete the HPV vaccination schedule compared with whites (8–10).
Beliefs play a key determining role in general acceptance and uptake of vaccines (11). More pertinently, research suggests that individuals’ awareness and beliefs about HPV, HPV infection, HPV vaccination, and cervical cancer are determinants of HPV vaccination uptake (12,13). For example, belief that HPV vaccine is effective in cervical cancer prevention has been shown to have a positive influence on acceptance and receipt of the HPV vaccine (14,15). Therefore, assessing factors that predict beliefs surrounding key benefits of HPV vaccination, particularly its success in cervical cancer prevention, would provide critical insight for targeted efforts aimed at increasing HPV vaccination rates (16).
Health behavior theories have been employed to explain the influential role that sociodemographic factors have on health-related attitudes and beliefs (17,18). Although previous studies have assessed the predictors of knowledge and awareness of HPV, the HPV vaccine, and HPV-related diseases in the United States (19–21), little is known about the factors that predict beliefs in the success of HPV vaccine in preventing cervical cancer. Hence, this study examines the beliefs of US adult women about the success of the HPV vaccine in preventing cervical cancer.
Materials and Methods
HINTS Data and Study Population
We obtained data from the Health Information National Trends Survey (HINTS) 5, Cycle 1, administered by the National Cancer Institute. HINTS is a nationally representative, publicly available probability survey of adults aged 18 years or older in the civilian noninstitutionalized population of the United States. Cycle 5 data (response rate = 32.4%, n = 3285) were collected from January 25 through May 5, 2017. Details of survey development, design, and methodology have been published elsewhere and are available online (22). All questionnaire items in the HINTS have been tested to be reliable and valid before being administered. More information about the validation of the HINTS survey can be found at https://hints.cancer.gov/faq.aspx. All HINTS questionnaires, data, and reports are available at http://hints.cancer.gov/hints5.aspx.
This study focused on female respondents (n = 1914) of whom we excluded those with a personal history of cervical cancer (n = 37) and those with missing data for the outcome variable (n = 26).
Outcome Variable
Our study outcome was derived from the HINTS question: “In your opinion, how successful is HPV vaccine at preventing cervical cancer?” We categorized individuals who responded “very successful” or “pretty successful” as “successful”; “don’t know” as “don’t know”; and “a little successful” or “not at all successful” as “not successful.”
Independent Variables
Independent variables were selected based on previous literature (23), including age, race and/or ethnicity, household income, education, health behavior, and access. They were categorized as follows: age (18–34, 35–49, 50–64, and 65 years or older); education (no greater than 12 years or completed high school, post–high school training or some college, and college graduate or higher); household income (< $35 000; $35 000–$49 999; $50 000–$74 999; and ≥ $75 000); health insurance (yes, no). Health behavior and access was assessed with the following questions: 1) “When was your last Pap screen?” (within the last 3 years, more than 3 years ago but less than 5 years ago, unknown or never), and 2) “In the last 12 months, has a doctor or health-care professional recommended that you or someone in your immediate family get an HPV shot or vaccine?” (yes, no, don’t know). Race and ethnicity was categorized as Hispanic, non-Hispanic black (NHB), non-Hispanic white (NHW), Asian, and other.
Cigarette smokers were categorized as current, former, or never smokers. Personal cancer history was assessed with the question: “Have you ever been diagnosed as having cancer?” (yes, no). Family cancer history was assessed with the question: “Have any of your family members ever had cancer?” (yes, no, not sure). Mental health was assessed with the question: “Has a doctor or other health professional ever told you that you had any of the following medical conditions: depression or anxiety disorder?” (yes, no). Residence was classified along urban and rural categories using 2013 Rural Urban Continuum Codes (RUCCs) (24). RUCCs classify metropolitan areas at the county level by population size and nonmetropolitan areas by proximity to metropolitan areas and urbanization. Thus, RUCC 1–3 was classified as metropolitan (urban); RUCC 4–6 as median rural; and RUCC 7–9 as isolated rural.
Statistical Analysis
Analyses were performed using SAS (Version 9.4; SAS Institute Inc, Cary, NC) procedures, which incorporate survey sampling weights to account for the complex sampling design used in HINTS and to provide representative estimates of the US population. Weighted, unadjusted prevalence estimates (n, %) with their 95% confidence intervals (CI) were used to describe beliefs about the HPV vaccine’s success and to compare potential predictors by HPV vaccine belief category. For covariates with missing data, a missing data category was created. We used weighted, multinomial logistic regression models (GLOGIT) to determine correlates of beliefs about the HPV vaccine’s success in preventing cervical cancer among US adult women. To assess the noteworthiness of the strength of association between potential predictors of beliefs in the HPV vaccine and the outcome variable, we calculated a measure of the probability of false discovery called Bayesian false-discovery probabilities (BFDP) (25). In the multiple hypothesis-testing context, BFDP allows the false-discovery rate to be controlled by reducing the number of “discoveries” that are reported but not replicated in subsequent investigations (25). We calculated the BFDP value using a prior probability of 0.05 for an association. The standard recommended threshold of BFDP less than 0.8 was used to declare noteworthy associations. All variables included in this study were considered to be potential predictors of beliefs in the HPV vaccine and knowledge and thus were included in the final model even though some of these variables were correlated.
Results
Descriptive Characteristics
Overall, 29.8% of eligible respondents believed that the HPV vaccine is successful at preventing cervical cancer. Nearly two-thirds (63.6%) did not know if the HPV vaccine is successful at preventing cervical cancer, and 6.6% believed that the HPV vaccine is not successful at preventing cervical cancer. Of the study respondents, 74.8% have had a Pap test within the last 3 years.
Characteristics of the study population by beliefs in the success of the HPV vaccine in preventing cervical cancer is reported in Table 1. Belief that the HPV vaccine is successful at preventing cervical cancer was higher among respondents who were aged 18–34 years (weighted percentage [Wt] = 40.8%, 95% CI = 30.0% to 51.7%), Hispanic (Wt = 33.3%, 95% CI = 23.3% to 43.3%), US born (Wt = 30.6%, 95% CI = 26.7% to 34.5%), college graduates or postgraduates (Wt = 41.1%, 95% CI = 36.1% to 46.1%), advised by a health-care provider to get an HPV shot (Wt = 47.5%, 95% CI = 37.3% to 57.8%), and with a household income no less than $75 000 (Wt = 42.8%, 95% CI = 36.4% to 49.3%). This belief was lower among uninsured (Wt = 22.6%, 95% CI = 4.3% to 40.9%), current smokers (Wt = 22.6%, 95% CI = 14.7% to 30.6%), and respondents who were unsure of a family history of cancer (Wt = 7.2%, 95% CI = 1.4% to 13.0%).
Table 1.
Characteristics of the study population by beliefs in the success of the HPV vaccine in preventing cervical cancer, Health Information National Trends, 2018
| Characteristics | No. | In your opinion, how successful is the HPV vaccine at preventing cervical cancer? |
||
|---|---|---|---|---|
| Successful | Do not know | Not successful | ||
| Wt % (95% CI) | Wt % (95% CI) | Wt % (95% CI) | ||
| Age, y | ||||
| 18–34 | 245 | 40.8 (30.0 to 51.7) | 50.6 (40.9 to 60.2) | 8.6 (3.4 to 13.8) |
| 35–49 | 384 | 28.7 (22.8 to 34.5) | 64.2 (58.8 to 69.6) | 7.1 (4.6 to 9.7) |
| 50–64 | 586 | 29.7 (23.6 to 35.7) | 63.0 (56.5 to 69.5) | 7.3 (4.0 to 10.7) |
| ≥65 | 569 | 21.5 (17.2 to 25.7) | 77.2 (73.1 to 81.3) | 1.3 (0.3 to 2.3) |
| Missing | 67 | 6.4 (0.0 to 12.9) | 78.7 (64.6 to 92.9) | 14.9 (1.1 to 28.6) |
| Race/ethnicity | ||||
| White, non-Hispanic | 1029 | 32.4 (27.6 to 37.1) | 60.9 (56.5 to 65.4) | 6.7 (3.9 to 9.5) |
| Black, non-Hispanic | 274 | 19.1 (13.1 to 25.1) | 74.6 (68.4 to 80.7) | 6.3 (2.4 to 10.3) |
| Hispanic | 238 | 33.3 (23.3 to 43.3) | 62.5 (52.3 to 72.7) | 4.1 (0.9 to 7.4) |
| Asian | 69 | 33.1 (16.0 to 50.3) | 59.2 (37.3 to 81.1) | 7.7 (0.0 to 18.3) |
| Others | 67 | 31.7 (13.5 to 50.0) | 64.9 (45.8 to 84.0) | 3.4 (0.0 to 8.2) |
| Missing | 174 | 13.1 (7.2 to 18.9) | 75.0 (66.3 to 83.7) | 11.9 (5.4 to 18.4) |
| Education | ||||
| ≤12 years/completed high school | 497 | 19.2 (12.9 to 25.5) | 78.0 (71.8 to 84.3) | 2.8 (1.0 to 4.5) |
| Post–high school/some college | 525 | 27.8 (20.8 to 34.8) | 62.3 (55.4 to 69.2) | 9.8 (4.8 to 14.8) |
| College graduate/postgraduate | 783 | 41.1 (36.1 to 46.1) | 52.2 (47.5 to 56.9) | 6.7 (4.2 to 9.2) ) |
| Missing | 46 | 13.2 (0.0 to 28.2) | 71.5 (53.3 to 89.7 | 15.3 (0.7 to 30.0) |
| Household income | ||||
| <$35 000 | 626 | 22.3 (17.1 to 27.5) | 71.1 (65.1 to 77.1) | 6.6 (2.3 to 10.9) |
| $35 000–<$50 000 | 218 | 24.3 (15.0 to 33.6) | 70.8 (61.3 to 80.3) | 4.9 (1.5 to 8.3) |
| $50 000–<$75 000 | 286 | 28.6 (21.9 to 35.3) | 62.4 (55.0 to 69.7) | 9.1 (4.4 to 13.8) |
| ≥$75 000 | 530 | 42.8 (36.4 to 49.3) | 50.8 (44.3 to 57.3) | 6.4 (3.5 to 9.3) |
| Missing | 191 | 20.3 (7.5 to 33.0) | 74.3 (61.4 to 87.2) | 5.4 (1.1 to 9.7) |
| Last Pap test | ||||
| Within the last 3 years | 1367 | 31.4 (27.4 to 35.3 | 61.6 (57.7 to 65.5 | 7.0 (4.9 to 9.2) |
