Background. Lack of a consolidated immunization record may lead to problems
with determining individual immunization needs at office visits as well as
measuring vaccination coverage levels of a clinician's practice or a commu
nity's population.
Objectives. For children with multiple immunization providers, evaluate the
difference in coverage levels using data from all responding immunization
providers compared with: 1) the most recent immunization provider's records
, 2) the first immunization provider's records, and 3) a randomly selected
immunization provider's records. Identify characteristics of the most recen
t provider that may be associated with reporting incomplete immunization hi
stories.
Methods. Data from the 1995 National Immunization Provider Record Check Stu
dy (NIPRCS) were used for analysis. The NIPRCS is a provider validation stu
dy of the household reported immunization histories of all children 19 to 3
5 months of age included in the National Health Interview Survey (NHIS). Pr
oviders identified by the child's parent during the NHIS interview are mail
ed a 2-page survey to report all immunizations (type and date) the child re
ceived, regardless of the provider who administered the shots, and child's
first and most recent visit dates to the practice.
Results. Of the 1352 children with provider data, 304 (22%) had received im
munizations from more than one provider. Compared with information from all
providers and depending on the vaccine, the most recent provider records u
nderestimated coverage by 9.6 to 13.4 percentage points; the initial provid
er records underestimated coverage by 15.6 to 34.6 percentage points; and t
he randomly selected provider records underestimated coverage by 10.0 to 20
.7 percentage points. Public facilities and having an immunization summary
sheet in the patient's chart were associated with having complete records.
Conclusion. Scattered immunization records significantly compromise the abi
lity of clinicians to determine the immunization status of their patients w
ho received immunizations at other sites of health care. Routinely assessin
g immunization coverage levels at the practice level, implementing a recall
system, and developing community-wide immunization registries are some str
ategies to reduce the problem of scattered immunization records.