Human Vaccines & Immunotherapeutics
ISSN: 2164-5515 (Print) 2164-554X (Online) Journal homepage: http://www.tandfonline.com/loi/khvi20
Does intention to recommend HPV vaccines impact HPV vaccination rates? Kristen A Feemster, Maria Middleton, Alexander G Fiks, Sarah Winters, Sara B Kinsman & Jessica A Kahn To cite this article: Kristen A Feemster, Maria Middleton, Alexander G Fiks, Sarah Winters, Sara B Kinsman & Jessica A Kahn (2014) Does intention to recommend HPV vaccines impact HPV vaccination rates?, Human Vaccines & Immunotherapeutics, 10:9, 2519-2526, DOI: 10.4161/21645515.2014.969613 To link to this article: http://dx.doi.org/10.4161/21645515.2014.969613
Published online: 30 Oct 2014.
Submit your article to this journal
Article views: 120
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=khvi20 Download by: [University of Otago]
Date: 11 November 2015, At: 06:03
RESEARCH PAPER Human Vaccines & Immunotherapeutics 10:9, 2519--2526; September 2014; © 2014 Taylor & Francis Group, LLC
Does intention to recommend HPV vaccines impact HPV vaccination rates? Kristen A Feemster1,2,3,4,*, Maria Middleton1, Alexander G Fiks3,4,5,6, Sarah Winters5, Sara B Kinsman7, and Jessica A Kahn8 1
Division of Infectious Diseases; The Children’s Hospital of Philadelphia; Philadelphia, PA USA; 2Vaccine Education Center; The Children’s Hospital of Philadelphia, Philadelphia; PA USA; 3University of Pennsylvania Perelman School of Medicine; Department of Pediatrics; Philadelphia, PA USA; 4Leonard Davis Institute of Health Economics, Philadelphia, PA USA; 5Division of General Pediatrics and Primary Care; The Children’s Hospital of Philadelphia; Philadelphia, PA USA; 6Pediatric Research Consortium; The Children’s Hospital of Philadelphia; Philadelphia, PA USA; 7Philadelphia Department of Health, Division of Maternal, Child, and Family Health; Philadelphia, PA USA; 8Cincinnati Children’s Hospital Medical Center; Division of Adolescent and Transition Medicine; Cincinnati, OH USA
Keywords: adolescent health, Human papillomavirus, human papillomavirus vaccines, immunizations, preventive care
Downloaded by [University of Otago] at 06:03 11 November 2015
Abbreviations: HPV, Human papillomavirus; EMR, Electronic Medical Record.
Despite recommendations for routine vaccination, HPV vaccination rates among adolescent females have remained low. The objective of this prospective cohort study was to determine whether clinician intention to recommend HPV vaccines predicts HPV vaccine series initiation among previously unvaccinated 11 to 18 year-old girls (N D 18,083) who were seen by a pediatric clinician (N D 105) from a large primary care network within 3 years of vaccine introduction. We used multivariable logistic regression with generalized estimating equations, Cox Regression and standardized survival curves to measure the association between clinician intention and time to and rate of first HPV vaccine receipt among eligible females. All models adjusted for patient age, race / ethnicity, payor category, visit type, and practice location. Eighty-5 percent of eligible 11 to 12 year-old and 95% of 13 to 18 year-old girls were seen by a provider reporting high intention to recommend HPV vaccines. However, only 30% of the cohort initiated the HPV vaccine series and the mean number of days from first eligible visit to series initiation was 190 (95% C.I. 184.2, 195.4). After adjusting for covariates, high clinician intention was modestly associated with girls’ likelihood of HPV vaccine series initiation (OR 1.36; 95 % C.I. 1.07, 1.71) and time to first HPV vaccination (HR 1.22; 95% 1.06, 1.40). Despite high intention to vaccinate among this cohort of pediatric clinicians, overall vaccination rates for adolescent girls remained low. These findings support ongoing efforts to develop effective strategies to translate clinician intention into timely HPV vaccine receipt.
