Purpose: We developed the Shared Child Health Record (SCHR) using the Fast Health Interoperability Resources International Patient Summary (FHIR IPS) standards to facilitate data interoperability between the Lao Electronic Health Record-Bahmni (EHR-Bahmni) and Electronic Immunization Record-District Health Information Software Version 2 (EIR-DHIS2). This study evaluated the impact of vaccination completeness and coverage on the value of the SCHR.

Method: We analyzed the data of Borlikhamxai Province between May 2023 and April 2024. The Stata software was used to assess and match patients across the two systems, and descriptive statistics were employed to examine demographics, compare vaccination completeness, and assess type-specific vaccine coverage across the sources.

Results: 11,422 EIR-DHIS2 and 2,500 EHR-Bahmni events were transferred to the SCHR (FHIR server). After deduplication, 13,813 children were used for analysis. We discovered that the SCHR has the potential to clarify the number of vaccinated children and increase the overall coverage by 0.40-1.60%. However, in Pakxan District, where provincial hospitals primarily use EHRs, integrating EHR and EIR data into the SCHR increased vaccination coverage by 2-9% compared to EIR estimates. In addition, we found that the EIR had a higher vaccination completeness rate than the SCHR at provincial and district levels, with differences of 6.22% and 21.82%, respectively, indicating a lack of comprehensive vaccination overview with the EIR compared to the SCHR.

Conclusion: Our findings suggest that the SCHR can clarify vaccination coverage and provide a more complete picture of vaccination completeness. However, the challenges encountered during the data collection process included data identification and matching, inconsistent standards, technical skill alignment, and disrupted internet connections. Nonetheless, the SCHR program potentially represents an effective method to achieve national interoperability in Lao PDR.