Question

6. An observational study (Bouchard, Bellinger, Wright, Weisskopf, Pediatric, 2010) examined a possible rela tionship between exposure to certain pesticides as measured in urinary metabolites (DAP) and diagnosis of ADHD. In reporting the results, the authors claim: • The threshold for statistical significance was set at p <.05." "The odds of meeting the criteria for ADHD increased with urinary concentration of total DAP metabolites." "The association was statistically significant." (a) What can we conclude about the p-value obtained in the study? (b) Based on these statements, can we distinguish whether the evidence of association was very strong versus moderately strong? Why or why not? (c) Can we conclude that exposure to pesticides is related to the likelihood of an ADHD diagnosis? (d) Can we conclude that exposure to pesticides causes more cases of ADHD? Why or why not?

Answer 1

(a) The study used a significance level of p < 0.05, considering p-values below this threshold as significant.

(b) The statements confirm a significant association between pesticide exposure and ADHD, but the strength of the association isn't specified.

(c) Pesticide exposure is related to a higher likelihood of ADHD diagnosis based on the study's findings.

(d) The study doesn't prove causation; it only shows an association. More research is needed to establish causation between pesticide exposure and ADHD.