Mentoring Corner: Disscussion Topics – Epidemiology

Pick out an article from the Journal of Occupational and Environmental Health.  Discuss and critique the article in terms of methods used, data analysis, results, conclusions, etc. Depending on the type of study, you’ll want to make the appropriate selection from the available checklists:   http://strobe-statement.org/index.php?id=available-checklists

Have the mentee choose the article to focus on.  He/She should present it, i.e. re-reads the abstract, then a presents a quick overview of each section (background, methods, analysis, results, conclusions…) and has prepared some points to bring up for discussion.  Preferably, they will have some background in the topic.

Additional goal of learning to evaluate the occupational epi literature by understanding how IH issues might affect the presented results, conclusions and differences in outcomes between publications? This way, the participants could see how their IH samples can affect outcomes in the published literature. Some common IH issues in evaluating the quality of the epi evidence are below and may prove useful topics of interest:

Job titles/self reported exposure versus IH measurements of exposure:

Were exposures classified by job titles, self report or lumped into exposed & non-exposed categories when associating exposure with the study disease outcome, or were actual IH exposure measurements made?

Job Exposure Matrices:

If this was a long term, cohort or prospective study, did the IH sampling period cover the entire period of study? Were they representative of the changes in worker tasks over the years that might account for differences between studies?

Area versus personal samples and biomarkers:

Were they area or personal samples or biomarkers? If they were biomarkers, have differences in individual metabolism been noted in previous studies? If so, did the study design account for within individual changes in biomarkers before and after exposure or were workers lumped into exposed and non-exposed groups for comparisons?

Exposure badge/meter placement:

Was the badge/exposure meter location appropriate for the disease outcome assessed?

Exposure sample and route of exposure:

The study may have collected airborne or wipe samples, but would some assessment of dermal exposure be appropriate considering the potential routes of biological absorption?

   < LOD samples:

How were the exposure measurements that were missing, or less than the Limit of Detection handled in the data analysis? Were a large percentage of the samples < LOD, and if so, were they used in creating the average exposure?

Confounders & Effect Modifiers:

Did the authors account for potential confounders or effect modifiers?

In terms of choosing what to focus upon in reading the articles, would suggest concentrating on both the Discussion (which usually has at least a paragraph on the study limitations) and the written Exposure Measurement details of the Methods sections, as well as invited commentaries and Letters to the Editor in the journals. The American Journal of Epidemiology sometimes offers “Environmental Health” features, Environmental Health Perspectives journal, and the Journal of Occupational and Environmental Medicine (which often seems to include extensive details of exposure assessment in their articles) would offer many opportunities for discussion. Mentors and Mentees can choose articles in their areas of experience or expertise to give them some IH background on the exposure methods to critique. They might even be able to submit their own “Letter to the Editor” regarding a recent article, or you could combine a few mentor/mentee discussions into a Synergist article, etc.

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