Occupational distribution and geographic clustering of deaths certified to be cryptogenic fibrosing alveolitis in england and wales.

STUDY
OBJECTIVES: The etiology of cryptogenic fibrosing alveolitis (CFA) remains largely obscure, although a 1996 report suggested an increased risk from occupational exposure to metal and wood dusts. Using data from death certificates in England and Wales, we sought evidence of any relationship between occupation and CFA and of the extent of any temporospatial clustering of place of birth and place of death as possible evidence of a geographically related environmental factor. DESIGN AND
SETTING: Data on occupation and address (postal code) were obtained from certificates of men and women dying as a result of CFA between 1981 and 1990 and were compared with national mortality statistics. Place of birth data were extracted from certificates for deaths between 1993 and 1995, the only available years, and were compared with national birth statistics. MEASUREMENTS AND
RESULTS: Standardized mortality ratios (SMRs) were raised (p<0.05) in the following four occupational groups: members of the armed forces (SMR, 217.8); miners and quarrymen (SMR, 142.0); service, sports, and recreation workers (SMR, 118.6); and electrical and electronic workers (SMR, 146.6). Of these four groups, the latter group might be worth testing in a future study. There was statistical evidence of geographic clustering in postal code sectors for the recorded place of death, but the high-rate areas were different in men and women. Deaths were increased for those subjects born in urban areas, although these did not follow a clear geographic pattern.
CONCLUSIONS: Overall, these analyses provide little evidence of any important contribution from environmental factors to the etiology of CFA and suggest that more consideration be given to alternative concepts of causation.