Incorporating individual-level distributions of exposure error in epidemiologic analyses: an example using arsenic in drinking water and bladder cancer.
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.
Meliker
Jaymie R
JR
Graduate Program in Public Health, Department of Preventive Medicine, Stony Brook University, Stony Brook, NY 11794-8338, USA. jaymie.meliker@stonybrook.edu
Goovaerts
Pierre
P
Jacquez
Geoffrey M
GM
Nriagu
Jerome O
JO
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*
D001152:Arsenicals
Int J Environ Res Public Health. 2010 Apr;7(4):1520-39
20617044
Health Phys. 2004 Jul;87(1):15-32
15194919
Epidemiology. 2003 Jul;14(4):451-8
12843771
Health Phys. 2007 Feb;92(2):99-111
17220711
Biometrics. 1991 Jun;47(2):535-48
1912260
Health Phys. 2008 Sep;95(3):277-90
18695409
Ann Epidemiol. 2006 Nov;16(11):834-41
16843678
Environ Health Perspect. 1993 Dec;101 Suppl 4:49-57
8206042
Int J Epidemiol. 2008 Apr;37(2):382-5
18184671
Occup Environ Med. 2009 Oct;66(10):650-6
19465410
Stat Med. 2006 Jan 15;25(1):87-103
16220473
Am J Epidemiol. 1991 Aug 15;134(4):433-7
1877603
Environ Health Perspect. 1993 Dec;101 Suppl 4:39-48
8206041
Annu Rev Public Health. 1993;14:69-93
8323607
Cancer Causes Control. 2010 May;21(5):745-57
20084543
J Epidemiol Community Health. 2008 Jul;62(7):655-63
18559450
Environ Res. 2008 Jan;106(1):42-50
17942092
Sci Total Environ. 2006 Oct 1;369(1-3):42-50
16750243
Am J Epidemiol. 1991 Nov 15;134(10):1233-44
1746532
Environ Health Perspect. 1993 Dec;101 Suppl 4:19-21
8206029
Biometrics. 1977 Jun;33(2):414-8
884199
Am J Epidemiol. 1990 Oct;132(4):746-8
2403115
Biometrics. 2001 Sep;57(3):689-97
11550916
Radiat Res. 2006 Jul;166(1 Pt 2):303-12
16808615
Epidemiology. 2002 Sep;13(5):507-16
12192219
Epidemiology. 2008 May;19(3):409-16
18379431
Int J Epidemiol. 2009 Dec;38(6):1662-73
19744933
Occup Environ Med. 1998 Oct;55(10):651-6
9930084
Biometrics. 2007 Dec;63(4):1226-36
18078484
Int J Epidemiol. 2005 Jun;34(3):680-7
15802377
Am J Epidemiol. 1981 Aug;114(2):253-9
7304560
Int J Epidemiol. 2005 Dec;34(6):1370-6
16172102
Radiat Res. 2007 Dec;168(6):757-63
18088178
Epidemiology. 2006 Nov;17(6):604-14
17028502
Biometrics. 2002 Mar;58(1):13-20
11890308
Am J Ind Med. 1991;19(5):587-601
2053577
JAMA. 1990 Aug 1;264(5):585-91
2366297
Am J Public Health. 1998 Mar;88(3):406-12
9518972