InternationalJournal of Rehabilitation and Health, VoL 2, No. 1, 1996
The Relationship Between Self-Efficacy and
Disability in Chronic Low Back Pain Patients
Jennifer B. Levin, 1 Kenneth R. Lofland, 1,2,4 Jeffrey E. Cassisi, 5
Amir M. Porch, 3 and E. Richard Blonsky 2,4
This study examined the reliability o f an adapted version o f the Arthritis
Self-Efficacy Scale in a sample of 59 chronic low back pain patients. The present
study also investigated the relationship between self-efficacy and measures o f
disability. Regression analyses indicated a significant negative relationship between
self-efficacy and low back pain disability. That is, patients who report higher levels
of self-efficacy have higher activity levels (R 2 = 0.34, P < 0.01), work more hours
(R 2 = 0.25, P < 0.01), and have lower levels of psychological distress (R 2 = 0.29,
P < 0.01), pain severity (R 2 = 0.46, P < 0.01), and pain behavior (R z = 0.27,
P < 0.01) after controlling for the demographic variables of gender, duration of
back pain, and having a lawyer on retainer. The results support the use of the Back
Pain Self-Efficacy Scale (BPSES) a~ a general measure of self-efficacy in the
chronic low back pain population.
KEY WORDS: low back pain; self-efficacy;chronic pain; disability;assessment.
INTRODUCTION
Bandura (1977, 1982) defined self-efficacy as the belief individuals have in
their ability to achieve a specific outcome. Bandura's (1977) theory suggests that
the strength of a particular self-efficacious belief determines the a m o u n t of
effort and persistence individuals will exert in coping with a difficult situation.
Recent studies confirm the importance of self-efficacy in the understanding
of various behavioral and cognitive mechanisms that underlie the maintenance,
2Department of Psychology,Illinois Institute of Technology,IIT Center, Chicago, Illinois 60616,
Rehabilitation Institute of Chicago, 345 East Superior, Chicago, Illinois 60611.
3Department of Psychology,Hebrew University, Sherman Building, Mount Scopus, Jerusalem 91905,
Israel.
4present address: Pain and Rehabilitation Clinic of Chicago, 640 North LaSalle, Suite 610, Chicago,
Illinois60610.
STo w h o m correspondence should be addressed at Department of Psychology,Jackson State University,
P.O. Box 17550, Jackson, Mississippi39217.
19
1068-9591/96/0100-0019509.50/0 9 1996 Plenum Publishing Corporation
20
Levin, Lofland, Cassisi, Poreh, and Blonsky
exacerbation, and treatment of chronic pain (Jensen et al., 1991b; Turk and Rudy,
1986, 1992). Laboratory studies on the impact of self-efficacy show that individuals who have high levels of self-efficacy are more likely to persevere in the
face of failure, work harder on difficult tasks, and exhibit fewer symptoms of
anxiety than do individuals with lower levels of self-efficacy (Bandura, 1984).
Clinical studies employing chronic pain patients support these findings and suggest that low self-efficacy expectancies may lead to noncompliance with treatment recommendations. Further, through modification of these self-efficacy
expectancies, it is possible to alter treatment outcomes (for a review see Dolce,
1987). In addition, such studies show that increasing self-efficacy has the potential to decrease medication use and chronic illness behavior (Council et al.,
1990).
Despite acknowledgment of the importance of the self-efficacy construct on
health outcomes, few standardized measures of self-efficacy exist (DeGood and
Shutty, 1992; Jensen et a t , 1991a). Rather, investigators have most often studied
self-efficacy using a series of behavior-specific questions developed to reflect one's
ability to perform the particular behaviors under study in a given population [i.e.,
"I can lift 5 lbs." (Kores et al., 1990, p. 166)].
