The population prevalence of persons in the United States who smoked fell significantly in 2007 than in 1965, particularly in California.
John P. Pierce, PhD, of the University of California San Diego, La Jolla, led a team that examined smoking-intensity trends using data obtained from two large population-based surveys with state estimates: National Health Interview Surveys, 1965-1994, and Current Population Survey Tobacco Supplements, 1992-2007. The surveys contained information from 139,176 respondents from California and 1,662,335 respondents representing the other 49 states. According to background information provided in the study write-up, California has led the United States in using public policies to reduce smoking.
Looking at the number of cigarettes per day (CPD) used by high-intensity (≥20 CPD), moderate-intensity (10-19 CPD), and low-intensity (0-9 CPD) smokers, Dr. Pierce and colleagues determined the following: In 1965—one year after the first surgeon-general report on smoking and health was issued—23.2% of adults in California and 22.9% of adults in the rest of the nation were high-intensity smokers, representing 56% of all smokers. By 2007, this prevalence had decreased to 23% of California smokers and 40% of smokers in the other states.
The ranks of moderate-intensity smokers thinned from 11.1% in California and 10.5% elsewhere in 1965 to 3.4% and 5.4%, respectively, in 2007.
The prevalence of moderate/high-intensity smoking (≥10 CPD) among US residents excluding California who were born 1920-1929 was 40.5% in 1965. This level of smoking declined across successive birth cohorts, and for the 1970-1979 birth cohort, the highest rate of moderate/high-intensity smoking was 9.7% in California and 18.3% in the rest of the United States.
“There was a marked decline in moderate/high-intensity smoking at older ages in all cohorts, but this was greater in California,” noted the investigators (JAMA. 2011;305:1106-1112). “By age 35 years, the prevalence of moderate/high-intensity smoking in the 1970-1979 birth cohort was 4.6% … in California and 13.5% … in the remaining United States.”
Dr. Pierce and colleagues added that the greater decline in high-intensity smoking prevalence in California over the total study period was related to reduced smoking initiation and a probable increase in smoking cessation.