306 Pain Management
Several assessment instruments are described below (for
comprehensive reviews see Turk and Melzack, 1992, 2001).
Self-Report Measurement of Pain
Often patients are asked to quantify their pain by providing a
single, general rating of pain: •Is your usual level of pain
•mild,• •moderate,• or •severe?•Ž or •Rate your typical pain
on a scale from 0 to 10 where 0 equals no pain and 10 is the
worst pain you can imagine.Ž More valid information may be
obtained by asking about currentlevel of pain or pain over
the past week and by having patients maintain regular diaries
of pain intensity with ratings recorded several times each day
(for example, at meals and bedtime) for several days or
weeks. There are a number of simple methods that can be
used to evaluate current pain intensity„numerical scale, de-
scriptive ratings scales, visual analog scales, and box scales.
One of the most frequently used pain assessment instru-
ments is the McGill Pain Questionnaire (MPQ) (Melzack,
1975). This instrument consists of several parts including a
descriptive scale (Present Pain Intensity) with numbers
assigned to each of “ve adjectives (namely, 1 mild, 2
discomforting, 3 distressing, 4 horrible, and 5
excruciating). A second part includes the front and back of a
drawing of a human “gure on which patients indicate the
location of their pain. Finally, a pain-rating index is derived
based on patients• selection of adjectives listed in 20 separate
categories re”ecting sensory, affective, and cognitive compo-
nents of pain. The MPQ provides a great deal of information;
however, it takes much longer to complete than simple rat-
ings of pain severity. The MPQ may be inappropriate for use
when frequent ratings of pain are required, for example,
hourly following surgery. A short form of the MPQ scale con-
sisting of 15 adjectival descriptors representing the sensory
and affective dimensions of the pain experience each of which
is rated on a 4-point scale (0 none, 1 mild, 2 moderate,
and 3 severe) may be more ef“cient (Melzack, 1987).
Assessment of Functional Activities
Physical and laboratory diagnostic measures are useful pri-
marily to the degree that they correlated with symptoms and
functional ability. However, the traditional measures of func-
tion performed as part of the physical examination are not
direct measures of symptoms or function, but are only ap-
proximations that may be in”uenced by patient motivation
and desire to convey the extend of their pain, distress, and
suffering to the physician. Commonly used physical exami-
nation maneuvers such as muscular strength and ranges of
motion are only weakly correlated with actual functional
activities. Similarly, radiographic indicators have been
shown to have little predictive value for the long-term func-
tional capacity of a patient.
Poor reliability and questionable validity of physical
examination measures has led to the development of self-
report functional status measures that seek to quantify symp-
toms, function, and behavior directly, rather than inferring
them. Self-report measures have been developed to assess
peoples• reports of their abilities to engage in a range of func-
tional activities such as the ability to walk up stairs, to sit for
speci“c periods of time, the ability to lift speci“c weights,
performance of activities of daily living, as well as the sever-
ity of the pain experienced during the performance of these
activities have been developed.
Some of the commonly used functional assessment scales
include the Roland-Morris Disability Scale (1983), the Sick-
ness Impact Pro“le (Ber gner, Bobbitt, Carter, & Gilson,
1981) and the Oswestry Disability Scale (Fairbank, Couper,
Davies, & O•Brien, 1980). These scales ask patients to report
on their ability to engage in speci“c activities such as sitting,
standing, and walking. The items tend to be quite speci“c.
For example, one item from the Oswestry Disability Scale
asks patients to indicate whether their pain prevents them
from •sitting at all, from sitting more than 10 minutes, sitting
more than^12 hour, or sitting more than hour, or whether they
are able to sit for as long as they like.Ž
Despite the obvious limitations of self-report instruments,
they have several advantages. They are economical, ef“cient,
enable the assessment of a wide range of behaviors that are
relevant to the patient, some of which may be private (sexual
relations) or unobservable (thoughts, emotional arousal).
Although the validity of such self-reports of the ability to per-
form functional activities is often questioned, studies have
revealed fairly high correspondence among self-reports, dis-
ease characteristics, physicians• or physical therapists• ratings
of functional abilities, and objective functional performance.
A more extensive instrument, the Sickness Impact Pro“le
(SIP; Bergner et al., 1981) examines a range of physical
activities and psychological features. The SIP covers the
areas of ambulation, mobility, body care, social interaction,
communication, alertness, sleep and rest, eating, work, home
management, recreation and pastime activities, and emo-
tional behavior. In addition to a total score, the SIP provides
subscores on the impact on physical activities and the psy-
chological impact. There are several limitations to the SIP. It
is lengthy, including over 150 questions, and it is designed
to be administered in an interview format. This can be con-
trasted with measures such as the Oswestry Disability
Questionnaire (Fairbank et al., 1980) that only includes
10 questions and the Roland-Morris Scale (1983) that