Pain Experience in Individuals With Chronic Low Back Pain

Study Overview
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Brief Summary
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Low back pain is a very common musculoskeletal condition that affects many people each year regardless of age, gender, and ethnicity. Most people get better however, some continue suffering from painful episodes despite treatment. Self-management strategies for the management of chronic low back pain are very important to patients as they help them develop skills to manage their pain more effectively. However, self-management strategies are not always effective as expected. It is possible that the brain has become very sensitive to signals coming from peripheral parts of the body (e.g. low back) affecting the ability of patients to self-manage their condition. The aim of this study is to establish whether central sensitisation (sensitivity of the brain to peripheral signals) predicts how effective self-management approaches will be. On three different occasions, scheduled sessions will include a clinical assessment session and completion of a questionnaire booklet. The clinical assessment will measure three features of central sensitisation: 1) sensitivity to blunt pressure on the forearm, 2) changes in pain, felt during repeated light pricking of the forearm skin, and 3) reduction in pain that accompanies inflation of a blood pressure cuff on the opposite arm. Participant involvement at each session is expected to last for 70 minutes. Individuals over 18, diagnosed with chronic low back pain and enlisted to follow a pain management program are eligible to participate. The clinical assessments, questionnaire completion and subsequent statistical analysis are expected to be completed within 18 months of study commencement. Based on our findings, future research may use similar clinical assessment to identify people who might be helped to self-manage by using treatment that reduces central sensitisation.

Detailed Description
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Low Back Pain (LBP) is considered a common condition consisting of a set of complains (pain, muscle tension, or stiffness), manifesting primarily to the lower back region (below the costal margin and above the inferior gluteal folds). LBP may or may not include radiating pain to the lower limb and can be caused by a number of underlying pathologies with varying levels of severity [1]. The condition can be the result of complex interactions between multiple physical and psychological factors including osteoarthritis (OA), degenerated discs, disc herniation, muscle dysfunction, obesity, poor posture, mental illness, negative affect (stress, anxiety, depression) [2]. LBP lifespan incidence appears to be 58-84% while it is estimated that 11% of males and 16% of females suffer from chronic LBP at any point in time [3]. It is expected that 40-50% of individuals suffering from acute LBP will continue to experience pain at three months and will demonstrate little or none further improvement, while 60-70% of those who improve will relapse within a year [4]. The global prevalence of LBP demonstrates continuously growing trends with a 17.3% increase in the last 10 years [5]. Self-management (SM) support is a portfolio of techniques and tools to help patients choose healthy behaviours as well as a fundamental transformation of the patient-caregiver relationship into a collaborative partnership [6]. Self-management support has to incorporate in its approach elements that aim to increase patients' self-efficacy, develop problem-solving, decision-making and goal-setting skills as well as to promote partner-like behaviour between patients and health professionals [7]. SM interventions pose as ideal rehabilitation strategies for chronic low back pain (CLBP) as they aim to address biological (neurophysiological, deconditioning, lifestyle) and psychosocial (self-efficacy, maladaptive beliefs, anxiety/depression) factors that have been identified as risk factors for poor outcome [8, 9] and are negatively affected by central sensitisation (CS) [10]. SM interventions are designed to be cost-effective by reducing health care utilisation associated with LBP [11]. Self-management programs (SMP) for CLBP demonstrate only small to moderate effects for long-term improvements in pain and disability. Currently, it is not known what factors predict effective self-management. Evidence of CS varies between individuals with chronic pain, and may contribute to the relatively poor efficacy of SMPs. CS is a marker of widespread and centrally augmented pain that refers to those neurophysiological processes that can occur throughout the central nervous system (CNS) distribution, leading to changes in the spinal cord as well as in the brain [12]. The presence of CS increases the complexity of the clinical picture [13] and negatively affects a range of outcomes (e.g. pain, disability, negative