Patterns of smoking initiation in Italian males and females from 1955 to 1985

The changes in patterns of smoking initiation in Italian males and females in 1955, 1965, 1975, and 1985 were analyzed using data from the 1990-1991 Italian National Health Survey, based on a sample of 18,483 males and 19,320 females ages 19 to 59. The sample was randomly selected within strata of geographic area and size of place of residence and of household in order to be representative of the general Italian population. The age of each subject was reconstructed for each calendar year of interest (1954 to 1956, centered on 1955, 1964 to 1966, 1974 to 1976, and 1984 to 1986). For each calendar period and year of age of interest (14 to 24), the numerator of the smoking initiation rate was the number of subjects who started smoking and the denominator was the number of subjects at risk, i.e., nonsmokers of the same age. The same procedure was repeated for three separate age groups (14 to 17, 18 to 20, and 21 to 24)