WPS-RA (item 4)$ | Item 4 from the Rheumatoid Arthritis-Specific Work Productivity Survey | Interference with work productivity | Last month | Arthritis | None | 0–10 (no interference to complete interference) |
WPAI (item 5)$ | Item 5 from the Work Productivity and Activity Impairment Questionnaire (specific health problem version) | Work productivity | Last 7 days | Can be adapted to any health condition (e.g., RA) | None | 0–10 (health problem had no effect on my work to completely prevented me from working) |
QQ method$ | Multiplication of 2 items (E1 and E2) from the Productivity and Disease Questionnaire (ProDISQ) | How much work performed and quality of the work | Last workday | None (not applicable) | Compared to “a normal work-day” | Quantity item: 0–10 (practically nothing to normal quantity); Quality item: 0–10 (very poor quality to normal quality) |
HPQ (item A12)$ | Item A12 from the Health and Work Performance Questionnaire | Work performance | 2 versions available: last 7 or 28 days | None | Performance of other workers (using HPQ item A10)* | 0–10 (worse performance to top performance)* |
WAI (item 1) | Item 1 from the Work Ability Index | Work ability | Current | None | In relation to lifetime best | 0–10 (0 = completely unable to work; assume work ability at its best has a value of 10) |