One measure previously developed to assess self-efficacy in patients with
chronic pain is the Arthritis Self-Efficacy Scale (ASES; Lorig et al., 1989). This
scale divides the self-efficacy construct for pain into three dimensions: self-efficacy for pain management (PSE), self-efficacy for physical function (FSE), and
self-efficacy for controlling other symptoms (OSE). The ASES has a high internal consistency and moderate test-retest reliability for chronic arthritis patients
undergoing rehabilitation (Lorig et al., 1989). Further, a study by Buescher et
al. (1991) shows that patients with rheumatoid arthritis with high levels of
self-efficacy, as measured by the ASES, exhibit fewer pain behaviors and
lower levels of depression and disease activity than patients with low levels
of self-efficacy. This suggests high concurrent validity of the ASES for this
population.
Two recent studies (Lomi, 1992; Lomi and Nordholm, 1992) attempted to
evaluate the factor structure and reliability of a Swedish version of the ASES in
24 rheumatology patients and 25 chronic pain patients, 10 of whom suffered from
chronic back pain. The results of the factor analysis replicated the three-factor structure previously obtained by Lorig et al. (1989).
The present study examined the reliability of a slightly adapted version of the
ASES to measure self-efficacy in a larger sample of chronic low back pain patients.
In addition, this study investigated the relationship between self-efficacy and various
self-report and objective measures of disability and pain in a chronic low back pain
sample. Following Lomi (1992), it was hypothesized that the measure would yield
a moderate test-retest reliability and high Cronbach alpha coefficients. In addition,
following Buescher et at (1991), it was hypothesized that there would be a significant relationship between the self-efficacy subseales and the various measures of
disability in this sample.
Self-Efficacy and Disability
21
METHOD
Subjects
Subjects were 59 chronic low back pain patients (29 males and 30 females)
referred for treatment to a Rehabilitation Hospital's Chronic Pain Program in the
Chicago area. The mean age of the sample was 42.4 years (SD = 11 years), and
the average educational level was 13.5 years (SD = 2.3 years). The ethnic distribution was 71% Caucasian, 20% African-American, 3% Hispanic, 2% Asian, and
4% other. Subjects reported their marital status as follows: 56% married, 28% single, 12% divorced or separated, and 4% widowed. Seventy-three percent of the
patients were unemployed.
The diagnostic distribution was 42% unspecified musculoskeletal backache,
16% intervertebral disc disorder, 4% spondyloarthritis, and 38% combined back
pain, defined as two or more of the previous three back diagnoses. All subjects
reported having low back pain for a minimum of 6 months. Twenty-eight percent
of the subjects reported active litigation in process at the time of testing, and 56%
of the subjects had previous back surgery. Medical characteristics and dependent
measures of disability appear in l~ble I.
Table I. Means and Standard Deviations of Medical Characteristics
and Dependent Measures of Disability for the Chronic Low Back
Pain Sample
Variable
Duration a
Surgery/'
Heightc
Weight
Activity Leveld
Psychological Distresse
Employment Hour~/
Pain Severityg
Pain Behaviorh
n
59
59
59
59
51
51
59
51
51
Mean
53.2
0.8
68.1
184.2
2.4
65.1
8.6
4.2
9.5
SD
65.3
0.9
3.6
46.4
0.9
10.2
16.1
1,2
10.9
aDuration of pain in weeks.
bNumber of previous back surgeries.
CHeight in inches.
'/Activity level from the General Activity Level subscale of the
Multidimensional Pain Inventory. Mean and SD are 2.047 and 0,985,
respectively, for the chronic pain norms.
epsychological distress from the Brief Symptom Inventory converted to
T scores with a mean of 50 and a SD of 10.
~'~lumber of hours employed per week.
sPain severity from the Pain Severity subscale of the Multidimensional
Pain Inventory. Mean and SD are 4.521 and 1.038, respectively, for the
chronic pain norms.
hPain behavior from Keefe and Block's behavioral observation method.
Mean and SD of total pain behavior are 14.13 and 8.38, respectively,
for low back pain norms.
