Matthew F. Daley

Human papillomavirus vaccination practices: a survey of US physicians 18 months after licensure.

OBJECTIVES: The objectives of this study were to assess, in a nationally representative network of pediatricians and family physicians, (1) human papillomavirus (HPV) vaccination practices, (2) perceived barriers to vaccination, and (3) factors associated with whether physicians strongly recommended HPV vaccine to 11- to 12-year-old female patients. METHODS: In January through March 2008, a survey was administered to 429 pediatricians and 419 family physicians. RESULTS: Response rates were 81% for pediatricians and 79% for family physicians. Ninety-eight percent of pediatricians and 88% of family physicians were administering HPV vaccine in their offices (P < .001). Among those physicians, fewer strongly recommended HPV vaccination for 11- to 12-year-old female patients than for older female patients (pediatricians: 57% for 11- to 12-year-old patients and 90% for 13- to 15-year-old patients; P < .001; family physicians: 50% and 86%, respectively; P < .001). The most-frequently reported barriers to HPV vaccination were financial, including vaccine costs and insurance coverage. Factors associated with not strongly recommending HPV vaccine to 11- to 12-year-old female patients included considering it necessary to discuss sexuality before recommending HPV vaccine (risk ratio: 1.27 [95% confidence interval: 1.07–1.51]) and reporting more vaccine refusals among parents of younger versus older adolescents (risk ratio: 2.09 [95% confidence interval: 1.66–2.81]). CONCLUSIONS: Eighteen months after licensure, the vast majority of pediatricians and family physicians reported offering HPV vaccine. Fewer physicians strongly recommended the vaccine for younger adolescents than for older adolescents, and physicians reported financial obstacles to vaccination.

A National Survey of Pediatrician Knowledge and Attitudes Regarding Human Papillomavirus Vaccination

OBJECTIVE. A human papillomavirus vaccine was licensed in June 2006. The vaccine is quadrivalent, protecting against 2 human papillomavirus strains that cause cervical cancer and 2 that cause genital warts. The objective of this study was to determine physician characteristics, knowledge, and attitudes associated with an intention to recommend human papillomavirus vaccination. METHODS. Between August and October 2005, a cross-sectional survey was administered to a national network of 431 pediatricians. The network was developed from a random sample of American Academy of Pediatrics members and was designed to be representative of the organization’s membership with respect to urban/rural location, practice type, and region. The survey was conducted before human papillomavirus vaccine licensure and therefore focused on a candidate quadrivalent human papillomavirus vaccine and a range of potential vaccination recommendations. The main outcome measure was intention to recommend a quadrivalent human papillomavirus vaccine to young adolescent (10- to 12-year-old) females. RESULTS. Survey response rate was 68%. If endorsed by national health organizations, 46% of respondents would recommend vaccination for 10- to 12-year-old females, 77% for 13- to 15-year-old females, and 89% for 16- to 18-year-old females. Corresponding rates for males were 37%, 67%, and 82%, respectively. Whereas 60% of respondents thought that parents would be concerned that human papillomavirus vaccination may encourage risky sexual behaviors, 11% reported that they themselves had this concern. Respondents who believed that other new adolescent immunization recommendations (eg, meningococcal, pertussis) would facilitate human papillomavirus vaccine implementation were more likely to intend to recommend vaccination. CONCLUSIONS. Although a national sample of pediatricians expressed a high level of acceptance of human papillomavirus vaccination in older adolescent females, fewer than one half anticipated giving human papillomavirus vaccine to younger female patients. Provider concerns about parental vaccine acceptance will need to be addressed to optimize human papillomavirus vaccination implementation.

Monitoring the safety of quadrivalent human papillomavirus vaccine: findings from the Vaccine Safety Datalink.

