Clinical Assessment Interview for Negative Symptoms (CAINS): A Systematic Review of Measurement Properties

BACKGROUND AND HYPOTHESIS

Negative symptoms are very important for the overall loss of functioning observed in patients with schizophrenia. There is a need for valid tools to assess these symptoms.

STUDY DESIGN

We used the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) systematic review guideline to evaluate the quality of the clinical assessment interview for negative symptoms (CAINS) as a clinician-rated outcome measurement (ClinROM).

STUDY RESULTS

The search strategy resulted in the retrieval of 13 articles, 11 of which were included in this evaluation. In terms of risk of bias, most articles reported on measures of internal consistency and construct validity, which were overall of good quality. Structural validity, reliability, measurement error, and cross-cultural validity were reported with less than optimum quality. There was a risk of bias in ClinROM development. According to the updated criteria of good measurement properties, structural validity, internal consistency, and reliability showed good results. In contrast, hypothesis testing was somewhat poorer. Results for cross-cultural validity were indeterminate. According to the updated GRADE approach from the COSMIN group the scale received a moderate grade.

CONCLUSIONS

The COSMIN standard allows a judgment of the CAINS as an instrument with the potential to be recommended for use, but which requires further research to assess its quality, in particular in the domains of content validity, internal consistency, and cross-cultural validity.

The Brief negative Symptom Scale (BNSS): a systematic review of measurement properties

BACKGROUND

Negative symptoms of schizophrenia are linked with poor functioning and quality of life. Therefore, appropriate measurement tools to assess negative symptoms are needed. The NIMH-MATRICS Consensus defined five domains for negative symptoms, which The Brief Negative Symptom Scale (BNSS) covers.

METHODS

We used the COSMIN guidelines for systematic reviews to evaluate the quality of psychometric data of the BNSS scale as a Clinician-Rated Outcome Measure (ClinROM).

RESULTS

The search strategy resulted in the inclusion of 17 articles. When using the risk of bias checklist, there was a generally good quality in reporting of structural validity and hypothesis testing. Internal consistency, reliability and cross-cultural validity were of poorer quality. ClinROM development and content validity showed inadequate results. According to the updated criteria of good measurement properties, structural validity, internal consistency and interrater reliability showed good results, while hypothesis testing showed poorer results. Cross-cultural validity and test-retest reliability were indeterminate. The updated GRADE approach resulted in a moderate grade.

CONCLUSIONS

We can potentially recommend the use of the BNSS as a concise tool to rate negative symptoms. Due to weaknesses in certain domains further validations are warranted.

The European Portuguese Version of the Brief Negative Symptom Scale

Negative symptoms reflect a currently much-untreated loss of normal functioning and are frequently found in psychotic disorders. We present the first translation of the Brief Negative Symptom Scale (BNSS) to European Portuguese and evaluate its validity in a sample of Portuguese male patients with a psychotic spectrum disorder. The Portuguese BNSS showed excellent internal consistency, high convergent validity (i.e., strong correlation with the PANSS negative factor), and high discriminant validity (i.e., a lack of association with the PANSS positive factor). In sum, the present European Portuguese BNSS has shown to be reliable, thus extending this instrument's clinical availability worldwide.

Updated perspectives on the clinical significance of negative symptoms in patients with schizophrenia

INTRODUCTION

Negative symptoms in schizophrenia are associated with poor response to available treatments, poor quality of life, and functional outcome. Therefore, they represent a substantial burden for people with schizophrenia, their families, and health-care systems.

AREAS COVERED

In this manuscript, we will provide an update on the conceptualization, assessment, and treatment of this complex psychopathological dimension of schizophrenia.

EXPERT OPINION

Despite the progress in the conceptualization of negative symptoms and in the development of state-of-the-art assessment instruments made in the last decades, these symptoms are still poorly recognized, and not always assessed in line with current conceptualization. Every effort should be made to disseminate the current knowledge on negative symptoms, on their assessment instruments and available treatments whose efficacy is supported by research evidence. Longitudinal studies should be promoted to evaluate the natural course of negative symptoms, improve our ability to identify the different sources of secondary negative symptoms, provide effective interventions, and target primary and persistent negative symptoms with innovative treatment strategies. Further research is needed to identify pathophysiological mechanisms of primary negative symptoms and foster the development of new treatments.

