Forgetting to remember? Prospective memory within the context of pain.

BACKGROUND: Pain interferes with cognitive functioning in several ways. Among other symptoms, pain patients often report difficulties with remembering future intentions. It remains unclear, however, whether it is the pain per se that impairs prospective remembering or other factors that often characterize people with pain (e.g. poor sleep quality). In this experiment, we investigated whether prospective memory is impaired within the context of pain, and whether this impairment is enhanced when the threat value of pain is increased. METHODS: Healthy participants engaged in an ongoing word categorization task, during which they received either experimental pain stimuli (with or without threatening instructions designed to increase the threat value of pain), or no pain stimuli (no somatic stimuli and no threatening instructions). Crucially, participants were also instructed to perform a prospective memory intention on future moments that would be signalled by specific retrieval cues. RESULTS: Threatening instructions did not differentiate the pain groups in terms of pain threat value; therefore, we only focus on the difference between pain and no pain. Pain and no-pain groups performed the prospective memory intention with similar frequency, indicating that prospective memory is not necessarily impaired when the intended action has to be performed in a painful context. CONCLUSIONS: Findings are discussed in the framework of the multiprocess theory of prospective memory, which differentiates between the spontaneous and the strategic retrieval of intentions. Methodological considerations and suggestions for future research are discussed. SIGNIFICANCE: This laboratory study combines established methods from two research fields to investigate the effects of a painful context on memory for future intentions. Painful context did not impair performance of a prospective memory intention that is assumed to be retrieved by means of spontaneous processing.

Biased pain reports through vicarious information: A computational approach to investigate the role of uncertainty.

Expectations about an impeding pain stimulus strongly shape its perception, yet the degree that uncertainty might affect perception is far less understood. To explore the influence of uncertainty on pain ratings, we performed a close replication of the study of Yoshida, Seymour, Koltzenburg, and Dolan (2013), who manipulated vicarious information about upcoming heat pain and found evidence for uncertainty-induced hyperalgesia. In our study, we presented eight fictitious ratings of previous participants prior the delivery of electrocutaneous pain. The vicarious information was either biased to over- or underreport pain levels based on the participant's psychometric function. We induced uncertainty by manipulating the variation of the vicarious information. As in Yoshida et al. (2013), four computational models were formulated, such that each model represented a different way of how the pain ratings might have been generated by the physical stimulus and the vicarious information. The four competing models were tested against the data of each participant separately. Using a formal model selection criterion, the best model was selected and interpreted. Contrary to the original study, the preferred model for the majority of participants suggested that pain ratings were biased towards the average vicarious information, ignoring the degree of uncertainty. Possible reasons for these diverging results are discussed.

Executive functions deficits impair extinction of generalization of fear of movement-related pain.

BACKGROUND: Generalization of fear of movement-related pain across novel but similar movements can lead to fear responses to movements that are actually not associated with pain. The peak-shift effect describes a phenomenon whereby particular novel movements elicit even greater fear responses than the original pain-provoking movement (CS+), because they represent a more extreme version of the CS+. There is great variance in the propensity to generalize as well as the speed of extinction learning when these novel movements are not followed by pain. It can be argued that this variance may be associated with executive function capacity, as individuals may be unable to intentionally inhibit fear responses. This study examined whether executive function capacity contributes to generalization and extinction of generalization as well as peak-shift of conditioned fear of movement-related pain and expectancy. METHODS: Healthy participants performed a proprioceptive fear conditioning task. Executive function tests assessing updating, switching, and inhibition were used to predict changes in (extinction of) fear of movement-related pain and pain expectancy generalization. RESULTS: Low inhibitory capacity was associated with slower extinction of generalized fear of movement-related pain and pain expectancy. Evidence was found in favor of an area-shift, rather than a peak-shift effect, which implies that the peak conditioned fear response extended to, but did not shift to a novel stimulus. CONCLUSIONS: Participants with low inhibitory capacity may have difficulties withholding fear responses, leading to a slower decrease of generalized fear over time. The findings may be relevant to inform treatments. SIGNIFICANCE: Low inhibitory capacity is not associated with slower generalization, but extinction of fear generalization. Fear elicited by a novel safe movement, situated outside the CS+/- continuum on the CS+ side, can be as strong as to the original stimulus predicting the pain-onset.

