of Diseases (1.C.D.)' has been used forall sites. Average annuaj age-adjusted mortalicy rates (per 100,000) were calculated for counties listed on the death certificate as the county of usual residence by site, race and sex with che toal U.S. population for 1960 used as the standard for the period 1950-1969, Rates have also been calculated for each of the 48 contiguous states and for the cotal United States, which includes Alaska and Hawaii. White and nonwhite county populations at risk were taken from the 1950, 1960, and 1970 censuses (1-3). Incercensal estimates were derived by linear incerpolation. The counties of Alaska and Hawaii were not included since mortality data werefirst available in 1959. The Districe of Columbia has been reported as a separate entity. The Sixth Revision of the Incernational Classification METHODS FRANK W. McKay Epidemiology Branch Nasional Cancer Institute THOMAS J. MASON, PH.D. agement in this endeavor. We wish co thank Dr. Robert N. Hoover for his suggestions with regard to the presentation of this material, Miss Anya Shevchenko for her programming assistance, and Mrs. Melvina Harren for her most efficient assistance in preparing the population files. Branch and Dr. Joseph F. Fraumeni, Jr., Associate Chief, for their encour- We are indebted to Dr. Robert W. Miller, Chief of the Epidemiology ACKNOWLEDGEMENTS == The number of years observed, which is 20. = A particular age group m years wide. == The number of age groups. t i n reported to two decimal places. less chan 0.049 per 100,000, ir was reported 0.0. All state rates have been For any given site and race, an individual county was included if there was at least one death for either sex. Blanks were used to denote no mortality for the particular site, race and sex. If the councy cate was |= The numberin age group i in the standard population in the base year. P(i) R(i,t) == The aumber in age group i in the population at risk over t years. D(i,t) = The number dead in age group i over t years. = The age-adjusted death rate over t years. ® 100,000 A(t) i=l n > P(i) = The age-specific death rate in age group i. over t years. ziz=l S(i,t) A(t) XD Stic) Pdi) n (40 = RGD The age-adjusted rate was calculated using the following: