Linear Mixed Models in Clinical Trials using PROC MIXED

نویسندگان

  • Danyang Bing
  • Xiaomin He
چکیده

This paper mainly illustrates how to use PROC MIXED to fit linear mixed models in clinical trials. We first introduce the statistical background of linear mixed models. We explore the situations under which the mixed effects are identified. A randomized complete block design is used to explain the difference between PROC GLM and PROC MIXED in dealing with the linear mixed models. Examples include applications of PROC MIXED in four commonly seen clinical trials utilizing splitplot designs, cross-over designs, repeated measures analysis and multilevel hierarchical models.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Calculation of Inbreeding Depression Effects on Subclinical Mastitis Using Three Different Models

Pedigree information of 3972 Holstein cows and bulls, from 1961 to 2008, was used to calculate inbreeding coefficients and their effects on production traits and subclinical mastitis of dairy farm cows inAzerbaijan province,Iran. Inbreeding was included in a linear mixed model as a class variable. Data were analyzed using the PROC MIXED of SAS by MIVQUE method. Results showed that average inbre...

متن کامل

Meta-Analysis Using SAS PROC MIXED 1 META-ANALYSIS USING LINEAR MIXED MODELS

Psychologists often use special computer programs to perform meta-analysis. Until recently, this had been necessary because standard statistical packages did not provide procedures for such analysis. This paper introduces linear mixed models as a framework for meta-analysis in psychological research, using a popular general-purpose statistical package, SAS. The approach is illustrated with thre...

متن کامل

An Intermediate Primer to Estimating Linear Multilevel Models using SAS PROC MIXED

This paper expands upon Bell et al.’s (2013) “A Multilevel Model Primer Using SAS PROC MIXED” in which we presented an overview of estimating two and three-level linear models via PROC MIXED. However, in our earlier paper, we, for the most part, relied on simple options available in PROC MIXED. In this paper, we present a more advanced look at common PROC MIXED options used in the analysis of s...

متن کامل

Bivariate linear mixed models using SAS proc MIXED

Bivariate linear mixed models are useful when analyzing longitudinal data of two associated markers. In this paper, we present a bivariate linear mixed model including random effects or first-order auto-regressive process and independent measurement error for both markers. Codes and tricks to fit these models using SAS Proc MIXED are provided. Limitations of this program are discussed and an ex...

متن کامل

Using PROC MIXED in Hierarchical Linear Models: Examples from two- and three-level school-effect analysis, and meta-analysis research

The study presents useful examples of fitting hierarchical linear models using the PROC MIXED statistical procedure in the SAS system. Hierarchical linear models are quite common in social science studies, in particular educational research, due to naturally occurring hierarchies or clusters (e.g., students belong to classes which are nested in schools). Despite their prevalence, the SAS PROC M...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2010