TY - JOUR

T1 - Rasch analysis of the PANSS negative subscale and exploration of negative symptom trajectories in first-episode schizophrenia – data from the OPTiMiSE trial

AU - Baandrup, Lone

AU - Allerup, Peter

AU - Nielsen, Mette

AU - Bak, Nikolaj

AU - Düring, Signe W.

AU - Leucht, Stefan

AU - Galderisi, Silvana

AU - Mucci, Armida

AU - Bucci, Paola

AU - Arango, Celso

AU - Díaz-Caneja, Covadonga M.

AU - Dazzan, Paola

AU - McGuire, Philip

AU - Demjaha, Arsime

AU - Ebdrup, Bjørn H.

AU - Kahn, René S.

AU - Glenthøj, Birte Y.

PY - 2020/7

Y1 - 2020/7

N2 - The observed heterogeneity in negative symptom treatment response may be partly attributable to inadequate measurement tools or limitations in methods of analysis. Previous Item Response Theory models of the Positive and Negative Syndrome Scale (PANSS) have only examined samples of chronic patients and with mixed results. We examined the scalability of the negative subscale embedded in the PANSS and subsequently explored negative symptom trajectories across four weeks of amisulpride treatment. Data were derived from the OPTiMiSE trial comprising 446 patients with first-episode schizophrenia or schizophreniform disorder. Using the Rasch Model to examine psychometric properties of the PANSS negative subscale, we found that the composite score across items was not an adequate measure of negative symptom severity. Consequently, we chose an exploratory statistical approach involving Principal Component Analysis which yielded one significant component clustering into two significant symptom trajectories: 1) Subtle but constant decrease in negative symptom severity (N = 323; 72%), and 2) symptom instability across visits (N = 19; 4%). Explorative analytic methods as presented here may pave the way for more efficient and sensitive methods of analyzing negative symptom response in research and in clinical practice.

AB - The observed heterogeneity in negative symptom treatment response may be partly attributable to inadequate measurement tools or limitations in methods of analysis. Previous Item Response Theory models of the Positive and Negative Syndrome Scale (PANSS) have only examined samples of chronic patients and with mixed results. We examined the scalability of the negative subscale embedded in the PANSS and subsequently explored negative symptom trajectories across four weeks of amisulpride treatment. Data were derived from the OPTiMiSE trial comprising 446 patients with first-episode schizophrenia or schizophreniform disorder. Using the Rasch Model to examine psychometric properties of the PANSS negative subscale, we found that the composite score across items was not an adequate measure of negative symptom severity. Consequently, we chose an exploratory statistical approach involving Principal Component Analysis which yielded one significant component clustering into two significant symptom trajectories: 1) Subtle but constant decrease in negative symptom severity (N = 323; 72%), and 2) symptom instability across visits (N = 19; 4%). Explorative analytic methods as presented here may pave the way for more efficient and sensitive methods of analyzing negative symptom response in research and in clinical practice.

KW - Composite score

KW - Item response theory

KW - Rating scale

KW - Symptom relief

KW - Treatment response

U2 - 10.1016/j.psychres.2020.112970

DO - 10.1016/j.psychres.2020.112970

M3 - Journal article

C2 - 32438207

AN - SCOPUS:85084521245

VL - 289

JO - Psychiatry Research

JF - Psychiatry Research

SN - 0165-1781

M1 - 112970

ER -