Analysis of factors affecting perinatal mortality. A multivariate statistical approach.

Despite important progress during recent decades, perinatal mortality is still a problem of major national importance. Today nearly 3 per cent. of all births result in perinatal death. To reduce this loss requires a better understanding of the way in which a large number of inter-related social and medical factors influence perinatal mortality risk. We are developing a series of studies to separate and examine the effects of these factors. For this purpose we shall employ a method of multivariate statistical analysis. The present paper discusses this method and illustrates it by analysing the effects of maternal age, parity, and social class. (Our social class categories are based on husband's occupation, according to the classification of the Registrar General (General Register Office, 1951)). The data used in these analyses was provided by the Perinatal Mortality Survey (Butler and Bonham, 1963). During one week in March, 1958, the Survey directed by Dr NeviUe Butler obtained information