Measures of material and social circumstances to adjust for deprivation in small-area studies of environment and health: review and perspectives.

he study objective is to describe cause specific mortality of employees in a plant engaged in production, recovery and refining of catalytic converters located in Rome. Previous epidemiological studies conducted in similar plants are not available. A total of 828 workers (642 males and 186 females) were followed up between 1956 and 31-12-2003. Cause specific standardized mortality ratio (SMR) and 90% confidence intervals (CI) were computed using regional rates for comparison. Among males hired between 1956 and 1993, followed up until 31/12/2003, mortality for all causes (SMR 0,8; 90% CI 0,7-1,0; 85 observed) and all neoplasms (SMR 0,6; 90% CI 0,42-0,87; 20 observed) is below expected; an increase is present for liver cirrhosis (SMR 2,74; 90% CI 1,47-5,1; 7 observed) and brain cancer (SMR 5,24; 90% CI 2,3-11,90; 4 observed). The present investigation complies with the proposed scientific standards for occupational cohort studies. The study was not prompted by well defined a priori hypotheses but it is included in a process intended to typify a potentially polluted site; the absence of a priori hypotheses and of previous epidemiological evidence, prevent from a causal interpretation of the increased mortality from liver cirrhosis and brain cancer. The implementation of cohort studies in industrial sites where industrial activities similar to the one here examined are present, are highly recommended.

The present review describes and critically analyzes the main characteristics of deprivation indices (DIs), meant as measures of material and social circumstances at a population level, used to adjust for deprivation in small-area studies of environment and health. A systematic search strategy in the period 1990-2009 was run on PubMed/Medline and Embase databases, and 41 articles were selected. In most of the reviewed studies DIs appear to be pragmatically applied and information is not adequate to evaluate whether the use of DIs is efficient. Suggestions for the use of DIs are given foreseeing that more data on exposure, outcomes and other predictive factors will be acquired, and information will be growingly available to disentangle the complex interplay between exposure, health and deprivation.