VRS have been used since the 1940s [5] and consist of
lists of descriptors that represent varying degrees of pain
intensity. The least intense descriptor is usually given
a score of 0, the next 1 and so on. The patient picks the most
appropriate descriptor from the list. For analysis purposes,
the patient’s intensity score is the number associated with
the chosen descriptor. The four-point VRS is most widely
used clinically and the five-point scale is commonly used for
treatment outcome studies. The main advantage of the VRS
is that they are relatively quick and simple to use. However,
there are disadvantages; they are language dependent, the
intervals between the categories may not be equal and
having a finite number of discrete terms may force patients
to pigeon hole their pain into a category that does not
describe their pain satisfactorily. Using scales with larger
numbers of descriptors increases the sensitivity of the tool
[6]. A further VRS has been developed for pain relief often
using a five-word scale.