Introduction In June 2006, the US. Food and Drug Administration approved a quadrivalent human papillomavirus (HPV) vaccine for females 9–26 years of age.1 The vaccine is highly effective in preventing persistent HPV infection, cervical, anal, vulvar and vaginal precancers and cancers and anogenital warts associated with the 4 HPV types targeted by the vaccine - HPV 6, 11, 16 and 18.2-5 A bivalent vaccine for HPV 16 and 18 was approved in October 2009 for the prevention of cervical cancers and precancers (MMWR).6 The bivalent vaccine is approved for females and the quadrivalent HPV vaccine is now approved for both females and males. Despite recommendations for routine vaccination of all 11–12 year olds with catch-up vaccination of 13–26 year old girls and 13–21 year old males, immunization rates have remained low compared to other adolescent vaccines and may have plateaued.7,8 Low vaccination rates have prompted many studies to evaluate facilitators and barriers to vaccination among parents and clinicians.9-26 These studies have shown overall positive attitudes toward the vaccine. Still, concerns remain including vaccine
safety, long-term efficacy, belief that vaccination is not necessary for young adolescents who are not sexually active and the perception that adolescents are at low risk for HPV infection. Surveillance data have also shown socioeconomic and racial disparities in completion of the vaccine series, suggesting potential barriers related to vaccine cost and access.8,27-31 Studies of compliance with vaccination guidelines consistently show that physician recommendation is one of the strongest predictors of vaccine receipt, and positive recommendations have the potential to significantly improve vaccination rates. Wellestablished behavioral change theories would also predict that clinicians’ intention to recommend HPV vaccines is one of the most powerful predictors of vaccine recommendation.32,33 However, this association has not been widely evaluated for HPV vaccination.34 Clinician support of vaccination is generally high, especially for older adolescents,17,35,36 yet rates remain well below Healthy People 2020 goals. Especially concerning are recent National Immunization Survey data that demonstrate lack of provider recommendation among parents of 13–17 males and declining parental intention to vaccinate for HPV despite increasing frequency of provider recommendation among parents
*Correspondence to: Kristen A Feemster; Email: [email protected] Submitted: 07/09/2014; Revised: 08/18/2014; Accepted: 08/21/2014 http://dx.doi.org/10.4161/21645515.2014.969613
www.landesbioscience.com
Human Vaccines & Immunotherapeutics
2519
of 13 to 17 year old girls. This suggests that other factors are impacting vaccine decision making.7 The objective of this study was to investigate the relationship between pediatric clinicians’ intention to recommend HPV vaccines and receipt of an HPV vaccine among adolescent girls. We hypothesized that likelihood of vaccine series initiation would be higher and time to series initiation would be shorter among eligible girls who were cared for by clinicians who reported high intention to recommend HPV vaccines. We also hypothesized that this effect would be most pronounced among 11–12 year old compared to 13–18 year-old girls.
Downloaded by [University of Otago] at 06:03 11 November 2015
Results Clinician characteristics Of 178 eligible clinicians, 105 (59%) consented to join the study and 101 fully completed the questionnaire (96% of those who consented) and were followed for the entire study period. Seventy-6 percent of the respondents were female, 86% were white, approximately 50% practiced in urban clinics and 46.8% reported >50% patients receiving Medicaid / SCHIP (State Children’s Health Insurance Program) insurance in their patient population. Seventy-8 percent of all respondents reported that they were extremely likely to recommend the vaccine to 11–12 year-old girls and 92% reported that they were extremely likely to recommend the vaccine to 13–18 year-olds girls. Child characteristics There were a total of 6,125 (33%) 11-12 and 12,250 (67%) 13-18 year-old girls (total N D 18,375) who were eligible to initiate the HPV vaccine series and had an encounter with one of the enrolled clinicians during the study period (Table 1). Approximately half of the encounters were for a well visit and 79% took place at a suburban practice. Sixty percent of the study population was white and 16% of girls were insured through Medicaid. These characteristics did not differ significantly between age groups (p > 0.05). Eighty-3 percent of 11–12 yearolds and 96% of 13–18 year-olds had an encounter with a provider who reported high intention to recommend HPV vaccines. Thirty percent of the cohort (23% of 11–12 year-olds and 34% of 13–18 year-olds) initiated the HPV vaccine series during the study period and the mean number of days from first eligible visit to receipt of the first HPV vaccine dose was 190 (95% CI: 184, 195). The mean number of days to vaccine receipt was 225 (95% C.I. 213.1, 236.9) among 11–12 year-olds and 177 (95% C.I. 171.3, 183.8) among 13–18 year-olds (p < 0.0001).
