Relationship between psychological factors and performance-based and self-reported disability in chronic low back pain

Factors associated with functional capacity test results in patients with non-specific chronic low back pain: a systematic review

INTRODUCTION

Functional capacity tests are standardized instruments to evaluate patients' capacities to execute work-related activities. Functional capacity test results are associated with biopsychosocial factors, making it unclear what is being measured in capacity testing. An overview of these factors was missing. The objective of this review was to investigate the level of evidence for factors that are associated with functional capacity test results in patients with non-specific chronic low back pain.

METHODS

A systematic literature review was performed identifying relevant studies from an electronic journal databases search. Candidate studies employed a cross-sectional or RCT design and were published between 1980 and October 2010. The quality of these studies was determined and level of evidence was reported for factors that were associated with capacity results in at least 3 studies.

RESULTS

Twenty-two studies were included. The level of evidence was reported for lifting low, lifting high, carrying, and static lifting capacity. Lifting low test results were associated with self-reported disability and specific self-efficacy but not with pain duration. There was conflicting evidence for associations of lifting low with pain intensity, fear of movement/(re)injury, depression, gender and age. Lifting high was associated with gender and specific self-efficacy, but not with pain intensity or age. There is conflicting evidence for the association of lifting high with the factors self-reported disability, pain duration and depression. Carrying was associated with self-reported disability and not with pain intensity and there is conflicting evidence for associations with specific self-efficacy, gender and age. Static lifting was associated with fear of movement/(re)injury.

CONCLUSIONS

Much heterogeneity was observed in investigated capacity tests and candidate associated factors. There was some evidence for biological and psychological factors that are or are not associated with capacity results but there is also much conflicting evidence. High level evidence for social factors was absent.

[Lifting capacity with low back pain : Discrepancy between self-rated and real lifting capacity in patients with back pain and pain-free controls]

BACKGROUND

The fear-avoidance model implies that in situations with physical demands patients with back pain will overestimate the demand and underestimate their own capacities.

PATIENTS AND METHODS

A total of 71 patients with back pain and 48 pain-free control subjects carried out a standardized lifting test with a preceding estimation of their lifting capacity.

RESULTS

In both groups the self-estimation and real lifting capacity were in concordance for most group members with patients showing less disconcordance than controls. In the control group 35% of the subjects even underestimated their lifting capacity, which was the case in only 14% of the patients. Patients more frequently overestimated their capacity than pain-free controls (14% vs. 2%). Within the patients subgroups could be identified where patients in general either underestimated or overestimated their own capacity. A comparison between the groups demonstrated significant differences in pain intensity, fear avoidance beliefs and effort.

CONCLUSION

As an explanation for these unexpected results it can be hypothesized that in cases of back pain, patients' attention is focused on pain-relevant issues which enables a more realistic estimation of their lifting capacity.

The relationship between psychological factors and performance on the Biering-Sørensen back muscle endurance test

BACKGROUND CONTEXT

Many studies report an association between low back pain (LBP) and reduced back muscle endurance and consider this to indicate muscular dysfunction. However, few have investigated the potentially confounding influence of psychological factors on performance during such endurance tests.

PURPOSE

This study examined whether psychological factors were associated with "underperformance" on the Biering-Sørensen (BS) test (ie, not performing as well as one is physiologically capable of).

STUDY DESIGN/SETTING

Cross-sectional study of the baseline data of patients with chronic (>3 months) nonspecific LBP (cLBP) before participation in a clinical trial of exercise therapy.

PATIENT SAMPLE

One hundred forty-eight patients with cLBP (43% men; age, 45±10 years).

OUTCOME MEASURES

The time for which the modified BS isometric endurance test could be performed to exhaustion minus the time that would have been predicted based on the rate of decline in median frequency of the surface electromyographic (EMG) signal recorded bilaterally from the erector spinae at L3 and L5.

METHODS

Back pain and disability, psychological disturbance, catastrophizing, fear-avoidance beliefs, back beliefs, and exercise self-efficacy were measured using validated questionnaires. Patients performed the BS test to exhaustion while physiological muscle fatigability was measured from continuous surface EMG recordings.

RESULTS

Multivariable regression analysis controlling for gender revealed that greater psychological disturbance (p=.003) and more negative back beliefs (p=.015) were unique predictors of the extent of "underperformance," accounting for 22.3% variance in expected endurance time minus actual time.

CONCLUSIONS

It is important that the underlying nature (psychological or physiological) of performance deficits be identified during such tests because this may influence the interpretation of prospective studies reporting risk factors for LBP and dictate the particular treatment or interventional approach required to remedy the situation in individuals with LBP.

