Researchers have developed models of the potential outcomes of screening versus not screening in an attempt to assist decision-making. They estimate the probabilities of increased life expectancy and adverse effects from treatment, based on the available research. Then they weigh preferences by using utilities—values assigned to the results of various courses of action. This allows the potential increase in life expectancy to be adjusted for the loss in treatment-related quality of life based on its importance to men. Gains in life expectancy with screening, for the average 50–60-year-old man, range from 17 days to about 10 months before utilities are considered. But, when adjusted for quality of life, this gain in life expectancy is reduced to almost nothing, even a loss of life expectancy from 2 days to 8 months in some reports.