13-18 year-old girls, there was an inverse association between clinician intention and patient vaccination: 33% of girls whose clinician reported high intention to vaccinate received the HPV vaccine, compared to 44% of those whose clinician reported low intention (p < 0.0001). Sociodemographic and health care utilization characteristics were also significantly associated with receipt of the first HPV dose across the total population and within each age group (Table 1). In multivariable models (Table 3), intention was significantly associated with vaccine receipt even after adjusting for patient age, race / ethnicity, payor category, practice location, and visit type (OR 1.36; 95 % CI 1.07, 1.71). When stratified by age group, intention was significantly associated with vaccine receipt among 11–12 year-olds (OR 1.58, 95% CI 1.05, 2.38) but not among 13–18 year-olds (OR 1.06 95% C.I. 0.85, 1.32). Likelihood of vaccination was also significantly associated with Medicaid coverage (OR 1.39, 95% CI 1.19, 1.61), presenting for a preventive visit at time of vaccination or first eligible visit (O.R. 5.70, 95% C.I. 4.64, 7.01) and older age (OR 1.56, 95% CI 1.35, 1.97 for ages 13–18 compared to 11–12 year-olds). Girls who received care in suburban practices and who were defined as Other race were less likely to be vaccinated (OR 0.55, 95% CI 0.41, 0.73 and OR 0.72, 95% C.I. 0.63, 0.82). Time to receipt of first HPV vaccine dose In univariable analysis, time to receipt of first vaccine dose was significantly shorter among girls seen by clinicians reporting high intention compared to clinicians reporting low intention (187.3 days vs. 217.8 days, p < 0.004) across the whole cohort and among 11–12 year-old girls (220 days vs. 253.3 days, p < 0.05) (Table 2). There was no significant association between time to first HPV vaccine dose and clinician intention among older girls. Conversely, sociodemographic characteristics were significantly associated with time to receipt of first vaccine dose among 13–18 year-old but not 11–12 year-old adolescents (Table 2). In multivariable models, intention was significantly associated with time to receipt of the first HPV vaccine dose across the entire study population even after adjusting for patient race / ethnicity, patient age, insurance, visit type and practice location (HR 1.29; 95% 1.16, 1.42). When stratified by age group, intention was significantly associated with time to HPV vaccine series initiation only among 11–12 year-olds (HR 1.44, 94% C.I. 1.21, 1.72). This is illustrated by standardized survival curves (Fig. 1).
Discussion Receipt of first HPV vaccine dose Intention was significantly associated with receipt of the first HPV dose for each age group in univariable analyses (Table 1). Among 11–12 year-old girls, there was a positive association between clinician intention and patient vaccination: 24% of girls whose clinician reported high intention to vaccinate received the HPV vaccine, compared to 20.4% of girls whose clinician reported low intention to vaccinate (pD0.009). However, among
2520
In this prospective cohort study of clinicians in a pediatric primary care network, we observed that higher intention to recommend HPV vaccines was associated with a shorter time to receipt of the first vaccine, particularly among 11–12 year-olds for whom the vaccine is recommended for routine administration. In our cohort, 11–18 year-olds who were seen by clinicians reporting high intention received their first vaccine dose about
Human Vaccines & Immunotherapeutics
Volume 10 Issue 9
Table 1. Characteristics of 11–18 year old girls eligible for HPV vaccine receipt who had an encounter with a participating clinician, stratified by age group, N (%) 11–12 years, N D 6,125 N (%)
Downloaded by [University of Otago] at 06:03 11 November 2015
TOTAL N D 18375
HPV 1437 (23)
No HPV 4688 (77)
13–18 years, N D 12,250 N (%) HPV 4137 (34)
P
ISSN: 2164-5515 (Print) 2164-554X (Online) Journal homepage: http://www.tandfonline.com/loi/khvi20
Does intention to recommend HPV vaccines impact HPV vaccination rates? Kristen A Feemster, Maria Middleton, Alexander G Fiks, Sarah Winters, Sara B Kinsman & Jessica A Kahn To cite this article: Kristen A Feemster, Maria Middleton, Alexander G Fiks, Sarah Winters, Sara B Kinsman & Jessica A Kahn (2014) Does intention to recommend HPV vaccines impact HPV vaccination rates?, Human Vaccines & Immunotherapeutics, 10:9, 2519-2526, DOI: 10.4161/21645515.2014.969613 To link to this article: http://dx.doi.org/10.4161/21645515.2014.969613
Published online: 30 Oct 2014.
