Miscounting Our Days (1 Letter) Re "Interactive Tools to Assess the Likelihood of Death" (Jan. 10): Physician-statisticians have compiled scores, equations and large electronic databases that judge the chances that dozens of conditions may shorten your life. Few of them are tested across diverse populations and demographics to establish their validity. In one study, investigators identified 240 assessments of 118 clinical prediction rules designed to estimate the risk of death. The researchers found they don't work too well. In another study, many patients were given months to live but actually entered the next world within 24 hours. Prognosticating death drives decisions that may end up as self-fulfilling prophesies. Steven Z. Kussin, M.D. Utica, N.Y.