Mortality of Russian cosmonauts, 1960–2018

Abstract

Introduction. From 1960 to 2018, 282 people were enrolled in cosmonaut groups in the USSR and Russia. Extreme special training and working conditions could lead to health disorders, which may be reflected in the causes and rates of mortality in the future. The goal of this work is to study the causes and rates of mortality in two cohorts of cosmonauts: those with and without spaceflight experience. The study aim is to research the causes and mortality rates of astronauts who have made and did not fly into space. Methods. A cohort study of mortality of 263 male cosmonauts was conducted, 118 cosmonauts with spaceflight experience formed cohort 1, 145 cosmonauts without it - cohort 2. The follow-up period was 59 yrs. (01.01.1960-31.12.2018) with 8351,4 person-years obtained. The reference group for both cohorts was the male population of Russia, cohort 2 was also the reference group for the cohort 1. Mortality risk was assessed using standardized mortality ratio (SMR) with 95% confidence interval (95% CI). Results. Death risk from all causes (A00-Y98) for each cohort was significantly lower than that for the male population (SMR=0,39, 95% CI 0,28-0,54 for cohort 1; SMR=0,53, 95% CI 0,41-0,69 for cohort 2). Moreover, the risk of death for cosmonauts with spaceflight experience is also lower than for cosmonauts without it (SMR=0,66, 95% CI 0,46-0,91). The most common causes of death in both cohorts were circulatory system diseases, and cosmonauts without spaceflight experience died at a younger age. Conclusion. Further research is required to understand the true influence of extreme working conditions on cosmonauts’ health, especially in the long-term period.