We thank Golombek et al for their thoughtful remarks on our article and for reporting their own data on physicians in Iowa. We fully endorse their views on the important role of primary care providers in assuring timely immunization of all children according to recommended schedules, and the need for establishing practice routines that will further this objective.
We suggest that one reason for differential use by specialty of hepatitis B vaccine relates to rural and urban distribution differences in hepatitis B virus infection, economics, and physician specialty. The high-risk behaviors for acquiring the hepatitis B virus typically involve intravenous drug use and sexual promiscuity, which tend to occur more often in urban areas. Furthermore, rural areas are more economically disadvantaged than metropolitan areas; hence, rural residents who are not eligible for free vaccines may have difficulty paying for the hepatitis B vaccine series because it is one of the more expensive routine immunizations. Pediatricians are more likely to serve in urban areas than are family physicians. Thus, primary care physicians' use of hepatitis B vaccine may depend in part on the frequency of hepatitis B virus infection, the frequency of high-risk behaviors in their locale, and economics.