CHICAGO — Between 1965 and 2007, the number of people with a pack-a-day habit significantly declined, as did the number of people who smoked 10 or more cigarettes a day, according to a study in the March 16 issue of the Journal of the American Medical Association.
During this period, California consistently has led the United States in using public policies to reduce cigarette smoking. There were faster declines in smoking prevalence in California, compared with the remaining United States, as well as in lung cancer rates, according to background information in the article.
"The intensity of smoking [i.e., the number of cigarettes smoked per day], not just prevalence, is associated with future health consequences," noted lead author John Pierce of the University of California San Diego.
The researchers found that in 1965, the prevalence of high intensity (20 or more cigarettes per day) of smoking among California adults did not differ from the remaining United States; prevalence of high-intensity smoking in California was 23.2%, compared with 22.9% in the remaining United States. These smokers represented 56% of all smokers. By 2007, this prevalence was 2.6%, or 23% of smokers in California, and 7.2%, or 40% of smokers in the remaining United States.
The population prevalence of moderate-intensity smoking (10 or more cigarettes per day) in 1965 was 11.1% in California and 10.5% in the remaining United States; in 2007, the prevalence in California was 3.4%, compared with 5.4% in the remaining United States.
The researchers suggested that one of the reasons why the decline in moderate-intensity smoking has been greater in California than in the remaining United States is its comprehensive tobacco control programs.
The authors noted that, as expected, the large decline in the prevalence of pack-a-day smoking has been reflected in declines in lung cancer deaths in California and the United States.