A visual analog scale (VAS) is a valuable tool in clinical research for measuring subjective experiences such as pain levels that are difficult to quantify directly. In EasyMedStat, setting up a VAS involves creating a numeric variable that can be adjusted to function as a scale. This guide provides straightforward instructions on incorporating a VAS in your ePRO questionnaires.

1. Navigate to Variable Creation: Log into EasyMedStat, go to the `Variables` section, and select `New variable` to begin creating a new variable.
2. Select Numeric Variable Type: Choose 'Numeric Variable' as the type for your new question. This option is suited for questions where the response is a number.
3. Set Minimum and Maximum Values: Specify the limits of your VAS. For example, for a pain scale, set it from 0 (no pain) to 10 (worst imaginable pain). This range helps define the endpoints of the scale for respondents.
4. Define a Minimum Interval: Establish a minimum interval between two values, such as 1, which allows respondents to select any whole number within the scale range, effectively creating steps on the VAS.

When this numeric variable is used in a questionnaire, it automatically displays as a horizontal visual analog scale, enabling respondents to easily indicate their level of pain or other subjective states.