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Åström J, Holmström L, Karshikoff B, Andreasson A, Kemani MK. Evaluating the construct validity and internal consistency of the Sickness Questionnaire in a Swedish sample of adults with longstanding pain. Scand J Pain 2022; 22:88-96. [PMID: 34931508 DOI: 10.1515/sjpain-2021-0070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 11/26/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Low-grade inflammation is a possible contributing factor in the development and persistence of chronic primary pain syndromes. Related to inflammatory activity is sickness behavior, a set of behavioral responses including increased pain sensitivity, fatigue, malaise, fever, loss of appetite, as well as depressive behavior and anhedonia. To capture these behavioral responses and their relation to longstanding pain, psychometrically sound self-report questionnaires are needed. The Sickness Questionnaire (SicknessQ) was developed to assess self-reported sickness behavior based on studies on acute immune activation while maintaining relevance for persistent conditions. The aim of the current study was to evaluate aspects of the validity and reliability of the SicknessQ in a Swedish sample of persons with longstanding pain. METHODS Aspects of construct validity were evaluated by means of performing a confirmatory factor analysis (CFA) (testing structural validity) and by relevant hypothesis testing i.e., that ratings of sickness behavior in combination with other related factors (e.g., depression and anxiety) would be significantly related to ratings of avoidance. Reliability was evaluated by means of analyzing the internal consistency of items. RESULTS Following the CFA, a non-significant Chi-Square test (χ2 [32, N=190] = 42.95, p=0.094) indicated perfect model fit. Also, the relative fit indices supported adequate model fit (CFI = 0.978; TLI = 0.969; RMSEA = 0.0430). Sickness behavior (p<0.0001), depression (p<0.05) and pain duration (p<0.05) significantly contributed to the regression model, explaining 45% of the total variance in avoidance. Internal consistency was adequate, as indicated by a Cronbach's α value of 0.82 for the entire questionnaire. CONCLUSIONS Results indicate that the SicknessQ has adequate structural validity as well as adequate internal consistency, and is significantly associated with avoidance. The SicknessQ appears to have utility as a self-report questionnaire to assess symptoms of sickness behavior for adults with longstanding pain.
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Affiliation(s)
- Jenny Åström
- Theme Women's Health and Allied Health Professionals, Medical Unit Medical Psychology, Karolinska University Hospital, Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Linda Holmström
- Theme Women's Health and Allied Health Professionals, Medical Unit Medical Psychology, Karolinska University Hospital, Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Bianka Karshikoff
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Social Studies, University of Stavanger, Stavanger, Norway
| | - Anna Andreasson
- Stress Research Institute, Stockholm University, Stockholm, Sweden
- Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Department of Psychology, Macquarie University, Macquarie Park, NSW, Australia
| | - Mike K Kemani
- Theme Women's Health and Allied Health Professionals, Medical Unit Medical Psychology, Karolinska University Hospital, Stockholm, Sweden
- Stress Research Institute, Stockholm University, Stockholm, Sweden
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Jonsjö MA, Åström J, Jones MP, Karshikoff B, Lodin K, Holmström L, Agréus L, Wicksell RK, Axelsson J, Lekander M, Olsson GL, Kemani M, Andreasson A. Patients with ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome) and chronic pain report similar level of sickness behavior as individuals injected with bacterial endotoxin at peak inflammation. Brain Behav Immun Health 2020; 2:100028. [PMID: 38377418 PMCID: PMC8474484 DOI: 10.1016/j.bbih.2019.100028] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/13/2019] [Accepted: 12/13/2019] [Indexed: 12/30/2022] Open
Abstract
Background Chronic sickness behavior is implicated in ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome) and chronic pain but the level of subjective sickness behavior in these conditions has not been investigated or compared to other clinical and non-clinical samples, or to the level in experimental inflammation. Furthermore, the relationship between sickness behavior and self-rated health and functioning is not known in patients with ME/CFS and chronic pain. The aim of the present study was to investigate how sickness behavior in patients with chronic conditions differs from that in individuals with experimental acute sickness, primary care patients, the general population and healthy subjects. In addition, we wanted to explore how sickness behavior is related to self-rated health and health-related functioning. Methods Sickness behavior was quantified using the sickness questionnaire (SicknessQ). Self-ratings were collected at one time-point in 6 different samples. Levels of sickness behavior in patients with ME/CFS (n = 38) and patients with chronic pain (n = 190) were compared to healthy subjects with lipopolysaccharide(LPS)-induced inflammation (n = 29), primary care patients (n = 163), individuals from the general population (n = 155) and healthy subjects (n = 48), using linear regression. Correlations and moderated regression analyses were used to investigate associations between sickness behavior and self-rated health and health-related functioning in ME/CFS, chronic pain and the general population. Results LPS-injected individuals (M = 16.3), patients with ME/CFS (M = 16.1), chronic pain (M = 16.1) and primary care patients (M = 10.7) reported significantly higher SicknessQ scores than individuals from the general population (M = 5.4) and healthy subjects (M = 3.6) all p's < 0.001). In turn, LPS-injected individuals, patients with ME/CFS and chronic pain reported significantly higher SicknessQ scores than primary care patients (p's < 0.01). Higher levels of sickness behavior were associated with poorer self-rated health and health-related functioning (p's < 0.01), but less so in patients with ME/CFS and chronic pain than in individuals from the general population. Conclusions Patients with ME/CFS and chronic pain report similar high levels of sickness behavior; higher than primary care patients, and comparable to levels in experimental inflammation. Further study of sickness behavior in ME/CFS and chronic pain populations is warranted as immune-to-brain interactions and sickness behavior may be of importance for functioning as well as in core pathophysiological processes in subsets of patients.
