DO LEFT-HANDERS HAVE INCREASED MORTALITY

To study the association between handedness and mortality, we evaluated the experience of a Swedish population-based cohort comprising 48,964 conscripts age 18-21 years in 1969-1970. We linked this cohort to the Cause-of-Death Register through 1989. Hand preference was measured by a simple question regarding handedness; to confirm the answer, the conscript held a dummy rifle while an observer recorded whether he was a left- or right-hand shooter. A total of 954 deaths occurred in the cohort, of which 82 were among left-handers, corresponding to a relative risk estimate of 1.0 (95% confidence interval = 0.8-1.3) for left-handers compared with right-handers. The relative risk estimate of death by motor vehicle accidents was 1.3 (95% confidence interval = 0.8-2.0). The data in this study refute previous reports indicating an increased overall mortality. The results regarding motor vehicle death indicate a slightly increased relative risk associated with left-handedness.