Validation of the Korean Version of the Clinical Assessment Interview for Negative Symptoms

Validity and Reliability Study of Turkish Version of Clinical Assessment Interview for Negative Symptoms (CAINS)

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 two-dimensional 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.

Validation of accelerometry as a digital phenotyping measure of negative symptoms in schizophrenia

Negative symptoms are commonly assessed via clinical rating scales; however, these measures have several inherent limitations that impact validity and utility for their use in clinical trials. Objective digital phenotyping measures that overcome some of these limitations are now available. The current study evaluated the validity of accelerometry (ACL), a passive digital phenotyping method that involves collecting data on the presence, vigor, and variability of movement. Outpatients with schizophrenia (SZ: n = 50) and demographically matched healthy controls (CN: n = 70) had ACL continuously recorded from a smartphone and smartband for 6 days. Active digital phenotyping assessments, including surveys related to activity context, were also collected via 8 daily surveys throughout the 6 day period. SZ participants had lower scores on phone ACL variables reflecting vigor and variability of movement compared to CN. ACL variables demonstrated convergent validity as indicated by significant correlations with active digital phenotyping self-reports of time spent in goal-directed activities and clinical ratings of negative symptoms. The discriminant validity of ACL was demonstrated by low correlations with clinical rating scale measures of positive, disorganized, and total symptoms. Collectively, findings suggest that ACL is a valid objective measure of negative symptoms that may complement traditional approaches to assessing the construct using clinical rating scales.

A blinded validation of the Swedish version of the Clinical Assessment Interview for Negative Symptoms (CAINS)

PURPOSE

The Clinical Assessment Interview for Negative Symptoms (CAINS) was developed in order to advance the assessment of negative symptoms. The aim of this study was to validate the Swedish version of the CAINS.

MATERIALS AND METHODS

Thirty-four out-patients with a schizophrenia spectrum disorder were recruited. All patients were videotaped while interviewed with the CAINS and the Brief Psychiatric Rating Scale (BPRS). Another rater watched the video recordings in the reverse order, enabling a blinded design. The patients also filled in self-reported measures of depression, quality of life, and social and vocational functioning. We calculated inter-rater agreement and internal consistency for the CAINS. We also calculated validity measures by correlating the subscales Motivation and Pleasure (CAINS-MAP) and Expression (CAINS-EXP) to subscales of the BPRS.

RESULTS

The blinded inter-rater agreement for the CAINS total score was high (ICC = 0.92) but slightly lower for the expression subscale (ICC = 0.76). Cronbach's alpha was 0.84 for the total score. Convergent validity with the negative symptoms subscale of BPRS was different for the blinded and the unblinded data, with a CAINS-MAP correlation of 0.10 (p = 0.580) and a CAINS-EXP correlation of 0.48 (p = 0.004) in the blinded data. The unblinded data had a CAINS-MAP correlation of 0.38 (p = 0.026) and a CAINS-EXP correlation of 0.87 (p < 0.001). Self-rated measures of anhedonia correlated to CAINS-MAP with a coefficient of 0.68 (p < 0.001), while the CAINS-EXP only had a correlation of 0.16 (p = 0.366) to these measures.

CONCLUSION

The Swedish version of the CAINS displays adequate psychometric properties in line with earlier validation studies.

EPA guidance on assessment of negative symptoms in schizophrenia

Background

During the last decades, a renewed interest for negative symptoms (NS) was brought about by the increased awareness that they interfere severely with real-life functioning, particularly when they are primary and persistent.

Methods

In this guidance paper, we provide a systematic review of the evidence and elaborate several recommendations for the conceptualization and assessment of NS in clinical trials and practice.

Results

Expert consensus and systematic reviews have provided guidance for the optimal assessment of primary and persistent negative symptoms; second-generation rating scales, which provide a better assessment of the experiential domains, are available; however, NS are still poorly assessed both in research and clinical settings.

This European Psychiatric Association (EPA) guidance recommends the use of persistent negative symptoms (PNS) construct in the context of clinical trials and highlights the need for further efforts to make the definition of PNS consistent across studies in order to exclude as much as possible secondary negative symptoms. We also encourage clinicians to use second-generation scales, at least to complement first-generation ones.

The EPA guidance further recommends the evidence-based exclusion of several items included in first-generation scales from any NS summary or factor score to improve NS measurement in research and clinical settings. Self-rated instruments are suggested to further complement observer-rated scales in NS assessment.

Several recommendations are provided for the identification of secondary negative symptoms in clinical settings.

Conclusions

The dissemination of this guidance paper may promote the development of national guidelines on negative symptom assessment and ultimately improve the care of people with schizophrenia.