title: Identifying clinically meaningful symptom response cut-off values on the SANS in predominant negative symptoms.
abstract: BACKGROUND
  The treatment and measurement of negative symptoms are currently at issue in schizophrenia, but the clinical meaning of symptom severity and change is unclear.
  
  
  OBJECTIVE
  To offer a clinically meaningful interpretation of severity and change scores on the Scale for the Assessment of Negative Symptoms (SANS).
  
  
  METHODS
  Patients were intention-to-treat participants (n=383) in two double-blind randomized placebo-controlled clinical trials that compared amisulpride with placebo for the treatment of predominant negative symptoms. Equipercentile linking was used to examine extrapolation from (a) CGI-S to SANS severity ratings, and (b) CGI-I to SANS percentage change (n=383). Linking was conducted at baseline, 8-14 days, 28-30 days, and 56-60 days of the trials.
  
  
  RESULTS
  Across visits, CGI-S ratings of 'not ill' linked to SANS scores of 0-13, and ranged to 'extreme' ratings that linked to SANS scores of 102-105. The relationship between the CGI-S and the SANS severity scores assumed a linear trend (1=0-13, 2=15-56, 3=37-61, 4=49-66, 5=63-75, 6=79-89, 7=102-105). Similarly the relationship between CGI-I ratings and SANS percentage change followed a linear trend. For instance, CGI-I ratings of 'very much improved' were linked to SANS percent changes of -90 to -67, 'much improved' to -50 to -42, and 'minimally improved' to -21 to -13.
  
  
  CONCLUSIONS
  The current results uniquely contribute to the debate surrounding negative symptoms by providing clinical meaning to SANS severity and change scores and so offer direction regarding clinically meaningful response cut-off scores to guide treatment targets of predominant negative symptoms.
authors: University of Haifa, Department of Community Mental Health, Israel. stezlev@gmail.com
authors: Stephen Z
authors: SZ
authors: Levine
authors: Stefan
authors: S
authors: Leucht
mesh_terms: D000077582:Amisulpride; D014150:Antipsychotic Agents / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D033182:Intention; D008297:Male; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000175:diagnosis* / Q000188:drug therapy; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D013469:Sulpiride / Q000031:analogs & derivatives / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D013469:Sulpiride; D000077582:Amisulpride