Fear of pain changes movement: Motor behaviour following the acquisition of pain-related fear.

BACKGROUND: According to current fear-avoidance models, changes in motor behaviour (e.g. avoidance) are a key component in the development and maintenance of chronic pain complaints. Yet, experimental research assessing actual behavioural changes following painful events is relatively sparse. This study investigated the effects of pain anticipation on changes in motor behaviour using a fear conditioning paradigm and robot-generated standardized movement trajectories of the upper extremities. METHODS: Pain-free participants (N = 20) performed clockwise and counterclockwise fixed, circular movements with a robotic arm without receiving visual feedback. During fear acquisition, moving in one direction (CS+) was paired with a painful stimulus (pain-US) whereas moving in the other direction (CS-) was not. During the subsequent extinction phase, the pain-US was omitted. We assessed self-reported pain-related fear and urge to avoid the movement, as well as several behavioural measures: Velocity, acceleration, exerted force and force direction. RESULTS: Movements that were paired with pain were associated with increased self-reported pain-related fear and urge to avoid. Moreover, movements that were associated with pain were performed faster, more forcefully and more accurately than movements that were not associated with pain. All these differences diminished during the extinction phase. CONCLUSIONS: The present study demonstrates the utility of robot-generated force feedback in the study of pain-related fear and associated changes in motor behaviour. SIGNIFICANCE: Fear of pain changes movement: Movements associated with pain are performed faster, with more force and higher accuracy than movements that are not associated with pain. These changes can inform us how fear of pain translates into avoidance and escape behaviour, two important constructs in the maintenance of chronic pain.

Effect of butorphanol tartrate on shock-related discomfort during internal atrial defibrillation.

BACKGROUND: In patients with atrial fibrillation, intracardiac atrial defibrillation causes discomfort. An easily applicable, short-acting analgesic and anxiolytic drug would increase acceptability of this new treatment mode. METHODS AND RESULTS: In a double-blind, placebo-controlled manner, the effect of intranasal butorphanol, an opioid, was evaluated in 47 patients with the use of a step-up internal atrial defibrillation protocol (stage I). On request, additional butorphanol was administered and the step-up protocol continued (stage II). Thereafter, if necessary, patients were intravenously sedated (stage III). After each shock, the McGill Pain Questionnaire was used to obtain a sensory (S), affective (A), evaluative (E), and total (T) pain rating index (PRI) and a visual analogue scale analyzing pain (VAS-P) and fear (VAS-F). For every patient, the slope of each pain or fear parameter against the shock number was calculated and individual slopes were averaged for the placebo and butorphanol group. All patients were cardioverted at a mean threshold of 4.4+/-3.3 J. Comparing both patient groups for stage II, the mean slopes for PRI-T (P=0.0099), PRI-S (P=0.019), and PRI-E (P=0.015) became significantly lower in the butorphanol group than in the placebo group. Comparing patients who received the same shock intensity ending stage I and going to stage II, in those patients randomized to placebo the mean VAS-P (P=0.023), PRI-T (P=0. 029), PRI-S (P=0.030), and PRI-E (P=0.023) became significantly lower after butorphanol administration. CONCLUSIONS: During a step-up internal atrial defibrillation protocol, intranasal butorphanol decreased or stabilized the value of several pain variables and did not affect fear. Of the 3 qualitative components of pain, only the affective component was not influenced by butorphanol. The PRI evaluated pain more accurately than the VAS.

Do health care providers' attitudes towards back pain predict their treatment recommendations? Differential predictive validity of implicit and explicit attitude measures.

The current study aimed to measure the differential predictive value of implicit and explicit attitude measures on treatment behaviour of health care providers. Thirty-six physiotherapy students completed a measure of explicit treatment attitude (Pain Attitudes And Beliefs Scale For Physiotherapists-PABS-PT) and a measure of implicit treatment attitude (Extrinsic Affective Simon Task-EAST). Furthermore, they gave treatment recommendations for a patient simulating back pain on three video scenes. The implicit and explicit measures of attitudes were only weakly related to each other. However, both were differentially related to treatment recommendations. The implications of the differential predictive value of implicit and explicit attitude measures for treatment behaviour are discussed.

