La Vecchia C, Decarli A, Pagano R
Istituto di Ricerche Farmacologiche, Mario Negri, Milan, Italy.
Prev Med. 1995 May;24(3):293-6. doi: 10.1006/pmed.1995.1047.
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).
Among males, there was a trend toward earlier age at start of smoking and higher initiation rates between 1955 and 1965, and a subsequent decline in initiation rate, particularly at age 18 or over and during the last calendar decade studied. In females, between 1955 and 1975 there was an increase of over fourfold in initiation rates and systematic tendencies toward earlier age at starting; only over the past decade have the starting rates begun to decline. The peak rate was reached at age 18-20 for males in 1965 (53.3%) and for females in 1975 (23.9%).
The recent declines in smoking initiation have been relatively limited among the younger age groups, and this reflects an earlier average age at smoking initiation.
利用1990 - 1991年意大利国家健康调查的数据,对1955年、1965年、1975年和1985年意大利男性和女性的吸烟起始模式变化进行分析,该调查样本包括18483名年龄在19至59岁的男性和19320名年龄在19至59岁的女性。样本是在地理区域、居住地点规模和家庭规模的分层内随机选取的,以便代表意大利普通人群。针对每个感兴趣的历年(1954年至1956年,以1955年为中心;1964年至1966年;1974年至1976年;1984年至1986年)重建每个受试者的年龄。对于每个感兴趣的日历时期和年龄(14至24岁),吸烟起始率的分子是开始吸烟的受试者数量,分母是处于风险中的受试者数量,即同一年龄的非吸烟者。对三个不同年龄组(14至17岁、18至20岁和21至24岁)重复相同的程序。
在男性中,1955年至1965年期间存在吸烟起始年龄提前和起始率上升的趋势,随后起始率下降,特别是在18岁及以上以及在所研究的最后一个日历十年期间。在女性中,1955年至1975年期间起始率增加了四倍多,且有起始年龄提前的系统性趋势;仅在过去十年中起始率才开始下降。1965年男性在18 - 20岁时达到最高起始率(53.3%),1975年女性在18 - 20岁时达到最高起始率(23.9%)。
在较年轻年龄组中,近期吸烟起始率的下降相对有限,这反映了吸烟起始的平均年龄更早。