BACKGROUND In 7 large managed care organizations (MCOs), we performed a post-licensure safety assessment of quadrivalent human papillomavirus vaccine (HPV4) among 9-26 year-old female vaccine recipients between August 2006 and October 2009. METHODS Sequential analyses were conducted weekly to detect associations between HPV4 exposure and pre-specified outcomes. The pre-specified outcomes identified by ICD-9 codes using computerized data at the participating MCOs included: Guillan-Barré Syndrome (GBS), stroke, venous thromboembolism (VTE), appendicitis, seizures, syncope, allergic reactions, and anaphylaxis. For rare outcomes, historical background rates were used as the comparison group. For more common outcomes, a concurrent unexposed comparison group was utilized. A standardized review of medical records was conducted for all cases of GBS, VTE, and anaphylaxis. RESULTS A total of 600,558 HPV4 doses were administered during the study period. We found no statistically significant increased risk for the outcomes studied. However, a non-statistically significant relative risk (RR) for VTE ICD-9 codes following HPV4 vaccination of 1.98 was detected among females age 9-17 years. Medical record review of all 8 vaccinated potential VTE cases in this age group revealed that 5 met the standard case definition for VTE. All 5 confirmed cases had known risk factors for VTE (oral contraceptive use, coagulation disorders, smoking, obesity or prolonged hospitalization). CONCLUSIONS In a study of over 600,000 HPV4 vaccine doses administered, no statistically significant increased risk for any of the pre-specified adverse events after vaccination was detected. Further study of a possible association with VTE following HPV4 vaccination is warranted.

Parental Refusal of Pertussis Vaccination Is Associated With an Increased Risk of Pertussis Infection in Children

OBJECTIVE. The objective of this study was to determine if children who contracted pertussis infection were more likely to have parents who refused pertussis vaccinations than a similar group of children who did not develop pertussis infection. METHODS. We conducted a case-control study of children enrolled in the Kaiser Permanente of Colorado health plan between 1996 and 2007. Each pertussis case was matched to 4 randomly selected controls. Pertussis case status and vaccination status were ascertained by medical chart review. RESULTS. We identified 156 laboratory-confirmed pertussis cases and 595 matched controls. There were 18 (12%) pertussis vaccine refusers among the cases and 3 (0.5%) pertussis vaccine refusers among the controls. Children of parents who refused pertussis immunizations were at an increased risk for pertussis compared with children of parents who accepted vaccinations. In a secondary case-control analysis of children continuously enrolled in Kaiser Permanente of Colorado from 2 to 20 months of age, vaccine refusal was associated with a similarly increased risk of pertussis. In the entire Kaiser Permanente of Colorado pediatric population, 11% of all pertussis cases were attributed to parental vaccine refusal. CONCLUSIONS. Children of parents who refuse pertussis immunizations are at high risk for pertussis infection relative to vaccinated children. Herd immunity does not seem to completely protect unvaccinated children from pertussis. These findings stress the need to further understand why parents refuse immunizations and to develop strategies for conveying the risks and benefits of immunizations to parents more effectively.

Influenza Among Healthy Young Children: Changes in Parental Attitudes and Predictors of Immunization During the 2003 to 2004 Influenza Season

BACKGROUND. In Colorado, the 2003 to 2004 influenza season was unusually early and severe and received substantial media attention. OBJECTIVES. Among parents of healthy young children, to determine how parental knowledge and attitudes regarding influenza infection and immunization changed during the 2003 to 2004 influenza season and to identify factors predictive of influenza immunization. METHODS. The study was conducted in 5 metropolitan Denver pediatric practices. A total of 839 healthy children age 6 to 21 months and their parents were randomly selected for participation. Parents were surveyed by telephone before (August 18 to October 7, 2003) and after (March 31 to June 10, 2004) the influenza season. RESULTS. Among 828 eligible parents, 472 (57%) completed the preseason survey; 316 (67%) of these parents subsequently completed the postseason survey. All analyses were performed for the 316 subjects who completed both preseason and postseason surveys. Compared with their attitudes before the influenza season, 48% of parents interviewed after the season viewed their child as more susceptible to influenza, 58% viewed influenza infections as more severe, and 66% perceived fewer risks associated with influenza vaccine. Ninety-five percent of parents reported hearing in the media about Colorado’s influenza outbreak, and having heard about the outbreak in the media was associated with viewing influenza infections as more severe. A total of 258 parents (82%) immunized their child against influenza. In multivariate analyses, positive predictors of immunization included a physician recommendation for immunization and a preseason to postseason increase in the perception that immunization was the social norm. Negative predictors of immunization included high perceived barriers to immunization, less parental education, and preseason intention not to immunize. CONCLUSIONS. Parent attitudes about influenza infection and immunization changed substantially during the 2003 to 2004 influenza season, with changes favoring increased parental acceptance of influenza vaccination for young children. During an intensively publicized influenza outbreak, a physician recommendation of vaccination was an important predictor of influenza immunization.