Behavioural treatment for chronic low-back pain.

BACKGROUND: Behavioural treatment, commonly used in the treatment of chronic low-back pain (CLBP), is primarily focused at reducing disability through the modification of environmental contingencies and cognitive processes. In general, three behavioural treatment approaches are distinguished: operant, cognitive and respondent. OBJECTIVES: To determine if behavioural therapy is more effective than reference treatments for CLBP, and which type of behavioural treatment is most effective. SEARCH STRATEGY: We searched the CENTRAL, MEDLINE, EMBASE, and PsycLIT databases up to October 2003. References of identified randomised trials and relevant systematic reviews were screened. SELECTION CRITERIA: Only randomised trials on behavioural treatment for non-specific CLBP were included. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed the methodological quality and extracted the data. The magnitude of effect was assessed by computing a pooled effect size for post-treatment and long-term results for each comparison, for each domain (i.e., behavioural outcomes, overall improvement, back pain specific and generic functional status, return to work, and pain intensity) using the random effects model. MAIN RESULTS: Seven studies (33%) were considered high quality. Comparing behavioural treatment to waiting list control (WLC) revealed strong evidence (4 trials, 134 people) in favour of a combined respondent-cognitive therapy for a medium positive effect on pain, and moderate evidence (2 trials, 39 people) in favour of progressive relaxation for a large positive effect on pain and behavioural outcomes (short-term only). When comparing operant treatment to WLC no significant differences could be detected on general functional status (strong evidence: 2 trials, 87 people) or on behavioural outcomes (moderate evidence; 3 trials, 153 people) (short-term only). There is limited evidence (1 trial, 98 people) that a graded activity program in an industrial setting is more effective than usual care for early return to work and reduced long-term sick leave. There is limited evidence (1 trail, 39 people) that there are no differences between behavioural treatment and exercises. Finally, there is moderate evidence (6 trials, 210 people) that there are no significant differences in short-term and long-term effectiveness when behavioural components are added to usual treatment programs for CLBP (i.e. physiotherapy, back education) on pain, generic functional status and behavioural outcomes. AUTHORS' CONCLUSIONS: Combined respondent-cognitive therapy and progressive relaxation therapy are more effective than WLC on short-term pain relief. However, it is unknown whether these results sustain in the long term. No significant differences could be detected between behavioural treatment and exercise therapy. Whether clinicians should refer patients with CLBP to behavioural treatment programs or to active conservative treatment cannot be concluded from this review.

Attention allocation to ambiguous health/somatic threat cues.

BACKGROUND: An influential idea is that attentional bias to information related to pain or pain-related negative affect underlies persistent pain problems. Such information is however often ambiguous. If ambiguous input is perceived as pain or threat related, attention to this stimulus would be enhanced compared with stimuli with no (dominant) pain-/threat-related meaning. Attentional bias to ambiguous stimuli related to somatic/health threat was expected to be more pronounced with higher levels of pain catastrophizing. METHODS: University students performed a spatial cueing task including four types of word cues that were combinations of word content (somatic/health threat vs. non-threat), and word ambiguity (unambiguous vs. ambiguous), each presented for 500 or 750 ms. Attentional bias to somatic/health threat is reflected in larger cue validity effects for somatic/heath threat words than for non-threat words. RESULTS: In the 500-ms condition, cue validity effects were larger for threat than for non-threat words in participants reporting low catastrophizing, but did not depend on word content in participants reporting higher catastrophizing. In the 750-ms condition, cue validity effects did not depend on pain catastrophizing or word content. Cue validity effects did not significantly differ between unambiguous words and ambiguous homographs. CONCLUSIONS: Low catastrophizers demonstrated attentional bias to threat content. Participants reporting higher catastrophizing showed overall enhanced attentional orienting. There was no evidence for differences in (biased) attention to unambiguous and ambiguous words. Further research is needed to determine attentional bias for ambiguous pain-/threat-related stimuli in the context of consistent attentional bias for unambiguous pain-/threat-related stimuli.

