Identify the population, data sources, and epidemiologic measures of association that the authors used.

Population: Residents of nine European areas.

Data sources: Cancer mortality databases, census data, and socio-economic indicators

Epidemiologic measures: Mortality rates, rate ratios, and relative inequalities (e.g., rate differences between socio-economic groups).

Share your insights about the appropriateness of the design for the study. Do you agree with the researchers’ choice of design?

The ecological approach is suitable for identifying macro level, socio economic disparities, but it does not include individual level exposure outcome data. A stronger causal inference might have been possible from a longitudinal cohort study.

Do you agree with the researchers’ conclusions? Justify your reasoning.

The researchers’ conclusions reveal worsening inequalities after the recession are likely accurate given the data, but should be interpreted with some degree of caution owing to the possibility of confounding and the problems inherent in aggregated data.

Study 2- Nguyen et al. (2020)

Focus on the study design and methods.

This study uses a national case control design to examine the relationship between antibiotic use and the risk of developing Inflammatory Bowel Disease (IBD) in Sweden. To identify cases of IBD (Crohn’s disease and ulcerative colitis), the researchers used Swedish national health registers and matched cases to controls by age, sex, and county of residence. To determine the association between prior antibiotic exposure and IBD risk, logistic regression models were developed and potential confounders were accounted for.