Deduplication of temporary names in an immunization registry using probabilistic linkage.

Context: Records with temporary names, such as Babygirl, BoyA, etc. are sometimes submitted to immunization information systems (IIS) with vaccinations that are administered before the child has a legal name.

Objectives: To 1) apply probabilistic record linkage to assist in the deduplication of children with temporary names in an IIS and 2) assess the impact of that deduplication on vaccination coverage rates.

Design: Cross-sectional study of vaccination records.

Setting: The Michigan Care Improvement Registry (MCIR), Michigan's statewide, population-based IIS.

Participants: Records in MCIR with a temporary first name and date of birth between 1/1/2020 and 12/31/2023.

Main Outcome Measure(s): Percentage of temporary name records matched to legal name records, and the difference in both temporary name and statewide primary childhood vaccination series (i.e. 4:3:1:3:3:1:4 series) coverage among 19-35 month olds after reconciliation of these records.

Results: Of the 16,806 temporary name records submitted to MCIR for births between 1/1/2020 and 12/31/2023, 9803 (58 %) were linked to a legal name record using probabilistic linkage. Among the subset of children aged 19-35 months who were assigned a temporary name at birth (n = 8548), 4:3:1:3:3:1:4 series completion coverage increased substantially, from 1.5 % to 39.6 % after reconciliation of vaccination histories. Statewide, 4:3:1:3:3:1:4 series coverage among children aged 19-35 months (n = 162,666) increased from 66.2 % to 68.2 % after reconciliation of vaccination histories.

Conclusions: Probabilistic linkage was found to be an effective method for identifying duplicate temporary name records in IIS.