| 3–5 years | 410 | 20.9 (14.7 to 27.0) | 73.1 (66.7 to 79.5) | 6.0 (2.2 to 9.8) |
| Never | 47 | 38.3 (10.3 to 66.3) | 57.7 (29.8 to 85.7) | 3.9 (0.0 to 9.7) |
| Missing | 27 | 18.6 (0.3 to 36.9) | 78.3 (59.4 to 97.2) | 3.1 (0.0 to 9.7) |
| Smoking status | ||||
| Current smoker | 228 | 22.6 (14.7 to 30.6) | 74.2 (66.3 to 82.1) | 3.2 (0.3 to 6.1) |
| Former smoker | 436 | 30.7 (24.2 to 37.1) | 61.0 (53.8 to 68.2) | 8.3 (2.3 to 14.3) |
| Never smoker | 1182 | 31.1 (26.6 to 35.6) | 62.1 (58.1 to 66.2) | 6.8 (4.9 to 8.8) |
| Missing | 5 | 34.9 (0.0 to 100.0) | 65.1 (0.0 to 100.0) | — |
| Personal cancer history | ||||
| Yes | 261 | 21.2 (13.6 to 28.8) | 73.2 (65.2 to 81.2) | 5.6 (1.8 to 9.4) |
| No | 1586 | 30.6 (26.8 to 34.4) | 62.7 (59.2 to 66.1) | 6.7 (4.8 to 8.6) |
| Family cancer history | ||||
| Yes | 1334 | 31.6 (27.7 to 35.6) | 61.9 (58.1 to 65.7) | 6.5 (4.1 to 8.8) |
| No | 386 | 29.9 (22.4 to 37.4) | 62.8 (55.0 to 70.6) | 7.2 (3.2 to 11.2) |
| Not sure | 80 | 7.2 (1.4 to 13.0) | 91.5 (85.2 to 97.9) | 1.3 (0.0 to 3.6) |
| Health care professional recommended HPV shot? | ||||
| Yes | 190 | 47.5 (37.3 to 57.8) | 45.4 (35.5 to 55.4) | 7.1 (2.1 to 12.0) |
| No | 388 | 33.3 (26.0 to 40.6) | 57.6 (50.5 to 64.6) | 9.1 (5.0 to 13.2) |
| Don’t know | 132 | 15.9 (5.4 to 26.5) | 82.6 (71.5 to 93.8) | 1.4 (0.0 to 3.2) |
| Inapplicable* | 940 | 26.6 (23.0 to 30.1) | 67.4 (63.2 to 71.6) | 6.0 (3.0 to 9.0) |
| Missing | 201 | 17.5 (10.8 to 24.3) | 77.3 (69.7 to 85.0) | 5.1 (1.1 to 9.2) |
| Born in United States | ||||
| Yes | 1575 | 30.6 (26.7 to 34.5) | 63.1 (59.4 to 66.8) | 6.3 (4.3 to 8.3) |
| No | 240 | 26.9 (19.7 to 34.2) | 65.5 (56.2 to 74.7) | 7.6 (2.3 to 12.9) |
| Depression | ||||
| Yes | 485 | 32.1 (25.6 to 38.6) | 61.8 (55.3 to 68.3) | 6.1 (2.2 to 10.1) |
| No | 1337 | 29.2 (25.2 to 33.2) | 64.1 (60.4 to 67.7) | 6.7 (4.8 to 8.5) |
| Residence | ||||
| Urban | 1600 | 29.9 (26.3 to 33.6) | 63.5 (60.2 to 66.8) | 6.6 (4.5 to 8.7) |
| Median rural | 178 | 31.4 (18.1 to 44.6) | 60.9 (48.2 to 73.6) | 7.7 (1.4 to 14.1) |
| Isolated rural | 73 | 23.1 (11.8 to 34.5) | 71.9 (60.8 to 83.0) | 5.0 (0.0 to 10.4) |
| Health insurance | ||||
| Yes | 1747 | 30.6 (27.1 to 34.0) | 63.1 (60.2 to 66.1) | 6.3 (4.4 to 8.2) |
| No | 92 | 22.6 (4.3 to 40.9) | 67.1 (44.2 to 90.1) | 10.2 (2.4 to 18.0) |
The category “inapplicable” refers to respondents to the Health Information National Trends Survey 5, Cycle 1 survey who responded “no” to the question, “Including yourself, is anyone in your immediate family between the ages of 9 and 27 years old?” and thus were not eligible to respond to the question, “In the last 12 months, has a doctor or health-care professional recommended that you or someone in your immediate family get an HPV shot or vaccine?” CI = confidence interval; HPV = human papillomavirus; Wt = weighted percentage.
A higher proportion of women who did not know if the HPV vaccine is successful at preventing cervical cancer were aged 65 years and older (Wt = 77.2%, 95% CI = 73.1% to 81.3%), NHBs (Wt = 74.6%, 95% CI = 68.4% to 80.7%), in the lowest household income strata (<$35 000; Wt = 71.1%, 95% CI = 65.1% to 77.1%), current smokers (Wt = 74.2%, 95% CI = 66.3% to 82.1%), and had education levels no greater than 12 years of completed high school (Wt = 78.0%, 95% CI = 71.8% to 84.3%). This proportion was lower in women who have been recommended by a health-care provider to get an HPV shot within the last 12 months (Wt = 45.4%, 95% CI = 35.5% to 55.4%), in those with no personal cancer history (Wt = 62.7%, 95% CI = 59.2% to 66.2%), and in women with a family cancer history (Wt = 61.9%, 95% CI = 58.1% to 65.7%).
