IIS Data Migration: Cleaning House Before the Big Move

Background:  In 2010, the Oregon ALERT Immunization Information System (IIS) migrated from a locally developed data warehouse platform to a customized public domain clinical records model IIS. Approximately 4.5 million demographic records and 31 million immunization records collected since 1996 were cleaned, standardized, and migrated to Oregon’s new system. Oregon utilized this transition to implement stronger data standards and business rules, including those produced through MIROW (Modeling Immunization Registry Operations Workgroup).

Setting:  Oregon’s IIS is supported by strong participation (93% for age 0-6) from public and private organizations statewide. The IIS supplies data for over 65,000 record requests per month, as well as for AFIX feedbacks, reminder recall, rate analysis, etc. 2008 legislation allowed IIS expansion from 0-18 years to lifespan.

Population:  July 2009 Census figures estimate Oregon population at approximately 3,825,657. IIS data suggest approximately 96% of the childhood population is represented, although proportion of capture varies by age cohort.

Project Description:  Oregon conducted three full dry-run migrations to test cleaning and migration strategies. Anomaly cleaning focused on eliminating known bad immunization and demographic values and on standardizing free-form entries wherever possible.  Patient deduplication emphasized capture of accurate current and historical demographics helpful for future deduplication. Finally, immunization cleaning emphasized a 14 day cleaning window, retention of all key immunization elements, and creation of a crosswalk to standardize linkages between vaccines, CPT, CVX, and NDC codes.

Results/Lessons Learned:  Data cleansing, rather than using previous methods to filter data on display, allowed Oregon to safely eliminate or update 677,000 demographic records and over 1,300,000 immunization records with known bad or repeat values, migrating the most accurate records into the IIS. Over 18 million immunizations were deduplicated prior to migration. Further data validation and precertification of sources is now underway as organizations are approved to submit data into the ALERT IIS.