REEXAMINING THREATS TO THE RELIABILITY AND VALIDITY OF PUTATIVE BRAIN-BEHAVIOR RELATIONSHIPS - NEW GUIDELINES FOR ASSESSING THE EFFECT OF PATIENTS LOST TO FOLLOW-UP

It often happens in behavioral and biomedical research that subjects i n prospective, multiple assessment investigations, including clinical trials, are lost to follow-up evaluations. The purpose of this report is to outline a model that will enable the investigators to determine the extent to which results based upon the maintained cohere can be ge neralized to the attrited cohort, or those subjects lost to follow-up. While our proposed model derives from a specific application pertaini ng to changes in personality and affect behaviors following left and r ight hemisphere stroke, it should apply, with appropriate study-specif ic modifications, to a wide range of follow-up research designs in neu ropsychology, behavioral science more generally, and other areas of bi omedical research.