Modeling Semicontinuous Longitudinal Expenditures: A Practical Guide.
Journal Article (Journal Article)
OBJECTIVE: To compare different strategies for analyzing longitudinal expenditure data that have a point mass at $0. We provide guidance on parameter interpretation, research questions, and model selection. DATA SOURCES, STUDY DESIGN, AND DATA COLLECTION: One-part models, uncorrelated two-part models, correlated conditional two-part (CTP) models, and correlated marginalized two-part (MTP) models have been proposed for longitudinal expenditures that often exhibit a large proportion of zeros and a distribution of continuous, highly right-skewed positive values. Guidance on implementing and interpreting each of these model is illustrated with an example of longitudinal (2000-2003) specialty care expenditures of veterans with hypertension, drawn from Veterans Administration data. PRINCIPAL FINDINGS: The four strategies answer different research questions, are appropriate for different structures of data, and provide different results. If there is a point mass at $0, then the MTP model may be most useful if the primary interest is in mean expenditures of the entire population. A CTP model may be most useful if the primary interest is in the level of expenditures conditional on them being incurred. CONCLUSIONS: Researchers should consider which modeling strategy for longitudinal expenditure outcomes is both consistent with research aims and appropriate for the data at hand.
Full Text
Duke Authors
Cited Authors
- Smith, VA; Maciejewski, ML; Olsen, MK
Published Date
- August 2018
Published In
Volume / Issue
- 53 Suppl 1 / Suppl Suppl 1
Start / End Page
- 3125 - 3147
PubMed ID
- 29315527
Pubmed Central ID
- PMC6056585
Electronic International Standard Serial Number (EISSN)
- 1475-6773
Digital Object Identifier (DOI)
- 10.1111/1475-6773.12815
Language
- eng
Conference Location
- United States