Table 2.

Potential clinical questions that can be addressed by regression discontinuity designs and proposed approach

Clinical questions	Threshold rules	Outcomes
What are optimal blood pressure goals for specific subpopulations, such as adults with diabetes?	Compare outcomes for people above and below systolic and diastolic blood pressure for different guideline based thresholds (which have changed over time)	Cardiovascular events, mortality
What is the optimal fluid resuscitation strategy in patients with sepsis?	Compare outcomes across different central venous pressure thresholds (which may vary across time, institutions)	Length of stay on intensive care unit stay, mortality
Are steroids appropriate in patients with alcoholic hepatitis and infections?	Compare outcomes for patients with both alcoholic hepatitis and infections just above and just below the Maddrey discriminant cut-off of 32 (above which steroids are indicated)	Mortality
Is liberal or conservative transfusion more appropriate in acute coronary syndromes?	Compare outcomes across different transfusion thresholds (such as hemoglobin <8 mg/L), which may vary across institutions and over time	Length of stay, mortality
What are the real world effects of cardiac resynchronization therapy?	Compare outcomes just above and just below a QRS complex duration of 120 ms (indication for cardiac resynchronization therapy placement)	Hospital admissions for heart failure, quality of life