Innate handedness and disease-specific mortality in women.

BACKGROUND

Left-handedness has been reported to be associated with reduced life expectancy, but the evidence is far from conclusive.

METHODS

We studied the association between innate handedness and total mortality, as well as cause-specific mortality, in a cohort of 12,178 middle-aged Dutch women who were followed for almost 13 years. The relation between handedness and mortality was analyzed using Cox regression in a case-cohort approach, in which a random sample of 1500 women was used to represent person-years under observation for the entire cohort.

RESULTS

During a median follow-up of 12.6 years, 252 women died. Hazard ratios comparing left-handed women with other women were 1.4 for all-cause mortality (95% confidence interval = 0.9-2.0), 1.7 for total cancer mortality (1.0-2.7), 2.0 for breast cancer mortality (0.8-4.6), 4.6 for colorectal cancer mortality (1.5-14.3), 1.3 mortality from diseases of the circulatory system (0.5-3.3), and 3.7 for cerebrovascular mortality (1.1-12.1), after adjusting for potential confounders (socioeconomic status, age, body mass index, and cigarette smoking status at study recruitment).

CONCLUSIONS

Left-handedness is associated with higher mortality in women.