Case Control Study Appraisal​

Understanding the Study

100

What was the main health issue studied?

• A) Gestational diabetes
• B) Postpartum hemorrhage
• C) Preeclampsia
• D) Infant birth weight

Postpartum hemorrhage

200

What was the definition of severe postpartum hemorrhage in this study?

• A) Blood loss ≥1000 mL
• B) Blood loss ≥1500 mL or need for transfusion
• C) Any bleeding after delivery
• D) More than 30 minutes of bleeding

Blood loss ≥1500 mL or need for transfusion

300

How were cases (women with severe PPH) identified?

• A) Patients volunteered for the study
• B) Researchers used hospital records
• C) Random selection
• D) A phone survey

Researchers used hospital records

400

Why do researchers use control groups in case-control studies?

• A) To increase sample size
• B) To eliminate bias
• C) To compare people with and without the condition 
• D) To follow patients over time

To compare people with and without the condition

Study Validity & Bias

100

Why do researchers use control groups?

• A) To compare with the cases
• B) To increase sample size
• C) To eliminate bias
• D) To follow patients over time

 To compare with the cases

200

What is one potential problem with this study?

• A) Blood loss was estimated visually
• B) The study was too small
• C) The study did not collect any data
• D) No one in the study had severe PPH

Blood loss was estimated visually

300

What defines a ‘clearly focused issue’ in a case-control study?

• A) The population, intervention, and outcomes are well-defined
• B) The study includes randomization
• C) The study uses only qualitative data
• D) The study does not define exposure variables

The population, intervention, and outcomes are well-defined

400

Did the severe PPH study use an appropriate method?

• A) No, a cohort study would have been better
• B) Yes, a case-control study was appropriate
• C) No, a randomized controlled trial was needed
• D) Can’t tell

Yes, a case-control study was appropriate

Study Findings

100

What was the strongest risk factor for severe PPH in this study?

• A) Previous severe PPH
• B) Maternal obesity
• C) Low birth weight
• D) Cesarean delivery

Previous severe PPH

200

Which of these was NOT a risk factor in the study?

• A) Use of anticoagulant medication
• B) Anemia
• C) High birth weight
• D) Drinking coffee

Drinking coffee

300

What does a wide confidence interval (e.g., 5.25–15.33) indicate?

• A) The estimate is very precise
• B) The true effect size has a lot of uncertainty
• C) The study found no significant effect
• D) It means the study has no bias

The true effect size has a lot of uncertainty

400

What does an odds ratio (OR) of 8.97 for previous severe PPH mean?

• A) Women with prior PPH are 8.97 times more likely to have it again 
• B) The study is 8.97% accurate
• C) 8.97% of the population will have severe PPH
• D) It means nothing

Women with prior PPH are 8.97 times more likely to have it again

Applying the Study

100

Can this study be applied to all pregnant women?

• A) Yes, all women are the same
• B) No, it was done in a specific country with its own population 
• C) Yes, because it was a randomized trial
• D) Can’t tell

D) Can't tell

200

What is one way hospitals could use this study?

• A) Identify women at higher risk for PPH
• B) Stop treating PPH altogether
• C) Ban labor inductions
• D) Only allow home births

 Identify women at higher risk for PPH

300

What should researchers do to reduce selection bias in a case-control study of severe postpartum hemorrhage?

• A) Randomly select both cases and controls from a large population
• B) Ensure that cases and controls are matched based on relevant variables like age, health history, and delivery type
• C) Use only the data from patients who experienced severe hemorrhage
• D) Select only patients who have been treated for PPH

Ensure that cases and controls are matched based on relevant variables like age, health history, and delivery type

400

How does the CASP checklist suggest determining the clarity and accuracy of outcome measures in a case-control study of PPH?

• A) The study should use multiple, validated outcome measures
• B) Outcome measures should only be subjective, based on patient self-reports
• C) Outcome measures should be vague and open to interpretation
• D) Outcome measures should be drawn from the author's opinions

The study should use multiple, validated outcome measures

Surprise Me

100

What does CASP stand for?

• A) Critical Appraisal Skills Programme
• B) Clinical Assessment Study Plan
• C) Case-control And Study Practices
• D) Can’t Answer Study Problems

 Critical Appraisal Skills Programme

200

If you wanted to impress your professor, which of these phrases should you say?

• A) "This study controls for confounding variables."
• B) "I didn't read the paper, but I heard it was cool."
• C) "Bias isn't real."
• D) "Let’s just trust our instincts!"

 "This study controls for confounding variables."

300

What’s the best way to win this Kahoot?

• A) Read the study and listen to the presentation 
• B) Click random answers as fast as possible
• C) Bribe the presenter
• D) Close your eyes and hope for the best

Read the study and listen to the presentation

400

If you were a researcher in this study, what would be the hardest part of data collection?

• A) Reading 3000 patient charts 
• B) Estimating blood loss by sight
• C) Explaining confidence intervals to a friend
• D) Remembering what CASP stands for

Reading 3000 patient charts