H1N1 and Seasonal Influenza Vaccine Safety in the Vaccine Safety Datalink Project

BACKGROUND The emergence of pandemic H1N1 influenza virus in early 2009 prompted the rapid licensure and use of H1N1 monovalent inactivated (MIV) and live, attenuated (LAMV) vaccines separate from seasonal trivalent inactivated (TIV) and live, attenuated (LAIV) influenza vaccines. A robust influenza immunization program in the U.S. requires ongoing monitoring of potential adverse events associated with vaccination. PURPOSE To prospectively conduct safety monitoring of H1N1 and seasonal influenza vaccines during the 2009-2010 season. METHODS The Vaccine Safety Datalink (VSD) Project monitors ∼9.2 million members in eight U.S. medical care organizations. Electronic data on vaccines and pre-specified adverse events were updated and analyzed weekly for signal detection from November 2009 to April 2010 using either a self-controlled design or a current versus historical comparison. Statistical signals were further evaluated using alternative approaches to identify temporal clusters and to control for time-varying confounders. RESULTS As of May 1, 2010, a total of 1,345,663 MIV, 267,715 LAMV, 2,741,150 TIV, and 157,838 LAIV doses were administered in VSD. No significant associations were noted during sequential analyses for Guillain-Barré syndrome, most other neurologic outcomes, and allergic and cardiac events. For MIV, a statistical signal was observed for Bells palsy for adults aged ≥25 years on March 31, 2010, using the self-controlled approach. Subsequent analyses revealed no significant temporal cluster. Case-centered logistic regression adjusting for seasonality demonstrated an OR for Bells palsy of 1.26 (95% CI=0.97, 1.63). CONCLUSIONS No major safety problems following H1N1 or seasonal influenza vaccines were detected in the 2009-2010 season in weekly sequential analyses. Seasonality likely contributed to the Bells palsy signal following MIV. Prospective safety monitoring followed by rigorous signal refinement is critical to inform decision-making by regulatory and public health agencies.

Barriers to the Use of Herpes Zoster Vaccine

BACKGROUND The herpes zoster vaccine is the most expensive vaccine recommended for older adults and the first vaccine to be reimbursed through Medicare Part D. Early uptake has been 2% to 7% nationally. OBJECTIVE To assess current vaccination practices, knowledge and practice regarding reimbursement, and barriers to vaccination among general internists and family medicine physicians. DESIGN Mail and Internet-based survey, designed through an iterative process and conceptually based on the Health Belief Model. SETTING National survey conducted from July to September 2008. PARTICIPANTS General internists and family medicine physicians. MEASUREMENTS Survey responses on current vaccination practices, knowledge and practice regarding reimbursement, and barriers to vaccination. RESULTS Response rates were 72% in both specialties (301 general internists and 297 family medicine physicians). Physicians in both specialties reported similar methods for delivering vaccine, which included stocking and administering the vaccine in their offices (49%), referring patients to a pharmacy to purchase the vaccine and bring it back to the office for administration (36%), and referring patients to a pharmacy for vaccine administration (33%). Eighty-eight percent of providers recommend herpes zoster vaccine and 41% strongly recommend it, compared with more than 90% who strongly recommend influenza and pneumococcal vaccines. For physicians in both specialties, the most frequently reported barriers to vaccination were financial. Only 45% of respondents knew that herpes zoster vaccine is reimbursed through Medicare Part D. Of respondents who began administering herpes zoster vaccine in their office, 12% stopped because of cost and reimbursement issues. LIMITATIONS Survey results represent reported but not observed practice. Surveyed providers may not be representative of all providers. CONCLUSION Physicians are making efforts to provide herpes zoster vaccine but are hampered by barriers, particularly financial ones. Efforts to facilitate the financing of herpes zoster vaccine could help increase its use. PRIMARY FUNDING SOURCE Centers for Disease Control and Prevention.

