Regional Deprivation and Suicide

An Ecological Study

Background: Regional deprivation due to regional economic and social differences can increase the risk of suicide. This study investigated whether regional structural deprivation in Germany is associated with a higher rate of suicide.

Methods: Data from cause-of-death statistics for the years 2015–2021 were analyzed. A regression analysis for data with a negative binomial distribution was used to study the association between suicide mortality and the German Index of Multiple Deprivation (GIMD), which is based on data from 2015 and includes 401 districts and independent cities in Germany.

Results: Among the districts and independent cities covered by the GIMD, the quintile with the highest deprivation had higher suicide rates than the quintile with the lowest deprivation (relative risk [RR]: 1.85; 95% confidence interval [1.72; 2.00]). A sensitivity analysis revealed similar associations when the analysis was restricted to men (RR = 1.99 [1.80; 2.18]) or women (RR = 1.69 [1.49; 1.92]). A stronger association, however, was found in a comparison of rural (RR = 2.29 [2.04; 2.57]) with urban areas (RR = 1.51 [1.36; 1.68]).

Conclusion: These findings document an association between regional deprivation and suicide. They highlight the need for a more targeted approach to suicide prevention in deprived regions. At the same time, more research is needed into the mechanisms and effects of regional deprivation on mortality due to suicide.

According to information from the World Health Organization, more than 700 000 people worldwide die from suicide every year (1). In Germany, suicide is a common cause of death with more than 9000 cases in 2021. Significant regional differences exist and men are three times more likely to commit suicide than women (2). It is assumed that unfavorable socioeconomic conditions at the levels of the individual (3) and the residential region (4) contribute to the development of suicidal actions.

The individual socioeconomic status (SES) comprises factors such as education, income and occupation (5). Exposure to an adverse socioeconomic environment in childhood is already associated with a higher risk of later suicidal behavior (6, 7).

In contrast, regional socioeconomic measures, in the form of deprivation indices, rather focus on material and social indicators, such as the unemployment rate, at the area level (8). So far, no studies on spatial structural differences in suicide rates and on associations with spatial deprivation have become available for Germany.

Based on data from the cause-of-death statistics of the Statistical Offices of the Federal States in Germany, this study investigated whether regional deprivation is associated with suicide rates at the level of districts and independent cities. This approach is based on the hypothesis that the mortality rate from suicide is higher among people living in regions with a high degree of deprivation.

Material and methods

Data on intentional self-harm (ICD-10: X60–X84), obtained from the cause-of-death statistics of the Statistical Offices of the Federal States in Germany for the years 2015–2021, were included in the analysis. The information was available on the level of 294 districts and 107 independent cities, both as absolute numbers and in an age-standardized form based on the standard population “Germany 2011“ (9), for women and men.

Regional deprivation was documented using the German Index of Multiple Deprivation (GIMD) (10, 11). Since the 2015 GIMD is based on data from 2015, it is related in time to the data from the cause-of-death statistics and takes into account seven different domains with different percentage weightings (12):

• Income (25%)
• Unemployment (25%)
• Education (15%)
• District income (15%)
• Social capital in the form of net migration (immigration minus emigration) and voter turnout (10%)
• The environment in the form of ground sealing by commercial, industrial and traffic areas (5%)
• Safety in the form of traffic accidents and crimes (5%).

The scores refer to the districts and independent cities where the deceased were resident. In addition, the official regional statistics distinguish between urban districts, rural districts with population concentrations and sparsely populated rural districts (13).

Statistical analyses

For ease of interpretation, the districts and independent cities (n = 401) were divided into quintiles on the basis of ascending GIMD 2015 scores, with the lowest GIMD 2015 scores (lowest deprivation) as the 1st quintile (reference). The first step was to carry out univariate and bivariate analyses and create quintile-based choropleth maps (map type for displaying ordinal-scaled data) to visualize regional distributions.

In order to investigate the relationship between suicide rate and the quintiles of GIMD 2015, a regression analysis was performed for data with a negative binomial distribution, in which the suicide rate at district level was analyzed in relation to GIMD 2015. Adjustments were made for the following variables:

• Calendar year
• Sex of the deceased
• Federal state
• District type according to settlement structure.

In addition, the logarithm of the mean populations of the districts and independent cities was used as an offset variable to allow for differences in population size.

A sensitivity analysis was performed to look at women and men as well as urban and rural areas separately. Relative risks (RRs) and corresponding 95% confidence intervals (CIs) were calculated. The statistical software package STATA/MP, version 18, was used for all analyses.

