Researchers recently presented results of a cohort study on

Researchers recently presented results of a cohort study on prenatal methylmercury exposure and neurocognitive deficits which showed a two-fold higher risk in pre-schoolers than any other published report. The study was conducted in an area where the local fish consumed were not only contaminated with mercury, but with other with industrial wastes, including polychlorinated biphenyls (PCBs) and dioxins. After being confronted by colleagues on the veracity of this high risk estimate, the researchers went back and adjusted the data analysis for intake of PCB and dioxin. In doing so, they ended up with a markedly lower risk estimate which approximated the risks reported in the literature. In this instance, one could safely conclude that confounding accounted for the initial high risk estimate reported by the researchers.

True or False

Solution

After reading this case, it is evident that the initial high risk report submitted by the researchers are contradictory. They contradicted their report after being questioned by their colleagues. So, the above statement is true. The area where the study was conducted is at a lower risk of the contamination by mercury, PCB and dioxins.