Examining Racial and SocioEconomic Disparities (ERASED) in Chronic Low Back Pain Study

Study Overview
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Brief Summary
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It remains unclear whether certain disadvantaged subgroups of society may be at heightened risk for poor chronic low back pain (cLBP) outcomes. The overall aim of this study is to incorporate a socioeconomic framework to characterize racial differences in cLBP severity and disability. Further, guided by the theory of fundamental causes, we aim to examine racial and socioeconomic status differences in biopsychosocial predictors of cLBP outcomes, particularly endogenous pain modulation.

Detailed Description
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Experimental session 1 Resting Blood Pressure and Body Mass Index will be assessed. Participants will complete the Rapid Estimation of Adult Literacy Measure-Short Form (REALM-SF) to determine health literacy. Participants will complete multiple questionnaires to measure Socioeconomic Status, Clinical Pain Assessment and Depression Scale. All participants will undergo quantitative sensory testing for assessment of endogenous pain modulation using painful heat, mechanical, and cold stimuli in a laboratory session lasting approximately 1 hour. Between Experimental Session 1 and Experimental Session 2 Sleep assessment: Sleep data will be collected by participants in their own homes using objective and subjective measures of their sleep. Participant instructions for how to collect and record their own sleep data will be provided at the end of study session 1. Experimental Session 2 Experimental session 2 will take place in the CCTS Clinical Research Unit (CRU) All blood will be collected as part of a single draw by research nurses. Participants will complete multiple questionnaires to measure Clinical Pain Assessment and Coping Strategies. Participants will then complete a battery of ecologically valid movement tasks that include: 1) getting in and out of a bed; 2) sitting in a chair, transitioning to a standing position, and then sitting again, and 3) lifting, Performance Battery (SPPB) and the Timed Up and Go test (TUG). Blood will be processed and stored and then used to measure Vitamin D, CRP assays and Oxytocin. Finally follow up data will be collected by phone once per week for four weeks following the completion of study session 2.

Official Title
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Racial and Socioeconomic Differences in Chronic Low Back Pain

Conditions
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Back Pain Lower Back Chronic

Intervention / Treatment
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* Other: QST


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Chronic low back pain that has been going on consistently for the last 6 months. Exclusion Criteria: Surgery (fusion, Laminectomy) in the last year, accident or trauma in the last year, uncontrolled high blood pressure, heart disease, cancer, diabetes HbA1c > 7%, Ankylosing Spondylitis, Infection, Parkinson's Disease, Multiple Sclerosis, Epilepsy, Stroke, Seizure (non-epileptic), Systemic Lupus Erythematosus, Fibromyalgia, Raynaud's disease, Major Depression/Bipolar Disorder, HIV

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| African American/Black QST<br>This group will consist of a full range of socioeconomic status in African American/Black individuals with chronic low back pain. | Other: QST<br>* All participants will undergo quantitative sensory testing for assessment of endogenous pain modulation using painful heat, mechanical, and cold stimuli in a laboratory session lasting approximately 1 hour.<br>|
| Caucasian/White QST<br>This group will consist of a full range of socioeconomic status in Caucasian/White individuals with chronic low back pain. | Other: QST<br>* All participants will undergo quantitative sensory testing for assessment of endogenous pain modulation using painful heat, mechanical, and cold stimuli in a laboratory session lasting approximately 1 hour.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Clinical Pain Severity | Participants will self-report a number between 0 - 100 describing the intensity of their low back pain, such that 0 = no pain and 100 = the most intense pain imaginable. Any integer from 0 to 100 can be provided. | Baseline to one week. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain threshold | Pain threshold refers to the intensity at which a stimulus is first perceived as painful. Heat stimuli will be delivered using a computer-controlled thermal stimulation system with a 30 millimeter X 30 millimeter probe. From a baseline of 32 degrees Celsius, the probe temperature will increase at a rate of .5 degrees Celsius/second until the participant responds by pressing a button on a handheld device. For heat pain threshold, participants will be instructed to press the button when the sensation first becomes painful | Baseline | 
| Pain tolerance | Pain tolerance refers to the maximum amount of pain produced by a stimulus that a person is able/willing to tolerate. Heat stimuli will again be delivered using the computer-controlled thermal stimulation system. From a baseline of 32 degrees Celsius, the probe temperature will increase at a rate of .5 degrees Celsius/second until the participant responds by pressing a button on a handheld device. For heat pain tolerance, participants will be instructed to press the button when they are no longer willing to tolerate the painful sensation. | Baseline | 
| Temporal summation of pain | Temporal summation of pain refers to a form of endogenous pain facilitation characterized by the perception of increased pain despite constant or even reduced peripheral afferent input. Temporal summation is presumed to be the psychophysical manifestation of wind-up. Wind-up is a phenomenon where repetitive stimulation of C primary afferents at rates greater than 0.3 Hertz produces a slowly increasing response of second-order neurons in the spinal cord. | Baseline | 
| Conditioned pain modulation | A routinely used quantitative sensory testing protocol for the measurement of endogenous pain inhibition is conditioned pain modulation, which refers to the reduction in pain from one stimulus (the test stimulus) produced by the application of a second pain stimulus at a remote body site (the conditioning stimulus). Conditioned pain modulation is believed to reflect the perceptual manifestation of diffuse noxious inhibitory controls, whereby ascending projections from one noxious stimulus activate supraspinal structures that trigger descending inhibitory projections to the dorsal horn. | Baseline | 
| C-reactive protein | A marker of systemic pro-inflammation | One week follow up | 
| Fibrinogen | A marker of systemic pro-inflammation | One week follow up | 
| Serum amyloid A | A marker of systemic pro-inflammation | One week follow up | 
| Vitamin D | hormone | One week follow up | 
| Oxytocin | Hormone | One week follow up | 
| Sleep quality | Measured via actigraphy | Between baseline and one week follow-up | 
| Self-reported disability | To be assessed with the Oswestry Low Back Pain Questionnaire. This measure is patient-completed questionnaire which gives a subjective percentage score of level of function (disability) in activities of daily living in those with low back pain. | One week follow up | 
| Evoked pain with movement | Participants will complete a serious of movements including getting in and out of bed as well as lifting a crate from the ground to a tabletop. They will provide a rating from 0 - 100 indicating how painful it was to complete each movement (0 = no pain, 100 = most intense pain imaginable). | One week follow up | 
| Functional performance | Participants will complete the short physical performance battery. This assessment represents is a group of measures that combines the results of the gait speed, chair stand and balance tests. | One week follow up | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Low back pain, Chronic pain, Health disparities in chronic low back pain