title: Estimation of coefficients of individual agreement (CIAs) for quantitative and binary data using SAS and R.
abstract: The coefficients of individual agreement (CIAs), which are based on the ratio of the intra- and inter-observer disagreement, provide a general approach for evaluating agreement between two fixed methods of measurements or human observers. In this paper, programs in both SAS and R are presented for estimation of the CIAs between two observers with quantitative or binary measurements. A detailed illustration of the computations, macro variable definitions, input and output for the SAS and R programs are also included in the text. The programs provide estimations of CIAs, their standard errors as well as confidence intervals, for the cases with or without a reference method. Data from a carotid stenosis screening study is used as an example of quantitative measurements. Data from a study involving the evaluation of mammograms by ten radiologists is used to illustrate a binary data example.
authors.affiliation: Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, 1518 Clifton Road NE, Atlanta, GA 30322, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Pan
authors.forename: Jingjing
authors.initials: J
authors.lastname: Gao
authors.forename: Michael
authors.initials: M
authors.lastname: Haber
authors.forename: Huiman X
authors.initials: HX
authors.lastname: Barnhart
mesh_terms: D016893:Carotid Stenosis / Q000175:diagnosis; D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000706:statistics & numerical data; D008327:Mammography / Q000706:statistics & numerical data; D015233:Models, Statistical; D015588:Observer Variation; D012984:Software