The contribution of missed opportunities to childhood underimmunization in Baltimore.

OBJECTIVE

To determine the community-wide incidence of missed opportunities to vaccinate, to describe the clinical settings in which they occur, and to estimate the impact of missed opportunities on immunization coverage.

DESIGN AND

METHODS

We abstracted outpatient medical records from a random, community-based sample of 2-year-old children whose residence was inner-city Baltimore. The date of each vaccine and the date, diagnoses, and temperature at each visit were collected for 502 children at 98 different provider sites.

MAIN OUTCOME MEASURES: Missed opportunities to vaccinate and up-to-date vaccination status.

RESULTS

By 24 months of age, 75% of the children had at least one missed opportunity and only 55% were up-to-date for the 4:3:1 series. Missed opportunities occurred at more than one third of eligible visits for each vaccine, including > 20% of preventative care visits. Diagnoses commonly associated with missed opportunities were "well child," otitis media, upper respiratory infection, gastroenteritis, skin infection, and resolving illness. If no missed opportunities had occurred, 73% of the children would have been up-to-date by 24 months.

CONCLUSIONS

Missed opportunities occurred commonly at providers serving inner-city children in Baltimore and represent a major factor in underimmunization. Reduction of missed opportunities by accurate screening at all visits and adherence to the contraindication guidelines is a provider-based, low-cost method to increase immunization coverage.