Factors associated with unnecessary immunization given to children.

OBJECTIVE

To determine the factors associated with unnecessary immunization during the pre-school years.

METHODS

Children were selected from birth certificates and their parents were interviewed to identify all immunizations to 72 months of age. The immunizations were verified.

RESULTS

Of 187 children studied 34 (18%) received unnecessary immunization. Unnecessary immunization was strongly associated with ever receiving immunization in a large system of public clinics (designated "Public A") (33%) compared with other providers (5%) (P < 0.00001). Among children immunized in Public A, unnecessary immunization was associated with the parent having an incomplete or no copy of the child's immunization record (P = 0.007) and with not being up to date for immunizations at 24 months of age (P = 0.04). Complete documentation of immunizations either in the Public. A record or in the parent's copy of the record was associated with a 4% rate of unnecessary immunization; incomplete or no documentation in both the Public A and the parent's record was associated with a 45% rate of unnecessary immunization (P = 0.001).

CONCLUSIONS

Access to a complete immunization record, be it the provider's, the parent's or ideally both, decreases substantially a child's risk of unnecessary immunization.