  In the context of cancer treatment and surgery, quality of life assessment is
a crucial part of determining treatment success and viability. In order to
assess it, patients completed questionnaires which employ words to capture
aspects of patients well-being are the norm. As the results of these
questionnaires are often used to assess patient progress and to determine
future treatment options, it is important to establish that the words used are
interpreted in the same way by both patients and medical professionals. In this
paper, we capture and model patients perceptions and associated uncertainty
about the words used to describe the level of their physical function used in
the highly common (in Sarcoma Services) Toronto Extremity Salvage Score (TESS)
questionnaire. The paper provides detail about the interval-valued data capture
as well as the subsequent modelling of the data using fuzzy sets. Based on an
initial sample of participants, we use Jaccard similarity on the resulting
words models to show that there may be considerable differences in the
interpretation of commonly used questionnaire terms, thus presenting a very
real risk of miscommunication between patients and medical professionals as
well as within the group of medical professionals.
