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Quantifying and Adjusting for Disease Misclassification Due to Loss to Follow-Up in Historical Cohort Mortality Studies.

Scott LL, Maldonado G - Int J Environ Res Public Health (2015)

Bottom Line: Disease classification parameters were defined using 2008 mortality data for the New Zealand population and the proportions of known deaths observed for the cohort.The geometric mean ORDM-LTF ranged between 1.65 (certainty interval (CI): 0.50-3.88) and 3.33 (CI: 1.21-10.48), and the geometric mean of the disease-misclassification error factor (εDM-LTF), which is the ratio of the observed odds ratio to the adjusted odds ratio, had a range of 0.91 (CI: 0.29-2.52) to 1.85 (CI: 0.78-6.07).The application of uncertainty analysis to historical cohort mortality studies with multi-level exposures can provide valuable insight into the magnitude and direction of study error resulting from losses to follow-up.

View Article: PubMed Central - PubMed

Affiliation: Division of Environmental Health Sciences, University of Minnesota School of Public Health, Minneapolis, MN 55455, USA. llfscott@umn.edu.

ABSTRACT
The purpose of this analysis was to quantify and adjust for disease misclassification from loss to follow-up in a historical cohort mortality study of workers where exposure was categorized as a multi-level variable. Disease classification parameters were defined using 2008 mortality data for the New Zealand population and the proportions of known deaths observed for the cohort. The probability distributions for each classification parameter were constructed to account for potential differences in mortality due to exposure status, gender, and ethnicity. Probabilistic uncertainty analysis (bias analysis), which uses Monte Carlo techniques, was then used to sample each parameter distribution 50,000 times, calculating adjusted odds ratios (ORDM-LTF) that compared the mortality of workers with the highest cumulative exposure to those that were considered never-exposed. The geometric mean ORDM-LTF ranged between 1.65 (certainty interval (CI): 0.50-3.88) and 3.33 (CI: 1.21-10.48), and the geometric mean of the disease-misclassification error factor (εDM-LTF), which is the ratio of the observed odds ratio to the adjusted odds ratio, had a range of 0.91 (CI: 0.29-2.52) to 1.85 (CI: 0.78-6.07). Only when workers in the highest exposure category were more likely than those never-exposed to be misclassified as non-cases did the ORDM-LTF frequency distributions shift further away from the . The application of uncertainty analysis to historical cohort mortality studies with multi-level exposures can provide valuable insight into the magnitude and direction of study error resulting from losses to follow-up.

No MeSH data available.


Related in: MedlinePlus

Geometric mean errors (εDM-LTF) (a), adjusted odds ratios (ORDM-LTF) (b) and 95% certainty intervals by scenario. The dashed horizontal black line in (b) indicates the crude odds ratio (ORobserved) of 3.05. In the Differential A scenarios, the “never-exposed” were more likely to be misclassified as alive than the highest exposed. In the Differential B scenarios, the “never-exposed” were less likely to be misclassified as alive than the highest exposed.
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ijerph-12-12834-f003: Geometric mean errors (εDM-LTF) (a), adjusted odds ratios (ORDM-LTF) (b) and 95% certainty intervals by scenario. The dashed horizontal black line in (b) indicates the crude odds ratio (ORobserved) of 3.05. In the Differential A scenarios, the “never-exposed” were more likely to be misclassified as alive than the highest exposed. In the Differential B scenarios, the “never-exposed” were less likely to be misclassified as alive than the highest exposed.

Mentions: Results for each simulation of the probabilistic uncertainty analysis are summarized in Table 2 and Figure 3. The geometric mean of the error term for disease misclassification due to loss to follow-up (εDM-LTF) had a range of 0.91 to 1.85. The geometric mean adjusted odds ratio (ORDM-LTF) ranged between 1.65 and 3.33. Estimated certainty intervals (CI) for the geometric mean ORDM-LTF excluded the for all four scenarios in which those categorized as “never-exposed” were less likely to be misclassified as alive than workers in the highest exposure category.