affect, quality of life) following treatment [14]. CS is not present within all patients with chronic pain [15] rendering identification of those patients and decision-making for the right management approach even harder [16]. Patients with potential development of CS should receive treatment that address the full biopsychosocial clinical spectrum consisting of cognitive behavioural therapy (CBT) as well as therapeutic pain neuroscience education [17]. Changes in pain mechanisms may explain the moderate levels of evidence for the effectiveness of self-management (SM) interventions in LBP populations [7] as CS has been shown to negatively affect the perception of back pain, pain-related disability and lead to poor physical and mental health-related quality of life as well as to greater levels of depression and anxiety [10]. Quantitative Sensory Testing (QST) is a reliable [18] and valid [19] method to assess for the presence of CS and demonstrates predictive capacity in relation to musculoskeletal (MSK) treatment outcomes [20]. The testing consists of pressure pain threshold (PPT), punctate thresholds, temperature sensitivity, temporal summation (TS) and conditioned pain modulation (CPM) used to quantify noxious or innocuous stimuli within healthy individuals and patients alike [21]. QST has been used, among others, as a screening and assessment tool for sensory abnormalities in patients with pain disorders [21], as well as to assist in the stratification of patients [22] and evaluate the clinical aspects of peripheral and CS [23]. The STarT Back screening tool [24] was developed for individuals of LBP with the aim to identify prognostic indicators that could potentially assist decision making concerning initial treatment options in primary care [25]. Start Back has been formally validated, displaying satisfactory reliability, and has demonstrated that a stratified management approach displays higher health gains for patients with LBP than a non-stratified one [26]. Nevertheless, the tool's predictive performance has not been examined when other biomarkers (CS) are included as prognostic indicators. Findings from this research will have an impact on differential diagnosis of chronic pain and CS identification as potential prognostic indicators for self-management. The results will assist effective patient subgrouping (stratification) based on CS measurements, aid appropriate self-management approaches in CLBP and potentially other chronic musculoskeletal pain states.

Official Title
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Pain Experience in Individuals With Chronic Low Back Pain: a Cohort Study

Conditions
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Low Back Pain

Intervention / Treatment
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* Diagnostic Test: Quantitative Sensory Testing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: have the ability to give informed consent. be 18 years old or over be diagnosed with chronic LBP be enlisted for participation in a self-management program be able to speak and understand English as all questionnaires are validated in the English language. Exclusion Criteria: Inability to give informed consent due to cognitive impairment or otherwise Inability to understand key aspects of the study due to cognitive impairment or otherwise Patients giving history of additional co-morbidities such as cancer, diabetic neuropathies, fractures or other conditions causing greater disability than their back pain. Pregnancy
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sensitised<br>Participants with sensitisation that significantly deviates from the normal mean as assessed by Quantitative Sensory Testing | Diagnostic Test: Quantitative Sensory Testing<br>* PPT: An electronic data collection unit will be used featuring an electronic algometer connected with a laptop where the amount of pressure will be displayed on the screen. When the pressure pain detection threshold is reached (the point where the pressure sensation starts to be experienced as pain), the individual will press a button at a handheld device, that will automatically store the pressure value in the system and serve as an indication, for the examiner, to stop the testing. TS: A pinprick stimulator (Weight: 256mNewton) will be used. The examiner will apply the pen that features a retractable blunt needle in a repetitive manner (once per second for ten seconds). The individual will be asked for the intensity of pain (NRS) at the first and at the last time and the given score will be noted. CPM: A manual blood pressure sphygmomanometer will be used in conjunction with the electronic algometer described above (PPT).<br>* Other names: Conditioned Pain Modulation (CPM);|
