Countries have reported a range of challenges leading to Big Catch-Up (BCU) data backlogs and reduced visibility of program performance. Data backlogs occur when vaccination data are not entered into national health information systems (such as DHIS2) or other reporting platforms on time, completely, or consistently, including cases where retrospective or partial data entry is required. These delays make it difficult for national programs to monitor progress, particularly from non-reporting or late-reporting sites, and can result in significant underestimation of achievements

This document aims to support BCU-implementing countries, as well as those institutionalizing catch-up monitoring, in strengthening the completeness and timeliness of catch-up data as part of routine immunization data. Specifically, it provides:

• A structured understanding of the root causes of data backlogs, including incomplete, delayed, or retrospective data entry across both paper-based and digital reporting systems.
• Practical diagnostic approaches that countries can use to identify where and why data backlogs occur along the data flow from service delivery points to national immunization information systems.
• Actionable short- and medium-term solutions to address backlog challenges.

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Version française: https://www.technet-21.org/en/resources/tool/amelioration-du-grande-rattrapage-completude-et-actualite-des-donnees-manuel-sur-les-causes-profondes-et-les-solutions-pour-remedier-aux-retards-dans-la-saisie-des-donnees

Versão em português: https://www.technet-21.org/en/resources/tool/melhoria-da-atualizacao-a-completude-e-a-pontualidade-dos-dados-um-manual-sobre-as-causas-fundamentais-e-as-solucoes-para-lidar-com-atrasos-nos-dados