Group Health Research Institute conducts first randomized trial to tackle vaccine hesitancy

Group Health Research InstituteJun 2 2015

Group Health Research Institute conducted the first randomized trial to test an intervention aimed at improving hesitancy about early childhood vaccines by working directly with doctors. Vax Northwest, a Washington state public-private partnership, developed the intervention. The results are reported in Pediatrics in "Physician Communication Training and Parental Vaccine Hesitancy: A Randomized Trial," with an accompanying editorial: "Physician Communication with Vaccine-Hesitant Parents: The Start, Not the End, of the Story."

Here's why the team did the research: Vaccines are children's best protection from infectious diseases, including ones that can cause death. But many parents hesitate to vaccinate their children, particularly in Washington state. And delaying or refusing vaccines can lead to outbreaks of vaccine-preventable diseases, as recently happened with measles at Disneyland. Doctors can influence decisions about childhood vaccines, but they may lack confidence in addressing concerns about vaccines.

The trial included 347 mothers of newborns receiving care at 56 primary care clinics in two western Washington counties. It tested a one-time, 45-minute training session and six months of follow-up communication for doctors in the intervention clinics--with comparison to control clinics with no training. The communication training encouraged providers to use respectful, open dialogue with parents while recommending vaccination, and it included anyone working in the clinic who wished to attend.

Trial results

Vaccine hesitancy rates declined slightly in both the 30 intervention and 26 control clinics over the six-month study period--and did not differ significantly between them. The intervention did not change either mothers' vaccine hesitancy, or doctors' confidence in communicating about vaccines.

The decrease in vaccine hesitancy may be related to a whooping cough (pertussis) outbreak that happened in Washington state during the study period, and new state legislation requiring a doctor's note for exemption from schools' vaccination requirements, according to lead author Nora Henrikson, PhD, a research associate at Group Health Research Institute. "If vaccine hesitancy is really decreasing, that's potentially good news." Dr. Henrikson added. "But we still don't understand how parents' hesitancy changes over time, and we still see outbreaks of vaccine-preventable disease."

The trial's novel intervention--called Ask, Acknowledge, and Advise--was developed and pretested by Vax Northwest, which includes Group Health, WithinReach, Seattle Children's, BestStart Washington, and the Washington State Department of Health. Vax Northwest is a public-private partnership working to ensure all children and communities in Washington state are protected from vaccine-preventable disease.

Ideally, the measured outcome would have been vaccinations. But because vaccine delay and refusal are so rare, testing an impact on this outcome would have required an extremely large and expensive study.

What's next?

"More research is needed to identify strategies that help primary-care doctors to address parents' vaccine hesitancy," said Dr. Henrikson's coauthor, principal investigator David C. Grossman, MD, MPH. He is a Group Health Research Institute senior investigator, Group Health pediatrician and medical director for population and purchaser strategy, and professor of health services at the University of Washington (UW) School of Public Health and adjunct professor of pediatrics at the UW School of Medicine.

The trial intervention was designed to be easily translated to practice, but perhaps a longer, higher-intensity version of the training might be more effective. Or, since most parents are already confident about vaccines, doctors might need a way to identify hesitant parents reliably so they can allow enough time during visits to discuss vaccines. "Doctors are the main source of vaccine information for most parents," Dr. Grossman said, "so they need evidence-based ways to address parental vaccine concerns." You can read a blog that he wrote about this work.

"Organizations across the country are looking for ways to communicate the value of vaccination to protect our families and communities," said another coauthor, Douglas J. Opel, MD, MPH. He is an investigator at the Treuman Katz Center for Pediatric Bioethics at Seattle Children's Hospital Research Institute, an assistant professor in the Divisions of Bioethics and General Pediatrics at the UW School of Medicine, and an affiliate investigator at Group Health Research Institute. "That's why we've done this research and will keep trying to tackle vaccine hesitancy."