- T: Treatment
- C: confounders; patient characteristics
- U: Unmeasured confounders
- H: Hospital
- Z: proportion of treated patients within each hospital
- Ī²CT: Effect of C on T
- Ī²UT: Effect of U on T; amount of unmeasured patient level confounding
- Ī²Cy: Effect of C on Y; amount of measured patient level confounding
- Ī²Uy: Effect of U on Y; amount of unmeasured patient level confounding
- Ī²Ht (a set of Ī²ās for each level of H) Effect of H on T
- Ī²HY (a set of Ī²ās for each level of H) Effect of H on Y separate from Z;
- Ī²T The ātrueā treatment effect (unknown in empirical data)