title: Incorporating individual-level distributions of exposure error in epidemiologic analyses: an example using arsenic in drinking water and bladder cancer.
abstract: OBJECTIVE
  Epidemiologic analyses traditionally rely on point estimates of exposure for assessing risk despite exposure error. We present a strategy that produces a range of risk estimates reflecting distributions of individual-level exposure.
  
  
  METHODS
  Quantitative estimates of exposure and its associated error are used to create for each individual a normal distribution of exposure estimates which is then sampled using Monte Carlo simulation. After the exposure estimate is sampled, the relationship between exposure and disease is evaluated; this process is repeated 99 times generating a distribution of risk estimates and confidence intervals. This is demonstrated in a bladder cancer case-control study using individual-level distributions of exposure to arsenic in drinking water.
  
  
  RESULTS
  Sensitivity analyses indicate similar performance for categorical or continuous exposure estimates, and that increases in exposure error translate into a wider range of risk estimates. Bladder cancer analyses yield a wide range of possible risk estimates, allowing quantification of exposure error in the association between arsenic and bladder cancer, typically ignored in conventional analyses.
  
  
  CONCLUSIONS
  Incorporating distributions of individual-level exposure error results in a more nuanced depiction of epidemiologic findings. This approach can be readily adopted by epidemiologists assuming distributions of individual-level exposure.
authors.affiliation: Graduate Program in Public Health, Department of Preventive Medicine, Stony Brook University, Stony Brook, NY 11794-8338, USA. jaymie.meliker@stonybrook.edu
authors.forename: Jaymie R
authors.initials: JR
authors.lastname: Meliker
authors.forename: Pierre
authors.initials: P
authors.lastname: Goovaerts
authors.forename: Geoffrey M
authors.initials: GM
authors.lastname: Jacquez
authors.forename: Jerome O
authors.initials: JO
authors.lastname: Nriagu
mesh_terms: D020261:Arsenic Poisoning / Q000150:complications* / Q000453:epidemiology; D001152:Arsenicals / Q000032:analysis*; D015986:Confounding Factors, Epidemiologic; D004781:Environmental Exposure / Q000009:adverse effects*; D004812:Epidemiologic Methods; D006801:Humans; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D011336:Probability; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D001749:Urinary Bladder Neoplasms / Q000139:chemically induced* / Q000453:epidemiology; D014881:Water Supply / Q000032:analysis*
chemical_list: D001152:Arsenicals
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