摘要：Objective. We examined the timeliness of vaccine administration among children aged 24 to 35 months for each state of the United States and the District of Columbia. Methods. We analyzed the timeliness of vaccinations in the 2000–2002 National Immunization Survey. We used a modified Bonferroni adjustment to compare a reference state with all other states. Results. Receipt of all vaccinations as recommended ranged from 2% (Mississippi) to 26% (Massachusetts), with western states having less timeliness than eastern states. Conclusions. Vaccination coverage measures usually focus on the number of vaccinations accumulated by specified ages. Our analysis of timeliness of administration shows that children rarely receive all vaccinations as recommended. State health departments can use timeliness of vaccinations along with other measures to determine children’s susceptibility to vaccine-preventable diseases and to evaluate the quality of vaccination programs. States can use the modified Bonferroni comparison to appropriately compare their results with other states. In the United States, the childhood immunization schedule recommends that children receive approximately 15 vaccinations by 19 months of age, and it specifies ages for administration of each vaccine dose. 1 These ages were selected to maximize protection as early as possible while minimizing potential risks. 1 Each year, the Centers for Disease Control and Prevention (CDC) publishes state-specific vaccination coverage rates. 2 – 4 State health departments use this information to assess the level of susceptibility of children residing in their state to vaccine-preventable diseases and to evaluate their vaccination programs. These vaccination rates typically focus on the number of vaccinations accumulated by the time of evaluation, which is conducted at age 19 to 35 months. With the exception of varicella, for which doses are included only if given after 12 months of age, these reports do not consider whether the vaccinations were given at appropriate ages. Children who are fully vaccinated at the time of the interview may have received some vaccinations too early for the vaccines to be effective, or they may have been undervaccinated during much of their first 2 years, when children are most susceptible to severe illness and complications from many vaccine-preventable diseases. In 2002, a national-level study found that although 73% of children received all vaccinations in the standard 4:3:1:3:3 series by age 19 to 35 months, 2 only 13% of children received all of these vaccinations at the recommended ages. 5 Similar information at a state-specific level will enable state vaccination program administrators to evaluate timeliness of vaccinations for children and to compare the state’s rates of timely vaccination with that of other states. Our study examined state-level timeliness of vaccine administration, and we present a statistically appropriate method for comparing rates of 1 state with all other states.
