Abstract 718 Poster Session I, Saturday, 5/1 (poster 218)

Poor immunization rates reported in US public and private healthcare settings have prompted careful assessment of populations at risk of poor immunization delivery. Studies in the public sector have shown that reminder/recall systems increase return visits and therefore enhance vaccine delivery. This study's primary objective was to compare a manual postcard (mail) reminder/recall system and a computer based telephone (autodialer) reminder/recall system to a control group in private providers' offices. A secondary objective was to assess the cost-effectiveness of immunization reminder/recall systems on return visits and immunization delivery. Six private pediatric practices were chosen to participate in the study based upon similar results from CDC CASA (Clinic Assessment Software Application) assessments (range 22-46%). Sites were randomized to a study arm: mail, autodialer, or control. Study participants were children < 12 months of age and eligible for their first, second, or third DTP/DTaP. Enrollment occurred between May 1997 and April 1998 with distribution of children across interventions: mail n=395, autodialer n=314, control n=429 (Total=1,138). Implementation of the reminder/recall systems included enrollment, delivery of reminder, follow-up and recall, and designation of off-study. Time spent by the study staff was estimated based on detailed activity logs. Return visit rates by intervention were mail 89%, autodialer 93%, and control 67%. The mail intervention resulted in 217 more visits (P-value < 0.001) and 161 more immunizations (P-value < 0.001) per 1,000 children relative to control. The autodialer intervention resulted in 261 more visits (P-value < 0.001) and 224 more immunizations (P-value < 0.001) per 1,000 children relative to control. The start-up costs were estimated at $3,627 for a computer for the practice and $17,785 for the autodialer (hardware, software, and maintenance). When the reminder/recall system was implemented, the incremental cost per visit was $9.52 in the mail group and $3.48 in the autodialer group relative to the control group. The corresponding incremental cost per immunization was $12.82 in the mail group and $4.08 in the autodialer group. The autodialer intervention was more effective and, excluding autodialer start-up costs, costs less than the mail intervention. Reminder/recall systems are effective in increasing return visits and immunizations in private providers' offices. The small extra cost per child of implementing reminders may still be cost effective considering the saved morbidity dollars per immunization delivered per child.