Improving immunization rates: A stick in time saves (almost) nine trips to pick up food stamps

An ounce of prevention is worth eight trips every year for food vouchers.

That was the offer for about a year and a half from health officials trying to boost immunization rates among children in Chicago. Keep your children's immunizations up to date, they said to women enrolled in the federal Women, Infants, and Children (WIC) program, and we'll allow you to pick up food vouchers once every three months rather than every month.

The carrot worked. Between April 1996 and June 1997, immunization rates among Chicago children in the program increased from 56% to 89%. Even more encouraging, the increase did not vary significantly with how much staff members counseled participants, the racial or ethnic status of the population served, or the availability of vaccinations on-site at the WIC office.

"It's a pretty cost-effective thing to do, and it improves coverage rates dramatically," says Abigail Shefer, MD, a medical epidemiologist with the Centers for Disease Control and Prevention (CDC) in Atlanta.

WIC officials already have the authority to vary the frequency of voucher pick-up and commonly use that discretion to monitor the health of high-risk children and women. Nevertheless, researchers in the immunization project also had to prove that the increased rate of visits in the so-called "high-risk" protocol of monthly visits did not deter women from seeking WIC services altogether.

As it turned out, women both inside and outside the high-risk protocols tended to have the same participation rate in WIC. When people dropped out, they tended to do so for the same reasons. The findings allay the fears that the increased frequency of visits in the high-risk protocol would prove to be a hassle.

"Parents were really appreciative if they were approached the right way," Ms. Shefer says.

The biggest roadblocks to broader implementation of the program appear to be lack of money and officials' fear of migrating too far from WIC's primary mission.

The annual labor costs for monitoring immunizations for about 17,000 children in Chicago was $271,000. Both staff members and their supervisors worked exclusively for the immunization project, a strategy that researchers feel was crucial to its success.

But the success of WIC in protecting the health status of women and children may be part of its problem. Ms. Shefer notes that because "whatever they do, they do very well," WIC program officials often have to fend off requests to extend their activities beyond their traditional focus.

Some state WIC directors are less supportive of this approach than others, Ms. Shefer says. "That's made it hard to implement, even if local WICs are interested," she notes.

With immunization rates for 2-year-olds stuck at around 70% in the mid-1990s, public health officials in Tennessee's Hamilton County were more than ready to try the WIC intervention. They already had run through a disappointing laundry list of interventions to boost immunization rates in the Chattanooga area.

"We tried incentives, we had developed a local registry, we ran publicity campaigns, tried to raise community awareness, and still weren't seeing the response we had hoped we would see," says Donna Needham, RN, BSN, immunization outreach coordinator in Chattanooga.

Depending upon how coverage was measured, immunization rates for children 24 to 27 months old improved from 7.1% to 17%. Weekly staff sessions dropped the rate of administrative errors and "missed opportunities" for immunizations from about 21% to negligible. At the same time, WIC participation remained level at about 5,000 clients.

"Our main concern was, we did not want people not to come back to WIC because of what we were doing with immunizations," Ms. Needham says.

"We tried to be very patient with them," she says. "We even put a couple of special staff members in the clinic to explain to parents what we were doing and how we were doing it. We would call doctors' offices and get immunization histories if we needed to. Our WIC clients were not used to bringing immunization records with them to WIC appointments, and many of them didn't even have immunization records."

Public health officials in Nashville and Memphis are considering implementing the WIC intervention. Rural areas, by comparison, seem to have less of a problem with immunization than do cities, Ms. Needham says.

"Our rural areas in Tennessee already have fairly high immunization rates, in the upper 80s or 90%," Ms. Needham says. "The smaller the county, the more tightly knit the community—they seem to have higher rates."

In Milwaukee, more than half of the babies born in each year participate in WIC. After a measles epidemic hit the city in 1989-91, public health officials saw WIC intervention as a way to prevent a recurrence. Not only did the intervention boost the children's immunization rate, it also significantly increased the average number of well-child visits and screenings for lead, tuberculosis, and anemia. (See chart depicting Milwaukee WIC vaccination coverage, above.)

"It's pretty exciting because it's a strategy that improves not just one aspect of their health care, but improves other aspects," says Ms. Shefer.

In addition, she says, the strategy of focusing on underimmunized children targets those who are most likely to have other health problems.

Increased interest in the WIC-linked intervention has led Wisconsin state officials this fall to develop a protocol for implementation on a local level. WIC programs must complete basic and additional immunization activities before initiating a monthly visit schedule.

"It's a last resort," Wisconsin WIC director Patti Herrick says.

In Tennessee, public health officials provided immunizations on-site or referred the parents of underimmunized children to their primary care provider. The system worked well there, in part because the WIC program brought area pediatricians into the program early. But Ms. Shefer at the CDC warns that overlaps and gaps in care can occur when WIC and private providers both provide immunizations, and generally recommends that underimmunized children are referred back to their primary care physicians for care.

When Tennessee children are immunized according to protocols other than the health department's, state health officials will consider the children's immunization to be up to date as long as the standards meet the guidelines of the CDC and the American Academy of Pediatrics.

The WIC intervention is a part of a larger public health strategy to eradicate measles in the United States. "The incidence of measles in general has been really low in the last few years," Ms. Shefer acknowledges, "but you never know when there's going to be an outbreak."

Contact Ms. Shefer at (404) 639-8233 and Ms. Needham at (423) 209-8190.