Submit your article to this journal
Article views: 120
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=khvi20 Download by: [University of Otago]
Date: 11 November 2015, At: 06:03
RESEARCH PAPER Human Vaccines & Immunotherapeutics 10:9, 2519--2526; September 2014; © 2014 Taylor & Francis Group, LLC
Does intention to recommend HPV vaccines impact HPV vaccination rates? Kristen A Feemster1,2,3,4,*, Maria Middleton1, Alexander G Fiks3,4,5,6, Sarah Winters5, Sara B Kinsman7, and Jessica A Kahn8 1
Division of Infectious Diseases; The Children’s Hospital of Philadelphia; Philadelphia, PA USA; 2Vaccine Education Center; The Children’s Hospital of Philadelphia, Philadelphia; PA USA; 3University of Pennsylvania Perelman School of Medicine; Department of Pediatrics; Philadelphia, PA USA; 4Leonard Davis Institute of Health Economics, Philadelphia, PA USA; 5Division of General Pediatrics and Primary Care; The Children’s Hospital of Philadelphia; Philadelphia, PA USA; 6Pediatric Research Consortium; The Children’s Hospital of Philadelphia; Philadelphia, PA USA; 7Philadelphia Department of Health, Division of Maternal, Child, and Family Health; Philadelphia, PA USA; 8Cincinnati Children’s Hospital Medical Center; Division of Adolescent and Transition Medicine; Cincinnati, OH USA
Keywords: adolescent health, Human papillomavirus, human papillomavirus vaccines, immunizations, preventive care
Downloaded by [University of Otago] at 06:03 11 November 2015
Abbreviations: HPV, Human papillomavirus; EMR, Electronic Medical Record.
Despite recommendations for routine vaccination, HPV vaccination rates among adolescent females have remained low. The objective of this prospective cohort study was to determine whether clinician intention to recommend HPV vaccines predicts HPV vaccine series initiation among previously unvaccinated 11 to 18 year-old girls (N D 18,083) who were seen by a pediatric clinician (N D 105) from a large primary care network within 3 years of vaccine introduction. We used multivariable logistic regression with generalized estimating equations, Cox Regression and standardized survival curves to measure the association between clinician intention and time to and rate of first HPV vaccine receipt among eligible females. All models adjusted for patient age, race / ethnicity, payor category, visit type, and practice location. Eighty-5 percent of eligible 11 to 12 year-old and 95% of 13 to 18 year-old girls were seen by a provider reporting high intention to recommend HPV vaccines. However, only 30% of the cohort initiated the HPV vaccine series and the mean number of days from first eligible visit to series initiation was 190 (95% C.I. 184.2, 195.4). After adjusting for covariates, high clinician intention was modestly associated with girls’ likelihood of HPV vaccine series initiation (OR 1.36; 95 % C.I. 1.07, 1.71) and time to first HPV vaccination (HR 1.22; 95% 1.06, 1.40). Despite high intention to vaccinate among this cohort of pediatric clinicians, overall vaccination rates for adolescent girls remained low. These findings support ongoing efforts to develop effective strategies to translate clinician intention into timely HPV vaccine receipt.
