THE SPECIFICITY OF THE 21-ITEM TEST IN TWO ELDERLY SAMPLES by

by Daniel M. Turpin The 21-Item Test was administered to 20 healthy elderly individuals dwelling in the community and 53 individuals residing in a nursing home. The 20 healthy elderly individuals had means for age, education, and Short Portable Mental Status Questionnaire (SPMSQ) of 76.25 years (SD = 7.19), 14.30 years (SD = 3.89), and .30 (SD = 4.70), respectively. The second group of 53 nursing home residents had means for age, education, and SPMSQ of 82.79 years (SD = 8.56), 11.14 years (SD =2.46), and 3.17 (SD = 2.46), respectively. The clinical cut-offs for the forcedchoice component of the 21-Item Test proposed by Iverson (1998) may be insensitive to age and cognitive impairment. Not a single individual scored in the range of biased responding. Thus, the 21-Item test is unlikely to produce false positive results in elderly patients with obvious cognitive deficits. THE SPECIFICITY OF THE 21-ITEM TEST IN TWO ELDERLY SAMPLES by Daniel M. Turpin A Thesis presented in partial fulfillment of the requirements for the degree of Master of Science in the Department of Psychology University of Central Missouri November, 2011 THE SPECIFICITY OF THE 21-ITEM TEST IN TWO ELDERLY SAMPLES by Daniel M. Turpin November 2011 APPROVED: Thesis Chair: Joseph J. Ryan, PhD. Thesis Committee Member: David S. Kreiner, PhD. Thesis Committee Member: Jonathan W. Smith, PhD. ACCEPTED: Chair, Department of Psychology: Joseph J. Ryan, PhD. UNIVERSITY OF CENTRAL MISSOURI WARRENSBURG, MISSOURI ACKNOWLEDGMENTS First, I wish to express my heartfelt appreciation to Dr. Joseph Ryan for your commitment to my education and this project. You are an invaluable thesis chair, mentor, educator, and friend. I appreciate your patience and guidance through this project. My continuing education in the field of psychology is solely due to the knowledge and passion you expressed as my educator. Thanks for believing in me, making me laugh, and always keeping your office door open. Special acknowledgment is also given to Drs. Jon Smith and David Kreiner for their commitment to this thesis project. I would also like to thank Tina Walker for assisting in the interpretation of data and her willingness to always provide a helping hand. Finally, my deepest appreciation is further extended to my parents Michael and Pamela, and to my sister, Kim. I am truly blessed to have such a caring family. Thank you for not giving up on me and encouraging me every step of the way. TABLE OF CONTENTS Page LIST OF TABLES ....................................................................................................................... viii CHAPTER 1: NATURE AND SCOPE OF THE STUDY ..............................................................1 Purpose of the Study ............................................................................................................1 Need for the Study ...............................................................................................................2 Thesis of the Study...............................................................................................................2 Procedural Overview ...........................................................................................................3 CHAPTER 2: REVIEW OF THE LITERATURE ..........................................................................4 Definitions of Malingering ...................................................................................................4 Prevalence of Malingering ...................................................................................................6 Floor Effect ...........................................................................................................................9 Performance Curve .............................................................................................................16 Magnitude of Error .............................................................................................................19 Atypical Presentation .........................................................................................................20 Symptom Validity Testing ..................................................................................................22 CHAPTER 3: METHODOLOGY .................................................................................................33 Participants ..........................................................................................................................33 Materials .............................................................................................................................36