Oct. 3, 2011 -- More than 1 in 10 parents of young children don't follow the recommended vaccination schedule, new research shows.
They decline some vaccines, delay others, or in other ways tweak the recommendations, the survey found.
The 1 in 10 finding is concerning, says researcher Amanda Dempsey, MD, PhD, MPH, assistant professor of pediatrics and communicable diseases at the University of Michigan in Ann Arbor. "That's enough to cause increases in vaccine-preventable disease outbreaks," she says.
Dempsey and her colleagues conducted a survey over the Internet of a nationally representative sample of parents of children ages 6 months to 6 years old. They asked them which vaccination schedule they used and whether their child got all recommended vaccines.
The parents answered other questions, including whether they had a regular health care provider for their child.
Dempsey's team evaluated 748 responses. The parents ranged from 18 to 59 years old, but most were ages 30 to 44.
Some of the 13% who followed an alternative schedule looked to well-known ones, such as those promoted by Dr. William Sears or Dr. Donald Miller. But much more commonly, parents on the alternative schedule tweaked it themselves or took a friend's advice on how to do so. Some said they worked with the child's doctor to develop the alternative schedule.
The patterns among those not following the recommended schedule varied. Among them:
17% said their child did not get any vaccines.
53% said they didn't get some vaccines.
55% said they delay some vaccines until older than the recommended age.
36% said they wait longer between multiple-dose vaccines than is recommended.
H1N1 influenza, refused by 86% of those on the alternative schedule
Seasonal influenza, 76%
Chickenpox (varicella), 46%
The vaccines least likely to be refused were polio and diphtheria-tetanus-acellular pertussis, each refused by 6% of parents.
"Our study is in the ballpark of what was shown before," Dempsey says. "A lot of parents are on the fence about vaccines and this is going to continue to be a problem."
Also troubling, she says, are some other findings. "We found almost a third of parents who are on an alternate vaccine schedule started out on a recommended schedule." And more than a fourth of those still following the recommended schedule said they thought delaying vaccines was safer.
Those most likely not to follow the schedule didn't have a regular health care provider. However, Dempsey isn't sure which situation came first. She doesn't know if those who tweak the schedule have a difficult time finding a doctor or that these parents who don't get regular health care are the ones who tend not follow the schedule.
Dempsey reports compensation for serving on an advisory board for Merck related to the male human papillomavirus vaccination. The company did not participate in this study.