Introduction In June 2006, the US. Food and Drug Administration approved a quadrivalent human papillomavirus (HPV) vaccine for females 9–26 years of age.1 The vaccine is highly effective in preventing persistent HPV infection, cervical, anal, vulvar and vaginal precancers and cancers and anogenital warts associated with the 4 HPV types targeted by the vaccine - HPV 6, 11, 16 and 18.2-5 A bivalent vaccine for HPV 16 and 18 was approved in October 2009 for the prevention of cervical cancers and precancers (MMWR).6 The bivalent vaccine is approved for females and the quadrivalent HPV vaccine is now approved for both females and males. Despite recommendations for routine vaccination of all 11–12 year olds with catch-up vaccination of 13–26 year old girls and 13–21 year old males, immunization rates have remained low compared to other adolescent vaccines and may have plateaued.7,8 Low vaccination rates have prompted many studies to evaluate facilitators and barriers to vaccination among parents and clinicians.9-26 These studies have shown overall positive attitudes toward the vaccine. Still, concerns remain including vaccine
safety, long-term efficacy, belief that vaccination is not necessary for young adolescents who are not sexually active and the perception that adolescents are at low risk for HPV infection. Surveillance data have also shown socioeconomic and racial disparities in completion of the vaccine series, suggesting potential barriers related to vaccine cost and access.8,27-31 Studies of compliance with vaccination guidelines consistently show that physician recommendation is one of the strongest predictors of vaccine receipt, and positive recommendations have the potential to significantly improve vaccination rates. Wellestablished behavioral change theories would also predict that clinicians’ intention to recommend HPV vaccines is one of the most powerful predictors of vaccine recommendation.32,33 However, this association has not been widely evaluated for HPV vaccination.34 Clinician support of vaccination is generally high, especially for older adolescents,17,35,36 yet rates remain well below Healthy People 2020 goals. Especially concerning are recent National Immunization Survey data that demonstrate lack of provider recommendation among parents of 13–17 males and declining parental intention to vaccinate for HPV despite increasing frequency of provider recommendation among parents
*Correspondence to: Kristen A Feemster; Email: [email protected] Submitted: 07/09/2014; Revised: 08/18/2014; Accepted: 08/21/2014 http://dx.doi.org/10.4161/21645515.2014.969613
www.landesbioscience.com
Human Vaccines & Immunotherapeutics
2519
of 13 to 17 year old girls. This suggests that other factors are impacting vaccine decision making.7 The objective of this study was to investigate the relationship between pediatric clinicians’ intention to recommend HPV vaccines and receipt of an HPV vaccine among adolescent girls. We hypothesized that likelihood of vaccine series initiation would be higher and time to series initiation would be shorter among eligible girls who were cared for by clinicians who reported high intention to recommend HPV vaccines. We also hypothesized that this effect would be most pronounced among 11–12 year old compared to 13–18 year-old girls.
Downloaded by [University of Otago] at 06:03 11 November 2015
Results Clinician characteristics Of 178 eligible clinicians, 105 (59%) consented to join the study and 101 fully completed the questionnaire (96% of those who consented) and were followed for the entire study period. Seventy-6 percent of the respondents were female, 86% were white, approximately 50% practiced in urban clinics and 46.8% reported >50% patients receiving Medicaid / SCHIP (State Children’s Health Insurance Program) insurance in their patient population. Seventy-8 percent of all respondents reported that they were extremely likely to recommend the vaccine to 11–12 year-old girls and 92% reported that they were extremely likely to recommend the vaccine to 13–18 year-olds girls. Child characteristics There were a total of 6,125 (33%) 11-12 and 12,250 (67%) 13-18 year-old girls (total N D 18,375) who were eligible to initiate the HPV vaccine series and had an encounter with one of the enrolled clinicians during the study period (Table 1). Approximately half of the encounters were for a well visit and 79% took place at a suburban practice. Sixty percent of the study population was white and 16% of girls were insured through Medicaid. These characteristics did not differ significantly between age groups (p > 0.05). Eighty-3 percent of 11–12 yearolds and 96% of 13–18 year-olds had an encounter with a provider who reported high intention to recommend HPV vaccines. Thirty percent of the cohort (23% of 11–12 year-olds and 34% of 13–18 year-olds) initiated the HPV vaccine series during the study period and the mean number of days from first eligible visit to receipt of the first HPV vaccine dose was 190 (95% CI: 184, 195). The mean number of days to vaccine receipt was 225 (95% C.I. 213.1, 236.9) among 11–12 year-olds and 177 (95% C.I. 171.3, 183.8) among 13–18 year-olds (p < 0.0001).
