Introduction: This study aims to translate and investigate the validity
and reliability of the Turkish version of the Clinical Assessment Interview
for Negative Symptoms (CAINS), which has additional features
compared to other scales in assessing negative symptoms in patients
with schizophrenia.
Methods: The Turkish version of CAINS was constructed upon an initial
translation to Turkish, and an English back translation of the scale was later
conducted. The patients diagnosed with schizophrenia (n=79) according to
Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-
5) diagnostic criteria were administered the Turkish version of CAINS,
the Positive and Negative Syndrome Scale (PANSS), the Scale for the
Assessment of Negative Symptoms (SANS), the Scale for the Assessment of
Positive Symptoms (SAPS), the Calgary Depression Scale for Schizophrenia
(CDSS), the Clinical Global Impression Scale (CGI), the Global Assessment
of Functioning Scale (GAF) and the Simpson-Angus Extrapyramidal Side
Effects Assessment Scale (SAS). In addition, two interviewers assessed the
video recordings of 11 patients for reliability analysis.
Results: Inter-rater reliability was found to be high (intraclass correlation
coefficient (ICC): 0.831). Exploratory and confirmatory factor analyses
indicated that Cronbach’s alpha was 0.956 for the full scale, and the twodimensional
structure explained the scale better. In convergent validity
analyses, CAINS overall scores correlated significantly with the SANS
total score (r=0,932) and PANSS negative score (r=0,902). In discriminant
validity analyses, CAINS overall scores markedly correlated with the
SAPS total (r=0,615), PANSS positive (r=0,497) and PANSS general
psychopathology (r=0,737) scores. Additionally, when CGI and GAF
scores were considered covariant, the significant correlation of CAINS
total scores with the SANS total and PANSS negative scores continued;
however, the correlation with PANSS positive score was prominently
reduced, and the correlation with PANSS general psychopathology
disappeared.
Conclusion: The Turkish version of the CAINS appears to be a valid and
reliable tool with strong psychometric properties in a sample consisting
of patients with schizophrenia.
Keywords: Negative symptoms, rating scale, reliability, validation