Module 3: Epidemiologic studies

Module 3

Module 3: Epidemiologic studies

Training course in research methodology, research protocol development and scientific writing 2025

September 17, 2025 - Geneva

Assignment

Part 1

Question 1: Read the abstract and method sections of the cohort study below.

Lin J, Gu W, Huang H. Effects of Paternal Obesity on Fetal Development and Pregnancy Complications: A Prospective Clinical Cohort Study. Front Endocrinol (Lausanne). 2022 Mar 14;13:826665.

Answer the following questions (8 marks):

1.1 What was the cohort in this study?

1.2 Identify with reason the study type based on time (prospective/retrospective/cross sectional).

1.3 What were the exposure and outcome variables?

1.4 Mention two advantages and two disadvantages of this study design.

Question 2: Read the abstract and method sections of the case-control study below.

Megersa BS, Ojengbede OA, Deckert A, Fawole OI. Factors associated with induced abortion among women of reproductive age attending selected health facilities in Addis Ababa, Ethiopia: a case control study. BMC Women’s Health. 2020 Sep 3;20(1):188.

Answer the following questions (6 marks):

2.1 Define the cases and controls in this study.

2.2 Were the cases matched with controls?

2.3 Why is matching used in a case control study?

2.4 Mention the risk factors/exposures studied.

Question 3: Go over the cross-sectional study below.

Yaya S, Odusina EK, Bishwajit G. Prevalence of child marriage and its impact on fertility outcomes in 34 sub-Saharan African countries. BMC International Health and Human Rights. 2019 Dec 19;19(1):33.

Answer the following questions (6 marks):

3.1 What was data source for the study?

3.2 What were the independent and dependent variables in the study?

3.3 What factor(s) did the researchers considered when examining the association between the variables? Mention at least eight.

Question 4: Read the abstract and method of the randomized control trial below.

Trummer C, Schwetz V, Kollmann M, Wölfler M, Münzker J, Pieber TR, Pilz S, Heijboer AC, Obermayer-Pietsch B, Lerchbaum E. Effects of vitamin D supplementation on metabolic and endocrine parameters in PCOS: a randomized-controlled trial. Eur J Nutr. 2019 Aug;58(5):2019-28.

Answer the following questions (5 marks):

4.1 What were the treatments in the intervention and control/placebo group?

4.2 How was allocation concealment done in this study? What is the objective of allocation concealment?

4.3 Was any blinding used? If yes, what type? What is the objective of blinding?

Part 2

Reflect over the topic, question and study design for your research protocol, revise if necessary and submit to your coach for review and feedback.