What are the definitions of disease or (outcome) and what are the definitions of exposure? Be sure to include what the exposures were and how were they measured.
This is about the article 'Association of Arsenic Exposure during pregnancy with Fetal Loss and Infant Death': A cohort study in Bangladesh (Rahman).
The study in question investigated the effects of arsenic exposure through drinking water (obtained from tube wells) on fetal loss and infant mortality.
The arsenic exposure was measured in terms of arsenic concentration in the tubewells that were used by the study subjects for drinking water. Briefly, in a separate study, researchers collected data on water sources used by people (of over 4 years of age) and another team collected water samples from these tubewells. Total arsenic concentration in water samples was measured by using hydride generation atomic absorption spectrophototmetry. Individual exposure levels were recorded as the arsenic concentration in the well water used by the particular pregnant woman.
The effect of arsenic exposure was measured in terms of early fetal loss (fetus loss within first 28 weeks, except for induced abortion and menstrual regulation), late fetal loss or still birth (birth of dead fetus after 28 weeks of gestation), neonatal death (death within first 28 days), postnatal death (between 28 days to 12 months of age) and infant death (death within first 12 months of age). These 5 outcomes were recorded.
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