Immigration, acculturation and chronic back and neck problems among Latino-Americans

Higher acculturation is associated with increased obesity and depression among Latino-Americans, but not much is known about how acculturation is related to their prevalence of back and neck problems. This study examines whether acculturation is associated with the 12-month prevalence of self-reported chronic back or neck problems among US-born and immigrant Latinos. We performed multivariable logistic regression analysis of data from 2,553 noninstitutionalized Latino adults from the 2002-2003 National Latino and Asian American Survey (NLAAS). After adjusting for demographic, physical and mental health indicators, English proficiency, nativity and higher generational status were all significantly positively associated with the report of chronic back or neck problems. Among immigrants, the proportion of lifetime in the US was not significantly associated. Our findings suggest that the report of chronic back or neck problems is higher among more acculturated Latino-Americans independent of health status, obesity, and the presence of depression.

Are performance-based measures predictive of work participation in patients with musculoskeletal disorders? A systematic review

Objective

Assessments of whether patients with musculoskeletal disorders (MSDs) can participate in work mainly consist of case history, physical examinations, and self-reports. Performance-based measures might add value in these assessments. This study answers the question: how well do performance-based measures predict work participation in patients with MSDs?

Methods

A systematic literature search was performed to obtain longitudinal studies that used reliable performance-based measures to predict work participation in patients with MSDs. The following five sources of information were used to retrieve relevant studies: PubMed, Embase, AMA Guide to the Evaluation of Functional Ability, references of the included papers, and the expertise and personal file of the authors. A quality assessment specific for prognostic studies and an evidence synthesis were performed.

Results

Of the 1,230 retrieved studies, eighteen fulfilled the inclusion criteria. The studies included 4,113 patients, and the median follow-up period was 12 months. Twelve studies took possible confounders into account. Five studies were of good quality and thirteen of moderate quality. Two good-quality and all thirteen moderate-quality studies (83%) reported that performance-based measures were predictive of work participation. Two good-quality studies (11%) reported both an association and no association between performance-based measures and work participation. One good-quality study (6%) found no effect. A performance-based lifting test was used in fourteen studies and appeared to be predictive of work participation in thirteen studies.

Conclusions

Strong evidence exists that a number of performance-based measures are predictive of work participation in patients with MSDs, especially lifting tests. Overall, the explained variance was modest.

Differences in the relationship between psychosocial distress and self-reported disability in patients with chronic low back pain in six pain rehabilitation centers in the Netherlands

STUDY DESIGN

A cross sectional multicenter study in six outpatient Rehabilitation Centers (RCs) in the Netherlands.

OBJECTIVE

This study aims to confirm or refute the finding that a strong relationship exists between psychosocial distress and self-reported disability in patients with nonspecific chronic low back pain (CLBP) by analyzing this relationship in patients with CLBP admitted for treatment in six RCs.

SUMMARY OF BACKGROUND DATA

A strong relationship between psychosocial distress and self-reported disability in patients with CLBP is suggested. However, in former research weak relationships were found in two of the RCs participating in this study.

METHODS

Total study sample consisted of 293 patients (30-66 per RC) with CLBP, admitted for outpatient multidisciplinary rehabilitation in one of the six participating RCs. Psychosocial distress was measured with the Symptom Checklist-90-Revised (SCL-90-R), self-reported disability with the Roland Morris Disability Questionnaire (RMDQ). Pearson correlation coefficients between psychosocial distress and self-reported disability were calculated. Multivariate regression analysis was performed to analyze the relationship between SCL-90-R and VAS pain (independent variables) and RMDQ (dependent variable) for the total group and for each RC separately. A multivariate regression analysis was performed to analyze the relationship between all baseline characteristics and RMDQ in the total group.

RESULTS

Correlation coefficient between the SCL-90-R and RMDQ was r = 0.38 for the total sample, indicating a significant (P < 0.05), but weak relationship. For the six individual RCs, correlation coefficients ranged between r = 0.22 and 0.67 (three of the six correlation coefficients were significant). The explained variance (r) of the regression models (SCL-90 and pain intensity as predictors of RMDQ) was 29% for the total sample, and varied between the RCs from 17% to 52%. Results of the multivariate regression analysis of all baseline characteristics of the total group revealed that the model explained 36% of the total variance observed in RMDQ score. Overall, the contributions of psychosocial distress to the models were smaller and more variable compared with pain intensity.

CONCLUSION

The overall relationship between psychosocial distress and self reported disability was weak, and differences between RCs were considerable. This indicates that the relationship between psychosocial distress and disability in patients with CLBP is not uniform.

Causal attributions and alexithymia in female patients with fibromyalgia or chronic low back pain

AIMS

Our general objective was to assess the psychological symptoms and the types of causal attributions linked to the symptoms among women chronic pain.

METHODS

70 fibromyalgia (FM) patients, 56 chronic low back pain (CLBP) patients and 72 healthy controls were assessed within a general hospital setting, using the Toronto Alexithymia Scale, Brief Symptom Inventory and Symptom Interpretation Questionnaire. Three-way analysis of variance and chi-square tests were used for inter-group comparisons, followed by multivariate correlation, covariate analysis and linear regression.

