Background: The National Immunization Survey (NIS) and the National Health
Interview Survey (NHIS) produce national coverage estimates for children ag
ed 19 months to 35 months. The NIS is a cost-effective, random-digit-dialin
g telephone survey that produces national and state-level vaccination cover
age estimates. The National Immunization Provider Record Check Study (NIPRC
S) is conducted in conjunction with the annual h:HIS, which is a face-to-fa
ce household survey. As the NIS is a telephone sun ey, potential coverage b
ias exists as the survey excludes children living in nontelephone household
s.
Methods: To assess the validity of estimates of vaccine coverage from the N
IS, we compared 1995 and 1996 NIS national estimates with results from the
NHIS/NIPRCS for the same years.
Results: Both the NIS and the NHIS/NIPRCS produce similar results.
Conclusion: The NHIS/NIPRCS supports the findings of the NIS.