| Non-sensitised<br>All other participants with sensitisation that is not significantly deviating from the normal mean as assessed by Quantitative Sensory Testing | Diagnostic Test: Quantitative Sensory Testing<br>* PPT: An electronic data collection unit will be used featuring an electronic algometer connected with a laptop where the amount of pressure will be displayed on the screen. When the pressure pain detection threshold is reached (the point where the pressure sensation starts to be experienced as pain), the individual will press a button at a handheld device, that will automatically store the pressure value in the system and serve as an indication, for the examiner, to stop the testing. TS: A pinprick stimulator (Weight: 256mNewton) will be used. The examiner will apply the pen that features a retractable blunt needle in a repetitive manner (once per second for ten seconds). The individual will be asked for the intensity of pain (NRS) at the first and at the last time and the given score will be noted. CPM: A manual blood pressure sphygmomanometer will be used in conjunction with the electronic algometer described above (PPT).<br>* Other names: Conditioned Pain Modulation (CPM);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Self-management | Self-management will be assessed with the Health Education Impact Questionnaire (heiQ) that measures the ability of a patient to self-manage their condition and features 40 questions that spread across 8 distinct domains (Health Directed Behavior: 4 items; Positive and Active Engagement in Life: 5 items; Self-Monitoring and Insight: 6 items; Constructive Attitudes and Approaches: 5 items; Skill and Technique Acquisition: 4 items; Social Integration and Support: 5 items Health Service Navigation: 5 items; and Emotional Wellbeing: 6 items). Each item is rated with a 4-level scale (Strongly agree to Strongly disagree) and a number (1-4) is allocated that leads to the calculation of a mean. No single value can be produced for heiQ. Rather, each domain must be used individually. The higher the value the best the self-management ability in all domains apart from Emotional Wellbeing where a high value represents a low self-management ability. | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Severity: Numerical Rating Scale (NRS) | Pain will be assessed with the Numerical Rating Scale (NRS) where patients will be asked to rate their current pain on a scale from 0 to 10 with 0 indicating no pain and 10 the worst pain imaginable. | 3 months | 
| Levels of Disability | Disability will be assessed with the Roland-Morris Disability Questionnaire (RMDQ) where patients are asked to tick a box if they agree with 24 statements regarding their ability to perform certain activities (dressing, housework, walking). If the don't agree with the statement (able to perform thoe activities) they need to leave the tick-box blank or unchecked. Every agreement (tick) counts as a point and an absolute value is formed (min: 0, max: 24). The higher the value the higher the disability level. | 3 months | 
| Patient Quality of Life: EQ-5D-5L questionnaire | Quality of Life will be assessed with the EQ-5D-5L questionnaire. EQ-5D-5L has two components: health state description and evaluation. In the description part, health status is measured in terms of 5 dimensions (5D); mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The respondents self-rate their level of severity for each dimension using a five-level (5L) scale (no problem to extremely severe). Each dimension can be used for analysis as a categorical variable or combined with the others as a 5-digit value according to responses (example 11231). On a single dimension, a categorical value of 1 signifies no problem and a value of 5 extremely severe problem. Similarly, a combined value of 11111 shows excellent quality of life whereas a value of 55555 shows a severely affected quality of life. | 3 months | 
| Self-efficacy: Pain Self-efficacy Questionnaire (PSEQ) | Self-efficacy will be assessed with the Pain Self-efficacy Questionnaire (PSEQ) where patients are asked to indicate their levels of confidence with a 0-6 scale (0 indicates not at all confident and 6 extremely confident)on an array of 10 questions. A sum of all responses is calculated (60 being the maximum) for analysis. The higher the value the higher the levels of self-efficacy. | 3 months | 
| Fatigue | Fatigue will be assessed with the Fatigue Severity Scale (FSS) where patients are asked to indicate their levels of agreement with a 0-7 scale (0 indicates strong disagreement and 7 strong agreement) at 9 questions. A sum of all responses is calculated (63 being the maximum) for analysis. The higher the value the higher the level of fatigue. Also, patients are asked to rate their global fatigue on a 0-10 scale with 0 being worst and 10 being normal fatigue. This sub-scale will be used on its own for analysis. | 3 months | 
| Anxiety | Anxiety will be assessed with the Anxiety part of the Hospital Anxiety and Depression Scale (HADS) where patients are asked to indicate their levels of emotion frequency with a 4-level scale (0-3: 0 indicates never and 3 all the time) at 7 questions. A sum of all responses is calculated (21 being the maximum) for analysis. The higher the value the higher the levels of anxiety. | 3 months | 
