Study pinpoints ways to boost vaccine compliance
July 1, 1997 6 minutes read
Study pinpoints ways to boost vaccine compliance
Nonrecipients fear side effects, doubt efficacy
Education about influenza vaccine safety and the reasons for targeting health care workers is one of the most important strategies for increasing immunization levels among hospital workers, according to researchers who sought to clarify factors associated with influenza vaccination of HCWs.1
Influenza outbreaks are not uncommon in hospitals, and unvaccinated HCWs have sometimes been implicated as sources.2,3 Workers can begin shedding virus before they experience symptoms, and some HCWs remain on the job even when they know they’re ill. (See related story in Hospital Employee Health, November 1996, pp. 128-130.)
Survey: Most employees don’t comply
The solution is widespread compliance with employee immunization programs, yet compliance remains unimpressive in most hospitals. An unpublished U.S. Centers for Disease Control and Prevention survey found that 48% of 849 hospitals reported less than 25% of HCWs were immunized against influenza. Another survey of 351 hospital employees revealed that only 31% of employees complied with their hospital’s vaccination program in 1993-94.4
The CDC recommends annual immunization for HCWs, particularly those who have contact with high-risk patients whose immunocompromised status renders them unable to fight off infection.5 More than 80% of influenza-associated deaths occur among the elderly and others with high-risk conditions.6
Concerned that HCW immunization rates at their institution might not be optimal, researchers at the Veterans Affairs Medical Center in Minneapolis mailed a 35-item self-administered questionnaire to all 1,031 staff physicians and nurses in 1994. Questions addressed demographic characteristics, lifestyle behaviors, knowledge, and attitudes regarding influenza immunization, and whether recipients had been vaccinated during the 1993-94 season. Statistical measurements were used to identify factors independently associated with receipt of flu vaccine.
The response rate was 38% (392/1,031). Mean age of respondents was 43.6 years, 71.5% were female, and 26.2% were physicians. More than 95% had daily or weekly contact with elderly or high-risk patients. During the 1993-94 season, 61.2% had been immunized, and two-thirds of respondents said they planned to be immunized the next year. Vaccine recipients also were more likely to have received vaccine in previous years.
Although a 61.2% vaccination rate exceeds most national estimates, "in a health care setting, a goal of 60% is not adequate," says Kristin L. Nichol, MD, MPH, chief of medicine at the Veterans Affairs Medical Center in Minneapolis and principal researcher for the influenza study. "For people who have contact with high-risk patients, it should be higher than that."
Nichol notes that the medical center has had an annual immunization program for patients and employees since 1987. The program has removed some of the barriers commonly cited in workers’ failure to receive vaccine, such as cost and accessibility. Flu vaccine is offered free at a conveniently located on-site walk-in clinic eight hours a day, five days a week, for two months, and mobile carts are taken to inpatient wards and clinic areas to facilitate vaccination of hospital personnel who have contact with high-risk patients.
Removing those barriers allowed researchers to uncover the existence of other barriers to vaccine compliance, Nichol tells Hospital Employee Health.
Survey results showed how vaccine recipients and nonrecipients ranked factors that might have influenced their decisions. Vaccine recipients indicated the most important factor influencing their decision was to avoid illness (58.8%), followed by convenience of receiving vaccine (12.5%) and the desire to protect patients (8.8%). Among nonrecipients, the most important factors influencing their decision was concern about side effects (30.9%), followed by the belief that they were not in a target group to receive vaccine (7.9%).
Even though physicians and nurses might be expected to know the facts about flu vaccine safety and the need for HCWs to be immunized, the survey’s results point to the need for improved education, Nichol says.
"I do not know if everyone has been exposed to the message effectively. In fact, one of the conclusions of our study is that presumably many health care workers have not effectively been exposed to that message. It suggests that we need to do a better job of educating, in particular about the rationale for why health care workers especially should be vaccinated," she says.
Side effects overestimated
Misconceptions about influenza vaccine side effects persist, Nichol points out. "I don’t want to get the flu from the flu shot.’ Have I heard that many times? Absolutely yes. Can people get the flu from the flu shot? Absolutely not. This [survey] suggests we need more effective strategies for disseminating the findings of research studies so that people are not misinformed. Even though they are professionals, I don’t know if that means they are aware of the scientific literature."
