What's Going On out There?-Measuring the Use of Alternative Immunization Schedules

Background: In response to vaccine safety concerns increasing numbers of parents are seeking alternatives to the ACIP recommended immunization schedule.  Physicians are spending more and more time negotiating the timing of immunizations with parents.  This trend seems to be increasing but is difficult to measure

Objectives: Evaluate the effectiveness of Immunization Information Systems (IIS) and managed care claims data for tracking trends in the use of alternative immunization schedules

Methods: We developed a set of queries to apply to both our local IIS-the San Diego Immunization Registry (SDIR) and to a local managed care claims database (CPMG) in an attempt to detect and track use of alternative immunization schedules among young children.  These queries explored non-simultaneous receipt of vaccines such as DTaP, IPV, PCV7, and Hib vaccines for children under 1 year of age and non-simultaneous receipt of MMR and Varicella vaccine in children between 12-23 months of age.  Data was evaluated over several years.

Results: The CPMG claims demonstrated that 7- 40% of patients in different pediatric practices appeared to be following an alternative schedule in 2007 and were more likely to be behind on immunizations.  The SDIR data demonstrated that in 2009 13.9% of patients between 12-23 months of age seen in private offices had received varicella vaccine but not MMR.  This compares to 6.2% in 2004 (p<0.001).  Mixed trends were observed in younger children.

Conclusions: Both IIS data and Health Plan claims data may provide an easy way to monitor trends in use of alternative immunization schedules.  Our data from San Diego suggest increasing use of alternative schedules, at least for some age groups over the past 5 years.