Are the epidemiological studies of suicide in Spain conclusive?

Dear Editor,

After reading the original work entitled “Suicide mortality trends in Spain, 1980−2016”,¹ we believe it to be important to suggest a reflection on the data it uses, and above all on the changes which occurred in registries during the period analysed, as these may affect the cases of suicide that are recorded in the country.

On the one hand, it is necessary to take into account that the National Institute of Statistics (INE), the source of the data used in the said study, has traditionally registered fewer suicides than actually occur in Spain.^2–4 Among other causes, this has been attributed to the fact that until January 2020 the Statistical Registry of Deaths with Judicial Intervention (BEDJ) was not completed by a forensic doctor, but rather by a civil servant in the Registry Office who often lacked information about the cause of death. A work published in 2014 by Giner and Guija,⁴ which compared the data registered in several IML with those recorded by the INE over a 5-year period, concluded that the average suicide rate was 15% higher than the one recorded in the INE. On the other hand, in Malaga, the province with the highest standardized suicide rate in Spain,⁵ Moreno-Küstner and González Sánchez found that in the year 2017 only 27% of suicides were identified as such in the BEDJ⁶; it must be borne in mind that the families involved were the main source of information used in this study, not the IML, which is the most reliable direct source.

Although the authors mention this under-reporting in the discussion, we understand that it should be taken very much into account, when the results show rates of incidence that may be compared to those published in other European countries.

In connection with the tendency described by Cayuela et al., it is necessary to underline that during the years they analyse changes were made in the data gathering system for violent deaths. Until 2009 deaths with medical-legal intervention required an additional document in the declaration, the MNP.52 (Natural Population Movement), which specified the cause of death and, together with the Statistical Registry of Deaths, was completed by the Court civil servant and then sent to the Registry Office and then the INE. In January 2009, with the aim of improving the quality of certification, the MNP.52 was replaced by the BEDJ, which is completed directly in the Registry Office.⁷ These changes may affect the final notification of the cases, which in turn will affect the tendency found in the period studied.

To finish, specifically in the Community of Madrid (which has 14.2% of the total population of Spain), until 2013 the INE had no access to the data of the Forensic Anatomical Institute of Madrid. After this year a change in methodology occurred, varying certain aspects of how cause of death was assigned in cases with judicial intervention.⁵ It should be taken into account that from 2010 to 2012, based on the data which the INE has given us, the average annual suicide rate in Madrid was 1.8 suicides per 100,000 inhabitants, and that this rate rose to 5.1 suicides per 100,000 inhabitants in 2013. The peculiarities of certain autonomous regions may affect the results found in connection with the tendency.

To conclude, although we consider the increase in the suicide rate described by Cayuela et al.¹ should lead to new detailed studies, and although there can be no doubt that the long period analysed by their work is a strong point, the registration of violent deaths in Spain has been highly deficient. Although the official suicide rates in our country are lower than the real rates, registration is improving and this may partially explain the increase in the rate in Spain.

Future works that analyse these statistics over time should take into account that in January 2020 the BEDJ started to be completed by forensic doctors, and that this will foreseeably lead to a greater increase in the number of registered suicides, even though this will not necessarily imply there has actually been a rise in their number.

Only by registering cases properly will it be possible to undertake sufficiently high-quality epidemiological studies and develop effective preventive campaigns.