Objective: To assess immunization levels for children of employees of a large corporation.
Design: A mail survey of a random sample of employees on the immunization history of one child per family.
Setting: US employees of Johnson & Johnson.
Participants: 1500 employees with children born between 1984 and 1991.
Main outcome measures: Coverage rates for recommended vaccines at different ages up to 6 years.
Main results: Only 45.2% and 55.3% of the study children at ages 2 and 6 years were current for all recommended immunizations (65.1% and 70.3%, respectively, excluding the Haemophilus influenzae type b vaccine). Using the minimum standard required by many states for school entry, the coverage level at age 6 years was 90.4%. Factors associated with higher immunization rates at age 2 years were the corporate health plan (choices), higher pay level, greater parental formal education, white race, and knowing when to initiate immunization. Lower immunization rates at age 2 years were associated with delayed receipt of the first dose of diphtheria, tetanus, and pertussis vaccine, use of city or county clinics, employee-reported barriers of difficulty leaving work, and provider access problems, but not cost of services. After adjusting for the effects of other variables through logistic regression, race, pay level, and plan choice were no longer significant. Modeling with the remaining variables predicted rates of adequate immunization at age 2 years from 15% to 81%.
Conclusion: Even in this relatively affluent group with good insurance (including immunizations), preschool immunization rates did not reach public health goals. Changing modifiable factors, such as knowing when to initiate immunization, enabling parents to leave work more easily, and improving provider access, might improve preschool immunization rates.