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Affiliation(s)
- Martin A. Jonsjö
- Stress Research Institute, Stockholm University, Stockholm, Sweden
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
- Behavior Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Jenny Åström
- Behavior Medicine, Karolinska University Hospital, Stockholm, Sweden
- Dept. of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | | | - Bianka Karshikoff
- Dept. of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Karin Lodin
- Dept. of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Dept. of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Linda Holmström
- Behavior Medicine, Karolinska University Hospital, Stockholm, Sweden
- Dept. of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden
| | - Lars Agréus
- Dept. of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Rikard K. Wicksell
- Dept. of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - John Axelsson
- Stress Research Institute, Stockholm University, Stockholm, Sweden
- Dept. of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Mats Lekander
- Stress Research Institute, Stockholm University, Stockholm, Sweden
- Dept. of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Gunnar L. Olsson
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Mike Kemani
- Stress Research Institute, Stockholm University, Stockholm, Sweden
- Behavior Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Andreasson
- Stress Research Institute, Stockholm University, Stockholm, Sweden
- Dept. of Psychology, Macquarie University, NSW, Australia
- Dept. of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
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Riikilä TI, Pylväinen JI, Åström J. Friction of Shear-Fracture Zones. Phys Rev Lett 2017; 119:255501. [PMID: 29303320 DOI: 10.1103/physrevlett.119.255501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Indexed: 06/07/2023]
Abstract
A shear fracture of brittle solids under compression undergoes a substantial evolution from the initial microcracking to a fully formed powder-filled shear zone. Experiments covering the entire process are relatively easy to conduct, but they are very difficult to investigate in detail. Numerically, the large strain limit has remained a challenge. An efficient simulation model and a custom-made experimental device are employed to test to what extent a shear fracture alone is sufficient to drive material to spontaneous self-lubrication. A "weak shear zone" is an important concept in geology, and a large number of explanations, specific for tectonic conditions, have been proposed. We demonstrate here that weak shear zones are far more general, and that their emergence only demands that a microscopic, i.e., fragment-scale, stress relaxation mechanism develops during the fracture process.
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Affiliation(s)
- T I Riikilä
- Department of Physics and Nanoscience Center, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 Jyväskylä, Finland
- Arctic Center, Lapland University, 96101 Rovaniemi, Finland
| | - J I Pylväinen
- Department of Physics and Nanoscience Center, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 Jyväskylä, Finland
| | - J Åström
- CSC-It-center for science, P.O.Box 405, FIN-02101 Esbo, Finland
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Linnarsson MK, Hallén A, Åström J, Primetzhofer D, Legendre S, Possnert G. New beam line for time-of-flight medium energy ion scattering with large area position sensitive detector. Rev Sci Instrum 2012; 83:095107. [PMID: 23020419 DOI: 10.1063/1.4750195] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A new beam line for medium energy ion mass scattering (MEIS) has been designed and set up at the Ångström laboratory, Uppsala University, Sweden. This MEIS system is based on a time-of-flight (ToF) concept and the electronics for beam chopping relies on a 4 MHz function generator. Repetition rates can be varied between 1 MHz and 63 kHz and pulse widths below 1 ns are typically obtained by including beam bunching. A 6-axis goniometer is used at the target station. Scattering angle and energy of backscattered ions are extracted from a time-resolved and position-sensitive detector. Examples of the performance are given for three kinds of probing ions, (1)H(+), (4)He(+), and (11)B(+). Depth resolution is in the nanometer range and 1 and 2 nm thick Pt layers can easily be resolved. Mass resolution between nearby isotopes can be obtained as illustrated by Ga isotopes in GaAs. Taking advantage of the large size detector, a direct imaging (blocking pattern) of crystal channels are shown for hexagonal, 4H-SiC. The ToF-MEIS system described in this paper is intended for use in semiconductor and thin film areas. For example, depth profiling in the sub nanometer range for device development of contacts and dielectric interfaces. In addition to applied projects, fundamental studies of stopping cross sections in this medium energy range will also be conducted.
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Affiliation(s)
- M K Linnarsson
- KTH Royal Institute of Technology, School of Information and Communication Technology, Integrated Circuits and Devices, P.O. Box E229, SE-16440 Kista-Stockhom, Sweden.
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