An audit of rubella IgG antibody status in antenatal women in a NHS Trust over 5 years (2005-2009).
1. Introduction Immunizations are among the most effective public health interventions to prevent disease and death. Currently, vaccine-preventable diseases are at their lowest level in U.S. history (1, 2). The availability of a large, high-quality, and reliable population-based immunization database provides a unique opportunity to monitor vaccination coverage. The CDC-sponsored National Immunization Survey (NIS) is designed to measure and monitor vaccine-specific coverage estimates for the nation and within each of the 78 Immunization Action Plan (IAP) areas, consisting of the 50 states, the District of Columbia, and 27 large urban areas. To monitor progress toward Healthy People 2000 and 2010 objectives, NIS data are used to produce timely estimates of vaccination coverage within each IAP area for each vaccine type and series of vaccines among children aged 19-35 months (3, 4). Since April 1994, the NIS has been collecting vaccination history data on children aged 19-35 months in the U.S. The NIS is based on a two-phase survey design. The first phase uses a list-assisted random-digit-dialing (RDD) sample design to screen and select a sample of telephone households with age-eligible children. A computer-assisted telephone interview (CATI) is then administered to obtain demographic information, vaccination history, and name(s) of the immunization provider(s) for each eligible child. In the second phase, after obtaining consent from the parent or guardian, an Immunization History Questionnaire (IHQ) is mailed to the identified immunization provider(s). The mailed questionnaires collect data on the immunization history of the selected child from the medical records maintained by the providers. The ongoing quality control (QC) procedures ensure the validity and accuracy of the vaccination coverage estimates. Details of the history, sample design and quality control procedures of the survey are published in Zell et al. (3). For the first time, CDC is planning to disseminate public-use data files (PUF) to allow other public health researchers to analyze the NIS data. While planning for the PUF, the quality of the data was evaluated to