RESULTS

Alexithymia, somatization, depression, anxiety and hostility scores were significantly higher in FM patients relative to CLBP patients and healthy controls (P < 0.05). Alexithymia was linked to psychological attributions in FM patients and to somatic attributions in CLBP patients. Psychological attributions, the number of symptoms and difficulty in describing emotions were related to increased anxiety in FM patients. Depression, anxiety and somatization were significantly increased in subjects with high alexithymia scores in the FM group. There was no difference between groups regarding causal attributions.

CONCLUSIONS

Causal attributions do not seem to have distinctive features between functional somatic syndromes like FM and CLBP, though differences might exist between groups as to the effects of coexisting psychological distress symptoms like anxiety and depression.

Prevalence of neck and low back pain in community-dwelling adults in Spain: a population-based national study

STUDY DESIGN

Cross-sectional epidemiological study.

OBJECTIVE

To determine the 1-year prevalence of neck pain and low back pain in the Spanish population and their association with sociodemographic and lifestyle habits, self-reported health status and comorbidity with other chronic disorders.

SUMMARY OF BACKGROUND DATA

No recent population-based epidemiological studies have estimated the prevalence of neck and low back pain in Spain.

METHODS

We analyzed data obtained from adults aged 16 years or older (n = 29,478) who participated in the 2006 Spanish National Health Survey, an ongoing, home-based personal interview which examines a nation-wide representative sample of civilian noninstitutionalized population residing in main family dwellings (household) of Spain. We analyzed prevalence data of neck and low back pain and their relationship with socio-demographic characteristics (sex, age, marital status, educational level, occupational status, or monetary income), self-perceived health status, lifestyle habits (smoking habit, alcohol consumption, sleep habit, physical exercise, or obesity), and the presence of concomitant chronic diseases or symptoms.

RESULTS

The 1-year prevalence was 19.5% (95% CI: 18.9-20.1) for neck pain and 19.9% (95% CI: 19.3-20.5) for low back pain. Both neck pain and low back pain were higher among female (26.4% and 24.5%) than male (12.3% and 15.1%). Subjects in the 31 to 50 years group were 1.5 times (95% CI: 1.3-1.8) more likely to report low back pain than participants in the 16 to 30 years group. Individuals reporting neck or low back pain showed worse self-reported health status (OR: 4.9, 95% CI: 4.5-5.3 for neck pain; OR: 4.7, 95% CI: 4.3-5.1 for low back pain) and were more likely to complain of depression (OR: 4.3, 95% CI: 3.9-4.7 or OR: 3.6, 95% CI: 3.3-3.9, respectively). Further, a strong association between neck and low back pain was found (OR: 15.6, 95% CI: 14.2-17.1). Finally, neck pain and low back pain were also associated with several other chronic conditions, particularly arthrosis (OR: 6.5, 95% CI: 6.0-7.0), and headaches (OR: 4.3, 95% CI: 3.9-4.8) for neck pain, and both arthrosis (OR: 5.7, 95% CI: 5.3-6.2), and osteoporosis (OR: 6.3, 95% CI: 5.6-7.2), for low back pain.

CONCLUSION

This Spanish population-based survey showed that neck and low back pain are prevalent and highly associated between them, more frequent in female (particularly neck pain) and associated to worse self-reported health status. Individuals with neck and low back pain were more likely than those without pain to have depression and other painful conditions, including headache and osteoporosis.

Correlation of DASH and QuickDASH with measures of psychological distress

PURPOSE

In an attempt to shorten the questionnaires given to patients in both clinical and research settings, we studied whether the correlation of commonly used psychological measures was comparable for the standard Disabilities of the Arm, Shoulder, and Hand (DASH) and the shorter QuickDASH questionnaires.

METHODS

A cohort of 839 patients with carpal tunnel syndrome, trigger finger, de Quervain's disease, trapeziometacarpal arthrosis, lateral epicondylosis, or a distal radius fracture 2 weeks after surgery, who completed the DASH and 1 or more measures of psychological distress, was created from 10 databases from previously implemented studies. Correlations of the DASH and the QuickDASH with several measures of psychological factors (Center for Epidemiologic Studies Depression Scale [CES-D], Pain Catastrophizing Scale [PCS], and Pain Anxiety Symptoms Scale [PASS-40]) were calculated in both univariate and multivariable analyses.

RESULTS

There was a large correlation between the DASH and QuickDASH (r = 0.79; p < .001). QuickDASH scores were significantly higher than DASH scores (p < .001). Correlations of the CES-D, PCS, and PASS-40 with the DASH and QuickDASH ranged from small to medium (range, 0.21-0.31; p < .001). There were no significant differences between correlations of the DASH and the QuickDASH with the psychological factors in the cohort including all patients, nor in subgroups according to diagnosis, gender, and limb dominance.

CONCLUSIONS

The correlations of the DASH and QuickDASH with the CES-D, PCS, and PASS-40 were comparable. Our analysis suggests that a shorter and therefore potentially more practical measure of arm-specific disability can be used in studies that evaluate psychosocial aspects of illness behavior.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic III.