Read the article https://www.nejm.org/doi/full/10.1056/NEJMoa2206734,

"Liquefied Petroleum Gas or Biomass for Cooking and Effects on Birth Weight".

Analyze the article addressing the following:

1. What is the purpose of the article?

2. What kind of sampling was used here?

3. What was the purpose of the study?

4. Which hypothesis test was used? What are the null and alternative hypotheses?

5. Was this an observational study or an experiment? Why?

6. Identify independent and dependent variables and classify them as either quantitative or qualitative.

7. Why did the authors use blinding?

8. What does it mean when the authors discuss a trial having high fidelity and adherence? Why is that important?

9. In table 2, discuss the meaning of the top row of numbers.

10. In figure 2, we see a forest plot. In a forest plot, each horizontal line is a confidence interval. The box in the middle of each horizontal line (confidence interval, CI) represents the point estimate of the effect for a single study. The size of the box is proportional to the weight of the study in relation to the pooled estimate. The dotted line represents what? What does it mean that the dotted line intersects every box and whisker plot? Why is that significant?

11. Where the results significant? Explain.