Weiss Functional Impairment Rating Scale (WFIRS)

The Weiss Functional Impairment Rating Scale (WFIRS) is a self-report measure for impairments that commonly occur in patients with ADHD and that are likely to represent the patients' targets of treatment (CADDRA, 2017). The WFIRS comprises 70 items that are divided into seven domains: Family (8 items), Work (11 items), School (11 items), Life Skills (12 items), Self-concept (5 items), Social (9 items), and Risk (14 items). Each item is scored on a four-point Likert scale scored from 0 to 3 (0 = never, not at all; 1 = sometimes, somewhat; 2 = often, much; 3 = very often, very much). An additional answering option is given with Not Applicable. A scale score per domain is calculated by summing up the responses to all items per domain (response values 0–3), and dividing this sum by the number of endorsed items (thereby not considering items that are answered with Not Applicable). Furthermore, any item score ≥ 2 was scored to indicate impaired functioning (CADDRA 2017). The WFIRS was reported to have high internal consistency with Cronbach’s alpha > 0.8 for each domain and the scale as a whole. For the purpose of the present study, only the Work subscale will be considered, including both individual item scores (scores ≥ 2) and the Work mean score. Table ​Table33 presents the eleven items comprising the Work subscale of the WFIRS.

WFIRS Work subscale

WFIRS Weiss Functional Impairment Rating Scale

Answers options include 0 (never), 1 (sometimes), 2 (often), 3 (very often), or ‘not applicable’