Modified Test for Functional Capacity in Schizophrenia Found Valid

Researchers have developed a modified Beijing Performance-based Functional Ecological Test (BJ-PERFECT), which was found to be psychometrically valid in assessing functional capacity in patients with schizophrenia, according to a recent article in Psychiatry Research.

Researchers focused on further revising and evaluating the validity of the BJ-PERFECT as a performance-based functioning instrument for use in China. A total of 105 individuals with schizophrenia and 45 individuals as healthy controls participated in the study.

The revised version of the BJ-PERFECT included 19 items belonging to 1 of 3 subdomains (transportation, financial management, or work ability) and assessed functional capacity by requiring patients to complete performance-based role-play tasks in the 3 functional subdomains. The modified version requires the same amount of time as the original, but certain tasks have been simplified, requiring fewer props and making the use of the measurement more efficient and convenient. Patients with schizophrenia scored significantly lower than healthy individuals on the modified BJ-PERFECT assessment (P <.05, Cohen’s d=0.41), supporting the overall validity of the modified test.

Investigators used 2 other assessments (University of California, San Diego, Performance-based Skills Assessment-Brief and Global Assessment of Functioning) to validate the criterion of the BJ-PERFECT. There was a moderate correlation of the total scores of the BJ-PERFECT with the University of California, San Diego, Performance-based Skills Assessment-Brief, but a low correlation of the total scores of the BJ-PERFECT with the results of the Global Assessment of Functioning. 

Limitations of the current study include a lack of demographic information that could inform functional capacity. However, basic demographic information was collected, and more detailed information collection may be time-consuming and hinder the recruitment of participants. Furthermore, the demographics of the 2 groups differed, requiring covariance analyses in their comparisons. Finally, the small sample size only allowed for an exploratory factor analysis to be conducted. 

The researchers conclude that “the modified BJ-PERFECT instrument has been found to have good construct validity based on the retainment and optimization of satisfactory psychometric properties of the original version.” The authors suggest that in future research “a rigorous and comprehensive assessment battery [such as neuropsychological tests] should be employed. The results from such research would provide a clearer picture of the role of functional capacity in individuals with schizophrenia, particularly clarifying the inconsistent relationships between functional capacity and cognitive function.”

Reference

Zhou Q, Chan RCK, Yu X, Zheng M, Shum DHK, Shi C. Modification and validation of a performance-based functional capacity instrument for individuals with schizophrenia [published online October 2, 2019]. Psychiatry Res. doi: 10.1016/j.psychres.2019.112572