In this panel, one can narrow down the subset of selected patients based on criteria that characterize the patient as a whole, such as HPV status or whether they are smokers. To do so, put the toggle buttons in one of the following three states:

• Only patients are selected where the respective characterisitc is *positive*. E.g. in the case of "smoking status" this would select all smokers.
• This selection means that no filtering will be performed regarding the corresponding patient characteristic.
• Selecting this will only include patients in the subset that do not have the respective characteristic or it is negative (e.g. not-smoking or HPV negative).

Note: Just below the buttons there are three numbers that give a preview of how many of the currently selected patients can be categorized according to the respective characteristic. Here, the middle number indicates for how many patients the characteristic is unknown.

Note: All filters in the Patient characteristics panel are combined via AND operations. This means, if one selects + for HPV status and - for neck dissection, the selection includes only patients who are HPV positive AND did not receive neck dissction.

Warning: Dont forget to hit compute after you have changed your selection criteria.