A 'barrier-free' health care system does not ensure adequate vaccination of 2-year-old children.

OBJECTIVES

To assess vaccination status in a cohort of 2 year olds with access to health care at no cost and to delineate factors associated with failure to be fully vaccinated.

DESIGN

Retrospective cross-sectional study. Children not up-to-date on vaccinations by age 2 years compared with children up-to-date by medical record review. A telephone survey was conducted for those without medical records or whose records lacked complete documentation.

SETTING

Large military tertiary care hospital.

PARTICIPANTS

A cohort of 844 children born between August 31, 1988, and September 1, 1989.

MAIN OUTCOME MEASURES

Timeliness of vaccination, factors associated with undervaccination, number and nature of missed opportunities.

RESULTS

Best estimate of coverage with entire primary vaccination series was 72% by age 2 years. Attendance at military day care was associated with full vaccination (odds ratio [OR] = 1.80, confidence interval [CI] = 1.12 to 3.24) as was completion of well-baby visits. Increasing number of other visits did not predict full vaccination. Children followed up by family practice were more likely to be up-to-date than children followed up by pediatrics (OR = 3.67, CI = 1.47 to 9.73). Seventy-two percent of children who were not up-to-date had at least one missed opportunity for vaccination. If vaccinations had been offered at all visits, 93% of children could have been fully vaccinated by age 2 years.

CONCLUSIONS

Offering free vaccinations in a "barrier-free" system will not ensure vaccination levels of 90%. Health care providers should offer vaccinations during acute, non-well visits to improve coverage.