Trend detection with non-detects in long-term monitoring, a mixed model approach.
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ABSTRACT:
SUBMITTER: Skold M
PROVIDER: S-EPMC10182149 | biostudies-literature | 2023 May
REPOSITORIES: biostudies-literature
Publications
Trend detection with non-detects in long-term monitoring, a mixed model approach.
Environmental monitoring and assessment 20230512 6
In long-term monitoring of contaminants in biota, a common approach is to use yearly geometric means of measured concentrations in sampled individuals as a basis for trend analysis. When some or all measurements in a particular year are reported as non-detects, it is unclear how to proceed in calculating the yearly mean. I argue that by casting the problem in terms of a mixed model, non-detects can be accounted for using statistical techniques for censored data. The approach is illustrated using ...[more]
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