Journal article
Treatment Effect Estimation Using Nonlinear Two-Stage Instrumental Variable Estimators: Another Cautionary Note
Health services research, Vol.51(6), pp.2375-2394
12/01/2016
DOI: 10.1111/1475-6773.12463
PMCID: PMC5134142
PMID: 26891780
Abstract
Objective. To examine the settings of simulation evidence supporting use of nonlinear two-stage residual inclusion (2SRI) instrumental variable (IV) methods for estimating average treatment effects (ATE) using observational data and investigate potential bias of 2SRI across alternative scenarios of essential heterogeneity and uniqueness of marginal patients.
Study Design. Potential bias of linear and nonlinear IV methods for ATE and local average treatment effects (LATE) is assessed using simulation models with a binary outcome and binary endogenous treatment across settings varying by the relationship between treatment effectiveness and treatment choice.
Principal Findings. Results show that nonlinear 2SRI models produce estimates of ATE and LATE that are substantially biased when the relationships between treatment and outcome for marginal patients are unique from relationships for the full population. Bias of linear IV estimates for LATE was low across all scenarios.
Conclusions. Researchers are increasingly opting for nonlinear 2SRI to estimate treatment effects in models with binary and otherwise inherently nonlinear dependent variables, believing that it produces generally unbiased and consistent estimates. This research shows that positive properties of nonlinear 2SRI rely on assumptions about the relationships between treatment effect heterogeneity and choice.
Details
- Title: Subtitle
- Treatment Effect Estimation Using Nonlinear Two-Stage Instrumental Variable Estimators: Another Cautionary Note
- Creators
- Cole G. Chapman - University of South CarolinaJohn M. Brooks - University of South Carolina
- Resource Type
- Journal article
- Publication Details
- Health services research, Vol.51(6), pp.2375-2394
- DOI
- 10.1111/1475-6773.12463
- PMID
- 26891780
- PMCID
- PMC5134142
- NLM abbreviation
- Health Serv Res
- ISSN
- 0017-9124
- eISSN
- 1475-6773
- Publisher
- Wiley
- Number of pages
- 20
- Grant note
- RC4AG038635 / National Institutes of Health, National Institute on Aging; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Institute on Aging (NIA) RC4AG038635 / NATIONAL INSTITUTE ON AGING; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Institute on Aging (NIA)
- Language
- English
- Date published
- 12/01/2016
- Academic Unit
- Pharmacy Practice and Science
- Record Identifier
- 9984365890402771
Metrics
25 Record Views