Figure 1
![Figure 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1472-6947-13-72/MediaObjects/12911_2013_Article_692_Fig1_HTML.jpg)
Proposed algorithm system for the evaluation of the Karnofsky performance status. The initial questions are answered with yes or no answers to discriminate between three statuses: A, B and C (see Table 1). The following questions further distinguish 11 derivative KPS values (100–0%). The items in round brackets () in the follow-up questions lend further suggestive clarification (Schag et al., 1984). The symptom characterization is based on the works of Karnofsky and Burchenal, 1949, and Abernethy et al., 2005 (Table 1).