13-18 year-old girls, there was an inverse association between clinician intention and patient vaccination: 33% of girls whose clinician reported high intention to vaccinate received the HPV vaccine, compared to 44% of those whose clinician reported low intention (p < 0.0001). Sociodemographic and health care utilization characteristics were also significantly associated with receipt of the first HPV dose across the total population and within each age group (Table 1). In multivariable models (Table 3), intention was significantly associated with vaccine receipt even after adjusting for patient age, race / ethnicity, payor category, practice location, and visit type (OR 1.36; 95 % CI 1.07, 1.71). When stratified by age group, intention was significantly associated with vaccine receipt among 11–12 year-olds (OR 1.58, 95% CI 1.05, 2.38) but not among 13–18 year-olds (OR 1.06 95% C.I. 0.85, 1.32). Likelihood of vaccination was also significantly associated with Medicaid coverage (OR 1.39, 95% CI 1.19, 1.61), presenting for a preventive visit at time of vaccination or first eligible visit (O.R. 5.70, 95% C.I. 4.64, 7.01) and older age (OR 1.56, 95% CI 1.35, 1.97 for ages 13–18 compared to 11–12 year-olds). Girls who received care in suburban practices and who were defined as Other race were less likely to be vaccinated (OR 0.55, 95% CI 0.41, 0.73 and OR 0.72, 95% C.I. 0.63, 0.82). Time to receipt of first HPV vaccine dose In univariable analysis, time to receipt of first vaccine dose was significantly shorter among girls seen by clinicians reporting high intention compared to clinicians reporting low intention (187.3 days vs. 217.8 days, p < 0.004) across the whole cohort and among 11–12 year-old girls (220 days vs. 253.3 days, p < 0.05) (Table 2). There was no significant association between time to first HPV vaccine dose and clinician intention among older girls. Conversely, sociodemographic characteristics were significantly associated with time to receipt of first vaccine dose among 13–18 year-old but not 11–12 year-old adolescents (Table 2). In multivariable models, intention was significantly associated with time to receipt of the first HPV vaccine dose across the entire study population even after adjusting for patient race / ethnicity, patient age, insurance, visit type and practice location (HR 1.29; 95% 1.16, 1.42). When stratified by age group, intention was significantly associated with time to HPV vaccine series initiation only among 11–12 year-olds (HR 1.44, 94% C.I. 1.21, 1.72). This is illustrated by standardized survival curves (Fig. 1).
Discussion Receipt of first HPV vaccine dose Intention was significantly associated with receipt of the first HPV dose for each age group in univariable analyses (Table 1). Among 11–12 year-old girls, there was a positive association between clinician intention and patient vaccination: 24% of girls whose clinician reported high intention to vaccinate received the HPV vaccine, compared to 20.4% of girls whose clinician reported low intention to vaccinate (pD0.009). However, among
2520
In this prospective cohort study of clinicians in a pediatric primary care network, we observed that higher intention to recommend HPV vaccines was associated with a shorter time to receipt of the first vaccine, particularly among 11–12 year-olds for whom the vaccine is recommended for routine administration. In our cohort, 11–18 year-olds who were seen by clinicians reporting high intention received their first vaccine dose about
Human Vaccines & Immunotherapeutics
Volume 10 Issue 9
Table 1. Characteristics of 11–18 year old girls eligible for HPV vaccine receipt who had an encounter with a participating clinician, stratified by age group, N (%) 11–12 years, N D 6,125 N (%)
Downloaded by [University of Otago] at 06:03 11 November 2015
TOTAL N D 18375
HPV 1437 (23)
No HPV 4688 (77)
13–18 years, N D 12,250 N (%) HPV 4137 (34)
P
