A Randomized Study of Tracking With Outreach and Provider Prompting to Improve Immunization Coverage and Primary Care

Objective. To compare and measure the effects and cost-effectiveness of two interventions designed to raise immunization rates. Settings. Nine primary care sites serving impoverished and middle-class children. Subjects. Complete birth cohorts (ages 0 to 12 months/ n = 3015) from these sites. Interventions. Two 18-month duration interventions: 1) tracking with outreach tracking/outreach to bring underimmunized children to their primary care provider office- and 2) a primary care provider office policy change to identify and reduce missed immunization opportunities (prompting). Design. Randomized- controlled trial- randomizing within sites using a two-by-two factorial design. Subjects were allocated to one of four study groups: control- prompting only- tracking/outreach only- and combined prompting with tracking/outreach. Outcomes were obtained by blinded chart abstraction. Measures. Immunization status for age/ number of days of delay in immunization/ primary care utilization/ and rates of screening for occult