Strategies are needed to improve immunization rates among adolescents, especially those with high-risk conditions
Research Activities, March 2009, No. 343
In their early years, children routinely receive immunizations during regular health checkups. When they become adolescents, however, vaccination rates tend to wane as checkups become less frequent. Two new studies show that opportunities to vaccinate adolescents are missed during health care visits. The first found that vaccination rates among 13-year-olds for hepatitis and measles-mumps-rubella (MMR) were lower than the national estimate. The second study found that influenza vaccination rates for adolescents with chronic conditions improved over a 10-year period, but rates are still low. Both studies, supported in part by the Agency for Healthcare Research and Quality (HS13908 and HS00063), are summarized here.
Lee, G.M., Lorick, S.A., Pfoh, E., and others (2008, October). "Adolescent immunizations: Missed opportunities for prevention." Pediatrics 122(4), pp. 711-717.
The researchers studied 1997 to 2001 data on 23,987 adolescents enrolled in a health maintenance organization in New England. They found that 13-year-olds were 84, 74, and 67 percent up-to-date on their tetanus-diptheria (Td), hepatitis B, and MMR vaccinations, respectively. The Td immunization rate (84 percent) was much higher than the national estimate of 48.3 percent for 13-year-olds. However, the vaccination rates among 13-year-olds for hepatitis and MMR were lower than the national estimate of 88.6 percent and 87 percent, respectively.
The rate for MMR vaccination was lower than expected, considering an up-to-date vaccination is required for attending school in Massachusetts, where much of the study population lived. Lower immunization rates may be explained, in part, because adolescents' immunizations records may be scattered in locations other than their primary care provider's office, such as schools. The authors also looked at missed opportunities to vaccinate adolescents for Td by determining whether the vaccine was given during or within 2 weeks of an adolescent's health care visit. They calculated an average of 4.8 missed opportunities for 18,011 adolescents who were eligible for vaccinations during a health care visit. Further, adolescents who did not use preventive care were less likely to receive a timely Td vaccination. These findings stress the need for providers to take every opportunity to assess and record adolescents' immunization status, especially for vaccines that are given in childhood.
Nakamura, M.M., and Lee, G.M. (2008, November). "Influenza vaccination in adolescents with high-risk conditions." Pediatrics 122(5), pp. 920-928.
Researchers reviewed records of 18,703 adolescents with high-risk chronic conditions who were enrolled in a health maintenance organization in New England from 1992 to 2002. Vaccination rates for influenza ranged from 8.3 to 15.4 percent, with a significant improvement from 8.3 to 12.8 percent from 1992 to 1993 and a high of 15.4 percent in 2001. For the 377 adolescents continuously enrolled from 1999 to 2002, just 11.1 percent received flu vaccine for all 4 flu seasons; 56.5 percent received no vaccine at all during the 4 seasons.
Of the adolescents who had an outpatient health care visit during the first 4 months of flu season (a prime opportunity to vaccinate), 45 to 55 percent left without receiving a flu shot. These visits were missed opportunities to vaccinate because the office visits were not for conditions that would have prevented receiving a flu shot.
Current practice guidelines recommend that adolescents who have chronic health conditions, such as asthma, HIV, diabetes, or heart disease, should receive yearly flu shots because they are more likely than healthy children to end up in the hospital, in a doctor's office, or on antibiotics if they have a bout of flu. Clearly, preventive health visits alone do not ensure immunization coverage. One solution for ensuring these patients receive yearly influenza vaccinations is to recommend universal influenza vaccination for all pediatric patients, the authors suggest, and interventions to increase vaccination rates should be aimed at providers as well as patients.