| Depression | Depression will be assessed with the Depression part of the Hospital Anxiety and Depression Scale (HADS) where patients are asked to indicate their levels of emotion frequency with a 4-level scale (0-3: 0 indicates all the time and 3 never) at 7 questions. A sum of all responses is calculated (21 being the maximum) for analysis. The higher the value the higher the levels of depression. | 3 months | 
| Catastrophization | Catastrophization will be assessed with the Pain Catastrophizing Scale (PCS) where patients are asked to indicate their levels of belief frequency with a 5-level scale (0-4: 0 indicates not at all and 3 all the time) at 13 questions. A sum of all responses is calculated (52 being the maximum) for analysis. The higher the value the higher the levels of catastrophizing. | 3 months | 
| Kinesiophobia | Kinesiophobia will be assessed with the Tampa Scale for Kinesiophobia (TSK) where patients are asked to indicate their levels of agreement with a 4-level scale (1-4: 1 indicates not at all and 3 all the time) at 17 questions. A sum of all responses is calculated (68 being the maximum) for analysis. The higher the value the higher the levels of kinesiophobia. | 3 months | 
| Neuropathic Pain: Pain-DETECT questionnaire (PD-Q) | Neuropathic pain will be assessed with the Pain-DETECT questionnaire (PD-Q) where patients are firstly asked to describe the course of their pain by choosing one of 3 different pictures. A value has been allocated to each picture (-1, 0, +1 and +1). Secondly they are asked to indicate (yes or no) whether their pain radiates to a different part of their body. Yes is marked with +2 whereas No with 0. Thirdly, patients are asked to indicate their symptom intensity with a 6-level scale (0-5: 0 indicates never and 5 very strongly) at 7 questions. A sum of all responses is calculated and a final value is formed with the addition of the values from step one and two (38 being the maximum) for analysis. The higher the value the higher the levels of neuropathic pain. | 3 months | 
| Widespread Pain | Widespread pain will be assessed with the the use of a blank body manikin where patients are asked to draw the areas of pain on the manikin. Unbeknownst to patients, the manikin is divided into 46 body areas. A categorical variable is entered (1 for pain on the area, 0 for no pain) according to the pain distribution of the patients. No single value can be produced for analysis. Areas distant to the primary area of pain (Lower Back), like the chest or the forearm, will be used as independent variables in a multivariate regression model. | 3 months | 
| Fibromyalgia Severity | Fibromyalgia severity will be assessed with the Fibromyalgia Severity Scale (FMSS) where patients are firstly asked to tick a box on a body manikin if they feel pain on that area. Each tick is marked with 1 point. Then, patients are asked to indicate their symptom severity with a 4-level scale (0-3: 0 = no problem and 3 = severe) at 3 questions about tiredness, sleep and forgetfulness. A sum of all responses is calculated and is added to the total manikin value. Lastly, patients are asked to indicate whether they experienced headaches, depression and abdominal pain amongst 37 other symptoms. If they did, a point for each symptom is added on their overall mark (min: 0, max: 31). The higher the overall value the higher the severity of fibromyalgia. | 3 months | 
| Health care utilisation | Health care utilisation will be measured with the unvalidated Health Care Utilisation Questionnaire for Low Back Pain (HCUQ-LBP) where patients will be asked to indicate the type and amount of health care utilisation (visits to hospital, visits/calls to general practitioners (GPs) and practice nurses, use of social care, physiotherapists, chiropractors, psychologists, osteopaths and occupational therapists) in the last 3 months. Every health care use will be marked with a point and a total value will be produced for analysis (min: 0, max: any). The higher the value the higher the health care utilisation. | 3 months | 
| Medication type utilisation | Medication type utilisation will be determined when patients will be asked to record on a specially designed sheet the type of received medication in the last three months. Separate categories will be formed according to medication type (e.g. anti-inflammatory non-steroidal drugs, steroids, opioids, non-opioids) and a categorical variable will be stored (1 for yes, 0 for no) on these categories. No single value can be produced for analysis for this sub-questionnaire. Categories of medication types will be used as categorical independent variables in a multivariate regression model. | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Low Back Pain, Central Sensitisation, Hyperalgesia, Hypersensitivity