Document pBnEE2e8L6rOeMGz7kywyy0da

/?A rt&- Ci -v //, / THE UNIVERSITY OF WESTERN AUSTRALIA DEPARTMENT OF MEOICINE Telephone: 380 U 22 cy ?C7Q la. cji o UNIT OF CLINICAL EPIDEMIOLOGY Medictl School Buildint. The Qucen Hl#beth H Medical Centre. Nedlvtdt. W.A.. 6009. 12th September, 1979 Mr. G. Hart, C.S.R. Limited, Box 483, G.P.O. , SYDNEY N.S.W. 2001 Dear Mr. Hart, Thank you for your letter'and comments. With regard to your queries: 1. We have been gradually improving the quality of our computer files. The figure referred to in February iy/a (6,677) is all the male and female employees for whom we have ABA records. 6,200 of these are male, 377 are female. As mentioned on page 1, a further 341 have been found at the Miners' Registry who initially did not appear to have ABA employment records. This has now been reduced to about 250. We are continuing to attempt to establish if these men definitely did work for ABA at Wittenoom. 2. We have accounted for 80% of the 6,200, either alive or dead. The remaining men {i.e. in the "previous" 341 qbove) have been difficult to trace as we only know of them from the Miners1 Registry (ABA records presumably lost) in which the quality of identifying information is not particularly good. 3. Steve Woodward is preparing some corrections to Table 3. I am asking him to send you a copy. 4. It would be possible to make tentative projections but these could not be regarded as reliable because of fairly substantial sampling errors in the rates due to small numbers. There are other difficulties - we have no way of knowing whether the incidence of new cases will further increase in those vith the longest follow-up periods. Long term projections of new cases must also take into account the number of deaths that are likely to occur from other causes in an ageing population. 5. The correct total is 53. 6. I enclose a corrected version of Table 5. Note that the line "all non-respiratory deaths" is a summary of all deaths less deaths from mesothelioma and respiratory cancer, and other chest diseases - Mr. G. Hart. 2. We have already met with the Wittenoom Trust and have undertaken to provide further data to help with the management of the Trust funds over time. Your comments bringing to our attention mistakes in the Tables have been extremely helpful. Yours sincerely, Iwe Lj, ' MICHAEL HOBBS, Associate Professor, Social and Preventive Medicine.