# DATA LINKAGE PROCESS - OPERATIONS ## Run *Once the tool has been deployed, there is still a need for lasting resources to support its adoption and ensure its maintenance. This section details these further actions.* ### Governance Once the data linkage is established, governance actions must be taken to ensure it remains aligned with its legal framework, vaccination policies and upcoming challenges. It includes: - **Progress of ongoing activities:** progress toward the objectives set during the design phase of the data linkage, or added afterward, requires continuous follow-up on the technical and operational levels. - **Evaluation of new research projects:** new projects or objectives related to the data linkage must be assessed to decide if they are a) technically feasible (i.e. data are available or can be obtained) and b) compliant with the legal framework and authorisations obtained. - **Expanding the data catalogue:** all the required databases will most likely not be available since the beginning. Continuous effort is needed to integrate agreed-upon data sources and update them when needed. Looking actively for new relevant databases is also encouraged to keep the tool relevant for new use cases. ### Monitoring To ensure optimal performance of the data linkage, two key technical aspects must be monitored: - **Dataflow continuity**: a regular data exchanges (be it daily, weekly, monthly, ... ) may be foreseen for some of the databases. For those, the dataflow should be monitored to ensure that the new data are coming in or be able to quickly fix any interruption. - **Data quality**: when a new database is added to the linkage, and periodically afterwards, the quality of the data must be assessed as it will impact the reliability of the generated outputs. **Communication** - **Citizens:** Information on the usage of citizens’ data and the measures taken to protect their privacy should be made available at all time. If public health insights are generated, it is also preferable that they are made available through punctual (e.g. press release) and continuous reporting (e.g. dashboard or regular bulletin). - **Health authorities:** Collaboration and communication with health authorities, and any relevant decision-makers, and expert committees involved in public health and vaccination strategies should be maintained to ensure that insights generated through data linkage can inform the development, refinement, and evaluation of evidence-based strategies. Additionally, depending on the use case, scientific knowledge building thanks to the data linkage should be communicated to the scientific community through e.g. conferences or journal articles. ### Routine and crisis settings’ implementation In light of the COVID-19 crisis, data linkage is an important tool for public health emergency management. However, its implementation is constrained by numerous factors, the main one being the legal framework and the authorisations associated with the secondary use of data. This barrier can be lifted in the event of a health emergency, as seen during the COVID-19 crisis, through amendments or decrees, but its implementation over time or outside of emergency situations remains restricted and challenging. **Data linkage in routine surveillance** Routine surveillance refers to the continuous, systematic collection, analysis and interpretation of health-related data to monitor the occurrence and distribution of diseases, health conditions, or risk factors within the population. It helps detect trends, identify emerging health threats, evaluate the effectiveness of interventions and guide public health actions. Routine surveillance is defined by its regularity (e.g., daily, weekly, monthly, annually) rather than in response to a specific outbreak or emergency. Building on the experiences from COVID-19, it is possible to extend the data linkage approach to any other pathogens, including unknown emerging pathogens, by incorporating diverse data sources and addressing various surveillance objectives. The main approach involves linking infectious diseases data, such as laboratory test results and clinical data (e.g. from the Severe Acute Respiratory Infections (SARI) surveillance system) with other health (e.g., vaccination registers, mortality data, etc.) and/or administrative datasets (e.g., socio-economic, demographic information, etc.). The overall aim is to link surveillance data with relevant clinical information and outcomes, in order to build an infrastructure that will improve routine surveillance of infectious diseases. If allowed, this infrastructure should be easily adaptable and could be used to inform the response to a public health emergency (PHE) as part of pandemic preparedness. **Data linkage in crisis situation** Given its sudden nature[^1], a public health emergency requires advance preparation in order to minimise its impact on the population. According to the European Centre of Diseases and Control (ECDC), there is a need to be better prepared for future public health crises, and this should be done through actions in different areas, including investing in and strengthening the public health workforce and improving surveillance of infectious diseases[^2]. [^1]: A public health emergency (PHE) refers to an occurrence or imminent threat of an illness or health condition, caused by bioterrorism, an epidemic or pandemic disease, or an infectious agent or biological toxin. Such events pose a substantial risk to human health by either causing a significant number of human fatalities, permanent or long-term disabilities, or overwhelming healthcare services. A public health emergency of international concern (PHEIC) is a formal declaration by the WHO of "*an extraordinary event which is determined to constitute a public health risk to other countries through the international spread of disease and to potentially require a coordinated international response*", formulated when a situation arises that is "*serious, sudden, unusual, or unexpected*", which "*carries implications for public health beyond the affected state's national border*" and "*may require immediate international action*" Wenham, C., & Stout, L. (2024). A legal mapping of 48 WHO member states' inclusion of public health emergency of international concern, pandemic, and health emergency terminology within national emergency legislation in responding to health emergencies. *Lancet*. [^2]: [Lessons from the COVID-19 pandemic](https://www.ecdc.europa.eu/sites/default/files/documents/COVID-19-lessons-learned-may-2023.pdf) - ECDC As noted above, the implementation of data linkage can be limited and complex, partly due to the applicable national legal framework. If it has not been possible to implement a data linkage process as part of routine surveillance, protocols and agreements between the key stakeholders involved can be prepared and signed in advance; furthermore, simulations using synthetic data (Module 09 *- Data*) can be set up and tested to ensure rapid, correct and efficient deployment in the event of a declared and confirmed crisis.