Self-report compared to electronic medical record across eight adult vaccines: do results vary by demographic factors?

Immunizations are crucial to the prevention of disease, thus, having an accurate measure of vaccination status for a population is an important guide in targeting prevention efforts. In order to comprehensively assess the validity of self-reported adult vaccination status for the eight most common adult vaccines we conducted a survey of vaccination receipt and compared it to the electronic medical record (EMR), which was used as the criterion standard, in a population of community-dwelling patients in a large healthcare system. In addition, we assessed whether validity varied by demographic factors. The vaccines included: pneumococcal (PPSV), influenza (Flu), tetanus diphtheria (Td), tetanus diphtheria pertussis (Tdap), Human Papilloma Virus (HPV), hepatitis A (HepA), hepatitis B (HepB) and herpes zoster (shingles). Telephone surveys were conducted with 11,760 individuals, ≥18, half with documented receipt of vaccination and half without. We measured sensitivity, specificity, positive and negative predictive value, net bias and over- and under-reporting of vaccination. Variation was found across vaccines, however, sensitivity and specificity did not vary substantially by either age or race/ethnicity. Sensitivity ranged between 63% for HepA to over 90% (tetanus, HPV, shingles and Flu). Hispanics were 2.7 times more likely to claim receipt of vaccination compared to whites. For PPSV and Flu those 65+ had low specificity compared to patients of younger ages while those in the youngest age group had lowest specificity for HepA and HepB. In addition to racial/ethnic differences, over-reporting was more frequent in those retired and those with household income less than $75,000. Accurate information for vaccination surveillance is important to estimate progress toward vaccination coverage goals and ensure appropriate policy decisions and allocation of resources for public health. It was clear from our findings that EMR and self-report do not always agree. Finding approaches to improve both EMR data capture and patient awareness would be beneficial.