Readiness to adopt the self-management approach to cope with chronic pain in fibromyalgic patients.

The effectiveness of cognitive-behavior therapy aimed at helping patients with the acquisition of self-management skills to cope with pain, is thought to depend partly on the patients' willingness to adopt a self-management approach. Some patients may not believe that self-management will be helpful while others have decided to adopt it and others already apply the self-management skills in their daily lives. The present study explored the concept of 'Readiness to change' in a population of Dutch fibromyalgic patients. A self-report questionnaire was completed by 321 patients. Factor analysis revealed three scales, each assessing the characteristic of one stage of readiness to change, the Precontemplation, Contemplation and Action scale. Firstly, the reliabilities of these scales were 0.61, 0.86 and 0.61, respectively, and only the latter two scales correlated significantly (r=0.14). Secondly, the scales were validated using subscales from the Multidimensional Pain Inventory, beliefs on the credibility of the self-management approach and subscales from the Illness Perception Questionnaire. These subscales explained 5, 22 and 8% of the variance of the scores on the Precontemplation, Contemplation and the Action scales, respectively. Thirdly, on the basis of the three scale scores, over 80% of the fibromialgia patients could be classified into one of five potentially psychological relevant subgroups: Precontemplation, Contemplation, Preparation, Action and Relapse. The data suggest that improvements in operationalizations of the Precontemplation and Action dimensions of readiness to change are needed and that the theoretical foundation of readiness to change needs further development.

Pain-related fear is more disabling than pain itself: evidence on the role of pain-related fear in chronic back pain disability.

There is growing evidence for the idea that in back pain patients, pain-related fear (fear of pain/physical activity/(re)injury) may be more disabling than pain itself. A number of questionnaires have been developed to quantify pain-related fears, including the Fear-Avoidance Beliefs Questionnaire (FABQ), the Tampa Scale for Kinesiophobia (TSK), and the Pain Anxiety Symptoms Scale (PASS). A total of 104 patients, presenting to a rehabilitation center or a comprehensive pain clinic with chronic low back pain were studied in three independent studies aimed at (1) replicating that pain-related fear is more disabling than pain itself (2) investigating the association between pain-related fear and poor behavioral performance and (3) investigating whether pain-related fear measures are better predictors of disability and behavioral performance than measures of general negative affect or general negative pain beliefs (e.g. pain catastrophizing). All three studies showed similar results. Highest correlations were found among the pain-related fear measures and measures of self-reported disability and behavioral performance. Even when controlling for sociodemographics, multiple regression analyses revealed that the subscales of the FABQ and the TSK were superior in predicting self-reported disability and poor behavioral performance. The PASS appeared more strongly associated with pain catastrophizing and negative affect, and was less predictive of pain disability and behavioral performance. Implications for chronic back pain assessment, prevention and treatment are discussed.

Patient utilities in chronic musculoskeletal pain: how useful is the standard gamble method?

The main goal of current pain management approaches is to increase the patients' quality of life by improving pain coping skills and by reducing the levels of disability in daily life, often despite persistent pain. Direct measurement of quality of life is of crucial importance in economic evaluation research, in which not only is the estimation of financial costs and benefits included, but so is the evaluation of costs and benefits in terms of changes in health states. The purpose of this study is to compare the psychometric qualities of two instruments for assessing patients' utilities, the rating scale (RS) and the standard gamble (SG). Such instruments are designed for their application in economic evaluation research, but have seldomly been used in chronic pain trials. Both methods provide a single measure between 0 and 1. The relationship between these utility measures and descriptive and domain-specific quality of life measures was examined in 133 fibromyalgia patients and 148 patients with chronic non-specific low back pain. Mean utility score at baseline was 0.43 with the RS and 0.78 for the SG. The correlation between both methods was found to be poor (r = 0.21). Both measures appeared to be fairly stable in a 2-week test-retest period (intra class correlation coefficient (ICC) = 0.74 and 0.77). Scores on the description of patient's own health on six domains, global assessment of change and domain specific measures correlated moderately with the RS scores and low with the SG. Multiple regression analyses demonstrated that 32% of the variance in RS values and only 13% of the variance in SG utilities could be explained by domain-specific measures. These results suggest an acceptable construct validity for the RS but insufficient construct validity for the SG. Valuations of ones own health appear only partially to be related to the assessment of the pain-specific measures and measures of distress. It can be concluded that the RS and domain-specific measures assess partly different, but nevertheless complementary aspects of health-related quality of life. It is therefore recommended to include in economic evaluation studies both domain-specific measures and valuation measures. Finally, in chronic musculoskeletal pain patients, RS scores were found to be more responsive in detecting significant changes in preferences than SG scores. For use in patients with chronic musculoskeletal pain, the RS is preferred to the SG for establishing accurate decisions about the impact of new interventions on their health outcomes.

