Table 3 Countries with data or mapping issues.

From: COVID-19 European regional tracker

Country Official machine-readable data available? NUTS 3 2016 mapping available? Additional comments
Belgium Yes Yes Regions with cases less than five are given as <5. For the homogenized dataset this is replaced with 1 to make the variable numeric.
Estonia Yes Yes Cases are only provided in ranges of 10. These middle point of each range is taken and multiplied by the number of cases. The sub-regions are then aggregated up to NUTS 3 boundaries.
Finland No No The data is provided at the Hospital District level. These do not correspond perfectly to NUTS 3 regions. See Fig. 5b for reference. The official website also shows more detailed municipality-level map but it is not clear how to access it. For hospital regions that do not perfectly overlap, the spatial merge is defined on the rule that 80% of a Hospital District needs to be contained within a NUT 3 boundary. This is done using QGIS and the correspondence between the regions is manually done in the script since there are only 21 regions.
Greece No No Data is available at the Prefecture level which corresponds perfectly to NUTS 2 2016 boundaries. See Fig. 6d.
Italy   No Data merges perfectly with NUTS 3 2021 boundaries. For 2016 boundaries, three regions on an island have their boundaries shifted. These have been skipped in the visualization. See Fig. 6c.
Latvia Yes Yes Regions with cases less than five are given as <5. For the homogenized dataset this is replaced with 1 to make the variable numeric.
Poland No No The data correspondence perfectly to NUTS 2 2016 definitions for all regions except Warsaw (PL90). Warsaw is split into two regions PL91 and PL92 in the NUTS 2 2016 definitions so for visualization purposes PL91 and PL92 are combined to represent the city. The data file switches from cumulative to daily cases in the same column after 23 November 2020. This is manually fixed in the script. The official website now provides NUTS 3 level data but the range in limited.
Portugal No Yes Portugal switched to releasing regional data at weekly intervals after 7 July 2020. From 26 October 2020 the reporting range was increased to 14-day intervals. Therefore most of daily cases data is limited to pre-July 2020 values. Only the daily cases reported in the weekly or bi-weekly data are added to the homogenized tracker. Please see the raw data and the Portugal GitHub page (https://github.com/dssg-pt/covid19pt-data) for details.
England No Yes NUTS 3 correspondence is extracted using a spatial merge between the Local Authority Districts (LADs) using April 2019 definitions and NUTS 3 2016 boundaries which overlap perfectly. See Fig. 6a for details.