STATISTICAL POWER TO DETECT OCCUPATIONALLY RELATED RESPIRATORY CANCERRISK IN A COHORT OF FEMALE EMPLOYEES IN THE US MAN-MADE VITREOUS FIBER INDUSTRY

The current update of the US man-made vitreous fiber production worker cohort includes women for the first time. Preliminary comparisons of 3,820 female and 27,767 male workers from 11 participating fibrous gla ss plants show different hiring patterns during World War II. The gend er-specific person-year distributions are similar with respect to dura tion of employment and time since first employment. The current follow -up of 118,559 person-years for women provides an estimated 80% power to detect a threefold relative risk of respiratory cancer for women wh o worked more than 14 years in these plants, based on a Poisson regres sion analysis of the cohort rates. When women comprise a small fractio n of the cohort, the statistical power may be inadequate to detect ris ks of the magnitude typically of interest in studies of men.