22
Levin, Lofland, Cassisi, Porch, and Blonsk7
Self-Report Measures
Back Pain Self-Efficacy Scale (BPSES). Self-efficacywas measured using a revised
version of the Arthritis Self-Efficacy Scale (ASES; Lorig et aL, 1989). The wording
of the original scale was revised substituting "back pain" for "arthritis pain" whenever
it appeared in the instructions or in an item. Subjects answered each question using
a Likert scale ranging from 10 (very uncertain) to 100 (very certain). Previous studies
have attempted to examine the factor structure of the ASES. An initial examination
of the factor structure of the ASES (Lorig et al., 1989) identified two factors, but a
reexamination identified three self-efficacy factors (Lorig et aL, 1989) including (1) a
self-efficacy for pain management (PSE) subscale consisting of nine items, such as,
"How certain are you that you can decrease your pain quite a bit?", (2) a self-efficacy
for physical function (FSE) subscale made up of six items such as, 'gts of now, how
certain are you that you can walk 10 steps downstairs in 7 seconds?"; and (3) a selfefficacy for controlling other symptoms (OSE) subscale made up of five items, such
as, "How certain are you that you can control your fatigue?"
Multidimensional Pain Inventory (MPI). General activity level and pain severity
were assessed using the subscale scores of the MPI (Kerns and Jacob, 1992). This
61-item self-report instrument consists of three sections, including two parts that
assess an individual's appraisal of pain and the impact of pain on various aspects
of their lives as well as a third part that assesses their perception of how significant
others respond to their distress. Scores from the general activity level and pain
severity subscales were used as dependent variables in the regression analyses.
Brief Symptom Inventory (BSI). General psychological distress was measured using the BSI (Derogatis, 1982). This 53-item short form of the Symptom Checklist-90
(Derogatis, 1977) consists of the following nine scales: depression, anxiety, hostility,
phobic anxiety, paranoid ideation, somatization, obsessive-compulsive, interpersonal
sensitivity, and psychoticism. The sum of the subscales makes up a Global Severity
Index (GSI) for which a standardized T-score exists (GSIT). This index correlates
with other measures of psychological distress (Cleeland and Syrjala, 1992, p. 372).
GSIT scores were used as the dependent variable of psychological distress.
Balanced Inventory of Desirable Responding (BIDR). Response style was measured
by the BIDR (Paulhus, 1984). This 40-item questionnaire measures a subject's degree of
socially desirable responding to self-report measures (Paulhus, 1991). This measure distinguishes between intentional and unintentional self-enhancement. The BIDR consists
of two subscales made up of 20 items each: (1) Self-Deceptive Enhancement (SDE),
which measures positive self-reports that an individual believes to be true, and (2)
Impression Management (IM), which measures consciously exaggerated positive selfreports for the purpose of making a positive impression. Prior studies provide adequate validation for this two-factor structure (Paulhus, 1984; Paulhus and Reid, 1991).
Behavioral Observations
The behavioral observations consisted of a 1O-min observation period. Observers rated subjects on the frequency of five pain behaviors, guarding, bracing,
Self-Efficacy and Disability
23
rubbing, grimacing, and sighing, while alternating between four activities, including
standing, sitting, walking, and laying, as instructed by the rater (Keefe and Block,
i982). As described by Keefe and Block (1982), there were a 1-min and a 2-min
standing period, a 1-min and a 2-min sitting period, two 1-min walking periods,
and two 1-min laying periods, with the order of the activities randomly determined.
Two clinical psychology graduate students rated subjects on a 20-sec observe, 10-sec
record design. The interrater reliability for total pain behavior scores, computed
on roughly half of the subjects selected at random, was r(27) = 0.97.
Procedure
Subjects completed an informed consent form followed by a demographic form.
Subjects then completed a series of self-report measures and Keefe and Block's
(1982) 10-min behavioral observation period in a random order. Internal consistency coefficients were then computed. Test-retest reliability coefficients for each
subscale and for the total score of the BPSES were calculated by correlating scores
on the two test administrations for chronic low back patients (N = 24) who agreed
to complete the BPSES a second time and return it to the investigators by mail.
Multiple regression analyses, were then performed. All data were analyzed using
SPSS for Windows Version 6.1.
