Response from the authors

Abstract

Dr Hocking raises a number of important issues in commenting on our paper about mortality in the cohort of current and former employees of the Australian Nuclear Science and Technology Organisation (ANSTO) (Aust N Z J Public Health 2005;29(3): 229-37).Our paper was not intended to demonstrate or disprove the carcinogenicity of ionising radiation per se, but to compare the mortality of the ANSTO worker cohort with that of the New South Wales population. We agree that our study shares characteristics in common with many retrospective occupational cohort studies, including the absence of comprehensive information on a range of potentially important exposure variables and incomplete follow-up of some cohort members. We doubt that major methodological improvements could have been made to the study, given the small size of the cohort, the limited availability of exposure data for several potential carcinogens, both occupational and non-occupational, and the chronological period covered by computerised mortality registers.