Prehypertension and Hypertension in Community-Based Pediatric Practice

OBJECTIVE: To examine the prevalence of prehypertension and hypertension among children receiving well-child care in community-based practices. METHODS: Children aged 3 to 17 years with measurements of height, weight, and blood pressure (BP) obtained at an initial (index) well-child visit between July 2007 and December 2009 were included in this retrospective cohort study across 3 large, integrated health care delivery systems. Index BP classification was based on the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents: normal BP, <90th percentile; prehypertension, 90th to 94th percentile; hypertension, 3 BP measurements ≥95th percentile (index and 2 subsequent consecutive visits). RESULTS: The cohort included 199 513 children (24.3% aged 3–5 years, 34.5% aged 6–11 years, and 41.2% aged 12–17 years) with substantial racial/ethnic diversity (35.9% white, 7.8% black, 17.6% Hispanic, 11.7% Asian/Pacific Islander, and 27.0% other/unknown race). At the index visit, 81.9% of participants were normotensive, 12.7% had prehypertension, and 5.4% had a BP in the hypertension range (≥95th percentile). Of the 10 848 children with an index hypertensive BP level, 3.8% of those with a follow-up BP measurement had confirmed hypertension (estimated 0.3% prevalence). Increasing age and BMI were significantly associated with prehypertension and confirmed hypertension (P < .001 for trend). Among racial/ethnic groups, blacks and Asians had the highest prevalence of hypertension. CONCLUSIONS: The prevalence of hypertension in this community-based study is lower than previously reported from school-based studies. With the size and diversity of this cohort, these results suggest the prevalence of hypertension in children may actually be lower than previously reported.

Effectiveness and Net Cost of Reminder/Recall for Adolescent Immunizations

OBJECTIVE: To assess the effectiveness of reminder/recall (R/R) for immunizing adolescents in private pediatric practices and to describe the associated costs and revenues. METHODS: We conducted a randomized controlled trial in 4 private pediatric practices in metropolitan Denver. In each practice, 400 adolescents aged 11 to 18 years who had not received 1 or more targeted vaccinations (tetanus-diphtheria-acellular pertussis, meningococcal conjugate, or first dose of human papillomavirus vaccine for female patients) were randomly selected and randomized to intervention (2 letters and 2 telephone calls) or control (usual care) groups. Primary outcomes were receipt of >1 targeted vaccines and receipt of all targeted vaccines 6 months postintervention. We calculated net additional revenue for each additional adolescent who received at least 1 targeted vaccine and for those who received all targeted vaccines. RESULTS: Eight hundred adolescents were randomized to the intervention and 800 to the control group. Baseline rates of having already received tetanus-diphtheria-acellular pertussis, meningococcal conjugate, and first dose of human papillomavirus vaccine before R/R ranged from 33% to 54%. Postintervention, the intervention group had significantly higher proportions of receipt of at least 1 targeted vaccine (47.1% vs 34.6%, P < .0001) and receipt of all targeted vaccines (36.2% vs 25.2%, P < .0001) compared with the control group. Three practices had positive net revenues from R/R; 1 showed net losses. CONCLUSIONS: R/R was successful at increasing immunization rates in adolescents and effect sizes were comparable to those in younger children. Practices conducting R/R may benefit financially if they can generate additional well-child care visits and keep supply costs low.

Misperceptions About Influenza Vaccination Among Parents of Healthy Young Children

A survey was administered to 828 parents from metropolitan Denver, Colorado, and 57% responded. Of the respondents, 47% thought their child was unlikely to contract influenza, 70% thought influenza vaccine could cause influenza, and 21% considered influenza vaccination unsafe for a 1-year-old child. The influenza immunization rate in children of surveyed parents was 71%. In multivariate analyses, the perception that influenza vaccination was the social norm was positively associated with immunization (odds ratio [OR], 1.32; 95% confidence interval [CI], 1.03-1.69), and anticipating immunization barriers was negatively associated with immunization (OR, 0.68; 95% CI, 0.49-0.95). Parents of young children hold a number of misperceptions about influenza disease and vaccination. Despite this, high immunization rates are achievable in this population.