RESULTS
Demographic Variables
All variables with absolute skewness values of 0.50 or greater were transformed.
The variables duration of back pain and total pain behavior underwent logarithmic
transformations and the variable number of hours employed underwent an inverse
transformation. The remaining statistical analyses that included any of these variables utilized the transformed values. Statistical analysis showed that male and female subjects did not differ in duration of low back pain or on number of surgeries.
A significant difference in employment status [~2 = 8.12 (1, N = 59), P < 0.01]
as well as the number of hours employed as measured on a continuous scale [t(57)
= -3.26, P < 0.01) was present across gender, with fewer employed women and
fewer hours worked by the employed women.
Reliability
Coefficient alpha estimates of internal consistency for the chronic low back
pain sample (N = 59) were 0.82, 0.91, 0.90, and 0.92 for the three subscales and
the total score, respectively. The test-retest correlations were rtt = 0.75 for PSE,
rtt = 0.84 for FSE, rtt = 0.68 for OSE, and rtt = 0.88 for the total score. The average
time between administrations was 16.3 weeks.
24
Levin, Lofland, Cassisi, Poreh, and Blonsky
Self-Efficacy
Means and standard deviations for the three self-efficacy scores and the corresponding means and standard deviations of Lorig et al.'s (1989) sample appear
in Table II. The three self-efficacy subscales evidenced high intercorrelations. Pearson product-moment correlations were 0.54 (P < 0.0001) for PSE and FSE, 0.76
(P < 0.0001) for PSE and OSE, and 0.52 (P < 0.0001) for FSE and OSE. In
addition, the three subscales displayed the same pattern of correlations with the
dependent variables. Thus, analyses were conducted using the total self-efficacy
score rather than the individual self-efficacy scores.
There was no significant difference in total self-efficacy (TOTSE) of the BPSES
across diagnoses [F(3,49) = 1.15, P > 0.05]. Females scored significantly higher
than males on TOTSE [t(57) = 3.79, P < 0.01]. TOTSE negatively correlated with
psychological distress [r(51) = -0.49, P < 0.01], pain severity Jr(51) = -0.60, P <
0.01], and pain behavior Jr(51) = -0.41, P < 0.01] and positively correlated with
general activity level [r(51) = 0.53, P < 0.01] and hours employed Jr(51) = 0.35,
P < 0.01].
Multiple Regression Analyses
To assess the extent to which the demographic and medical variables related
to the dependent measures of disability, a series of correlational analyses were
performed. Significant correlations were evident between duration of back pain
and pain severity [r(51) = -0.31, P = 0.029]; between gender and number
Table II. Means and Standard Deviations of the Back Pain Self-Efficacy
Scale (BPSES) and the Arthritis Self-Efficacy Scale (ASES)
Measure
na
BPSES
nb
ASES
PSEc
Male
Female
Total
29
30
59
18.48 (09.0)
27.87 (10.8)
23.25 (11.0)
95
52.04 (21.1)
FSEd
Male
Female
Total
29
30
59
52.83 (21.5)
65.93 (19.4)
59.49 (21.4)
95
73.27 (20.2)
OSEe
Male
Female
Total
29
30
59
24.76 (11.6)
37.07 (12.3)
31.02 (13.4)
95
55.62 (21.6)
Note. Means for ASES extracted from the table of means of Lodget aL (1989).
aNumber of subjects in back pain sample.
bNumber of subjects from arthritis study (Lorig et aL, 1989).
cSeif-Efficacy for Pain Management; items 1-5.
dSelf-Efficacy for Functional Ability; items 6-14.
eSelf-Efficacy for Controlling Other Symptoms; items 15-20.
Self-Efficacy and Disability
25
of hours employed [rpb(51 ) ---- 0.40, P = 0.002]; and between having a lawyer on
retainer and pain severity [rpb(51) = -0.38, P = 0.006], general activity level
[rpb(51) = 0.28, P = .044], general psychological distress [rpb(51) = -0.30, P =
0.032], and total pain behavior [rpb(51) = -0.37, P = 0.008]. T h e latter correlations indicate that subjects who had a lawyer on retainer had higher scores on
pain severity, psychological distress, and pain behavior and lower scores on general activity level.
A series of five regression analyses were performed to determine the relationship between the total self-efficacy score and various aspects of disability in the
chronic low back pain population. The dependent measures were the general activity subscale score from the MPI, the psychological distress score from the BSI,
the pain severity subscale score from the MPI, the total pain behavior score from
the behavioral observation period, and the reported n u m b e r of hours employed.
T h e demographic and medical variables of gender, duration of back pain, and having a lawyer on retainer were forced into each equation as a block in the first step
of each model due to their significant correlation with one or more of the dependent variables. T h e total self-efficacy score was then entered into the regression
analysis. Results of the regression analyses appear in Table III.
The total self-efficacy score (TOTSE) positively related to general activity level
(P < 0.01) and negatively related to psychological distress (P < 0.01). Consistent
Table HI. Stepwise Regression Ahalyses of Total Self-EfficacyScores on Dependent
Measures of Disability
Independent
Variable
Step
R2
'i~'a
df
R2
F
c h a n g e changeb
df
Dependent variable = general activity level
Blockc
Total SEa
1
2
0.103
0.337
1.80
5.86*
3,47
4,46
0.234
16.26"
1,46
9.74*
1,46
21.74"
1,46
7.74*
1,46
1.93
1,46
Dependent variable = general psychologicaldistress
Block
Total SE
1
2
0.139
0.290
2.53
4.69*
3,47
4,46
0.150
Dependent variable = pain severity
Block
TOtal SE
1
2
0.199
0.456
3.89*
9.64*
3,47
4,46
0.257
Dependent Variable = Total Pain Behavior
Block
Total SE
1
2
0.143
0.266
2.61
4.17"
3,47
4,46
0.124
Dependent variable = hours employed
Block
Total SE
1
2
0.255
0.252
5.23*
4.47*
3,47
4,46
0.027
aF test of the overall significance of the regression equation.
bF test of the change in R 2.
CBlock -- gender, duration of back pain, and having a lawyer on retainer.
dTotal SE = total self-efficacyscore.
*P < 0.01.
26
I~
Lofland. Cassisk ]Poreh. and Bions[o,
with the l i t e r a t e (D,ush,et aL, 199~4;~Flor and' Turk, 1988), d~ation of back pain,
ha*ng:~a lawyer on ret:ain.er, an#: TO,TSE score negaHvely' related to pain
s~everity (P ,~ 0,05) s~ch, tha~ pa~ of, longer d~ra,fi0n, not having a l~wyer on re,
tainer,~ and..Mgh se~-~.effica,cyscores, were associated with less sev~ere pain. The
TOTSE score: negatively related to the tot.Mp ~ , behavior s~ore (P .< 0,0I). Finally,
the number of h , 9 ~ emplo~e.d~sig~c.anfly re!ated, to gender & <_. 0~01) and duration: of back pain (P < 0.01) such. that men worked more hours, than wome,n. :an,d
pa~eo~.with. 19ng~r back pain d~ations worked fewer hours tha~athose with shorter
back pain, durations,
DISCUSSION
The present study Pr0vides. evide,n ~ f0r the ut'di'ty of~the BPSF~, a modified
,~ersion of the A S ~ , as a g!ob.al,~measure., of s.elf-efficacyin, c~onic low back pain
pa~e.n.~. Th e, ori.g~ali three subscal,es 0f the: ASES did not have a.d~quate discr'tmin~am vah'dity m. t~his sample ~ they evi.denced high intercorrelations and: demonstrated~ a similar pattern of relationships with the dependent variables. Thus , it
appears that the best use of the BPSES is as a general rather than a specific measure of self-efficacy in, this population.
The test-retest reliability and internal consistency coefficients of the BPSES
were in. t:h~ m0derate and .high..~anges,, respecfiye,ly, as ~ e fluid natur,e of the selfefficacy construct would, pre.dict. Tla~ correlation matrix between self-efficacy and
the.. other measles of disability and~pain were all- in the expected .,dir.,ection.That
is, as self-efficacy "me,teased, general activity level and hours employed, increased
and general psychological distress, p.ain severity, an d pain behavior decreased. The
fact that this relationship was present for all five dependent measures, including
the total pain. behavior S~c0re(wM~h trai0ed obse~ers objectively meas~ed),, lends
support to the construct validity of the BPSES. Furthermore, the lack of a significant correlati0n wi~, t:he BID~ sugges.ts that self-effi.cacywas not merely a measure
of social: desirability.
The regression models suggest that self-efficacy predicts some objective measures of disability and pain. in,~the, chromc low,:back pain population beyond the
control variables of gender, d~ati0n of back pain, :a0,d having a lawyer on ret.ainer.
The r~.ults indicate that the TOTSE factor accounted for 12% of the v:ariance in
pain behavior, compared to 5% "m Buesc.h.eret aL's (t99!) study with arthritis patients, sugges~g that. self,effica~ may have more predictive, utility for the chronic
back p ~ popdgti;'0n than for ~e a~hrifis p opulaO0n.
The ab07e ~dMgs als.0..sugg~t that the AS.F_k$,may be usedl as a general meas~ e of se~-e~ffi'ea~ a~r0ss, differem chronic pain populations by modifying the spe,
cific descriptor, of P ~ , wl~ e, m~ta!n!ng_,~ e o r i ~ : content of the items. This
f l e ~ b ~ a!lows for. ~.mp .afi'sous of:,the, s~ff,efficaey_,me_arts.ar
various types of
pain: patients. For e.mp!e,. ~b!e,-.~ sho.w_~-~a!~the, 0ri~...~ s~ple, of; ~ f i s
patients: (;I~ori,'g:et-q~, ~9,89)~0bt,~e.d.~ Mgbe.,r~serf,?e~ffica~:scores than the 10W back
pain. patien~ in ~e, p~es~./nt~S~p[e. This: observation is consistent with Lomi, and
Nordholm's (1,99,2),r~po~- that. chronic, pain pa.ti.'en~,evidence lower lev,els ot~self-
Self-EEficacyand Disabmty
27
efficacy for controlling pain and other symptoms than do rheumatology patients;
The results of the present study also indicate that females score significantly lfi'gher
on self-efficacy than do males. This finding is consistent with other gender differences noted in the literature for chronic pain patients, such as females demonstrating higher functional status than males (Tait et al., 1990). Thus,. demographic
variables, such as gender and age, unrelated to type of pain experienced may have
accounted for the former group differences in self-efficacy.
As Bandura's (1977) concept of self-efficacy is behavior and situation specific,
some researchers might argue that it is not possible to have a standardized measure
of self-efficacy (for reviews see DeGood and Shutty, 1992; Jensen et al., 1991a).
The current study does not argue that self-efficacy is not behavior specific. Rather,
it suggests that there are certain dimensions within the self-efficacy construct that
chronic pain patients share, dimensions that one can measure using a single standard instrument that focuses on common symptoms, behaviors, and functions.
One additional limitation of the present study concerns the interpretation of
the relationship between serf-efficacy and disability. As is the case with all correlational designs, the present study does not permit determination of cansality. Thus,
it is unclear whether low back pain disability causes a reduction in self-efficacy or,
alternatively, whether limited self-efficacy causes an increase in low back pain.
Future studies using larger sample sizes are necessary to assess and compare
self-efficacy scores of various chronic pain populations on the ASES. Such studies
need to control for background variables while they alter the type of pain experienced (e,g., back versus arthritis). They also need to examine stability of the selfefficacy factors in order to assess their validity. Using such methodology, it will be
possible to develop norms for different'types of chronic pain patients and to create
some uniformity in the assessment of self-efficacy among related populations.
ACKNOWLEDGMENT
This research received support from a Rehabilitation Institute Research Corporation Grant.
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