In a letter entitled The need for detailed COVID-19 data in Spain published on 10 October in the journal The Lancet Public Health, researchers from several areas of the CED-UAB, the Max Planck Institute, the IDAEA-CSIC and the Universitat Politècnica de Catalunya · BarcelonaTech (UPC) expose the difficulties in not having data classified by age and sex of those affected by SARS-CoV2 in Spain, which hinders a better understanding of the dynamics of the pandemic.

The letter is signed by a team led by the demographer Sergi Trias-Llimós, from the Centre for Demographic Studies-Universitat Autònoma de Barcelona (CED-UAB); Ainhoa Alustiza and Tim Riffe, from the Max Planck Institute for Demographic Research; Clara Prats, from the Department of Physics and the Computational Biology and Complex Systems Group (BIOCOM-SC) at the UPC; and Aurelio Tobias, from the Institute of Environmental Assessment and Water Research of the Spanish National Research Council (IDAEA-CSIC). The letter can be read here: https://www.thelancet.com/journals/lanpub/onlinefirst.

The researchers explain in this letter that Spain is one of the European countries most affected by COVID-19. At the end of September, more than 700,000 people tested positive and there were over 31,000 deaths with a positive test. In view of these facts, the authors of the text claim that “throughout the past weeks there have been changes and some improvements made by the Spanish Ministry of Health with regard to the information and data shared with citizens. Nevertheless, these changes do not reflect an improvement in the level of detail of the data nor its format. The data disaggregated by age and sex on positive cases and deaths is only published in PDF format and in a series that begins in May, which makes it difficult to compare with other available data.”

The authors provide examples of other countries releasing open and exhaustive updates on several COVID-19 metrics disaggregated by age and sex, which is helping to compare the evolution of the pandemic in different countries.

At the same time, the letter acknowledges that the responsibility of managing data falls on each autonomous community in the first instance. According to the researchers, some autonomous communities do offer detailed data, although not necessarily in the same format or with the same definitions. However, the majority do not publish open data on their websites.