The effects of failure feedback and pain-related fear on pain report, pain tolerance, and pain avoidance in chronic low back pain patients.

The aim of this study was to investigate the influence of non-pain-related failure experiences and pain-related fear on pain report, pain tolerance and pain avoidance in chronic low back pain (CLBP) patients. Moreover, the mediating and moderating role of negative affectivity (trait-NA) in the relationship between failure experiences and pain was examined. Seventy-six patients were divided into high and low pain-related fear groups and within each group they were randomly assigned to the failure or success feedback condition. In the first part of the study patients completed a 'social empathy test' and experimenter 1 subsequently delivered false failure or success feedback. A second experimenter, who was blind for the condition, subsequently administered two lifting tasks in order to obtain measures of pain report, tolerance and avoidance. Failure feedback did have an effect on pain avoidance but unexpectedly, and not as hypothesized, pain avoidance was reduced instead of enhanced. With regard to pain report and pain tolerance similar patterns were found, but these were not statistically significant. The effect of failure feedback on pain avoidance was moderated by trait-NA. Only in the subgroup of patients who scored low on trait-NA did failure feedback decrease pain avoidance. State-NA did not mediate the effects of feedback. In line with previous findings, pain-related fear resulted in lower pain tolerance. Moreover, this study was the first to show that pain-related fear predicted higher pain report in CLBP patients. Pain-related fear did not predict pain avoidance when pre-lifting pain and gender were controlled for. Finally, pre-lifting pain turned out to be the strongest predictor with regard to all pain measures. The role of pain-related fear and unexpected findings with regard to feedback are discussed as well as some clinical implications.

The cost diary: a method to measure direct and indirect costs in cost-effectiveness research.

From a societal perspective long-term clinical trials or follow-up studies should preferably not only include an evaluation of the health effect for the patient, but also an economic evaluation. In order to yield comprehensive medical and nonmedical resource use data, we at least partly depend on respondents' recall for collecting these costing data. A patient cost diary was developed in order to estimate total resource use, expenses, and lost production due to illness and treatment. We applied the cost diary in two randomized clinical trials evaluating the cost-effectiveness of behavioral rehabilitation in 205 fibromyalgia and chronic low back pain patients. The use of the diary was evaluated, studying the feasibility, the influence of the period of data collection on the results, and some aspects of validity. Eighty-five percent of the patients completed at least one diary and in total 68% of the diaries were returned. Although the results for the three alternative periods of data collection (keeping the diary 1 week every month, 2 weeks every 2 months, or a full year) were not significantly different, they were only moderately correlated. Finally, self-reported specialist care contacts were generally in agreement with data from an insurance company. However, for physiotherapy contacts there were differences between the self-reported and insurance data. This study shows how the cost diary might be used successfully in cost-effectiveness studies.

Does failure hurt? The effects of failure feedback on pain report, pain tolerance and pain avoidance.

In this study an experiment was conducted to examine whether failure experiences have an effect on pain report, pain tolerance and pain avoidance. Furthermore, it was investigated if negative affectivity (NA) affected the impact of failure feedback on pain report, either as a mediator, in the case of negative state affect, or as a moderator when NA as a personality trait was considered. Fifty-four healthy female volunteers were included and randomly assigned to one of three conditions: (1) failure feedback; (2) success feedback; (3) neutral control task. After the manipulation, subjects were given a cold pressor task in order to obtain pain measures. Regarding the effects of failure feedback on pain report, it was found that, in comparison with success feedback, failure feedback led to increased pain report. With regard to pain tolerance, pain was tolerated for longer when preceded by success feedback than when preceded by failure feedback. Differences between failure and control conditions did not reach significance. With regard to pain avoidance, no differences between the conditions were found. The hypothesized mediating role of negative state affect was not found. Though in the hypothesized direction, no significant effect was found for NA-trait moderating the influence of failure on pain. The discussion focuses on a number of research questions that remain to be answered, and the clinical relevance of the effects of failure and success experiences on pain report and pain tolerance.

