Survey checkbox

Vaccine hesitancy is on the rise. Nationally, it’s an issue, and the non-medical exemption rate continues to increase annually. According to the Centers for Disease Control and Prevention, 4.6 percent of children entering kindergarten in Washington state in 2012 had an exemption, and the figure was 6.1 percent in Illinois and Vermont.

Our Seattle-based team of researchers has been investigating if there’s a valid way of identifying parents who are hesitant enough early on in their child’s life that they will accept fewer immunizations than is recommended. Knowing early whether a parent is hesitant and will under-immunize their child might be helpful to clinicians as they try to understand and lessen a parent’s vaccine concerns.

Survey designed to identify vaccine-hesitant parents

We created the Parent Attitudes about Childhood Vaccines survey (PACV) to identify hesitant parents who under-immunize their children. Our new study assessing the survey, released today in JAMA Pediatrics, found that the PACV, when given to parents when their child is 2 months old, does indeed predict childhood immunization status at 19 months of age. We validated the results with 437 parents in different geographic and demographic samples.

We gave the survey to English-speaking parents of children who were 2 months old and were born between July 10 and December 10, 2010.The children were patients at Group Health Cooperative in Seattle. The PACV was scored on a scale of zero to 100, with 100 indicating high hesitancy about vaccines. Childhood immunization status was measured as the percentage of days from birth to 19 months of age that children were immunized according to the recommended schedule.

We looked at six vaccines to assess immunization status: Diphtheria, tetanus, and acellular pertussis; inactivated poliovirus; measles, mumps, and rubella; Haemophilus influenza type b (HIB); hepatitis B; and varicella. We determined whether a child received a specific vaccine dose late by calculating the difference between the age in days the dose was received and the latest age at which it should have been received according to the American Academy of Pediatrics’ Advisory Committee on Immunization Practices 2011 immunization schedule.

Higher survey scores lead to under-immunized children

We found that higher parent survey scores when their child was 2 months old were associated with more under-immunization when the child was 19 months old. Parents who scored 50 to 69 on the survey had children who were under-immunized for 8.3 percent more days than parents who scored less than 50. Parents who scored 70 to 100 had children who were under-immunized 46.8 percent more days than children of parents who scored less than 50.

What does all of this mean? We know that the person who most influences a parent’s decision to immunize is that family’s clinician. Having parents take this survey may help provide valuable information to clinicians. The survey can help better inform pediatricians and can be an important tool in clinical and research interventions to improve parental acceptance of childhood immunizations.

The information gleaned from the PACV is perhaps more important now than ever, given public health announcements about measles cases earlier this year in Seattle and Brooklyn, NY.

“The Relationship between Parent Attitudes about Childhood Vaccines Survey Score and Future Child Immunization Status: A Validation Study” is published in JAMA Pediatrics.

Dr. Opel is corresponding author on the study. Dr. Opel is an investigator at Seattle Children’s Research Institute, assistant professor in the Department of Pediatrics at the University of Washington and an affiliate investigator at Group Health Research Institute.

Co-authors include: James A. Taylor, MD (Seattle Children’s, University of Washington); Chuan Zhou, PhD (Seattle Children’s Research Institute); Sheryl Catz, PhD (Group Health Research Institute); Mon Myaing, PhD (Seattle Children’s Research Institute); and Rita Mangione-Smith, MD, MPH (Seattle Children’s Research Institute, University of Washington).

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If you’d like to arrange an interview with Dr. Opel, please contact Children’s PR team at 206-987-4500 or press@seattlechildrens.org.