Socioeconomic deprivation and notification rates for tuberculosis in London during 1982-91

Abstract
Objectives: To investigate the association between four sociodemographic measures (unemployment, overcrowding, low social class, and the proportion of migrants from areas of high prevalence of tuberculosis) and average level and rate of change of notification rates for tuberculosis. Design: Ecological analysis of both the average and the rate of change of standardised annual notification rates for tuberculosis from 1982-91 and sociodemographic measures from the 1981 and 1991 censuses. Setting: 32 London boroughs. Subjects and data: Sociodemographic measures from the 1981 and 1991 censuses and tuberculosis notification rates for 1982-91. Main outcome measures: A measure of the association between average levels and rate of change in tuberculosis notification rates and four sociodemographic measures in 1981 and between the rate of change in tuberculosis notification rates between 1981 and 1991 and changes in sociodemographic measures between 1981 and 1991. Results: The average level of notifications was correlated with overcrowding and the proportion of migrants but not with unemployment or social class. No significant association was found between the rate of change in notification rates and sociodemographic measures in 1981. An association was found between increases in unemployment and the rate of change in notification rates, but the effect was small. Changes in the levels of unemployment explained 23% of the variation between boroughs in the rate of change in their notification rates. Conclusion: The average tuberculosis notification rates were related to overcrowding and the proportion of migrants in 1981. Only increases in unemployment from 1981 to 1991, however, were significantly associated with the rate of change in notifications over the same period. Key messages Sociodemographic variables such as poverty, overcrowding, and migration (from parts of the world with relatively high rates of tuberculosis) are known to be associated with higher rates of tuberculosis The recent rates of change in notification rates in London boroughs in the past decade do not seem to be associated with the absolute levels of overcrowding, unemployment, social class distribution, or proportion of migrants as measured in the 1981 census An association, however, was found between changes in unemployment levels between 1981 and 1991 and the rates of change in tuberculosis notification rates in the same period, but the effect was small Further research is necessary to determine the reasons for the association found and to investigate the other factors contributing to the changing rates of tuberculosis in the developed world