Chronic low-back pain: what does cognitive coping skills training add to operant behavioral treatment? Results of a randomized clinical trial.

This study examined the supplemental value of a cognitive coping skills training when added to an operant-behavioral treatment for chronic low-back pain patients. The complete treatment package (OPCO) was compared with an operant program + group discussion (OPDI) and a waiting-list control (WLC). After the WL period, the WLC patients received a less protocolized operant program usually provided in Dutch rehabilitation centers (OPUS). Regression analyses showed that, compared with WLC, both OPCO and OPDI led to less negative affect, higher activity tolerance, less pain behavior, and higher pain coping and pain control. At posttreatment, OPCO led to better pain coping and pain control than OPDI. Calculation of improvement rates revealed that OPCO and OPDI had significantly more improved patients than OPUS on all the dependent variables. The discussion includes findings regarding treatment credibility, compliance, and contamination bias.

Pain catastrophizing predicts pain intensity, disability, and psychological distress independent of the level of physical impairment.

OBJECTIVE: The aim of the current study was to examine the relation between catastrophizing and pain intensity, pain-related disability, and psychological distress in a group of patients with chronic pain, controlling for the level of physical impairment. Furthermore, it was examined whether these relations are the same for three subgroups of chronic pain patients: those with chronic low back pain, those with chronic musculoskeletal pain other than low back pain, and those with miscellaneous chronic pain complaints, low back pain and musculoskeletal pain excluded. DESIGN: Correlational, cross-sectional. PATIENTS AND SETTING: Participants in this study were 211 consecutive referrals presenting to a university hospital pain management and research center, all of whom had a chronic pain problem. RESULTS: Overall, chronic pain patients who catastrophize reported more pain intensity, felt more disabled by their pain problem, and experienced more psychological distress. Regression analyses revealed that catastrophizing was a potent predictor of pain intensity, disability, and psychological distress, even when controlled for physical impairment. No fundamental differences between the three subgroups were found in this respect. Finally, it was demonstrated that there was no relation between physical impairment and catastrophizing. CONCLUSIONS: It was concluded that for different subgroups of chronic pain patients, catastrophizing plays a crucial role in the chronic pain experience, significantly contributing to the variance of pain intensity, pain-related disability, and psychological distress. These relations are not confounded by the level of physical impairment. Some clinical implications of the results are discussed. Finally, the authors concluded that these results support the validity of a cognitive-behavioral conceptualization of chronic pain-related disability.

A behavioral treatment for sitting and standing intolerance in a patient with chronic low back pain.

This study reports on the effectiveness of an individualized shaping treatment program for sitting and standing intolerance in a patient with chronic low back pain following a laminectomy for removal of an intradural tumor. Functional assessment of sitting and standing tolerance, observation of pain behaviors, and a self-report measure regarding the pain experience were carried out during baseline, treatment, posttreatment, and at a 6-month follow-up. By the end of the 6-week inpatient treatment, the patient was able to stand still for 25 min and to sit for 15 min. The overall pain behavior diminished significantly. These findings underscore the importance of relatively simple and cost-effective individualized behavioral programs for chronic pain patients.

Dutch version of the Pain Vigilance and Awareness Questionnaire: validity and reliability in a pain-free population.