Results

The number of deaths from suicide declined in Germany between 2015 and 2021 (10 078 deaths and 9215 deaths, respectively) by 8.6%. The age-standardized mortality rate (2015: 12.1; 2021: 10.6 per 100 000 population) fell by 12.4%. In the 401 districts and independent cities, the age-standardized suicide rates ranged between 0 and 52.5 (men between 0 and 52.5; women between 0 and 33) per 100 000 population. Figure 1 illustrates the distribution of mean suicide rates, showing significant regional differences. North Friesland and Dithmarschen in the north as well as individual districts and independent cities along the Elbe (from Hamburg to Dresden), in the Harz Mountains, around Wiesbaden and in Bavaria (from Nuremberg to Munich) have some very high suicide rates. In contrast, low rates are found in Lower Saxony, North Rhine-Westphalia and Brandenburg.

Figure 1

Suicide rate distribution by districts and independent cities in Germany

Figure 2 shows the probability distribution (density function) of the age-standardized suicide rates, separately for men and women, and reveals that the median rate for women (5.1 per 100 000) is about 70% lower than the median rate for men (16.8 per 100 000). A choropleth map, depicting the distribution of suicide rates by districts and independent cities for men and women, is provided in eFigures 1 and 2.

Figure 2

Density function of suicide rates in districts and independent cities in Germany

eFigure 1

Suicide rate distribution by districts and independent cities in Germany for women

eFigure 2

Suicide rate distribution by districts and independent cities in Germany for men

The age-standardized suicide rate increased along the quintile of GIMD 2015; the rate in the 5^th quintile was 1.85 [1.72; 2.00] times higher than in the 1^st quintile (Table 1).

Table 1

Association between the quintiles of the GIMD 2015 and the age-standardized rates 2015–2021 in the 401 districts and independent cities in Germany, by sex and total

The regression analysis revealed similar associations for men and women (Table 1), but showed a stronger association for rural areas (2.29 [2.04; 2.57]) compared to urban areas (1.51 [1.36; 1.68]) (Table 2).

Table 2

Association between the quintiles of the GIMD 2015 and the age-standardized suicide rates 2015–2021 by area type

Discussion

The analyses of this study show an association between regional deprivation and suicide rates in Germany. Studies conducted in other countries have found similar associations (14, 15, 16, 17, 18, 19). In the quintile of the districts and independent cities with the highest deprivation, suicide mortality was 85% higher than in the quintile with the lowest deprivation. A study from Ireland, focusing on the age group 15 to 64 years, found somewhat greater differences along the regional deprivation dimension (17).

In addition to these results, it was revealed that the differences along the regional deprivation dimension were considerably lower in urban areas compared to rural areas, a finding that is in line with study results from other countries (16, 20, 21).

Thus, this study complements the findings from studies focusing on the individual level and underscores the public health relevance of suicide prevention measures at population and district levels.

Having not taken socioeconomic heterogeneity within the districts and independent cities into account, this study may have somewhat underestimated the strength of the association. However, other studies (16, 22, 23, 24) have shown independent associations between regional deprivation and suicide after adjusting for individual socioeconomic factors.

The strengths of this study include the high case numbers and the analysis of cause-of-death statistics on a small-scale level in Germany.

Limitations include the lack of data on migration background and socioeconomic status at an individual level and individual risk factors such as suicide attempts, suicidal ideation and familial clustering. However, it would seem to be an almost impossible task to collect representative data at an individual level for Germany and its districts and independent cities. Other general limitations must also be considered, such as the reliability of death certificate data for cause-of-death statistics (25) and methodological challenges in ecological studies, such as the ecological fallacy (26, 27, 28). No definite conclusions about the causality of the associations investigated can be drawn from the findings of this study.

Further studies should seek to ideally compare very small spatial units with each, e.g. on the level of districts or neighborhoods in large cities. The districts and independent cities analyzed in this study vary widely in terms of population size and deprivation can be very heterogeneous within a single district. When suicide data is analyzed on a smaller scale, the conclusions may change—a phenomenon known as modifiable area unit problem (MAUP) (29). For Berlin, first studies, investigating the association between regional deprivation and health indicators on the level of small spatial units are now available (30). However, as this data is not available for the whole of Germany, it is very challenging to perform analyses on a smaller scale.

Conclusion

This study provides evidence of an association between regional deprivation and suicide rates in Germany. Consequently, suicide prevention efforts need to focus more on deprived regions.

Conflict of interest statement

The author declares no conflict of interest.

Manuscript received on 18 December 2023; revised version accepted on 5 April 2024

Translated from the original German by Ralf Thoene, M.D.

Corresponding author
Dr. PH Matthias Hans Belau

Universitätsklinikum Hamburg-Eppendorf

Institut für Medizinische Biometrie und Epidemiologie

Martinistraße 52, 20246 Hamburg, Germany

Cite this as
Belau MH: Regional deprivation and suicide—an ecological study. Dtsch Arztebl Int 2024; 121: 449–53. DOI: 10.3238/arztebl.m2024.0069

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