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Logo of bmcpsycBioMed Centralsearchsubmit a manuscriptregisterthis articleBMC Psychiatry
BMC Psychiatry. 2011; 11: 113.
Published online Jul 18, 2011. doi:  10.1186/1471-244X-11-113
PMCID: PMC3146924
Is the PANSS used correctly? a systematic review
Michael Obermeier,corresponding author1 Rebecca Schennach-Wolff,1 Sebastian Meyer,1 Hans-Jürgen Möller,1 Michael Riedel,1,2 Daniela Krause,1 and Florian Seemüller1
1Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Nussbaumstrasse 7, 80336 Munich, Germany
2Vinzenz von Paul Hospital, Psychiatry, Schwenninger Str. 55, 78628 Rottweil, Germany
corresponding authorCorresponding author.
Michael Obermeier: Michael.Obermeier/at/; Rebecca Schennach-Wolff: Rebecca.Schennach-Wolff/at/; Sebastian Meyer: Sebastian.Meyer/at/; Hans-Jürgen Möller: Hans-Juergen.Moeller/at/; Michael Riedel: M.Riedel/at/; Daniela Krause: Daniela.Krause/at/; Florian Seemüller: Florian.Seemueller/at/
Received March 18, 2011; Accepted July 18, 2011.
The PANSS (Positive and Negative Syndrome Scale) is one of the most important rating instruments for patients with schizophrenia. Nevertheless, there is a long and ongoing debate in the psychiatric community regarding its mathematical properties.
All 30 items range from 1 to 7 leading to a minimum total score of 30, implying that the PANSS is an interval scale. For such interval scales straightforward calculation of relative changes is not appropriate. To calculate outcome criteria based on a percent change as, e.g., the widely accepted response criterion, the scale has to be transformed into a ratio scale beforehand. Recent publications have already pointed out the pitfall that ignoring the scale level (interval vs. ratio scale) leads to a set of mathematical problems, potentially resulting in erroneous results concerning the efficacy of the treatment.
A Pubmed search based on the PRISMA statement of the highest-ranked psychiatric journals (search terms "PANSS" and "response") was carried out. All articles containing percent changes were included and methods of percent change calculation were analysed.
This systematic literature research shows that the majority of authors (62%) actually appear to use incorrect calculations. In most instances the method of calculation was not described in the manuscript.
These alarming results underline the need for standardized procedures for PANSS calculations.
Keywords: PANSS, scale level, literature search
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