title: Poor symptom and performance validity in regularly referred Hospital outpatients: Link with standard clinical measures, and role of incentives.
abstract: We investigated the frequency of symptom validity test (SVT) failure and its clinical correlates in a large, heterogeneous sample of hospital outpatients referred for psychological assessment for clinical purposes. We studied patients (N=469), who were regularly referred for assessment to the psychology departments of five hospitals. Background characteristics, including information about incentives, were obtained with a checklist completed by the clinician. As a measure of over-reporting, the Structured Inventory of Malingered Symptomatology (SIMS) was administered to all patients. The Amsterdam Short-Term Memory test (ASTM), a cognitive underperformance measure, was only administered to patients who were referred for a neuropsychological assessment. Symptom over-reporting occurred in a minority of patients, ranging from 12% to 19% in the main diagnostic patient groups. Patients with morbid obesity had a low rate of over-reporting (1%). The SIMS was positively associated with levels of self-reported psychological symptoms. Cognitive underperformance occurred in 29.3% of the neuropsychological assessments. The ASTM was negatively associated with memory test performance. We found no association between SVT failure and financial incentives. Our results support the recommendation to routinely evaluate symptom validity in clinical assessments of hospital patients. The dynamics behind invalid symptom reporting need to be further elucidated.
authors.affiliation: Department of Psychiatry and Psychology, School for Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands. Electronic address: b.fitzgerald@maastrichtuniversity.nl.
authors.forename: Brechje
authors.initials: B
authors.lastname: Dandachi-FitzGerald
authors.affiliation: Department of Clinical and Medical Psychology, Atrium Medical Centre Parkstad, Heerlen, The Netherlands.
authors.forename: Björn
authors.initials: B
authors.lastname: van Twillert
authors.affiliation: Department of Medical Psychology, St Elisabeth Hospital Tilburg, The Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: van de Sande
authors.affiliation: Department of Medical Psychology, Elkerliek Hospital Helmond, The Netherlands.
authors.forename: Yindee
authors.initials: Y
authors.lastname: van Os
authors.affiliation: Department of Psychiatry and Psychology, School for Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Rudolf W H M
authors.initials: RW
authors.lastname: Ponds
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006761:Hospitals / Q000592:standards*; D006801:Humans; D008297:Male; D008306:Malingering / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D008570:Memory, Short-Term; D008875:Middle Aged; D009042:Motivation; D009426:Netherlands / Q000453:epidemiology; D009483:Neuropsychological Tests / Q000592:standards*; D010045:Outpatients / Q000523:psychology*; D012017:Referral and Consultation / Q000592:standards*; D015203:Reproducibility of Results; D063189:Symptom Assessment / Q000379:methods / Q000592:standards*; D055815:Young Adult
keywords: Amsterdam Short-Term Memory test (ASTM); Assessment; Hospital outpatients; Performance validity; Structured Inventory of Malingered Symptomatology (SIMS); Symptom validity