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.

Defining negative symptoms remission in schizophrenia using the Brief Negative Symptom Scale

INTRODUCTION

This study aimed to propose criteria for negative symptoms remission (NSR) in schizophrenia using the Brief Negative Symptom Scale (BNSS).

MATERIAL AND METHODS

274 participants were assessed on the Positive and Negative Syndrome Scale (PANSS), BNSS and Social and Occupational Functioning Assessment Scale (SOFAS). Two criteria for NSR on the BNSS were proposed - NSR based on the BNSS domains scores (NSR_{BNSS_DOMAINS}) and NSR based on 5 key items of the BNSS (NSR_{BNSS_5ITEMS})_. A SOFAS score of 61 and above was considered as functional remission (FR). Logistic regressions were run to examine the association between FR and NSR. Receiver operating characteristic (ROC) curve analysis was performed for the NSR criteria on FR. Kappa agreement statistic was used to evaluate the agreement between the two NSR criteria.

RESULTS

Eighty-nine (32.5%) participants fulfilled NSR_{BNSS_DOMAINS} criterion whereas 70 (25.6%) participants fulfilled NSR_{BNSS_5ITEMS} criterion. The two NSR criteria had substantial agreement (Kappa statistic=0.797) with each other. Sixty-one (25.3%) participants were in FR. FR was significantly associated with NSR, irrespective of the criterion used. To predict FR, the Area Under the Curve for NSR_{BNSS_DOMAINS} and NSR_{BNSS_5ITEMS} were 0.761 (CI: 0.696-0.826, p<0.001) and 0.723 (CI: 0.656-0.790, p<0.001), respectively. Hence, both NSR criteria demonstrated a fair ability to discriminate between functional remitters and non-remitters.

CONCLUSIONS

Depending on the setting and needs, clinicians and researchers might employ either the full BNSS or an abbreviated 5-item BNSS scale to identify NSR in schizophrenia. More research is needed to further examine the validity of these criteria in schizophrenia.

Association of Negative Symptoms of Schizophrenia Assessed by the BNSS and SNS Scales With Neuropsychological Performance: A Gender Effect

Objective: The relationship between negative symptoms and neurocognitive performance in schizophrenia is well documented, but the mechanism of these connections remains unclear. The study aims to measure the relationship between the results on the new scales for the assessment of negative symptoms such as Brief Negative Symptom Scale (BNSS) and Self-evaluation of Negative Symptoms (SNS), and the results of some neurocognition tests. The second aim is to assess a possible gender effect on these associations. Methods: The study included 80 patients (40 men, 40 women) with schizophrenia, aged 19-63 (mean 38 years), during the improvement period (total PANSS score <80, unchanged pharmacological treatment in the last 3 weeks). They were assessed using the BNSS, SNS, Personal and Social Performance (PSP) scales, and the tests for neuropsychological performance such as the Trail Making Test (TMT-A, TMT-B), Stroop Color-Word Interference Test, Verbal fluency tests (VFT), Category fluency test (CFT), and Digit Symbol Substitution Test (DSST). Results: Male patients obtained higher scores than females on some PANSS and BNSS items. No gender differences were observed for the SNS scale. Female patients scored better in the PSP and CFT. In male patients, a significant positive correlation between the intensity of negative symptoms measured by the BNSS and the results of PSP with the Trail Making Test was observed. In female patients, we found a positive correlation between the results of BNSS and PSP with the Stroop Color-Word Interference Test. Conclusion: The obtained results confirm the relationship between negative symptoms and neurocognition in schizophrenia patients. However, in male and female patients such association was observed for different cognitive domains. Further research is needed to explain the nature of these differences.

Negative symptoms in schizophrenia, assessed by the brief negative symptom scale, self-evaluation of negative symptom scale, and social cognition: a gender effect

OBJECTIVE

Negative symptoms of schizophrenia can be related to social cognition. The aim was to measure a relationship between the results on the new scales for the assessment of negative symptoms such as the Brief Negative Symptom Scale (BNSS) and Self-evaluation of Negative Symptoms (SNS), and the measures of social cognition.