Higher proportions in the belief that the HPV vaccine is not successful at preventing cervical cancer were reported among women aged 18 to 34 years (Wt = 8.6%, 95% CI = 3.4% to 13.8%), Asians (Wt = 7.7%, 95% CI = 0.0% to 18.3%), uninsured (Wt = 10.2%, 95% CI = 2.4% to 18.0%), and those who have not been recommended by a health-care provider to get an HPV shot within the last 12 months (Wt = 9.1%, 95% CI = 5.0% to 13.2%). Lower proportions of this belief were found in women living in isolated rural areas (Wt = 5.0%, 95% CI = 0.0% to 10.4%), current smokers (Wt = 3.2%, 95% CI = 0.3% to 6.1%), and those unsure of a family cancer history (Wt = 1.3%, 95% CI = 0.0% to 3.6%) (Table 1).
Results of Multinomial Logistic Regression Analyses
Table 2 summarizes correlates of beliefs about the HPV vaccine’s success in preventing cervical cancer in a multinomial logistic regression analysis. In this table, the first half of the columns (Do not know [vs Successful]) presents the associations of predictor variables with women who did not know if the HPV vaccine is successful at preventing cervical cancer compared with those who believed that the HPV vaccine is successful at preventing cervical cancer (reference category); whereas the second half of the columns (Not successful [vs Successful]) displays the associations between predictor variables with women who believed that the HPV vaccine is not successful at preventing cervical cancer compared with those who believed that the HPV vaccine is successful at preventing cervical cancer. After adjusting for covariates, NHBs vs NHWs (aOR = 1.80; P = .010; BFDP = 0.754), women with high school education or lower vs college and/or postgraduate education (aOR = 2.05; P = .013; BFDP = 0.785), and women who did not know if they received an HPV shot recommendation by a health-care provider vs those who were recommended by a health-care provider to get an HPV shot within the last 12 months (aOR = 4.19; P = .012; BFDP = 0.775) were more likely to not know if the HPV vaccine was successful at preventing cervical cancer. In addition, those not sure of a family history of cancer vs those who had no family cancer history (aOR = 5.17; P = .012; BFDP = 0.788) were more likely to not know if the HPV vaccine was successful at preventing cervical cancer.
Table 2.
Association between beliefs on the success of HPV vaccine in preventing cervical cancer and characteristics of US female adults, Health Information National Trends, 2018*
| Characteristics | Do not know (vs successful) |
Not successful (vs successful) |
||||||
|---|---|---|---|---|---|---|---|---|
| aOR (95% CI) | P | BFDP | aOR (95% CI) | P | BFDP | |||
| Age, y | ||||||||
| ≥65 | (Referent) | (Referent) | ||||||
| 18–34 | 0.61 (0.35 to 1.06) | .080 | 0.941 | 12.68 (2.23 to 72.20) | .005 | 0.768 | ||
| 35–49 | 1.22 (0.74 to 2.02) | .432 | 0.982 | 13.27 (3.07 to 57.46) | .001 | 0.454 | ||
| 50–64 | 0.91 (0.59 to 1.40) | .650 | 0.987 | 10.01 (3.05 to 32.89) | <.001 | 0.187 | ||
| Race/ethnicity | ||||||||
| White, non-Hispanic | (Referent) | (Referent) | ||||||
| Black, non-Hispanic | 1.80 (1.16 to 2.79) | .010 | 0.754 | 1.23 (0.45 to 3.37) | .682 | 0.973 | ||
| Hispanic | 0.93 (0.49 to 1.75) | .807 | 0.982 | 0.59 (0.18 to 1.88) | .361 | 0.963 | ||
| Asian | 0.97 (0.28 to 3.31) | .953 | 0.971 | 1.12 ( 0.11 to 11.29) | .923 | 0.960 | ||
| Others | 1.24 (0.54 to 2.87) | .607 | 0.976 | 0.68 (0.06 to 7.86) | .750 | 0.959 | ||
| Born in United States | ||||||||
| Yes | (Referent) | (Referent) | ||||||
| No | 1.44 (0.67 to 3.09) | .347 | 0.971 | 1.51 (0.51 to 4.44) | .446 | 0.968 | ||
| Education | ||||||||
| College graduate/postgraduate | (Referent) | (Referent) | ||||||
| ≤12 years/completed high school | 2.05 (1.17 to 3.60) | .013 | 0.785 | 0.78 (0.26 to 2.34) | .653 | 0.971 | ||
| Post–high school or some college | 1.50 (0.96 to 2.35) | .076 | 0.947 | 2.02 (0.78 to 5.22) | .145 | 0.947 | ||
| Household income | ||||||||
| <$35 000 | (Referent) | (Referent) | ||||||
| $35 000–$49 999 | 1.28 (0.65 to 2.56) | .468 | 0.977 | 0.60 (0.19 to 1.90) | .380 | 0.964 | ||
| $50 000–$74 999 | 0.81 (0.48 to 1.37) | .423 | 0.981 | 1.13 (0.35 to 3.63) | .839 | 0.972 | ||
| ≥ $75 000 | 0.59 (0.37 to 0.93) | .024 | 0.873 | 0.52 (0.17 to 1.62) | .257 | 0.958 | ||
| Residence | ||||||||
| Urban | (Referent) | (Referent) | ||||||
| Median rural | 0.80 (0.42 to 1.53) | .488 | 0.978 | 0.84 (0.24 to 2.96) | .779 | 0.970 | ||
| Isolated rural | 1.01 (0.44 to 2.35) | .977 | 0.978 | 0.95 (0.15 to 5.90) | .958 | 0.964 | ||
| Health insurance | ||||||||
| No | (Referent) | (Referent) | ||||||
| Yes | 0.74 (0.23 to 2.40) | .612 | 0.970 | 0.40 (0.12 to 1.32) | .129 | 0.940 | ||
| Health-care professional recommended HPV shot? | ||||||||
| Yes | (Referent) | (Referent) | ||||||
| No | 1.82 (1.08 to 3.06) | .025 | 0.866 | 1.49 (0.40 to 5.50) | .545 | 0.966 | ||
