The need for detailed COVID-19 data in Spain.

The COVID-19 epidemic has impacted the population of Spain far more than most feared or projected. As of Sept 25, 2020, more than 700 000 individuals had tested positive, and more than 31 000 deaths with a positive test had been recorded. Earlier in this pandemic, the Spanish Ministry of Health provided data by age and sex for the whole country in its daily COVID-19 situation updates (in Adobe PDF format), as well as daily data on total hospitalisations, intensive care unit admissions, discharges, and deaths by region. However, since May 19, 2020, disaggregated data have not been provided in the daily updates. In recent months, data improvements have been made by the National Centre of Epidemiology (CNE), and open data on total counts by region are updated and revised daily. However, at the time of writing, age-specific data from the CNE is given only in weekly publications (as Adobe PDF files), without geographic detail or retrospective corrections, and with cumulative counts tabulated only from mid-May onwards. Therefore, properly merging age-specific time series after the first wave is difficult or impossible.

We recognise that, in the first instance, COVID-19 data depends on the 17 autonomous communities of Spain. Five of these independently offer selected COVID-19 metrics disaggregated by age and sex, but the data provided are not always comparable across these few regions.

The urgency of this pandemic has pushed several countries worldwide (such as the Netherlands, Germany, the Philippines, and Mexico) to openly release coherent and exhaustive daily updates of detailed COVID-19 cases and deaths, including disaggregations by age group, sex, and geographical area, as well as ongoing retrospective corrections in machine-readable data files. Accurate and detailed data are essential for understanding the pandemic and to guide policy. Furthermore, examining differences between countries is crucial for gauging the impact of different preventive health policies, and for designing better policies that would reduce the health risks associated with COVID-19.

In Spain, COVID-19 data currently published at the country and regional levels are insufficient to understand the dynamics of COVID-19 and to take action. We now urge the health authorities in charge of COVID-19 data in Spain and elsewhere to release consistent daily open data updates on tests, cases, hospitalisations, intensive care unit admissions, recoveries, and deaths, including ongoing retrospective series corrections. Each of these variables should be broken down by age, sex, and geographic detail, to better monitor the demographic impacts of the pandemic, and to better inform a public health response.