Please refer to this article fo the following question: Nielsen C, et al. Tattoos as a risk factor for malignant lymphoma: a population-based case-control study. eClinicalMedicine. 2024

https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(24)00228-1/fulltext

- Build a 2 x 2 table to look at the association between having a tattoo (exposure) and lymphoma (outcome). Based on that 2 x 2 table, estimate the odds ratio (OR) of the association between tattoos and lymphoma.

- Interpret the OR you calculated in question 1.

- Calculate and interpret the relative risk (RR) for the same association.

- Is OR a good approximation of RR? Why or why not? (Hint: think of study design features that can make it a good or a bad approximation.)

- Underline all study designs in which you can directly calculate (not approximate!) RRs: prospective cohort; retrospective cohort; randomized clinical trial; case-control; cross-sectional; ecological; case series.