Young docs not so keen on immunizations: Survey

By Dr. Ananya Mandal, MDOct 20 2011

According to researchers young doctors value the importance of immunization lesser than their older counterparts.

A cross-sectional survey of 551 healthcare providers and noted that more recent graduates were less likely to think that vaccines were efficacious said Saad Omer, assistant professor of Emory University in Atlanta. They were also more likely to have doubts about the safety of some vaccines, Omer told reporters at the 49^th annual meeting of the Infectious Diseases Society of America (IDSA).

Overall, however, the physicians who took part in the survey remained highly supportive of childhood vaccines, Omer explained with nearly 90% agreeing that vaccines are getting better and safer. “What we picked up were relative differences – relative, subtle, but important differences,” he said. The findings are significant because doctors are one of the most powerful influences on parental decisions about vaccination, he said. They signal “a potentially important change in immunization beliefs in the new generation of providers, compared with their older counterparts,” he and co-author Michelle Mergler, of Johns Hopkins Bloomberg School of Public Health, argued in their poster presentation on 21^st of October 2011.

“For a long time, we've suspected this kind of thing,” commented Bruce Gellin, director of the National Vaccine Program Office in Washington, who was not involved in the study but who moderated a press conference at which some details were presented. “As familiarity with the disease goes away, they're only hearing about the vaccine and don't often link up with what the vaccines are designed to do,” Gellin said. “In some ways this mimics the situation in society at large, where young parents are not familiar with these diseases…This tells us where we need to focus our efforts,” he added.

For the study the researchers questioned healthcare providers identified by a cohort of parents in Colorado, Massachusetts, Missouri, and Washington whose children were either fully vaccinated or exempt from one or more school immunization requirements. In all 84.3% of the doctors answered the questionnaire, which asked for their views on the risk of a range of vaccine-preventable diseases, including polio and influenza, and their opinions on the efficacy and safety of vaccines against them. The researchers stratified the participants into five-year blocks, depending on the year they graduated from medical school, and used logistic regression methods to look for associations between beliefs and time since beginning practice.

Results of the survey revealed that 81.2% doctors agreed that vaccines are one of the safest forms of medicine ever developed, and 89.1% thought that they were getting both safer and more effective. However with each increase of five years in the year of graduation there was a 20% decrease in the odds of a doctor believing the statements were true. Each increase of five years in the year of graduation was also associated with a significant 18% reduction in the odds that a doctor would believe in high vaccine efficacy overall. However, younger doctors were significantly more likely to question the safety of vaccines against polio (both inactivated and oral), varicella, and measles/mumps/rubella.

In one way, Omer said, the finding may be a result of the very success of vaccination programs. “With such a low burden of disease, the efficacy and real or perceived side effects of vaccines may be the most significant factors contributing to vaccination behaviors,” he and Mergler argued.

In a second study, Dr. Thomas Tryon and his colleagues from Children’s Mercy Hospitals and Clinics in Kansas City, Mo., surveyed 909 pediatricians in nine Midwestern states about patients’ reasons for refusing or questioning vaccinations.

They found that parents most frequently refuse or ask the pediatrician to defer administration of the measles, mumps, and rubella (MMR) vaccine, human papillomavirus (HPV) vaccine, and influenza vaccine. The most frequent reasons given were fear of causing autism, too many shots, and serious side effects.

Nearly all of the respondents (95%) said they engaged the family in discussion of or presentation of options, 66% referred families to evidence-based Web sites, and 63% handed out or referred patients to evidence-based literature as a means of intervention.

Overall, 21% of practitioners said they discharged vaccine-refusing families from their practices. Minnesota-based practitioners were least likely (0.9%) to report removing a family that had consistently refused vaccinations. In contrast, 38% of pediatricians in Iowa said they had removed vaccine-refusing families from their practice.

Dr. Omer’s study was internally funded. He reported having no relevant disclosures. Ms. Mergler reported having no relevant disclosures. Dr. Tryon’s study was supported by a research grant from GlaxoSmithKline to coauthor Dr. Christopher Harrison. Dr. Tryon reported no relevant disclosures.