METHODS

The study included 80 patients (40 men, 40 women) with schizophrenia, aged 19-63 (mean 38 years), during the improvement period. They were assessed using the BNSS, SNS, Personal and Social Performance (PSP) scales, and the tests for social cognition such as the Facial Emotion Identification Test, Reading the Mind in Eyes Test, Strange Stories and Faux Pas Test.

RESULTS

Male patients obtained higher scores than females when assessed by the BNSS. No gender differences were observed for the SNS scale. Female patients scored better in the PSP and both parts of the Faux Pas test and obtained a significant correlation between the results of the SNS scale, BNSS, PSP, and the affective part of the Faux-Pas test what was not the case in males.

CONCLUSIONS

Gender differences were found in the assessment of negative symptoms by a clinical scale and the relationship between negative symptoms and social cognition.KEY POINTSFemale patients scored better in the BNSS, PSP and both parts of the Faux-Pas testGender differences were present in the assessment of negative symptoms by clinical (BNSS) but not the self-assessment (SNS) scale.Female patients obtained a significant correlation between the results of the SNS scale, BNSS, PSP, and the affective part of the Faux-Pas test what was not the case in male subjects.

Metabolic indices in schizophrenia: Association of negative symptoms with higher HDL cholesterol in female patients

OBJECTIVES

Negative symptoms of schizophrenia can be related to metabolic abnormalities. The study aimed to assess negative symptoms using the Positive and Negative Syndrome Scale (PANSS) and the Brief Negative Symptoms Scale (BNSS), and their relationship with body mass index (BMI) and lipid indices, in male and female schizophrenic patients.

METHODS

Fifty chronic schizophrenia patients (29 males, 21 females) were included. They have mild to moderate severity of the illness (total PANSS score <80), and received unchanged pharmacological treatment in the last three weeks. Psychopathology symptoms were assessed using the PANSS and BNSS. The measurements of BMI and serum lipids were done in all patients.

RESULTS

In female patients, a significant positive correlation between the intensity of negative symptoms measured by the PANSS and BNSS scales and the concentration of high-density lipoprotein (HDL) cholesterol, and a trend for negative correlation with BMI was observed. Such correlations were not found in male patients.

CONCLUSIONS

Assessing the negative symptoms of schizophrenia, and investigating the relationship of these symptoms with metabolic indices, we showed distinctive features in male and female schizophrenia patients. The positive correlation between negative symptoms and HDL cholesterol in female patients needs to be confirmed in further studies.

Defining negative symptoms remission in schizophrenia using the Brief Negative Symptom Scale

INTRODUCTION

This study aimed to propose criteria for negative symptoms remission (NSR) in schizophrenia using the Brief Negative Symptom Scale (BNSS).

MATERIAL AND METHODS

274 participants were assessed on the Positive and Negative Syndrome Scale (PANSS), BNSS and Social and Occupational Functioning Assessment Scale (SOFAS). Two criteria for NSR on the BNSS were proposed - NSR based on the BNSS domains scores (NSRBNSS_DOMAINS) and NSR based on 5 key items of the BNSS (NSRBNSS_5ITEMS). A SOFAS score of 61 and above was considered as functional remission (FR). Logistic regressions were run to examine the association between FR and NSR. Receiver operating characteristic (ROC) curve analysis was performed for the NSR criteria on FR. Kappa agreement statistic was used to evaluate the agreement between the two NSR criteria.

RESULTS

Eighty-nine (32.5%) participants fulfilled NSRBNSS_DOMAINS criterion whereas 70 (25.6%) participants fulfilled NSRBNSS_5ITEMS criterion. The two NSR criteria had substantial agreement (Kappa statistic=0.797) with each other. Sixty-one (25.3%) participants were in FR. FR was significantly associated with NSR, irrespective of the criterion used. To predict FR, the Area Under the Curve for NSRBNSS_DOMAINS and NSRBNSS_5ITEMS were 0.761 (CI: 0.696-0.826, p<0.001) and 0.723 (CI: 0.656-0.790, p<0.001), respectively. Hence, both NSR criteria demonstrated a fair ability to discriminate between functional remitters and non-remitters.

CONCLUSIONS

Depending on the setting and needs, clinicians and researchers might employ either the full BNSS or an abbreviated 5-item BNSS scale to identify NSR in schizophrenia. More research is needed to further examine the validity of these criteria in schizophrenia.

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.

The brief negative symptom scale in translation: A review of psychometric properties and beyond

Negative symptoms are a core feature of schizophrenia and associated with social and occupational impairment. To encourage treatment development and address the limitations of existing rating instruments in this area across culture, the Brief Negative Symptoms Scale (BNSS) was developed. The authors reviewed studies published since the BNSS was published in 2010 that examined the psychometric properties of the instrument in translation and compared for consistency, psychometric performance and related features. Eleven published cross-cultural validation studies demonstrated the translated versions of the BNSS have strong psychometric properties, similar to the original English version. The internal consistency ranged from 0.88 to 0.98 and the inter-rater reliability ranged from 0.81 to 0.98 for the total score. The BNSS exhibited good convergent validity with existing measures of similar constructs and function, and good discriminant validity relative to other constructs. Recent research also reported that the BNSS is sensitive to drug effects, with effect sizes comparable to established scales. The results of confirmatory factor analyses revealed that the 5-factor structure of negative symptoms in schizophrenia (blunted affect, anhedonia, avolition, asociality, and alogia) crosses cultures. This psychometric evidence suggests that the BNSS is a valid and reliable instrument for assessing pathological mechanism underlying the negative symptoms of schizophrenia across cultures and can be a useful instrument in global clinical trials.

Validation of the Dutch Version of the Brief Negative Symptom Scale

PURPOSE

The Brief Negative Symptom Scale (BNSS) was developed to measure negative symptoms of schizophrenia. However, the Dutch translation of this instrument, called the "Korte Schaal voor Negatieve Symptomen" (KSNS), has not yet been validated. This study investigates the validity and reliability of this Dutch version of the instrument.

PATIENTS AND METHODS

The Psychotic Symptom Rating Scale (PSYRATS), Calgary Depression Scale for Schizophrenia (CDSS), the Health of the Nation Scale (HoNOS) and the KSNS were used for routine outcome monitoring to measure symptoms in 28 patients with a psychotic disorder who were being treated on a long-stay ward.

RESULTS

The internal consistency of the KSNS is fair to good. The inter-rater reliability is excellent. The concurrent validity is moderate but acceptable. The correlations between the KSNS and scales for depression and positive symptoms were not significant, which indicate good divergent validity.

CONCLUSION

Despite the small sample size of the current study, we conclude that the BNSS, called the KSNS in Dutch, appears to be a reliable and valid tool for investigating negative symptoms in detail in patients with psychotic disorders.

Pilot Validation Study of the Japanese Translation of the Brief Negative Symptoms Scale (BNSS)

PURPOSE

The brief negative symptoms scale (BNSS) is a concise instrument used to assess negative symptoms of subjects with schizophrenia covering five domains of negative symptoms and is suitable for use in clinical, experimental, and epidemiological settings. The original and translated version of BNSS has thus far been shown to have adequate psychometric properties. This study aimed to examine internal consistency, inter-rater and test-retest reliability, discriminant and convergent validity, and factor structure of the Japanese version of BNSS.

PATIENTS AND METHODS

The assessment was performed by 11 raters using interview videos of nine subjects. Reliability was calculated with Cronbach's alpha for internal consistency and intra class correlation coefficient (ICC) for inter-rater reliability. Pearson's correlation coefficients were calculated to estimate the test-retest reliability. In addition to BNSS, Scale for assessment of negative symptoms (SANS) and scale for assessment of positive symptoms (SAPS) was obtained to assess the convergent and discriminant validity. Factor structure was assessed using principle factor analysis.

RESULTS

The Japanese BNSS showed excellent internal consistency (Cronbach's alpha=0.95), inter-rater reliability (intra class correlation coefficient=0.97), and test-retest reliability (r=0.94, p<0.001). The convergent validity shown by correlation with SANS total score (r=0.87, p<0.001) and discriminant validity shown by correlation with SAPS total score (r=0.17, p=-0.68) were also good. Principal factor analysis revealed a two-factor structure of BNSS, although the loading of each item differed from that in the literature.

CONCLUSION

Our pilot study demonstrated that Japanese BNSS had good psychometric properties which were achieved with relatively brief training. Further studies with more subjects and raters with various backgrounds recruited from multiple sites are warranted.