Quantifying and Adjusting for Disease Misclassification Due to Loss to Follow-Up in Historical Cohort Mortality Studies.

Scott LL, Maldonado G - Int J Environ Res Public Health (2015)

Geometric mean errors (εDM-LTF) (a), adjusted odds ratios (ORDM-LTF) (b) and 95% certainty intervals by scenario. The dashed horizontal black line in (b) indicates the crude odds ratio (ORobserved) of 3.05. In the Differential A scenarios, the “never-exposed” were more likely to be misclassified as alive than the highest exposed. In the Differential B scenarios, the “never-exposed” were less likely to be misclassified as alive than the highest exposed.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4627002&req=5

ijerph-12-12834-f003: Geometric mean errors (εDM-LTF) (a), adjusted odds ratios (ORDM-LTF) (b) and 95% certainty intervals by scenario. The dashed horizontal black line in (b) indicates the crude odds ratio (ORobserved) of 3.05. In the Differential A scenarios, the “never-exposed” were more likely to be misclassified as alive than the highest exposed. In the Differential B scenarios, the “never-exposed” were less likely to be misclassified as alive than the highest exposed.
Mentions: Results for each simulation of the probabilistic uncertainty analysis are summarized in Table 2 and Figure 3. The geometric mean of the error term for disease misclassification due to loss to follow-up (εDM-LTF) had a range of 0.91 to 1.85. The geometric mean adjusted odds ratio (ORDM-LTF) ranged between 1.65 and 3.33. Estimated certainty intervals (CI) for the geometric mean ORDM-LTF excluded the for all four scenarios in which those categorized as “never-exposed” were less likely to be misclassified as alive than workers in the highest exposure category.

Bottom Line: Disease classification parameters were defined using 2008 mortality data for the New Zealand population and the proportions of known deaths observed for the cohort.The geometric mean ORDM-LTF ranged between 1.65 (certainty interval (CI): 0.50-3.88) and 3.33 (CI: 1.21-10.48), and the geometric mean of the disease-misclassification error factor (εDM-LTF), which is the ratio of the observed odds ratio to the adjusted odds ratio, had a range of 0.91 (CI: 0.29-2.52) to 1.85 (CI: 0.78-6.07).The application of uncertainty analysis to historical cohort mortality studies with multi-level exposures can provide valuable insight into the magnitude and direction of study error resulting from losses to follow-up.

View Article: PubMed Central - PubMed

Affiliation: Division of Environmental Health Sciences, University of Minnesota School of Public Health, Minneapolis, MN 55455, USA. llfscott@umn.edu.

ABSTRACT
The purpose of this analysis was to quantify and adjust for disease misclassification from loss to follow-up in a historical cohort mortality study of workers where exposure was categorized as a multi-level variable. Disease classification parameters were defined using 2008 mortality data for the New Zealand population and the proportions of known deaths observed for the cohort. The probability distributions for each classification parameter were constructed to account for potential differences in mortality due to exposure status, gender, and ethnicity. Probabilistic uncertainty analysis (bias analysis), which uses Monte Carlo techniques, was then used to sample each parameter distribution 50,000 times, calculating adjusted odds ratios (ORDM-LTF) that compared the mortality of workers with the highest cumulative exposure to those that were considered never-exposed. The geometric mean ORDM-LTF ranged between 1.65 (certainty interval (CI): 0.50-3.88) and 3.33 (CI: 1.21-10.48), and the geometric mean of the disease-misclassification error factor (εDM-LTF), which is the ratio of the observed odds ratio to the adjusted odds ratio, had a range of 0.91 (CI: 0.29-2.52) to 1.85 (CI: 0.78-6.07). Only when workers in the highest exposure category were more likely than those never-exposed to be misclassified as non-cases did the ORDM-LTF frequency distributions shift further away from the . The application of uncertainty analysis to historical cohort mortality studies with multi-level exposures can provide valuable insight into the magnitude and direction of study error resulting from losses to follow-up.

No MeSH data available.


Related in: MedlinePlus