| Don’t know | 4.19 (1.39 to 12.60) | .012 | 0.775 | 0.77 (0.10 to 5.74) | .798 | 0.962 | ||
| Smoking status | ||||||||
| Never smokers | (Referent) | (Referent) | ||||||
| Former smokers | 0.95 (0.65 to 1.37) | .760 | 0.989 | 1.49 (0.58 to 3.85) | .402 | 0.969 | ||
| Current smokers | 1.42 (0.82 to 2.48) | .209 | 0.969 | 0.49 (0.14 to 1.66) | .244 | 0.955 | ||
| Last Pap test | ||||||||
| Within the last 3 years | (Referent) | (Referent) | ||||||
| 3–5 years | 1.09 (0.68 to 1.73) | .727 | 0.986 | 1.49 (0.62 to 3.59) | .369 | 0.969 | ||
| Unknown or never | 0.82 (0.16 to 4.25) | .806 | 0.965 | 0.35 ( 0.03 to 4.39) | .412 | 0.954 | ||
| Depression | ||||||||
| No | (Referent) | (Referent) | ||||||
| Yes | 0.83 (0.56 to 1.23) | .347 | 0.983 | 0.79 (0.38 to 1.66) | .531 | 0.977 | ||
| Personal cancer history | ||||||||
| No | (Referent) | (Referent) | ||||||
| Yes | 1.18 (0.72 to 1.94) | .510 | 0.983 | 1.48 (0.55 to 3.95) | .427 | 0.969 | ||
| Family cancer history | ||||||||
| No | (Referent) | (Referent) | ||||||
| Yes | 0.99 (0.63 to 1.54) | .957 | 0.987 | 0.89 (0.39 to 2.05) | .778 | 0.978 | ||
| Not sure | 5.17 (1.48 to 18.21) | .012 | 0.788 | 0.48 (0.01 to 269.37) | .817 | 0.952 | ||
In the regression analysis, a “missing data” category for variables with missing data was included in the model. For reader’s convenience, the results of this “missing data” category are not displayed in this table. The following factors were adjusted for in the multinomial logistic regression analysis: age, race and/or ethnicity, place of birth, education, household income, residence, health insurance, health-care professional recommended HPV shot, smoking status, last Pap test, depression, personal cancer history, family cancer history. aOR = adjusted odds ratio; BFDP = Bayesian false-discovery probability; CI = confidence interval; HPV= human papillomavirus.
Compared with women aged 65 years or older, women aged 50 to 64 years (aOR = 10.01; P <.001; BFDP = 0.187), those aged 35 to 49 years (aOR = 13.27; P = .001; BFDP = 0.454); and those aged 18 to 34 years (aOR = 12.68; P = .005; BFDP = 0.768) were more likely to believe that the HPV vaccine is not successful at preventing cervical cancer.
Discussion
In this study, we examined the beliefs of US adult women as to the success of the HPV vaccine in preventing cervical cancer. Using the HINTS data, we found that only 29.8% of women believed that the HPV vaccine is successful at preventing cervical cancer. Alarmingly, nearly two-thirds (63.6%) did not know if the HPV vaccine is successful. This remarkably high level of poor awareness of a key benefit of the HPV vaccine among US women could be a contributing factor to the low HPV vaccination rates in the United States. Only half of eligible teenagers completed their HPV vaccination series in 2017 (7), compared with the more than 80% coverage rate in other developed countries, including Australia, the United Kingdom, Belgium, Portugal, Spain, Sweden, and Iceland (26,27).
Several US studies have conducted population-level assessments on knowledge and awareness surrounding HPV, the HPV vaccine, and HPV-related diseases (19–21,28). However, US women’s beliefs as to the success of the HPV vaccine preventing cervical cancer has not been previously examined. Therefore, this study goes a step further in characterizing individuals based not only on their knowledge of the virus or the vaccine but also what they stand to benefit from receiving the vaccine, which has a stronger predictive value on vaccination intention. In the same vein, although studies have shown HPV-related knowledge boosts vaccine acceptance and uptake (14,15), belief regarding the effectiveness of HPV vaccines against cervical cancer was found to be a stronger predictor of HPV vaccination intent (14).
One key finding of this study was that NHBs had increased odds of not knowing whether the HPV vaccine prevents cervical cancer. This corroborates with other studies that have reported relatively lower levels of knowledge and awareness on topics related to HPV or HPV vaccination among minorities in the United States, particularly among African Americans (20,26,29). Given that morbidity and mortality associated with cervical cancer is higher in NHBs compared with NHWs (30), this finding is indicative of a need to develop culturally appropriate and targeted interventions such as awareness campaigns aimed at boosting knowledge surrounding HPV vaccination and its benefits in this demographic. We also found that low levels of education (high school completion or lower) doubled the odds of not knowing about the success of the HPV vaccine in preventing cervical cancer, which may play a mediating role in the observed association between levels of education and HPV vaccination uptake (31,32).
