[Avoidance-endurance fast screening (AE-FS) : Content and predictive validity of a 9­item screening instrument for patients with unspecific subacute low back pain]. / Avoidance-Endurance Fast-Screen (AE-FS) : Inhalts- und Vorhersagevalidität eines 9­Item-Screeninginstruments für Patienten mit unspezifischen subakuten Rückenschmerzen.

BACKGROUND: Among screening measures to assess psychosocial risk factors (yellow flags) for chronic low back pain (LBP) economic tools which address dysfunctional endurance pain responses besides emotional distress and fear-avoidance pain processing are rare. Targeting contrasting types of pain processing might improve stratified patient counselling. OBJECTIVE: The aim of the study was to develop a short screening method, based on the avoidance-endurance model of pain and to investigate the prognostic validity for pain intensity, disability and physical function. MATERIAL AND METHODS: A prospective observational study was carried out on 144 patients with subacute LBP (<3 months) from 7 general practitioners and 5 orthopedic practices. The 9­item avoidance-endurance fast screening (AE-FS) was derived from a previous 37-item screening using correlational and receiver operating curve (ROC) analyses and the agreement of subgrouping was calculated using Cohen's kappa. Primary outcomes were assessed after 6 months by mail in 124 patients (86%). Endpoints were pain intensity and disability. RESULTS: The classification of subgroups as high and low risk by both measures had considerable agreement with a value of 0.71 (Cohen's Kappa). The sensitivity to predict pain intensity >2 was high (82%) as was the positive predictive value (80%) but the negative predictive value was moderate (61%). The ROC (AUC) characteristics (95% confidence interval CI) were 0.70 (0.60-0.80) for pain intensity and for limitations in the pain disability index (PDI) 0.70 (0.55-0.87). DISCUSSION: The 9­item AE-FS displayed sufficient prognostic validity for all three outcomes in a sample of primary care patients with subacute LBP. The differentiation of the high-risk patients into fear-avoidance and endurance-related pain processing enables the physician to provide an individualized counselling with the aim of a healthy balance between stress and relaxation.

[Cognitive bias research and depression in chronic pain]. / Cognitive-bias-Forschung und Depressivität bei chronischem Schmerz.

Chronic back pain is of enormous health and economic relevance for industrialized countries because a small group of patients with chronic disease is responsible for a large proportion of medical costs. The prevention of chronic disease is therefore a primary goal in the treatment of patients with acute low back pain. Psychological factors are the central risk factors for later chronification. Above all, especially depressive symptoms and occupational distress, as well as various maladaptive forms of pain management are central risk factors. It remains unclear which exact cognitive mechanisms are involved in the maintenance and reinforcement of depression and pain-related disability. In this review, the current results of cognitive bias research and theoretical models are presented and summarized regarding the relationship between chronic pain and depression. Finally, the clinical implications and recommendations for clinical research will be presented.

Brain structural alterations associated with dysfunctional cognitive control of pain in patients with low back pain.

BACKGROUND: Recent evidence has shown that chronic back pain (CBP) can lead to functional alterations in the circuitry underlying the cognitive control of pain. Thought suppression (TS) is a common type of cognitive control of pain. Previous research has shown that TS has paradoxical effects that may increase the awareness of pain. Pain-related TS may also increase individuals' attention to pain, which may also increase pain sensation, but thus far, the relationship between pain-related TS and structural brain alterations is unknown. METHODS: In this study, we investigated a group of 30 patients 6 months after lumbar disc surgery by applying voxel-based morphometry (VBM) to identify brain regions correlated with TS scores. RESULTS: Since pain-related TS has been positively correlated with depression, all calculations were controlled for depression and age. VBM revealed a negative correlation between the TS score and regional grey matter volume (GMV) in the left superior temporal gyrus (LSTG) and the left middle temporal gyrus (L MTG), which is part of the left temporoparietal junction (L TPJ). In addition, a mediation analysis revealed a significant mediation effect of the pain-related TS on the association between GMV of the left TPJ and reported pain intensity in the last 7 days. CONCLUSIONS: These findings are consistent with previous research on the dysfunctional cognitive control of pain and may therefore provide potential insights into the neural substrates of obstructive cognitive control in chronic low back pain, with a special emphasis on pain-related TS. SIGNIFICANCE: The link between pain-related thought suppression and brain morphology may provide a new perspective on the understanding of cognitive control of pain in chronic low back pain, which may help improve cognitive behavioural therapy.

[Pilot study on pain response patterns in chronic low back pain. The influence of pain response patterns on quality of life, pain intensity and disability]. / Schmerzverarbeitungspattern bei chronischen Rückenschmerzen Pilotstudie. Der Einfluss von "Avoidance-Endurance"-Modell-Pattern auf die Lebensqualität, Schmerzintensität und Beeinträchtigung.

BACKGROUND: The variables pain intensity (SI), disability (DS) and quality of life (QoL) belong to a set of primary patient-based outcomes in chronic low back pain (CLBP). The avoidance-endurance model (AEM) assumes three maladaptive and one adaptive pain response pattern. The purpose of this study was to study the level and course of the outcomes with regard to the four AEM patterns. PATIENTS AND METHODS: A total of 52 CLBP inpatients were investigated at 2 points in time: during the first days after admission and 6 months after the acute exacerbation of pain. Differences between AEM patterns were analyzed with repeated measurement analyses of variance. RESULTS: Groups differences were found for SI (F((3, 48))=2.82, p<0.05), general (F((3, 48))=6.78, p<0.05) and health-related QoL (F((3, 48))=5.99, p <0.05). In contrast, for the variable disability only a significant time effect was found. CONCLUSION: The results show differences in the level and process of SI, DS and QoL between the subgroups. An AEM-based classification of subgroups is also reasonable for CLPB patients.