An introduction to analyzing dichotomous outcomes in a longitudinal setting: a NIDRR traumatic brain injury model systems communication.
An untapped wealth of temporal information is captured within the Traumatic Brain Injury Model Systems National Database. Utilization of appropriate longitudinal analyses can provide an avenue toward unlocking the value of this information. This article highlights 2 statistical methods used for assessing change over time when examination of noncontinuous outcomes is of interest where this article focuses on investigation of dichotomous responses. Specifically, the intent of this article is to familiarize the rehabilitation community with the application of generalized estimating equations and generalized linear mixed models as used in longitudinal studies. An introduction to each method is provided where similarities and differences between the 2 are discussed. In addition, to reinforce the ideas and concepts embodied in each approach, we highlight each method, using examples based on data from the Rocky Mountain Regional Brain Injury System.
Craig Hospital (Drs Pretz and Cuthbert) and Traumatic Brain Injury National Statistical and Data Center (Drs Pretz and Cuthbert), Englewood, Colorado; and Department of Biostatistics, Virginia Commonwealth University, Richmond (Dr Ketchum). This work was prepared at the Traumatic Brain Injury Model Systems National Data and Statistical Center, Craig Hospital, Englewood, Colorado.
Christopher R
CR
Pretz
Jessica M
JM
Ketchum
Jeffery P
JP
Cuthbert
D001930:Brain Injuries / Q000534:rehabilitation*; D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D006801:Humans; D016014:Linear Models; D017063:Outcome Assessment, Health Care