When to Select Observational Studies Interactive Case Study Quiz: Dan Jonas, MD, MPH Meera Viswanathan, PhD Karen Crotty, PhD, MPH RTI-UNC Evidence-based Practice Center Authors have no actual or potential conflicts of interest in relation to this activity

Interactive Case Quiz: Instructions Open this presentation as a slideshow. This will activate the hyperlinks. When you come to a decision slide, choose the red box corresponding to the correct choice. If you are correct, you will be directed forward in the case. If you are incorrect, you will be directed back to the decision slide to choose again. – – Click on forward hyperlinks (Red Boxes) to follow through cases based on your responses – – Click on home hyperlink (Blue House Icon) to go back to the last correct step in the series

Participation Quiz: Question 1 When should observational studies be considered for inclusion in a CER? Observational studies should never be considered for inclusion. Observational studies should always be considered for inclusion as the “default strategy.” There are no observational studies in CERs.

Never This is incorrect. Observational studies should always be considered for inclusion as the “default strategy.” [Click on Blue Box to Go Back]

Default Strategy You are correct! CERs should always consider observational studies as the “default strategy.” [SELECT RED BOX]

No Observational Studies in CERs This is incorrect. Observational studies regularly form part of the evidence for CERs. [Click on Blue Box to Go Back]

Participation Quiz: Question 2 Which of the following is the first question to consider when deciding whether to include observational studies to assess benefits in CERs? Will trials provide valid and useful information to address key questions? Are there gaps in the available observational evidence? Are there gaps in trial evidence for the review questions under consideration?

Valid and Useful Information This is incorrect. Trials generally provide valid and useful information and are the first source of evidence when selecting data for inclusion in a CER. The second question to consider when deciding whether to include observational studies in CERs is whether observational studies provide valid and useful information to address key questions. [Click on Blue Box to Go Back]

Gaps in Observational Evidence This is incorrect. Whether there are gaps in the observational evidence is not the first consideration when selecting evidence. [Click on Blue Box to Go Back]

Gaps in Trial Evidence This is correct. The first of two steps when considering whether to include observational studies is to determine if there are gaps in the trial evidence under review. [SELECT RED BOX]

Participation Quiz: Question 3 A CER comparing PCI vs. CABG for coronary disease identified 23 RCTs. Experts (TEP) raised concerns that the studies enrolled patients with a relatively narrow spectrum of disease relative to those having the procedures in current practice. Should you: Change your key questions to focus on the types of patients for whom research is available? Complete your review including only the 23 trials that were identified? Expand the review to include observational studies?

Change Key Questions This is incorrect. The lack of trial data is not a reason to change prespecified key questions that were developed to answer an important question. [Click on Blue Box to Go Back]

Include Only the 23 Trials This is incorrect. You should consider the advice from your TEP suggesting that the evidence to date poorly represents clinical practice and will result in poor applicability of the results of your CER. [Click on Blue Box to Go Back]

Include Observational Studies This is correct! Expanding your review to include suitable observational studies will improve the applicability of your CER. [SELECT RED BOX]

Participation Quiz: Question 4 Once gaps in the trial evidence to assess benefits have been established and you have decided to include observational studies, should you: Include all suitable observational studies found to answer the initial key questions? Exclude trial data that can be answered by the selected observational studies? Refocus the study question on the gaps in trial evidence?

Include All Suitable OS This is incorrect. You should include observational studies that address the gaps in trial evidence. [Click on Blue Box to Go Back]

Exclude Trial Data This is incorrect. You should not exclude suitable trial data. [Click on Blue Box to Go Back]

Refocus on Gaps This is correct! Observational studies should seek to answer the questions that trial data were unavailable to answer by refocusing the key questions. [SELECT RED BOX]

Participation Quiz: Question 5 In the absence of sufficient trial data, which types of observational studies should CERs routinely search for and include evidence of harms? Case reports Cross-sectional studies Cohort and case-control studies

Case Reports This is incorrect. [Click on Blue Box to Go Back]

Cross-sectional This is incorrect. [Click on Blue Box to Go Back]

Cohort and Case-control This is correct! [SELECT RED BOX]

Congratulations! You have selected the correct evidence and are now equipped with the skills necessary to sift confidently through the scientific literature, selecting the evidence most suited to answering your CER questions.