Abstract
OBJECTIVESThis study compared the results of meta-analysis with and without adjustment for the healthy worker effect on the association between working in the semiconductor industry and cancer mortality.METHODSSix studies that reported standardized mortality ratios (SMRs) for cancers were selected for meta-analysis. Using a random-effects model, the SMR results from each study were combined for all cancers and leukemias to estimate the summary SMRs (95% confidence interval, CI). To adjust for the healthy worker effect, the relative standardized mortality ratio (rSMR=SMRx/SMRnot x) were calculated using observed and expected counts for the specific cause of interest (i.e., all cancers and leukemias) and the observed and expected counts for all other causes of mortality. Then, the rSMR results were combined to estimate the summary rSMRs (95% CIs).RESULTSThe SMRs for all causes of mortality among semiconductor industry workers ranged from 0.25 to 0.80, which reflects a significant healthy worker effect. A remarkable difference was found between the summary SMRs and the summary rSMRs. The summary SMR for all cancers was 0.70 (95% CI, 0.63 to 0.79) whereas the summary rSMR was 1.38 (95% CI, 1.20 to 1.59). The summary SMR for leukemia was 0.88 (95% CI, 0.72 to 1.07), and the summary rSMR was 1.88 (95% CI, 1.20 to 2.95).CONCLUSIONSOur results suggest that adjustment for the healthy worker effect (i.e., rSMR) may be useful in meta-analyses of cohort studies reporting SMRs.
Highlights
Semiconductor manufacturing has become the core of the entire microelectronics industry
We adopted the relative standardized mortality ratio (rSMR) method to adjust for the healthy worker effect in a meta-analysis of 6 retrospective cohort studies which evaluated whether semiconductor industry workers are at increased risk of cancer mortality
After adjusting for the healthy worker effect, we found that there were significant associations between working in the semiconductor industry and increased cancer mortality
Summary
Semiconductor manufacturing has become the core of the entire microelectronics industry. The concern of the semiconductor industry for the health of its workers includes the cancer risk from recirculated air for particle control and suspected carcinogens including ionizing radiation, asbestos, arsenic and arsenical compounds, chromium compounds, sulfuric acid mist, ultraviolet light, trichloroethylene, carbon tetrachloride, nickel, and antimony trioxide [1,2]. The semiconductor industry is known to be highly chemical-intensive, especially for the wafer fabrication A definitive association between working in semiconductor manufacturing and cancers has not been found [16]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
