Measuring functional impairment: Preliminary psychometric properties of the Columbia Impairment Scale‐Youth Version with youth accessing services at an outpatient substance use programme

Abstract

Aim Functional impairment is a key aspect of mental disorders, yet it is poorly defined and operationalized, particularly for youth. The Columbia Impairment Scale (CIS) has been indicated as a potentially useful measure to assess functional impairment. This study provides an initial psychometric evaluation of the CIS‐Youth (CIS‐Y) Version in a sample of youth accessing an outpatient substance use programme. Methods The CIS‐Y Version was administered to youth aged 15 to 24 years accessing an outpatient substance use programme in Ontario, Canada. Demographic data on age, sex, ethnicity and current occupational and/or educational status were also collected. Exploratory factor analysis (EFA) was used to identify what factor structure best fits our sample of youth. Results The sample included 134 youth, with a mean age of 19.3 (SD = 2.1; range = 15‐24). Over 34% of the sample had at least some item‐level missing data, overwhelming this was item‐level “not applicable” responses. The CIS‐Y exhibited good internal consistency (α = .84), and EFA revealed that a one‐factor structure was the best fit for the data. Conclusions Results suggest that continued use of the CIS‐Y with populations of youth, including emerging adults, is warranted. The scale has good internal consistency, loads onto one factor and discriminates between groups known to have lower and higher functioning. Further research is recommended that uses larger and more varying samples, as well as research that investigates optimal coding of non‐applicable responses.