Definition and evaluation of the monotonicity condition for preference-based instruments.

ABSTRACT:

Background

Preference-based instrumental variable methods are often used in comparative effectiveness research. Many instrumental variable studies estimate the local average treatment effect (ie, the effect in the "compliers") under the assumption of monotonicity, ie, no "defiers," and well-defined compliance types. However, the monotonicity assumption has not been empirically tested and the meaning of monotonicity itself is unclear.

Methods

Here, we clarify the definition of local and global monotonicity and propose a novel study design to assess the monotonicity assumption empirically. Our design requires surveying physicians about their treatment plans and prescribing preferences for the same set of patients. We also discuss measures of monotonicity that can be calculated

SUBMITTER: Swanson SA 

PROVIDER: S-EPMC4669963 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature