Joumal of Advanced Nursing, 1991,16, 974-981

Factors which contribute to fatigue associated with rheumatoid arthritis LeannaJ Crosby DNSc RN Axistant Professor, Umversity of Anzona, College of Nursing, Tucson, Anzona 85721, USA

Accepted for publicahon 22 January 1991

CROSBY L J (1991) Joumal of Advanced Nurstng 16, 974-981 Factors which contribute to fatigue associated with rheumatoid arthritis The purpose of this research was to identify the factors which people with rheumatoid arthntis (RA) believed contnbuted to their fatigue A second purpose was to examme the relationships among identified factors and the sensation of fatigue One hundred people with RA were asked to identify verbally factors which they believed contnbuted to their fatigue The three most frequently identified factors mcluded RA disease activity, disturbed sleep and increased physical effort These factors were operationalized and measured as jomt pam usmg the Modified McGiU Pam Inventory, fragmented sleep through overnight electroencephalographic (EEG) sleep studies, and reduced physical ability usmg walkmg time and gnp strength measures Fifteen of the ongmal subjects with RA and 12 age and gender matched control subjects completed the second phase of the research Five of the RA subjects were expenencmg a disease flare while the remammg 10 were either m remission or their disease was mildly active Those subjects m flare had significantly (P< 0 01) more joint pam, significantly (P< 0 05) more fragmented sleep, and significantly reduced functional capaaty as measured through walkmg time (P< 0 05) and gnp strength (P< 0 05) when compared to non-flare and control subjects Fatigue levels of the subjects m flare were positively correlated with jomt pain (r = 0 62), fragmented sleep ( r = 0 42) and gnp strength of the nght hand (r = 0 52) and left hand {r = 0 S8) Fatigue levels of non-flare and control subjects were negatively correlated with the majonty of measured vanables While the data assoaated with this exploratory research did not address causahty, valuable mformation has been gamed by assessmg relationships among the factors which people with RA indicated contnbuted to their level of fatigue

INTRODUCTION

addihon, a recent study highlighted the prevalence and impact of fatigue 52% of 101 people with RA stated that A great deal of hme has been spent descnbmg and/or they consistently lacked energy and 32% indicated they measunng fatigue and far too httle hme has been spent on were too tired to work for more than 4 hours without discovenng the basis of fatigue assoaated with rheumatoid restmg (Crosby 1988) arthnhs (RA) The fact that fahgue is a dmical feature of RA But again, what is the basis of fatigue? Unhl that quesls not disputed Fahgue has been listed, for a number of hon is answered, httle will have been accomplished by years, m the Pnmer on the Rheumattc Diseases as a present- contmuously measunng the sensahon, using a mulhtude of ing symptom of the disease process (Bennett 1988) In different mstruments, most of which were developed and 974

Fahgue and rheumatoid arthritis

tested with healthy people expenenang acute fahgue verCameron (1973), another pioneer m the lnveshgahon of sus ill people expenencmg chronic fahgue Acute fahgue is fatigue, attempted to develop a theory of fatigue He cntiusually of short durahon and relieved by rest, sleep or a cally evaluated pnor research efforts directed toward either change in situation Chronic fatigue is persistent, cumulat- measunng or defining the sensation and concluded that ive and not eliminated by rest In other words, acute fahgue 'fatigue has its ongm m the personal state of the mdividual' IS episodic and usually associated with temporal situahons The author stressed that fatigue was multidimensional whereas chronic fahgue is persistent and usually associated yet situahon specific and should be mveshgated m a with an illness situation Thus, the basis of fatigue may like manner be totally different, acute versus chronic, and should be While both Cameron (1973) and Yoshitake (1971) evaluated and measured with those differences m mmd were pnmanly interested m acute fatigue assoaated with employment, their careful attenhon to identifymg the mihatmg factors has provided direction for much of the Chronic fatigue syndrome current research In addihon, the point that fahgue is highly subjechve and should only be charactenzed m terms of Another important difference that should be kept in mmd is what the person is expenenang, should always be kept m the difference between fahgue which is chronic in nature mind Clearly, the basis for the sensation may be totally versus the chronic fahgue syndrome (CFS) The CFS is different, populahon to populahon charactenzed by debilitating fatigue that has lasted for at Interest m the sensation of fahgue has expanded to least 6 months To qualify for the diagnosis of CFS, the include not only evaluatmg healthy people expenenang person must not have any other medical or psychiatric acute fatigue assoaated with work-related situahons but condihons that produce similar symptoms This does not also studymg ill individuals expenencmg chronic fatigue preclude an overlapping of CSF with other well-established associated with altered physical responses Chronic fahgue illnesses such as RA, lupus and fibromyalgia However, has been reported to be a troublesome clinical manifesinvestigators believe that CFS is a separate disease entity tation associated with viral infechons (Schluederberg that may follow mfechon by one or more retroviruses 1990), end-stage renal disease (Snvastava 1989), as well as (Schluederberg 1990) rheumatoid arthnhs (Crosby 1988, Tack 1990) In addihon, The ongin of fatigue associated with RA is just as mystreatment regimes such as radiation therapy (Haylock & tenous as the ongm of fahgue m CFS Perhaps the basis is Hart 1979) and chemotherapy Qamar 1989) have been again viral Or there may be a composite of factors which associated with sigmficant levels of fahgue leads to the sensahon of fatigue Until the physiological basis has been discovered, it would seem prudent to identify other factors which may contnbute to the sensation of Multidimensional model fahgue v«thin this populahon The value of such research Piper (1989) proposed a multidimensional model designed would be the ldentificahon of points for intervention to explain the complexity of fahgue assoaated with illness designed to reduce the level of fatigue The author stressed that the symptom pattems of fahgue The purpose of this research was to identify the factors may vary according to the illness Furthermore, the subjecwhich RA subjects believed contnbuted to their fatigue A hve and objective mdicators of fatigue may not be highly second purpose was to examine the relationships among correlated, that is, how the health care provider perceives the idenhfied factors and the sensation of fatigue the patient's level of fatigue may not be an accurate reflection of what the person is expenenang This mcongruity may be due to the highly subjective nature of the process BACKGROUND and underscores the difficulty m measunng fatigue In summary, the theoretical wntmgs as well as clinical Fatigue was first studied by investigators mterested m mveshgahons to date imply that one or more inihahng skilled performance (Drew 1940, Davis 1948) and profactors may lead to the development of both acute and duchvity (Chambers 1961) Yoshitake (1971), a pioneer in the field, focused much of his research on acute fatigue chronic fatigue One goal should be to identify the preapiassociated with employment He defined fahgue as a 'feel- tatmg factors which serve as the basis for the sensahon of ing of overall unpleasantness' and reported that specific fahgue A second goal should be to understand how the factors, such as non-shmulahng work, led to boredom or preapitatmg factors relate to the sensation of fahgue decreased abihty to concentrate Over time, these factors Fatigue assoaated with RA has not been mvestigated m culminated m the actual sensation of fahgue

this manner

975

LJ Crmby

RESEARCH QUESTIONS The queshons which guided this research were 1 What are the factors which RA subjects believe contnbute to their fatigue? 2 What are the relahonships between the factors which contnbute to fahgue and how are those factors related to the sensahon of fatigue? Resenrdi design and statistical analysis An exploratory design was used to answer the first research question while a descnphve correlational design was used to answer the second research queshons Pearsons product-moment correlahons, analysis of vanance and independent f-tests were used stahstically to evaluate the data The selected level of significance was a = (H)5 Research question J

One hundred non-randomized subjects with RA were contacted dunng their regularly scheduled appointment withm a rheumatology clinic Following informed consent, all subjects were asked to ldenhfy verbally factors which they believed contnbuted to then- fahgue Table 1 illustrates their responses The majonty of subjects (64%) idenhfied RA disease achvity as the pnmary cause of their fatigue An additional 30% idenhfied RA disease activity as the secondary cause of their fahgue When asked to explam how their disease activity contnbuted to their fahgue, the majonty stated that it was the amount of joint pam they expenenced that seemed not only to mdicate that their disease was more achve but also to lead to mcreased fahgue Hie second most frequently identiAed factor was disturbed sleep Thirty-six per cent idenhfied disturbed sleep as either the pnmary cause {n = 26) or secondary cause (n = IO) of their fahgue Agam, subjects were asked to explam what it was about their sleep that contnbuted to their fahgue Some explained that they could only sleep for short penods of time Others said that they awakened many hmes dunng the rught and fi^equently could not return to sleep Others simply said their sleep was not restful The third most frequently idenhfied factor was increased physical effort needed to accomplish daily achvihes Sixtyfour per cent idenhfied mcreased physical difort as either the pnmary (M = 10) or secondary (n=54) cause of their fahgue A fi-equent explanahon was that smce they had developed RA, they were required to exert twics the effort and expend twice the energy m order to accompbsh the same amount of work. 976

Table 1 Subject-identified factors which contnbute to fatigue associated with rheumatoid arthntis (m percentages) (n = 100) Factors RA disease activity Disturt)ed sleep Increased physical effort

Pnmary cause

Secondary cause

64

30

26

10

10

54

In summary, the 100 subjects mterviewed in this phase of the research identified increased RA disease activity accompanied by mcreased jomt pain, disturbed sleep which was charactenzed as fi"agmented sleep, and mcreased physical effort with a subsequent reduction m functional ability, as the pnmary factors which contnbuted to their level of fatigue Research question 2

A descnptive correlational study was designed with the goal of answenng the second research question Table 2 shows the identified factors as well as the descnptive terms and operational measures that were used to evaluate joint pain, sleep fragmentation and reduced functional ability

VARIABLES/INSTRUMENTS The following vanables were measured on the evenmg ofa scheduled overnight electroencephalographic (EEG) sleep study joint pam, sleep fi-agmentation, reduced functional ability and fahgue Joint pain Joint pam assoaated with RA disease achvity was measured usmg the Modified McGill Pain Inventory (MMPI) (Melzack 1975) The measures of pam that were denved fi'om usmg the inventory mcluded the Present Pain Intensity Iitdex and the Pam Rahng Index The Present Pam Intensity Index is based on a numencal scale that ranges fi'om 1 to 5, with the greater the score, the more severe the pam This sub-scale of the MMPI was used to group subjects based on jomt pain The Pam Rahng Index consists of 20 mdividual groups of descnphve words with each word bemg assigned a numencal value Words are saded so that 1 to 2 pomts represent mild pain while 3 to 4 points rqiresent mo005) m gnp strength, both mg awakening Table 3 illustrates that the RA subjects m flare awakened nearly twice the number of times as the pre-sleep and post-sleep, between the two RA groups However, there was a sigmficant difference between the non-flare and control subjects RA flare and control group both pre-sleep (P=002) and The overall difference among the groups, based on post-sleep ( P = 0 001) for the nght hand and pre-sleep analysis of vanance (ANOVA), approached significance (P=OOOI) and post-sleep (P= 0-000) for the left hand (F(2,22) 2 78,P—0 08) Post hoc mdependent ^tests demonLikewise, there were significant differences between the strated a statistically sigmficant ( P = 0 05) difference m the non-flare and control group both pre-sleep (P=003) and number of awakenings between the RA flare and non-flare post-sleep (P=0000) for the nght hand and pre-sleep group and the RA flare and control group (P=0 002) and post-sleep (P= 0 000) for the left hand Reduced functional ability Walkmg time and gnp strength measures were used to assess the degree of reduced functional ability Table 3 illustrates both the pre-sleep and post-sleep values for these measures Walhrtg time The RA group m flare required twice as many seconds to walk the same distance as the control group and nearly a third more time than the non-flare group The mcrease in walking time was slightly more pronounced, following sleep, for the RA group in flare and slightly less pronounced for the non-flare and control groups ANOVA indicated that a stahshcally significant difference existed in walkmg time among the groups both pnor to (F(2,23) = 4 63, P = 0 02) and followmg sleep (F(2,23) = 4 31, P=0-02) Post hoc independent f-tests mdicated there was no significant difference (P>005) m walkmg hme, both pre-sleep and post-sleep, between the two RA groups However, there was a significant difference

behveen the RA flare and conh-ol group, pre-sleep (P= 001) and post-sleep (P=003), and a s i g ^ c a n t differ-

Fatigue One of the most interestmg fmdmgs was the similanty m fatigue scores across the three groups ANOVA mdicated no significant difference between the groups (F(2,23) = 135, P = 0 28) A review of anecdotal data revealed that the majonty of RA subjects complained of feelmg 'womout' or 'exhausted' on the night of the sleep study, while the control subjects complamed of feelmg tired Demographic data mdicated that all of the control subjects were employed and had worked the day of the sleep study while only five of the 15 RA subjects were employed Tiredness followmg a day of employment versus exhaushon followmg a day of being at home, with a chronic illness, may be two totally different sensahons ongmating from two totally different sources, l e acute fahgue versus chrome fahgue This raises the queshon of whether or not a companson of fatigue between healthy control subjects and chromcally ill subjects is a valid measure Rather, the companson may be more appropnate if the sensahon is evaluated between groups of people expenenang the same process, i e RA at different stages of disease activity Table 3 lUustrates tiiat the 979

LJ€rod>y Table 4 Pearson prcxiuct-moment correlations between fatigue and joint pain, number of awakenings, pre-sleep walking tunes and gnp strength Fatigue Control

Joint pain

Number of awakenings Walking tune Gnp strength Right hand Left hand

RA flare

RA non-flare

r=0-62 NA r= -O23 r=0-42

r= -0-24 r=-038

r=012

r=-030

r=014

r=-043 r=0-52 r = - 0 40 r=0-88*

r=-OOI r=030

The RA si^jects m flare, whai compared to the ort»er two groups, scored very differently m terms of the number of awakenings, waikmg time, gnp strength aiui level of fatigue In fact, the non-flare and control grcnips were so similar that future investigators, conductmg similar research, might consider usmg only a non-flare group for comparison versus healthy control subjects This certainly would be recommended when assessing a concept such as fatigue since control subjects, free of acute or chronic illness, would no doubt be expenencmg acute fatigue versus RA subjects who would be expenenang chronic fatigue

Sleep

Other mteresting differences emerged when the EEG records were compared between the groups The sleep of P0-05) within the moderate to strong withm the RA flare group yet weak RA group m flare yet inversely related to pam (r = — 0 24, and frequently mversely related withm the non-flare and P > 0 05) and fatigue (r = -0-38, P>005) m the non-flare control group group DISCUSSION This study was conducted to identify factors which people with RA believed contnbuted to their fahgue A second purpose was to assess the relationships among the identified factors as well as to assess how the factors related to the sensation of fatigue Withm the first phase of this research, RA subjects identified disease activity as the primary factor which contnbuted to their fatigue Disease activity was assessed, m this study, by measunng jomt pam Jomt pam was the one factor that related most positively with all other measured variables and most dearly difJFerentiated between the two groups of RA subjects Those subjects in flare expenenced sigruficantly (P