Women who were unaware of prior HPV vaccination recommendation by a health-care provider were found to have an increased likelihood of not knowing about the HPV vaccine’s success in preventing cervical cancer. This finding may provide some explanation to studies that document health-care provider recommendation as a strong predictor of HPV vaccination (33,34). This underlines the major influence providers have on HPV vaccination and the potential role they can play in boosting uptake. Therefore, this potential can be harnessed through educational programs aimed at boosting physician self-efficacy in promoting HPV vaccination of eligible patients and managing difficult situations such as vaccine hesitancy. A study that employed an innovative approach to increase provider participation in administering effective recommendations for HPV vaccination noted improvements in the rate of HPV vaccination recommendations among clinicians, as well as uptake of the vaccine (35).
We found that women younger than 65 years were more likely to believe that HPV vaccine is not successful at preventing cervical cancer. Two distinct populations are implicated in the interpretation of this finding. The first population is women in the older age categories who are parents or grandparents and have assent and decision-making responsibility over HPV vaccination of the children in their care. The influence of parental decision on child and adolescent HPV vaccination is well documented (36). The second population is young adults in the youngest age group, who have autonomy and are largely responsible for their own HPV vaccination. This population largely includes those participating in HPV vaccination during the later stages of the catch-up phase (ages 18–26 years) and beyond. In fact, in line with the recent Food and Drug Administration extended approval of the HPV vaccine to early mid-age, the Advisory Committee on Immunization Practices took a stand in favor of an expansion of the upper age limit for catch-up HPV vaccination to 45 years. With advancing age, the odds of believing that the HPV vaccine is not successful at preventing cervical cancer goes down. A possible explanation for this trend is that older women tend to use health-care services more frequently than younger women, and the resulting contact with health-care providers may expose them to more accurate information about the HPV vaccine. Although we acknowledge that women older than 65 years are generally not recommended to receive cervical cancer screening, they may still have an influence on the health-related beliefs and practices of their grandchildren, at least in some communities. In African American families, for instance, the social structure includes the commonality of intergenerational guardianship of children (37). In 2011, about 22% of African American grandparents acted as caregivers of their grandchildren, a trend that increases during periods of economic recession (38).
Because the economic, sociocultural, and physical environment tend to vary between urban and rural areas (39), we anticipated that women’s beliefs toward the HPV vaccine may differ among residents in urban and rural areas. However, rurality did not affect beliefs about the HPV vaccine in our study. This is consistent with the study by Degarege et al. (40), in which no statistically significant difference was found among parents residing in urban and rural areas in their beliefs about the ability of the HPV vaccine to protect against cervical cancer. Therefore, the difference observed in HPV vaccine uptake and cervical cancer incidence rates between rural and urban dwellers in the United States may be explained by factors other than people’s beliefs about the HPV vaccine.
With a background of suboptimal HPV vaccination coverage in the United States (7) compared with other developed nations (27), our study findings are indicative of substantial knowledge gaps of a key benefit of HPV vaccination (cervical cancer prevention) among adult women in the United States. Knowledge of rewards and benefits is a well-documented promoter of health behaviors. Hence, it is plausible to state that embarking on population-level initiatives aimed at boosting knowledge of HPV vaccination benefits (prevention of cervical cancer in this case) has the potential to enhance HPV vaccination uptake in the United States.
This study assesses predictors of beliefs about the success of the HPV vaccine in preventing cervical cancer in a nationally representative sample of adult women. Limitations of the present study include the following. First, HINTS cycles do not assess current health-care provider awareness, knowledge, and practices regarding HPV, as well as actual vaccination patterns. These missing variables could explain some of the differences seen in our study. Second, our data could be affected by a variety of biases, including low-response bias and social desirability bias. However, considerable efforts were made to reduce potential for bias through modality coverage and sampling (41). Low-response rates in HINTS data could lead to low-response bias and, as such, could lead to an underestimation of the association between potential predictors of HPV vaccine beliefs and the outcome variable. However, the HINTS investigators conducted a nonresponse bias analysis of these data to characterize the potential impact of nonresponse (42). Findings from their study revealed that many of the demographic influences on nonresponse can be compensated for through application of standard weighting procedures, which was employed in the present study. Concerning the social desirability bias, the strategy commonly used to prevent this bias is to validate the self-reporting instrument before implementing it for data collection. For each cycle of the HINTS survey for which data about the American public’s use of cancer-related information is routinely collected, all questionnaires are tested to be reliable and valid before being administered. Other limitations are related to the cross-sectional nature of the HINTS data. Because the presence of risk factors and outcomes are measured simultaneously, it is difficult to confidently infer causal association.
This study reveals severe knowledge gaps and inaccurate beliefs surrounding a key benefit of the HPV vaccination among US women. Interventions aimed at increasing population-level knowledge about the benefits of the HPV vaccine have the potential to enhance HPV vaccination uptake in the United States. To boost HPV vaccination coverage, as well as tackle disparities in cervical cancer burden in the United States, future interventions should target young adults, NHBs, and women with a lower level of education. Finally, strategies must be developed to increase health-care providers’ participation in promotion of patient education about HPV vaccination.
