Smoking cessation and mortality trends among 118,000 Californians, 1960-1997

We assessed the impact of smoking cessation on subsequent death rates among a cohort of 51,343 men and 66,751 women in California enrolled in late 195 9 in the original American Cancer Society (ACS) Cancer Prevention Study (CP S I) and followed for 38 years. We compared the age adjusted death rate, ex pressed as deaths per 1,000 person-years, among all subjects who smoked cig arettes in 1959 but who had largely quit as of 1997 with the death rate amo ng never smokers over a 38-year period. The all causes death rate for males decreased from 20.67 during 1960-1969 to 18.68 during 1960-1997 for smoker s and decreased from 10.51 to 9.46 for never smokers. The lung cancer death rate for males increased from 1.558 to 1.728 for smokers and increased fro m 0.127 to 0.133 for never smokers. The all causes death rite fur females i ncreased from 9.54 to 10.14 for smokers and decreased from 6.95 to 6.44 for never smokers. The lung cancer death rate for females increased greatly fr om 0.208 to 0.806 for smokers and increased from 0.094 to 0.116 for never s mokers. These results indicate there has been no important decline in eithe r the absolute or relative death rates from all causes and lung cancer for cigarette smokers as a whole compared with never smokers in this large coho rt, in spin of a substantial degree of smoking cessation. While cessation c learly reduces the mortality risk among long-term former smokers, the popul ation impact of cessation appears to be less than currently believed.