Validity and reliability of the Cognitive Complaints in Bipolar Disorder Rating Assessment (COBRA) in Japanese patients with bipolar disorder

Abstract

In Japan, there are currently no reliable rating scales for the evaluation of subjective cognitive impairment in patients with bipolar disorder. We studied the relationship between the Japanese version of the Cognitive Complaints in Bipolar Disorder Rating Assessment (COBRA) and objective cognitive assessments in patients with bipolar disorder. We further assessed the reliability and validity of the COBRA. Forty-one patients, aged 16-64, in a remission period of bipolar disorder were recruited from Hokkaido University Hospital in Sapporo, Japan. The COBRA (Japanese version) and Frankfurt Complaint Questionnaire (FCQ), the gold standard in subjective cognitive assessment, were administered. A battery of neuropsychological tests was employed to measure objective cognitive impairment. Correlations among the COBRA, FCQ, and neuropsychological tests were determined using Spearman's correlation coefficient. The Japanese version of the COBRA had high internal consistency, good retest reliability, and concurrent validity-as indicated by a strong correlation with the FCQ. A significant correlation was also observed between the COBRA and objective cognitive measurements of processing speed. These findings are the first to demonstrate that the Japanese version of the COBRA may be clinically useful as a subjective cognitive impairment rating scale in Japanese patients with bipolar disorder.

Assessing and addressing cognitive impairment in bipolar disorder: the International Society for Bipolar Disorders Targeting Cognition Task Force recommendations for clinicians

“…Two particularly feasible, easy‐to‐administer tools are the SCIP and the Cognitive Complaints in Bipolar Disorder Rating Assessment (COBRA). Both tools are short and feasible and have been shown in several studies to have high internal consistency, retest reliability and concurrent validity …”

“…The COBRA is a subjective cognitive impairment rating scale for patients with BD that consists of 16 questions about cognitive difficulties in daily life scenarios (eg, “Do you find it hard to concentrate when reading a book or a newspaper?”, “Do you have difficulties to find objects of daily use (keys, glasses, wristwatch…)?”, “Do you have the feeling that you do not finish what you begin?”). Despite general poor correlation between subjective and objective measures of cognition, the COBRA has shown some correlation with objective memory and executive function . However, when used alone, the sensitivity and specificity of the COBRA for objective cognitive impairment are suboptimal (ie, < 70%) and the instrument should therefore ideally be used in combination with an objective cognition measure such as the SCIP.…”

Associations between cognitive impairment and quality of life in euthymic bipolar patients

“…Relatively few studies have examined the relationship between cognitive impairment evaluated with the COBRA and QoL measurements that include both SF-36 and SDS. Bipolar and mood disorders have been studied predominantly in Western countries (North America and Europe); therefore, a Japanese version was developed, validated, and applied in bipolar patients (Toyoshima et al, 2017). The current study further elucidated the relationship between cognitive impairment, as assessed with the COBRA, and QoL in euthymic patients with bipolar disorder in a Japanese sample.…”

“…The original Spanish version of the COBRA was developed by the Bipolar Disorder Program at the Hospital Clinic of Barcelona to assess cognitive complaints (Rosa et al, 2013). Successively, it was translated into Japanese and a back-translation was approved by the original authors (Toyoshima et al, 2017) to ensure that the translated version remained unaltered. The International Society for Bipolar Disorders Targeting Cognition Task Force recommends the COBRA for screening, in addition to an objective cognitive measure in a clinical context (Miskowiak et al, 2018).…”

Validity and reliability of the Cognitive Complaints in Bipolar Disorder Rating Assessment (COBRA) in Brazilian bipolar patients

“…Our finding is consistent with previous validation studies with BD in other countries. 11,12,17,19 The Portuguese version of The present study has a number of limitations. First, this was a cross-sectional study, conducted in a tertiary hospital, where participants tend to present more severe symptoms, which may limit the generalization of the findings.…”