Validation of the Excited Component of the Positive and Negative Syndrome Scale (PANSS-EC) in a naturalistic sample of 278 patients with acute psychosis and agitation in a psychiatric emergency room

Montoya Alonso, Valladares Amparo, Lizán Luis, San Luis, Escobar Rodrigo, Paz, Paz Silvia

Description

Despite the wide use of the Excited Component of the Positive and Negative Syndrome Scale (PANSS-EC) in a clinical setting to assess agitated patients, a validation study to evaluate its psychometric properties was missing. Methods Data from the observational NATURA study were used. This research describes trends in the use of treatments in patients with acute psychotic episodes and agitation seen in emergency departments. Exploratory principal component factor analysis was performed. Spearman's correlation and regression analyses (linear regression model) as well as equipercentile linking of Clinical Global Impression of Severity (CGI-S), Agitation and Calmness Evaluation Scale (ACES) and PANSS-EC items were conducted to examine the scale's diagnostic validity. Furthermore, reliability (Cronbach's alpha) and responsiveness were evaluated. Results Factor analysis resulted in one factor being retained according to eigenvalue ≥1. At admission, the PANSS-EC and CGI-S were found to be linearly related, with an average increase of 3.4 points (p < 0.001) on the PANSS-EC for each additional CGI-S point. The PANSS-EC and ACES were found to be linearly and inversely related, with an average decrease of 5.5 points (p < 0.001) on the PANSS-EC for each additional point. The equipercentile method shows the poor sensitivity of the ACES scale. Cronbach's alpha was 0.86 and effect size was 1.44. Conclusions The factorial analyses confirm the unifactorial structure of the PANSS-EC subscale. The PANSS-EC showed a strong linear correlation with rating scales such as CGI-S and ACES. PANSS-EC has also shown an excellent capacity to detect real changes in agitated patients.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2011
• Nombre de lectures: 397
• Langue: English

Extrait

Montoyaet al.Health and Quality of Life Outcomes2011,9:18 http://www.hqlo.com/content/9/1/18

R E S E A R C H

Open Access

Validation of the Excited Component of the Positive and Negative Syndrome Scale (PANSS EC) in a naturalistic sample of 278 patients with acute psychosis and agitation in a psychiatric emergency room 1* 1 2 3 4 2 Alonso Montoya , Amparo Valladares , Luis Lizán , Luis San , Rodrigo Escobar and Silvia Paz

Abstract Background:Despite the wide use of the Excited Component of the Positive and Negative Syndrome Scale (PANSSEC) in a clinical setting to assess agitated patients, a validation study to evaluate its psychometric properties was missing. Methods:Data from the observational NATURA study were used. This research describes trends in the use of treatments in patients with acute psychotic episodes and agitation seen in emergency departments. Exploratory principal component factor analysis was performed. Spearman’s correlation and regression analyses (linear regression model) as well as equipercentile linking of Clinical Global Impression of Severity (CGIS), Agitation and Calmness Evaluation Scale (ACES) and PANSSEC items were conducted to examine the scale’s diagnostic validity. Furthermore, reliability (Cronbach’s alpha) and responsiveness were evaluated. Results:Factor analysis resulted in one factor being retained according to eigenvalue≥1. At admission, the PANSS EC and CGIS were found to be linearly related, with an average increase of 3.4 points (p < 0.001) on the PANSSEC for each additional CGIS point. The PANSSEC and ACES were found to be linearly and inversely related, with an average decrease of 5.5 points (p < 0.001) on the PANSSEC for each additional point. The equipercentile method shows the poor sensitivity of the ACES scale. Cronbach’s alpha was 0.86 and effect size was 1.44. Conclusions:The factorial analyses confirm the unifactorial structure of the PANSSEC subscale. The PANSSEC showed a strong linear correlation with rating scales such as CGIS and ACES. PANSSEC has also shown an excellent capacity to detect real changes in agitated patients.

Background Agitation and aggressive behaviour due to primary psy chiatric disturbances are particularly prevalent in emer gency psychiatric services and specialist psychiatric units for acute psychoses [1]. During these emergency situa tions, some injuries to both patients and staff may occur, and rapid and effective action is required to mini mize the risks [2]. A series of instruments are used in

* Correspondence: [e-mail] 1 Lilly Research Laboratories, Avenida de la Industria 30, 28108 Alcobendas, Madrid, Spain Full list of author information is available at the end of the article

clinical and research settings, allowing the rapid assess ment of the levels of aggression and anxiety in patients. The preferred measure in modern trials is a subset of items derived from the Positive and Negative Syndrome Scale (PANSS) [3]. PANSS specifically assesses both positive and negative symptoms of schizophrenia as well as general psychopathology. To unravel the structure of the PANSS items, a considerable number of factor ana lyses have been performed and most published studies favour a fivefactor solution: negative, positive, disorga nised (or cognitive), excited and depression/anxiety factors [4,5].

© 2011 Montoya et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.