Box 1.

EQ-VAS coding procedures used in the NHS PROMs programme

1. When completed correctly, the question will be coded as the value where the line crosses the VAS

2. If a line has been drawn from the box but does not actually meet the VAS, then the verifier will code by scoring the end of the line in relation to the scale

3. Where a patient has circled/drawn a mark on the scale itself, the responses will be coded at the value of the central point/mark

4. If a patient has drawn a line from the bottom of the scale to a point further up the page, the question will be coded as the highest point relative to the VAS

5. Where a patient has drawn a line indicating a range of health status, e.g., from 20 to 55, our verifiers will code as the lowest point

6. Where there is doubt due to multiple lines or marks, the question will be left blank (Coded as 999). Source: [32]