Is an association encountered between Reaction Time and cancer morbidity across the entire adult age range during 19 years of follow-up? -Measures on the Health and Lifestyle Survey.

Objective: To investigate the relationship between cognition as measured by reaction time (RT) and specific cancer morbidity. Methods: Information concerning socio-economic status, health status and health behaviors and both simple and choice RT mean and variability were included for 5870 participants obtained from the 1984/1985 collection of the Health and Lifestyle Survey (HALS). RT mean and variability was investigated for a correlation with specific cancer morbidity over 19 years of follow-up collected in May 2003 follow up for cancer registration. Results: T-tests comparing specific cancers to healthy individuals found an inverse relationship between certain RT measures and lung cancer, stomach cancer and prostrate cancer. A positive relationship was found between all RT measures and breast cancer morbidity in a female only population (p < 0.01). Survival analysis was non-significant for lung cancer outcome on all four exposure variables of RT in both genders but significant for the exposure variable of simple RT mean and breast cancer morbidity (HR = 0.74 CI = 0.62-0.89, p < .01) in females only. The effect suggested that an increase in standard deviation (SD) of reaction time was predictive of breast cancer morbidity after 19 years and the effect was not attenuated for by any of the covariates included in subsequent models. Conclusion: Slower simple RT means are highly correlated with breast cancer morbidity independent of hypothesized covariates. There is a suggestion of a RT correlation with other specific cancers but sample sizes were too small for further survival analysis. A recommendation for further study of the RT specific cancer morbidity and mortality in a larger sample size is suggested