Funding
This study was supported by the National Cancer Institute 5P30CA016672 (SS); a Cancer Prevention Fellowship supported by the Cancer Prevention and Research Institute of Texas grant award, RP170259 (to JFD; PI: S Chang and S Shete); a cancer prevention fellowship award supported by the Mrs Harry C. Wiess Cancer Research Fund and the Laura and John Arnold Foundation (to OGC-A); the Duncan Family Institute for Cancer Prevention and Risk Assessment (SS); the Barnhart Family Distinguished Professorship in Targeted Therapy (SS); and the Betty B. Marcus Chair in Cancer Prevention (SS).
Notes
Affiliations of authors: Department of Epidemiology (JFD, OGC-A, SS) and Division of Cancer Prevention and Population Science (JFD, OGC-A, SS) and Department of Gynecologic Oncology and Reproductive Medicine (JFD) and Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX (RKY, SS).
Conflicts of interest: None.
JFD and OGC-A contributed equally to this work.
References
- 1. Castellsague X. Natural history and epidemiology of HPV infection and cervical cancer. Gynecol Oncol. 2008;110(3)(suppl 2):S4–S7. [DOI] [PubMed] [Google Scholar]
- 2. Schiffman MH, Bauer HM, Hoover RN, et al. Epidemiologic evidence showing that human papillomavirus infection causes most cervical intraepithelial neoplasia. J Natl Cancer Inst. 1993;85(12):958–964. [DOI] [PubMed] [Google Scholar]
- 3. Siegel RL, Miller KD, Jemal A.. Cancer statistics, 2018. CA-Cancer J Clin. 2018;68(1):7–30. [DOI] [PubMed] [Google Scholar]
- 4. Darragh TM, Colgan TJ, Thomas Cox J, et al. The lower anogenital squamous terminology standardization project for HPV-associated lesions: background and consensus recommendations from the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology. Int J Gynecol Pathol. 2013;32(1):76–115. [DOI] [PubMed] [Google Scholar]
- 5. Garner EI. Cervical cancer: disparities in screening, treatment, and survival. Cancer Epidemiol Biomarkers Prev. 2003;12(3):242s–247s. [PubMed] [Google Scholar]
- 6. Markowitz LE, Dunne EF, Saraiya M, et al. Human papillomavirus vaccination: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2014;63(RR-05):1–30. [PubMed] [Google Scholar]
- 7. Walker TY, Elam-Evans LD, Yankey D, et al. National, regional, state, and selected local area vaccination coverage among adolescents aged 13-17 years - United States, 2017 [Erratum in: MMWR Morb Mortal Wkly Rep. 2018;67(41):909]. MMWR Morb Mortal Wkly Rep. 2018;67(41):1164. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8. Kessels SJ, Marshall HS, Watson M, Braunack-Mayer AJ, Reuzel R, Tooher RL.. Factors associated with HPV vaccine uptake in teenage girls: a systematic review. Vaccine. 2012;30(24):3546–3556. [DOI] [PubMed] [Google Scholar]
- 9. Okafor C, Hu X, Cook RL.. Racial/ethnic disparities in HPV vaccine uptake among a sample of college women. J Racial Ethnic Health Disparities. 2015;2(3):311–316. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Williams WW, Lu P, O'Halloran A, et al. Surveillance of vaccination coverage among adult populations—United States, 2015. MMWR Surveill Summ. 2017;66(No. SS-11):1–28. [DOI] [PMC free article] [PubMed]
- 11. Smith LE, Amlot R, Weinman J, Yiend J, Rubin GJ.. A systematic review of factors affecting vaccine uptake in young children. Vaccine. 2017;35(45):6059–6069. [DOI] [PubMed] [Google Scholar]
- 12. Sabeena S, Bhat PV, Kamath V, Arunkumar G.. Global human papilloma virus vaccine implementation: an update. J Obstet Gynaecol Res. 2018;44(6):989–997. [DOI] [PubMed] [Google Scholar]
- 13. Chan KKL, Kwan TTC, Yao TJ, Tam KF, Cheung ANY, Ngan H.. Human papillomavirus vaccine: what are women most concerned about? J Obstet Gynaecol Re. 2012;38(1):23–30. [DOI] [PubMed] [Google Scholar]
- 14. Fazekas KI, Brewer NT, Smith JS.. HPV vaccine acceptability in a rural Southern area. J Womens Health (Larchmt). 2008;17(4):539–548. [DOI] [PubMed] [Google Scholar]
- 15. Suryadevara M, Bonville JR, Kline RM, et al. Student HPV vaccine attitudes and vaccine completion by education level. Hum Vaccin Immunother. 2016;12(6):1491–1497. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16. Schiffman M, Castle PE.. Human papillomavirus: epidemiology and public health. Arch Pathol Lab Med. 2003;127(8):930–934. [DOI] [PubMed] [Google Scholar]
- 17. Rosenstock IM. Historical origins of the health belief model. Health Educ Monogr. 1974;2(4):328–335. [Google Scholar]
- 18. Bandura A. Social Foundations of Thought and Action: A Social Cognitive Theory. Englewood Cliffs, NJ: Prentice‐Hall; 1986. [Google Scholar]
- 19. McBride KR, Singh S.. Predictors of adults’ knowledge and awareness of HPV, HPV-associated cancers, and the HPV vaccine: implications for health education. Health Educ Behav. 2018;45(1):68–76. [DOI] [PubMed] [Google Scholar]
- 20. Boakye EA, Tobo BB, Rojek RP, Mohammed KA, Geneus CJ, Osazuwa-Peters N.. Approaching a decade since HPV vaccine licensure: racial and gender disparities in knowledge and awareness of HPV and HPV vaccine. Hum Vacc Immunother. 2017;13(11):2713–2722. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21. Mohammed KA, Subramaniam DS, Geneus CJ, et al. Rural-urban differences in human papillomavirus knowledge and awareness among US adults. Prev Med. 2018;109:39–43. [DOI] [PubMed] [Google Scholar]
- 22. National Cancer Institute. Health Information National Trends Survey, 2018. https://hints.cancer.gov/data/survey-instruments.aspx. Accessed January 18, 2019.
