Lieu T A, Black S B, Ray P, Schwalbe J A, Lewis E M, Lavetter A, Morozumi P A, Shinefield H R
Division of Research, Permanente Medical Group, Oakland, CA.
Pediatr Infect Dis J. 1997 Jan;16(1):28-33. doi: 10.1097/00006454-199701000-00007.
To evaluate the effectiveness and cost effectiveness of computer-generated recall letters to parents of children overdue for immunizations.
This randomized controlled trial included children of two facilities in a regional health maintenance organization. Parents of 20-month-olds who had not yet received a measles-mumps-rubella (MMR) immunization were identified via a computerized immunization tracking system. One half were mailed personalized letters that included the recommended immunization schedule and a request to call for an appointment; the other half served as a control group. Receipt of the MMR between 20 and 24 months of age was evaluated with the computerized tracking system. A telephone survey was conducted with parents whose children had not received the MMR by 24 months. Decision analysis was used to project the theoretical outcomes and costs of a recall letter policy for other populations.
Among 20-month-old children 10% had not received the MMR; 289 families were included in the analysis. Of families who were mailed letters, 54% (82 of 153) received the MMR by 24 months of age, compared with 35% (47 of 136) of those in the control group (P = 0.001). The telephone survey was completed with 110 parents of children who still did not appear on the health plan computer as having received the MMR by 24 months. Fifteen percent said the child had received an immunization at an outside provider, and of the rest 62% said they had not been aware that an immunization was due. In the cost effectiveness analysis it was projected that recall letters would increase the immunization rate for the regional population of approximately 30000 children from 86% to 90% at a total cost of $5031 annually. The cost per additional child appropriately immunized was $4.04. In sensitivity analyses this cost effectiveness ratio varied depending on the baseline population coverage rate as well as the estimated effectiveness of recall letters.
Computer-generated letters to recall children overdue for immunizations resulted in a higher proportion of children appropriately immunized in this setting. However, the strategy was not as cost-effective as intuition might suggest. Further studies in health maintenance organization (HMO) settings should compare the cost effectiveness of letters with other low cost strategies including automated telephone reminders.
评估向逾期未接种疫苗儿童的家长发送计算机生成的召回信的有效性和成本效益。
这项随机对照试验纳入了一个地区性健康维护组织中两个机构的儿童。通过计算机化免疫追踪系统识别出20个月大但尚未接种麻疹-腮腺炎-风疹（MMR）疫苗的儿童家长。其中一半家长收到了个性化信件，信中包含推荐的免疫接种时间表，并要求致电预约；另一半作为对照组。通过计算机化追踪系统评估儿童在20至24个月龄时MMR疫苗的接种情况。对孩子在24个月时仍未接种MMR疫苗的家长进行了电话调查。决策分析用于预测召回信政策对其他人群的理论结果和成本。
在20个月大的儿童中，10%尚未接种MMR疫苗；289个家庭纳入分析。收到信件的家庭中，54%（153个家庭中的82个）在孩子24个月龄时接种了MMR疫苗，而对照组这一比例为35%（136个家庭中的47个）（P = 0.001）。对110名孩子在24个月时仍未在健康计划计算机记录中显示接种MMR疫苗的家长进行了电话调查。15%的家长表示孩子在外部机构接种了疫苗，其余家长中62%表示他们不知道孩子该接种疫苗了。在成本效益分析中预测，召回信将使该地区约30000名儿童的免疫接种率从86%提高到90%，每年总成本为5031美元。每额外有一名儿童得到适当免疫接种的成本为4.04美元。在敏感性分析中，这一成本效益比因基线人群覆盖率以及召回信的估计有效性而异。
计算机生成信件召回逾期未接种疫苗的儿童，在这种情况下使更多儿童得到了适当免疫接种。然而，该策略的成本效益并不像直觉认为的那样高。在健康维护组织（HMO）环境中进行的进一步研究应比较信件与其他低成本策略（包括自动电话提醒）的成本效益。
