2.2. Data Extraction

Three researchers independently extracted the following information: article characteristics, including title, authors, data, region, and study design; study population (e.g., pediatric versus adult); IIS policy and/or functional component, such as centralized reminder/recall and bidirectional interoperability; and, where applicable, outcomes or direct impact of IIS policies and functional components, such as vaccination rates and vaccine data quality. Researchers extracted statistical outcomes (e.g., results associated with point estimates and measures of significance) from observational and experimental articles. Only the original results of systematic literature reviews (SLRs) were extracted; any secondary research results referenced in the SLRs had their original sources cited. Extraction conflicts were resolved through review and consensus discussions.