The survey showed that both vaccinated and unvaccinated HCWs frequently overestimated the occurrence of side effects following vaccination. Among vaccine recipients, nearly 52% estimated that between 1% and 10% of vaccine recipients experience systemic side effects following vaccination. More than 60% of vaccine nonrecipients indicated the same, and 11.5% of them estimated that between 10% and 20% of vaccine recipients experience side effects. Eight percent estimated that more than 20% suffer systemic side effects.
Nichol says many misconceptions stem from the swine flu vaccine campaign in the 1970s, when Guillain-Barre syndrome developed in approximately one per 100,000 vaccine recipients.7
Many doubt efficacy
Some people have even longer memories. "The very early influenza vaccines in the 50s and early 60s were reactogenic; they were much less pure than they are now," she adds.
Another reason for fear of side effects relates to what Nichol calls "heightened somatic awareness" of symptoms that people tend to blame on something unusual that happened to them recently, such as receiving a flu shot.
"If you look at a population that gets a shot today of anything, including saline, tomorrow a certain percentage of that population is going to feel ill," she explains. "But that is a completely unrelated phenomenon because they would have gotten ill even if they hadn’t gotten the shot."
CDC recommendations note that because the vaccine contains only inactive noninfectious viruses, it cannot cause influenza. Most frequently reported side effects are localized reactions such as soreness at the vaccination site. Systemic side effects occur rarely after vaccination and probably result from hypersensitivity to residual egg protein among people who have severe egg allergy.5 A recent placebo-controlled clinical trial in healthy working adults demonstrated that flu vaccine was not associated with higher rates of systemic side effects than were placebo injections.8
Survey results also indicated that uncertainty about vaccine efficacy influences vaccination behavior. While 55.4% of vaccine recipients believe the vaccine is "very effective," only 22.3% of nonrecipients believe this. CDC data show that when there is a good match between vaccine and circulating viruses, vaccine has been shown to prevent illness in approximately 70% of healthy people less than 65 years old.5
Although most HCWs surveyed were aware that influenza and its complications for elderly and high-risk patients are "very serious" (98.7% of vaccine recipients and 84.7% of nonrecipients), only 29.7% of nonrecipients believe it’s "very important" for HCWs to be vaccinated to prevent influenza transmission to patients.
HCWs must remember the dictum "first do no harm" as the underlying rationale for receiving influenza vaccination, Nichol says. In addition, workers who receive vaccine are better examples for their elderly and high-risk patients who also should be vaccinated.
Previous education efforts at the medical center focused on posters and a mailing to workers publicizing vaccine availability and reviewing information about it and the disease. This year, Nichol says she plans to work with the education department in designing materials and strategies for a campaign that will highlight the rationale for vaccination, the health benefits to patients and employees, and the safety and efficacy of the vaccine.
References
1. Nichol KL, Hauge M. Influenza vaccination of healthcare workers. Infect Control Hosp Epidemiol 1997; 18:189-194.
2. Pachucki CT, Walsh-Pappas SA, Fuller GF, et al. Influenza A among hospital personnel and patients: Implications for recognition, prevention, and control. Arch Intern Med 1989; 149:77-80.
3. Weingarten S, Friedlander M, Rascon D, et al. Influenza surveillance in an acute care hospital. Arch Intern Med 1988; 148:113-116.
4. Bratcher DF, Stover BH, Lane NE, et al. Compliance with national recommendations for TB screening/immunization of health care workers: Report from a children’s hospital. Presented at the 22nd annual conference of the Association for Professionals in Infection Control and Epidemiology, Poster #120. Las Vegas; 1995.
5. Centers for Disease Control and Prevention. Prevention and control of influenza: Recommendations of the Advisory Committee on Immunization Practices. MMWR 1996; 45(No. RR-5):1-24.
6. Lui K, Kendal AP. Impact of influenza epidemics on mortality in the United States from October 1972 to May 1985. Am J Public Health 1987; 77:712-716.
7. Safranek TJ, Lawrence DN, Kurland LT, et al. Reassessment of the association between Guillain-Barre syndrome and receipt of swine influenza vaccine in 1976-1977: Results of a two-state study. Am J Epidemiol 1991; 133:940-951.
8. Nichol KL, Margolis KL, Lind A, et al. Side effects associated with influenza vaccination in healthy working adults. Arch Intern Med 1996; 156:1546-1550.
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