The current study examined validity and reliability of the Pain Vigilance and Awareness Questionnaire (PVAQ) in two samples of healthy college students. Exploratory and confirmatory factor analysis showed that a two-factor model of the PVAQ was most suitable in the present study. The first factor could be referred to as attention to pain whereas the second factor could be specified as attention to changes in pain. With regard to the convergent and divergent validity, the PVAQ was found to correlate highly with related constructs like catastrophising (PCS) and general body vigilance (BVQ). The correlation between PVAQ and pain-related fear (FPQ) was moderate, whereas correlations with unrelated constructs like trait anxiety (STAI-T) and fear of spiders (FSQ) were low. Furthermore, the PVAQ showed good internal consistency and fair test-retest reliability. Altogether, these findings suggest that the PVAQ is a valid and reliable measure of pain vigilance in healthy individuals. The results of this study can be regarded as a starting point for further validation of the PVAQ in clinical pain populations. Implications for future research and treatment interventions are discussed.

Graded exposure in vivo in the treatment of pain-related fear: a replicated single-case experimental design in four patients with chronic low back pain.

The aim of this investigation was to examine the effectiveness of a graded exposure in vivo treatment with behavioural experiments as compared to usual graded activity in reducing pain-related fears, catastrophising and pain disability in chronic low back pain patients reporting substantial fear of movement/(re)injury. Included in the study were four consecutive CLBP patients who were referred for outpatient behavioural rehabilitation, and who reported substantial fear of movement/(re)injury (Tampa Scale for Kinesiophobia score>40). A replicated single-case cross-over design was used. After a no-treatment baseline measurement period, the patients were randomly assigned to one of two interventions. In intervention A, patients received the exposure first, followed by graded activity. In intervention B, the sequence of treatment modules was reversed. Sixty-three daily measures of pain-related cognitions and fears were recorded with visual analogue scales. Before and after the treatment, the following measures were taken: pain-related fear, pain catastrophising, pain control and pain disability. Using time series analysis on the daily measures of pain-related cognitions and fears, we found that improvements only occurred during the graded exposure in vivo, and not during the graded activity, irrespective of the treatment order. Analysis of the pre-post treatment differences also revealed that decreases in pain-related fear concurred with decreases in pain catastrophising and pain disability, and in half of the cases an increase in pain control. This study shows that the external validity of exposure in vivo also extends to the subgroup of chronic low back pain patients who report substantial fear of movement/(re)injury.

Behavioural treatment for chronic low back pain.

BACKGROUND: The treatment of chronic low back pain is not primarily focused on removing an underlying organic pathology, but at the reduction of disability through the modification of environmental contingencies and cognitive processes. Behavioural interventions are commonly used in the treatment of chronic (disabling) low back pain. OBJECTIVES: The objective of this systematic review was to determine if behavioural therapy is more effective than reference treatments for chronic non-specific low back pain, and which type of behavioural treatment is most effective. SEARCH STRATEGY: We searched the Medline, PsycLit databases, and the Cochrane Controlled Trials Register up to April 1999, Embase up to September 1999. We also screened references of identified randomised trials and relevant systematic reviews. SELECTION CRITERIA: Only randomised trials on any type of behavioural treatment for non-specific chronic low back pain were included. DATA COLLECTION AND ANALYSIS: Methodological quality assessment and data extraction was done by two reviewers independently. The magnitude of effect was assessed by computing a pooled effect size for each domain (i.e., behavioural outcomes, overall improvement, back pain specific and generic functional status, return to work, and pain intensity) using the random effects model. MAIN RESULTS: Only 6 studies (25%) were high quality. There is strong evidence (level 1) that behavioural treatment has a moderate positive effect on pain intensity (pooled effect size 0.62; 95% CI 0.25, 0.98), and small positive effects on generic functional status (pooled effect size 0.35; 95% CI -0.04, 0.74) and behavioural outcomes (pooled effect size 0.40; 95% CI 0.10, 0.70) of chronic low back pain patients when compared to waiting list controls or no treatment. There is moderate evidence (level 2) that an additional behavioural component to a usual treatment program for chronic low back pain has no positive short-term effect on generic functional status (pooled effect size 0.31; 95% CI - 0.01, 0.64), pain intensity (pooled effect size 0.03; 95% CI - 0.30, 0. 36) and behavioural outcomes (pooled effect size 0.19; 95% CI - 0.08, 0.45). REVIEWER'S CONCLUSIONS: Behavioural treatment seems to be an effective treatment for chronic low back pain patients, but it is still unknown what type of patients benefit most from what type of behavioural treatment.