How much does a regional immunization registry increase documented immunization rates at primary care sites in rural Colorado?

Objective.-To determine increases in immunization up-to-date (UTD) rates at a rural pediatric practice with the sequential addition of records from ot her sites in a 2-county region. Design/Methods.-UTD rates for children aged 3 months to 35 months (n = 876) were determined for the index practice and then recalculated after sequent ial addition of records from 1) the other private practice in the region, 2 ) 7 public primary care sites, and 3) 2 public health clinics in the region . Results.-Adding records from all sites increased documented UTD rates in th e index practice from 49% to 64% at 3 months (N = 33, P = 0.025), 50% to 68 % at 5 months (N = 38, P = 0.008), 28% to 45% at 7 months (N = 113, P < .01 ), 29% to 54% at 12 months (N = 200, P < .001), 11% to 35% at 19 months (N = 124, P < .001), and 10% to 33% at 24 months (N = 368, P < .001). Conclusions.-Regional registries will be valuable tools for immunization de livery if there is an ongoing commitment to effective collection of current and historical immunization data.