Socio-economic factors and political status shape mortality risk from suicide attacks linked to climate variability

BACKGROUND: Suicide attacks are among the most lethal forms of political violence and impose substantial public health and societal burdens. However, the associations between temperature and precipitation variability and mortality from suicide attacks (MFSA) remain poorly understood. METHODS: We employed a spatio-temporal fixed-effects panel regression model to examine the nonlinear associations between temperature and precipitation variability and MFSA risk, while simultaneously assessing their quantitative and heterogeneous effects. RESULTS: We did not observe significant associations between temperature or precipitation variability and MFSA, except for a positive association with monthly mean temperature above 25.4 °C and a negative association with monthly mean precipitation above 170 mm. The heterogeneity analysis showed that lower gross domestic product, larger refugee populations, and closer proximity to primary roads and border lines were associated with stronger positive temperature-MFSA associations, corresponding to relative risks of 1.34 (95% CI, 1.11-1.57), 1.28 (95% CI, 1.09-1.47), 1.32 (95% CI, 1.12-1.52), and 1.37 (95% CI, 1.13-1.61), respectively. Lower scores for political rights, electoral process, and freedom of expression and belief, as well as periods within three months of a presidential election, were also associated with stronger positive temperature-MFSA associations, corresponding to relative risks of 1.34 (95% CI, 1.17-1.51), 1.42 (95% CI, 1.19-1.65), 1.35 (95% CI, 1.17-1.53), and 1.32 (95% CI, 1.16-1.46), respectively. CONCLUSION: Our findings demonstrate the robust statistical associations between climate variability and MFSA risk. The identified socio-economic and political contexts may help identify settings where climate variability is more strongly associated with MFSA risk. These findings provide a basis for future studies evaluating the potential application of climate information in conflict risk assessment and public health surveillance.