[Methodological problems in bio-demographic research. A sample study of the age at menopause]

Two methods for the analysis of age at menopause, the longitudinal, or retrospective, method and the transversal, or status quo, method, are compared. The differences between these two methods are emphasized. "The former describes an historically ended situation and estimates the probability that a woman will reach such condition at age x. The latter considers the phenomenon from the viewpoint of its composite actuality and estimates the probability that a woman of age x is undergoing menopause." The different results obtained from the application of the two methods to data sets concerning 767 and 270 women born in Bologna, Italy, between 1920 and 1945 are described (SUMMARY IN ENG AND FRE)