Parental Receptiveness to a Hypothetical HPV Vaccine AJ

Parental Receptiveness to a Hypothetical HPV Vaccine AJ Lenar, E Anderson, M Wentworth, K Connolly MVD Business Research, Merck & Company

Study Objectives • To assess parental awareness of cervical cancer and HPV • To measure the extent of parental receptiveness to a hypothetical HPV vaccine • To identify differentiating demographic and attitudinal characteristics of more vs. less receptive parents

Methodology • Internet survey conducted with 2, 053 parents of daughters 9 -17 years of age – Average of 26 minutes to complete • Respondents had to have either primary responsibility or shared responsibility for deciding whether their children would receive a particular vaccine • Concept provided information regarding the incidence of cervical cancer, genital warts, the role of sexual activity in contracting these diseases, and described a hypothetical HPV vaccine

Sample Characteristics • Sample was balanced across age, gender, marital status, income, geographic location, and ethnicity • Sample generally paralleled the US Census for families that include 9 -17 year old daughters except: – Internet sample generally better educated – African-Americans (n=170) and Hispanics (n=160) were underrepresented • Since responses did not differ across racial/ethnic categories, the sample was not weighted

Analytic Framework • Research explored variables affecting willingness to vaccinate • T-tests between groups were first used to test statistical significance – Focused on differences that achieve or surpass p<. 01 to p<. 001 (two-tailed, 95% level of confidence) • Cumulative logistic regression models were used to further clarify and prioritize variables that contributed to receptiveness

Results

Awareness of Cervical Cancer • 60% of parents said they knew some or a lot about cervical cancer • Only 5% of parents were unaware of cervical cancer 16% 60% 5% 11% 24% Unaware Almost Nothing Know A Little 46% Know Some 14% Know A lot Q. 21 "Have you ever heard of cervical cancer? " Q. 22 "Would you say you know a lot, some, a little or almost nothing about cervical cancer? " (n=2, 053)

Awareness of Genital Warts • Parents claim to have greater knowledge of cervical cancer than genital warts (60% vs. 49%) 23% 6% 17% Unaware Almost Nothing 49% 29% Know A Little 38% 11% Know Some Know A lot Q. 23 "Have you ever heard of genital warts? " Q. 24 "Would you say you know a lot, some, a little or almost nothing about them? " (n=2, 053)

Knowledge of Relationship • 71% of parents were unaware of the relationship between genital warts and the virus that causes cervical cancer 71% 100% 75% 50% 25% % No/Don't Know 29% 0% 25% 50% % Yes (n=2, 053) Q. 25 "Are you aware of any relationship between genital warts and the virus that causes cervical cancer? "

Vaccination Interest Segments for a Hypothetical HPV Vaccine • Based on the concept alone, 62% of parents said they would definitely (30%) or probably (32%) have their daughters vaccinated before their 18 th birthdays 11% 62% 50% Leave The Decision Up To Her Once She Turns 18 25% Definitely Probably Not Average Current Age Of Daughter: 0% Might/ Might Not 25% Probably Would 50% Definitely Would Likelihood To Vaccinate Before 18 Yrs. 13 yrs. 75% (n=2, 053) 13 yrs.

Vaccination Interest Segments for a Hypothetical HPV Vaccine for Males • Parents with 9 -17 year old sons were as receptive to vaccinating their sons as their daughters Daughter 1 (n=2, 053) 62% Sons 9 -17 Yrs. Old (n=783) 62% 50% Reluctant 25% 0% Might or Might Not 25% Probably Would 50% Definitely Would 75% Likelihood To Vaccinate Before 18 Yrs. 1 For parents with more than one 9 -17 year old daughter, parents were asked about their attitudes towards vaccinating the daughter with the most recent birthday.

Impact Of Physician Recommendations On Vaccination Segments HPV Concept Only 62% With Strong Physician Recommendation a “If It Were My Daughter. . . ” 79% Physician Characterizes Vaccine As a Good/Leaves It Up To Parent 61% Physician Characterize HPV Vaccine a As Helpful, But Unnecessary 49% Physician States: "Today Your Daughter a Will Be Receiving The HPV Vaccine" 50% Resistant a 69% 25% Hesitant 0% 25% Tempted 50% 75% Convinced 100% (n=2, 053) 1%-2% of respondents answered "don't know. " Q. 26 "Think about what you are likely to do between now and the next few years. And, for purposes of this study, assume that the cost of this vaccine will be about the same as you have experienced in the past for other childhood vaccinations. Based on what you’ve read so far, would you say that eventually, before she turns 18, you…vaccinate? " Q. 33 "Physicians may offer different advice about the vaccine. Suppose that, on your daughter’s next visit to the doctor, her physician explained the HPV vaccine and said, (ITEM). How likely or unlikely are you to get your daughter vaccinated at or around the time of that visit? " Q. 34 "(IF NOT “DEFINITELY WOULD” OR “PROBABLY WOULD” FOR ITEM IN Q. 33: ) If her physician said, (ITEM), how likely or unlikely would you be to get your daughter vaccinated at some point before she turns 18? "

Predicting Likelihood To Vaccinate • Cumulative logistic regression was carried out to understand which independent variables contribute most to distinguishing between receptiveness segments • Any individual variable for which the correlation with receptiveness was not significant at p. 05 or less was dropped – 26 demographic and attitudinal variables remained • Correctly classified 83. 3% of parents, chance gives 32% • Increased the odds of correctly classifying a parent 2. 6 fold (83. 3% ÷ 32% = 2. 6)

Predicting Likelihood To Vaccinate Maximum a Odds Ratio P-Value "No Matter How Well You've Raised Your Children, It's A Good Idea To Get Them The Added Protection Of The HPV Vaccine. “ 9. 70 <. 0001 "I Wish This Vaccine Had Been Available For Me When I Was An Adolescent. “ 3. 49 <. 0001 "There May Be Long-Term Side Effects Of The Vaccine That We Don't Know About Yet. " (Negative) 3. 00 <. 0001 "It's A Parent's Responsibility To Be Sure Their Daughters Get 2. 68 Vaccinated Against The HPV Virus In Order To Protect Future Spouses Or Partners. “ <. 0001 "The Vaccine Only Protects To Some Extent Against The Diseases. " b (Negative) 2. 53 <. 002 "This Is A Vaccine For Nearly Any Girl. " 2. 50 <. 0002

Predicting Likelihood To Vaccinate Maximum a Odds Ratio P-Value "Suppose In The Future It Became Possible To Give The HPV Vaccine Earlier In Childhood As Part Of Childhood Vaccination Programs. Which One Of The Following Time Periods Would You Consider The Best Time Period For A Female Child To Be Vaccinated? " (15 years or younger) 1. 79 <. 0001 "Do You Consider Your Views On Social Policies Strongly Conservative, Middle Of The Road, Liberal, Or Very Liberal? " (Negative) 1. 59 . 0779

Summary • Most parents were aware of cervical cancer and genital warts • Parents felt they know more about cervical cancer than genital warts • When questioned further, 71% said they were unaware of the relationship genital warts and the virus that causes cervical cancer • Based on the concept alone, 62% of parents said they would definitely (30%) or probably (32%) vaccinate their daughters with a hypothetical HPV vaccine

Summary • Most of the remainder (30%) were unsure—might or might not—rather than reluctant (11%) – Among reluctant parents, only 2% said they definitely would not vaccinate • Parents were equally receptive to vaccinating their sons • A strong personal recommendation from a physician increased parent receptivity (definitely or probably would) from 62% to 79% • A parent’s general desire to protect his or her children was the greatest predictor of parental receptiveness