학술논문

Validity of Simpson-Angus Scale (SAS) in a naturalistic schizophrenia population.
Document Type
Article
Source
BMC Neurology. 2005, Vol. 5, p5-6. 6p. 3 Charts.
Subject
*MEDICAL equipment
*PARKINSON'S disease
*SCHIZOPHRENIA
*PEOPLE with schizophrenia
*DIAGNOSIS
Language
ISSN
1471-2377
Abstract
Background: Simpson-Angus Scale (SAS) is an established instrument for neuroleptic-induced parkinsonism (NIP), but its statistical properties have been studied insufficiently. Some shortcomings concerning its content have been suggested as well. According to a recent report, the widely used SAS mean score cut-off value 0.3 of for NIP detection may be too low. Our aim was to evaluate SAS against DSM-IV diagnostic criteria for NIP and objective motor assessment (actometry). Methods: Ninety-nine chronic institutionalised schizophrenia patients were evaluated during the same interview by standardised actometric recording and SAS. The diagnosis of NIP was based on DSM-IV criteria. Internal consistency measured by Cronbach's α, convergence to actometry and the capacity for NIP case detection were assessed. Results: Cronbach's α for the scale was 0.79. SAS discriminated between DSM-IV NIP and non- NIP patients. The actometric findings did not correlate with SAS. ROC-analysis yielded a good case detection power for SAS mean score. The optimal threshold value of SAS mean score was between 0.65 and 0.95, i.e. clearly higher than previously suggested threshold value. Conclusion: We conclude that SAS seems a reliable and valid instrument. The previously commonly used cut-off mean score of 0.3 has been too low resulting in low specificity, and we suggest a new cut-off value of 0.65, whereby specificity could be doubled without loosing sensitivity. [ABSTRACT FROM AUTHOR]