Page 216 - Encyclopedia of Nursing Research

FATIGuE n 183

In the research and clinical literature, and fatigue experienced at the time of mea-
fatigue related to childbearing and fatigue surement. More recent concern about the
related to cancer have received the most debilitating and distressing health effects F
attention. Even these areas, however, remain of fatigue in clinical populations has led to
largely understudied and poorly understood. the development of other measures targeting
Although fatigue has been studied in numer- fatigue in ill persons.
ous chronic illnesses, such as AIdS, multiple There are now a plethora of generic mea-
sclerosis, and rheumatoid arthritis, cancer- sures of fatigue, as well as a growing list
related fatigue is somewhat unique in that it of measures of fatigue in specific illnesses
is often fatigue associated with the treatment (e.g., cancer, AIdS). However, because there
for cancer (both radiation and chemotherapy) is no known biochemical test or marker for
that is most troublesome in terms of distress fatigue, and because fatigue is first and fore-
to the individual. In fact, fatigue associated most a subjective symptom, these measures
with cancer treatment has been cited as a of fatigue generally rely on self-reports.
major reason for prematurely discontinuing A major problem with so many differ-
treatment. ent measures of fatigue is that each taps into
Fatigue has also been consistently asso- a somewhat different aspect of fatigue and,
ciated with fever and infectious processes, consequently, it is not clear whether they are
and one of the more puzzling manifestations all measuring the same thing. Some focus on
of fatigue is what is currently called chronic the emotional and cognitive expression of
fatigue syndrome (CFS). CFS is a diagno- fatigue; others include the physical expres-
sis used for cases of severe and persistent sion of fatigue. Some attempt to quantify
fatigue for which no specific cause has been the amount of fatigue; others include atten-
identified. under varying names (e.g., neur- tion to how fatigue interferes with activities
asthenia, myalgic encephalomyelitis, postin- of daily living. When different measures of
fectious or postviral syndrome, and chronic fatigue are used in different studies, it is dif-
fatigue immune disorder syndrome), a syn- ficult to know if discrepant findings are due
drome of unexplained, chronic, persistent to real substantive differences in fatigue, or
fatigue has been documented in the litera- simply to the differences in the measures.
ture since the late nineteenth century. This dilemma, in part, is why the National
difficulty in studying, understand- Institutes of Health roadmap for research
ing, and consequently, treating fatigue is initiative, aimed at patient-reported out-
largely due to its ubiquitous nature and comes, is concerned with identifying and
the unknown, but likely multiple, causes of standardizing self-report measures, includ-
fatigue. untangling the relationship between ing fatigue. Identifying a set of standardized
fatigue and depression, in particular, fur- measures of fatigue with strong psychomet-
ther confounds investigations of fatigue. ric properties that clearly address the differ-
Although fatigue is an identified symptom ent aspects of fatigue and its expression will
of depression, long-standing chronic fatigue, go far in aiding future research on this elu-
unrelated to an existing affective disorder, sive symptom.
actually may precipitate depression. There may well be many causes of
A lack of consistent, valid, and reliable fatigue and each may ultimately be traced
measures of fatigue also contribute to prob- to a specific disruption in the HPA axis, in
lems in studying and understanding fatigue. the immune system, or in both. If so, then
Early work focused on fatigue in the work- continued investigations into CFS, in partic-
place and was conducted by industrial psy- ular, may lead to a better understanding of
chologists, hygienists, and the military. These fatigue in other, more clearly diagnosed clin-
measures focused on healthy individuals ical problems. until such work is done that