Assessing the severity of functional impairment of psychiatric disorders: equipercentile linking the mini-ICF-APP and CGI

Abstract

Abstract Background The assessment of functioning and impairment due to psychiatric illness has been acknowledged to be crucial for research and practice. This led to the development of the mini-ICF-APP, which provides a reliable and time-efficient measure of functioning and impairment. Although its use is increasing, it remains unclear how it reflects severity and how change might be interpreted from a clinical perspective. Methods In a clinical sample of 3067 individuals hospitalized for mental health treatment, we used an equipercentile approach to link the mini-ICF-APP with the Clinical Global Impression scale (CGI) at admission and discharge. We linked the mini-ICF-APP sum score to the CGI-S scale and the mini-ICF-APP proportional change between admission and discharge to the CGI-I scale. Results The mini-ICF-APP and CGI scales showed a Spearman correlation of 0.50 (p .000); “no-change” in the CGI-I corresponded to an increase or decrease of 2%; “minimally-improved” to a mini-ICF-APP reduction of 3–30%; “much-improved” to a reduction of 31–63%; “very-much-improved” to a reduction of ≥64% “minimally-worse” to an increase of 3–34% “much-worse” to an increase of 35–67%; and finally “very-much-worse” with an increase of ≥68%. Conclusions Our findings improve understanding of the clinical meaning of the mini-ICF-APP sum score and percentage change in patients hospitalized for treatment.

Keywords

• Psychiatric disorders
• Functionality
• Severity
• Mini-ICF-APP
• CGI
• Equipercentile