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. Author manuscript; available in PMC: 2018 Sep 1.
Published in final edited form as: Curr Environ Health Rep. 2017 Sep;4(3):364–372. doi: 10.1007/s40572-017-0156-x

Table 1.

Target Populations and Target Parameters for Selected Recent Applications of G-Methods to Control for Bias due to Mechanisms of the Healthy Worker Survivor Effect

Study Reference Target Population Target Parameter
Study Population Inception Cohort Reported Target Parameter Estimation Method Measured Time Varying Confounders True Value of Target Parameter Affected by HWSE Mechanism
Neophytou et al 2014 Aluminum smelter and fabrication workers No Hazard ratio for ischemic heart disease while at work, comparing hypothetical intervention in which all workers were always exposed above the cutoff for PM2.5 to one in which all workers were always exposed below the cutoff IPTW Composite health score Yes
Keil & Richardson 2016 Copper smelter workers No Cumulative incidence for respiratory cancers, heart disease, and other causes under each intervention on arsenic exposure, compared to the natural course of each disease G-computation Employment status Yes
Neophytou et al 2016 Underground non-metal miners Yes* Risk ratio/difference and attributable fraction of lung cancer under interventions eliminating occupational exposure to diesel exhaust G-computation Employment status Job location Yes
Brown et al 2015 Aluminum smelter and fabrication workers No 12-year cumulative incidence of ischemic heart disease under hypothetical intervention in which all workers remained at work and were exposed above the median PM2.5 compared to one in which all workers were always exposed below median TMLE Composite health score Co-morbidities No
Keil et al 2015 Uranium miners No Ratio of median survival times for lung cancer mortality corresponding to a 100 working-level month increase in cumulative radon exposure G-estimation Employment status No
Björ et al 2015 Iron ore miners No Hazard ratio for mortality not known to be related to dust exposure, comparing hypothetical intervention in which all workers were exposed above the cutoff for respirable dust during the first 15 years of follow-up to one in which all workers were never exposed above the cutoff G-estimation Employment status Sick leave/Time off Job Location No
Picciotto et al 2015 Autoworkers Yes Total number of person-years of life lost in the cohort due to cardiovascular disease that could have been saved by enforcing various exposure limits on certain metalworking fluids G-estimation Employment status Intermittent time off Other metalworking fluids Yes
Picciotto et al 2016 Autoworkers Yes Average number of years of life lost due to cardiovascular disease that could have been saved per person among the ever-exposed workers by enforcing a ban on exposure to certain metalworking fluids G-estimation Employment status Intermittent time off Other metalworking fluids Yes
Costello et al 2016 Aluminum smelter workers Yes Hazard ratio for ischemic heart disease while at work, comparing hypothetical intervention in which all workers were always exposed above the cutoff for PM2.5, to one in which all workers were always exposed below the cutoff IPTW Composite health score Yes
Aluminum fabrication workers Yes Ratio of risk within a population of workers who were hired and then assigned to specific jobs by the employer thereby defining their exposure histories to PM2.5 without intervention Cox Model Composite health score Yes

HWSE: Healthy Worker Survivor Effect IPTW: Inverse Probability Weighting TMLE: Targeted Maximum Likelihood Estimation

PM2.5: Particulate Matter <2.5μm in diameter

*

Follow-up started at dieselization at each mine so the cohort was an inception cohort with respect to diesel exhaust exposure, though not with respect to employment.

Estimate of model coefficient that is unaffected by HWSE mechanism was combined with data and assumptions to obtain an estimate of a target parameter that is affected by HWSE mechanism.