摘要：Objectives. We compared the effectiveness and cost-effectiveness of population-based recall (Pop-recall) versus practice-based recall (PCP-recall) at increasing immunizations among preschool children. Methods. This cluster-randomized trial involved children aged 19 to 35 months needing immunizations in 8 rural and 6 urban Colorado counties. In Pop-recall counties, recall was conducted centrally using the Colorado Immunization Information System (CIIS). In PCP-recall counties, practices were invited to attend webinar training using CIIS and offered financial support for mailings. The percentage of up-to-date (UTD) and vaccine documentation were compared 6 months after recall. A mixed-effects model assessed the association between intervention and whether a child became UTD. Results. Ten of 195 practices (5%) implemented recall in PCP-recall counties. Among children needing immunizations, 18.7% became UTD in Pop-recall versus 12.8% in PCP-recall counties ( P < .001); 31.8% had documented receipt of 1 or more vaccines in Pop-recall versus 22.6% in PCP-recall counties ( P < .001). Relative risk estimates from multivariable modeling were 1.23 (95% confidence interval [CI] = 1.10, 1.37) for becoming UTD and 1.26 (95% CI = 1.15, 1.38) for receipt of any vaccine. Costs for Pop-recall versus PCP-recall were $215 versus $1981 per practice and $17 versus $62 per child brought UTD. Conclusions. Population-based recall conducted centrally was more effective and cost-effective at increasing immunization rates in preschool children. Vaccination is recognized as one of the greatest public health achievements of the 20th century. 1 Childhood vaccines developed in the previous century were associated with declines in the incidence of major childhood infectious diseases by 98% or more compared with baseline 20th century annual morbidity rates. 2,3 Despite this, only 44.3% of children aged 19 to 35 months received all recommended vaccines in 2009. 4 Because of the importance of timely vaccination in young children, one of the nation’s top health goals as outlined in Healthy People 2020, is to increase the proportion of children aged 19 to 35 months who receive all recommended doses of childhood vaccines to 80%. 4 Based on strong evidence of effectiveness, the Community Preventive Services Task Force 5,6 recommends the use of reminder/recall for increasing immunization rates, including notification for upcoming immunizations (reminders) or recall notices for overdue immunizations (recall). The use of regional or state immunization information systems (IISs) can greatly facilitate reminder/recall because such systems cannot only identify children who need immunizations but often can also generate reminder postcards or electronic data that can be used to produce autodialer messages. Current national data suggest that despite strong national recommendations, few providers are doing any type of reminder/recall for immunizations. 7 Because of this, there has been interest in determining whether reminder/recall efforts might be more feasible and less costly to conduct centrally by health departments using a regional or state IIS. We conducted a population-based, cluster-randomized pragmatic trial comparing the effectiveness of practice-based recall versus population-based recall conducted by the state health department using the Colorado Immunization Information System (CIIS) in increasing immunization rates among children aged 19 to 35 months as well as the cost-effectiveness of each method.
