title: Comparison of models for analyzing two-group, cross-sectional data with a Gaussian outcome subject to a detection limit.
abstract: A potential difficulty in the analysis of biomarker data occurs when data are subject to a detection limit. This detection limit is often defined as the point at which the true values cannot be measured reliably. Multiple, regression-type models designed to analyze such data exist. Studies have compared the bias among such models, but few have compared their statistical power. This simulation study provides a comparison of approaches for analyzing two-group, cross-sectional data with a Gaussian-distributed outcome by exploring statistical power and effect size confidence interval coverage of four models able to be implemented in standard software. We found using a Tobit model fit by maximum likelihood provides the best power and coverage. An example using human immunodeficiency virus type 1 ribonucleic acid data is used to illustrate the inferential differences in these models.
authors.affiliation: Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, USA rwiegand@cdc.gov.
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Wiegand
authors.affiliation: Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, USA.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Rose
authors.affiliation: Apex Systems, Inc., Richmond, Virginia, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Karon
mesh_terms: D019380:Anti-HIV Agents / Q000627:therapeutic use; D015982:Bias; D003430:Cross-Sectional Studies / Q000379:methods*; D015658:HIV Infections / Q000188:drug therapy / Q000821:virology; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification*; D006801:Humans; D016013:Likelihood Functions; D057230:Limit of Detection; D015999:Multivariate Analysis; D016011:Normal Distribution; D011336:Probability; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics; D000068898:Raltegravir Potassium / Q000627:therapeutic use; D012984:Software; D019562:Viral Load / Q000187:drug effects
chemical_list: D019380:Anti-HIV Agents; D012367:RNA, Viral; D000068898:Raltegravir Potassium
keywords: limit of detection; regression; statistical power