- 23. Blake KD, Ottenbacher AJ, Finney Rutten LJ, et al. Predictors of human papillomavirus awareness and knowledge in 2013: gaps and opportunities for targeted communication strategies. Am J Prev Med. 2015;48(4):402–410. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24. United States Department of Agriculture, Economic Research Service. Rural-Urban Continuum Codes. https://www.ers.usda.gov/data-products/rural-urban-continuum-codes.aspx. Accessed January 15, 2019.
- 25. Wakefield J. A Bayesian measure of the probability of false discovery in genetic epidemiology studies. Am J Hum Genet. 2007;81(2):208–227. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.National HPV Vaccination Program Register. HPV vaccination coverage by dose number (Australia) for males/females by age group in 2017. 2018. www.hpvregister.org.au/research/coverage-data. Accessed January 12, 2019.
- 27. Brotherton JML, Bloem PN.. Population-based HPV vaccination programmes are safe and effective: 2017 update and the impetus for achieving better global coverage. Best Pract Res Cl Ob. 2018;47:42–58. [DOI] [PubMed] [Google Scholar]
- 28. Tiro JA, Meissner HI, Kobrin S, Chollette V.. What do women in the US know about human papillomavirus and cervical cancer? Cancer Epidemiol Biomarkers Prev. 2007;16(2):288–294. [DOI] [PubMed] [Google Scholar]
- 29. Read DS, Joseph MA, Polishchuk V, Suss AL.. Attitudes and perceptions of the HPV vaccine in Caribbean and African-American adolescent girls and their parents. J Pediatr Adol Gynec. 2010;23(4):242–245. [DOI] [PubMed] [Google Scholar]
- 30. American Cancer Society. Cancer Statistics Center: Cancer Type – Cervix. 2018. https://cancerstatisticscenter.cancer.org/#/cancer-site/Cervix. Accessed January 18, 2019.
- 31. Reiter PL, Gilkey MB, Brewer NT.. HPV vaccination among adolescent males: results from the National Immunization Survey-Teen. Vaccine. 2013;31(26):2816–2821. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32. Ogilvie G, Anderson M, Marra F, et al. A population-based evaluation of a publicly funded, school-based HPV vaccine program in British Columbia, Canada: parental factors associated with HPV vaccine receipt. PloS Med. 2010;7(5):e1000270. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33. Ylitalo KR, Lee H, Mehta NK.. Health care provider recommendation, human papillomavirus vaccination, and race/ethnicity in the US National Immunization Survey. Am J Public Health. 2013;103(1):164–169. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 34. Mohammed KA, Geneus CJ, Osazuwa-Peters N, Boakye EA, Tobo BB, Burroughs TE.. Disparities in provider recommendation of human papillomavirus vaccination for US adolescents. J Adolescent Health. 2016;59(5):592–598. [DOI] [PubMed] [Google Scholar]
- 35. Henninger ML, McMullen CK, Firemark AJ, Naleway AL, Henrikson NB, Turcotte JA.. User-centered design for developing interventions to improve clinician recommendation of human papillomavirus vaccination. Perm J. 2017;21:16–191. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36. Holman DM, Benard V, Roland KB, Watson M, Liddon N, Stokley S.. Barriers to human papillomavirus vaccination among US adolescents a systematic review of the literature. JAMA Pediatr. 2014;168(1):76–82. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37. Billingsley A. Climbing Jacob’s Ladder: The Enduring Legacies of African-American Families. New York: Simon and Schuster; 1994. [Google Scholar]
- 38. Pew Research Center. At grandmother’s house we stay, one-in-ten children are living with a grandparent; 2013. https://www.pewsocialtrends.org/2013/09/04/at-grandmothers-house-we-stay/. Accessed March 15, 2019.
- 39. Eberhardt MS, Pamuk ER.. The importance of place of residence: examining health in rural and nonrural areas. Am J Public Health. 2004;94(10):1682.. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 40. Degarege A, Krupp K, Fennie K, et al. Urban-rural inequities in the parental attitudes and beliefs towards human papillomavirus infection, cervical cancer, and human papillomavirus vaccine in Mysore, India. J Pediatr Adolesc Gynecol. 2018;31(5):494–502. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 41. Cantor DC, Crystal-Mansour S, Davis T, Dipko S, Sigman R.. Health Information National Trends Survey (HINTS) 2007: Final Report. Rockville, MD: Westat; 2009. [Google Scholar]
- 42. Finney Rutten LJ, Blake KD, Skolnick VG, Davis T, Moser RP, Hesse BW.. Data resource profile: the National Cancer Institute’s Health Information National Trends Survey (HINTS). Int J Epidemiol. 2019:1–11. [DOI] [PMC free article] [PubMed] [Google Scholar]