Structure and change in causes of death: An international summary

Abstract Model patterns of the cause structure of mortality at different levels were established for males and females, based on data for 165 national populations. These patterns suggest that the cause of death most responsible for mortality variation is influenza/bronchitis, followed by 'other infectious and parasitic diseases', respiratory tuberculosis, and diarrhoeal disease. Together, these causes typically account for about 60 per cent of the change in level of mortality from all causes combined. Their respective contributions have not depended in an important way on the initial level of mortality. These results - especially tbe importance of the respiratory and diarrhoeal diseases - imply that past accounts may have over-emphasized the role in mortality decline of specific and well-defined infectious diseases and their corresponding methods of control. There is strong statistical support for the suggestion that most of the remainder of mortality variation should be ascribed to changes in cardio-vascular diseases, but that methods of cause-of-death assignment in high-mortality populations have often obscured the importance of these diseases. When death rates from 'other and unknown' causes are held constant, changes in cardio-vascular disease account for about one-quarter of the decline in mortality from 'all causes'.Although the causal factors are poorly established, corroborative results have been demonstrated cross-sectionally in the United States. The composition of the group of populations most deviant from the structural norms is apparently dominated by differentials in the mode of assigning deaths to cardio-vascular disease. However, when broad groups of regions or periods are distinguished, more subtle differences emerge. Controlling mortality level for all causes combined, diarrhoeal diseases are significantly higher in non-Western populations and southern/eastern Europe than in overseas Europe or northern/western Europe. These differences are probably related to standards of nutrition and personal hygiene, but may also reflect climatic factors. Much higher cardio-vascular mortality in overseas European populations than in non-Western populations at similar overall levels probably reflects variation in habits of life. Regional differences in death rates from violence, maternal mortality, respiratory tuberculosis and influenza/pneumonia/bronchitis are briefly noted and commented upon. Cause-of-death structures at a particular level of mortality display some important changes over time. Respiratory tuberculosis and 'other infectious and parasitic diseases' have tended to contribute less and less to a certain level of mortality. They have in part been 'replaced' by diarrhoeal disease, specifically in non-Western populations. These developments reflect an accelerating rate of medical and public health progress against the specific infectious diseases, and a disappointing rate of progress against diarrhoeal disease. Western and non-western populations have shared to approximately the same extent in the accelerating progress against infectious diseases, and developments during the post-war period are more appropriately viewed as an extension of prior trends rather than as radical departures therefrom. For males, cardio-vascular disease and cancer have significantly increased their contribution to a particular level of mortality, while no such tendency is apparent for females. These developments may be related to changes in personal behaviour and in environmental influences whose differential impact on the sexes has been demonstrated in epidemiological studies. Although we have avoided an explicit treatment of age by having recourse at the outset to standardization, certain of the results are apparently reflected in studies of age patterns of mortality. The joint occurrence in non-Western populations and Southern/Eastern populations of exceptionally high death rates from diarrhoeal disease may explain why the 'South' age-pattern, with it high death rates between ages one and five, is often the most accurate referent for use in Latin America and Asia. The fact that the list of populations with the least deviation cause structure is almost exclusively confined to members of the 'West' group of Coale and Demeny may account for the lack of persistent deviation in this group's age patterns. Finally, tbe increasing importance of cardio-vascular disease and neoplasms in cause-of-death structures for males but not females is probably associated with the changing age patterns of male mortality noted by Coale and Demeny.     

Life cycle of families in an urban community

This study is based on a sample of 1203 families in the city of Sholapur, conducted in 1955 using a cross-section analytical method based on income and family size, in relation to age of head of household. The nature of the life cycle is representational rather than statisitical. Nearly half the household heads were between ages 26-40; 10% were 15-25; and 40% were over 40. The average family size increased steadily and continuously from 3.9 members when the head was under 20, to 6.6 when the head was 55. The number of dependents at this age increased from 2.7 to 4.6. The average number of earners increased from 1.3 to 2. After age 55 the average family size declined from 6.6 to 5.4 for the 56-60 age group. Until the age of 40 the head of the family is usually the only earner. The son at age 20 begins to earn. At 55 the head may retire, but another son may take his place as an earner. The proportions of families with income below Rs. 500 decreased continuously from about 42%, when the family head was under 20; to 15% when he was between 26-40; rose to 25% between ages 46-50; and declined to 12% at ages 56-60. The proportion rose again to 32% over age 60. The proportion of families below Rs. 1000 decreased from 89% in the 0-20 age group to 41% in the 51-55 group, after which it rose to 64% in the over 60 group. The median income of the family increased continously from Rs. 591 when the head was under 20, and increased to the highest level of Rs. 1275 between ages 51-55.     

Some population characteristics of villages differentiated by size,location, and growth

Selected social characteristics of individuals were examined for groups of villages simultaneously dichotomized by size, location relative to larger cities, and population change. The percent of people having a selected characteristic in each village group of the resulting eight-fold classification was taken as the dependent variable, and difference scores indicating main effects and first order interactions were obtained for each characteristic. The universe is the 375 incorporated places under 2500 in 1950outside the SMSAs of Wisconsin. Size of place was found to be important for the sex ratio, education and income levels, and labor force and occupational variables. Characteristics associated with nearness to a large city included income, male labor force participation, occupation, and industry. Growth was important for age and sex differences, education, income, and some labor force, occupation, and industry variables. An interaction between location and growth was found for several occupation and industry characteristics. The consistency between some of the results and previous research on larger places supports the contention that villages, although classified as rural, share many characteristics of urban centers. The industry and occupation differences by location, and the interaction between location and growth, strongly suggest that location is tied closely to function here. Places near cities over 25,000, especially those that are growing, may serve as residences for commuting blue-collar workers, or perhaps as small manufacturing centers, while most places more remote from cities continue to function as small service centers for a rural hinterland.