Inadequate history as a barrier to immunization

Objectives: To evaluate how lack of immunization history contributes to missed opportunities for immunization and to document the effort required to obtain immunization history. Design: Cross-sectional. Setting: Urban, inner-city primary care pediatric clinic serving a low-income, multiethnic population. Patients: Ninety-five new patients seen for either well-child care (53 patients) or acute illnesses (42 patients) during a 4-month period in 1993. Fifty-nine patients were aged 3 to 59 months and 36 were aged 5 to 15 years. Measurements: Efforts to obtain immunization history were documented by means of a standardized data collection form. Results: Immunization history was obtained for only 26 (27%) of 95 patients during the initial visit. Caregivers of 74 (78%) of 95 patients did not bring immunization records to the initial visit; they were no more likely to bring records for well-child care than for acute care or for younger vs older children. Parents brought immunization records more often than did nonparents. A total of 145 telephone calls were made and 30 letters were sent in an attempt to obtain immunization histories. Immunization records were never found for 10 new patients (11%). Thirty-two patients (34%) were found to be lacking immunizations. Of these, only three patients had contraindications to immunization at the initial visit. Therefore, in one third of our new patients, opportunities to immunize were missed solely because their immunization records were unavailable at the initial visit. In another one third of cases, caregivers had incorrectly believed their child's immunizations to be up to date. Conclusions: Opportunities to immunize children were often missed because of a lack of immunization history. Our experience supports the need for improved documentation of immunization histories.