Normality analysis of numeric rating scale scores in patients with chronic axial spine pain before and after medial branch blocks: a multicenter study.

OBJECTIVE: The statistical analysis typically used to compare pain before and after interventions assumes that scores are normally distributed. The present study evaluates whether numeric rating scale (NRS) scores, specifically NRS-11 scores, are indeed normally distributed in a clinically relevant cohort of adults with chronic axial spine pain before and after analgesic intervention. METHODS: Retrospective review from 4 academic medical centers of prospectively collected data from a uniform pain diary administered to consecutive patients after they had undergone medial branch blocks. The pain diary assessed NRS-11 scores immediately before injection and at 12 different time points after injection up to 48 hours. D'Agostino-Pearson tests were used to test normality at all time points. RESULTS: One hundred fifty pain diaries were reviewed, and despite normally distributed pre-injection NRS-11 scores (K2 = 0.655, P = .72), all post-injection NRS-11 data were not normally distributed (K2 = 9.70- 17.62, P = .0001-.008). CONCLUSIONS: Although the results of parametric analyses of NRS-11 scores are commonly reported in pain research, some properties of the NRS-11 do not satisfy the assumptions required for these analyses. The data demonstrate non-normal distributions in post-intervention NRS-11 scores, thereby violating a key requisite for parametric analysis. We urge pain researchers to consider appropriate statistical analysis and reporting for non-normally distributed NRS-11 scores to ensure accurate interpretation and communication of these data. Practicing pain physicians should similarly recognize that parametric post-intervention pain score statistics might not accurately describe the data and should expect articles to utilize measures of normality to justify the selected statistical methods.

[Evidence-based interventions to treat chronic low back pain: treatment selection for a personalized medicine approach : German version]. / Evidenzbasierte Interventionen zur Behandlung von chronischem Schmerz im unteren Rücken ­ Therapieauswahl für einen personalisierten Behandlungsansatz : Deutsche Fassung.

INTRODUCTION: Chronic low back pain (cLBP) is highly prevalent in the United States and globally, resulting in functional impairment and lowered quality of life. While many treatments are available for cLBP, clinicians have little information about which specific treatment(s) will work best for individual patients or subgroups of patients. The Back Pain Research Consortium, part of the National Institutes of Health Helping to End Addiction Long-termSM (HEAL) Initiative, will conduct a collaborative clinical trial, which seeks to develop a personalized medicine algorithm to optimize patient and provider treatment selection for patients with cLBP. OBJECTIVE: The primary objective of this article is to provide an update on evidence-based cLBP interventions and describe the process of reviewing and selecting interventions for inclusion in the clinical trial. METHODS: A working group of cLBP experts reviewed and selected interventions for inclusion in the clinical trial. The primary evaluation measures were strength of evidence and magnitude of treatment effect. When available in the literature, duration of effect, onset time, carryover effect, multimodal efficacy, responder subgroups, and evidence for the mechanism of treatment effect or biomarkers were considered. CONCLUSION: The working group selected 4 leading, evidence-based treatments for cLBP to be tested in the clinical trial and for use in routine clinical treatment. These treatments include (1) duloxetine, (2) acceptance and commitment therapy, (3) a classification-based exercise and manual therapy intervention, and (4) a self-management approach. These interventions each had a moderate to high level of evidence to support a therapeutic effect and were from different therapeutic classes.

CAPER: patient preferences to inform nonsurgical treatment of chronic low back pain: a discrete-choice experiment.

OBJECTIVE: We developed and used a discrete-choice measure to study patient preferences with regard to the risks and benefits of nonsurgical treatments when they are making treatment selections for chronic low back pain. METHODS: "CAPER TREATMENT" (Leslie Wilson) was developed with standard choice-based conjoint procedures (discrete-choice methodology that mimics an individual's decision-making process). After expert input and pilot testing, our final measure had 7 attributes (chance of pain relief, duration of relief, physical activity changes, treatment method, treatment type, treatment time burden, and risks of treatment) with 3-4 levels each. Using Sawtooth software (Sawtooth Software, Inc., Provo, UT, USA), we created a random, full-profile, balanced-overlap experimental design. Respondents (n = 211) were recruited via an emailed online link and completed 14 choice-based conjoint choice pairs; 2 fixed questions; and demographic, clinical, and quality-of-life questions. Analysis was performed with random-parameters multinomial logit with 1000 Halton draws. RESULTS: Patients cared most about the chance of pain relief, followed closely by improving physical activity, even more than duration of pain relief. There was comparatively less concern about time commitment and risks. Gender and socioeconomic status influenced preferences, especially with relation to strength of expectations for outcomes. Patients experiencing a low level of pain (Pain, Enjoyment, and General Activity Scale [PEG], question 1, numeric rating scale score<4) had a stronger desire for maximally improved physical activity, whereas those in a high level of pain (PEG, question 1, numeric rating scale score>6) preferred both maximum and more limited activity. Highly disabled patients (Oswestry Disability Index score>40) demonstrated distinctly different preferences, placing more weight on achieving pain control and less on improving physical activity. CONCLUSIONS: Individuals with chronic low back pain were willing to trade risks and inconveniences for better pain control and physical activity. Additionally, different preference phenotypes exist, which suggests a need for clinicians to target treatments to particular patients.

The Back Pain Consortium (BACPAC) Research Program: Structure, Research Priorities, and Methods.

In 2019, the National Health Interview survey found that nearly 59% of adults reported pain some, most, or every day in the past 3 months, with 39% reporting back pain, making back pain the most prevalent source of pain, and a significant issue among adults. Often, identifying a direct, treatable cause for back pain is challenging, especially as it is often attributed to complex, multifaceted issues involving biological, psychological, and social components. Due to the difficulty in treating the true cause of chronic low back pain (cLBP), an over-reliance on opioid pain medications among cLBP patients has developed, which is associated with increased prevalence of opioid use disorder and increased risk of death. To combat the rise of opioid-related deaths, the National Institutes of Health (NIH) initiated the Helping to End Addiction Long-TermSM (HEAL) initiative, whose goal is to address the causes and treatment of opioid use disorder while also seeking to better understand, diagnose, and treat chronic pain. The NIH Back Pain Consortium (BACPAC) Research Program, a network of 14 funded entities, was launched as a part of the HEAL initiative to help address limitations surrounding the diagnosis and treatment of cLBP. This paper provides an overview of the BACPAC research program's goals and overall structure, and describes the harmonization efforts across the consortium, define its research agenda, and develop a collaborative project which utilizes the strengths of the network. The purpose of this paper is to serve as a blueprint for other consortia tasked with the advancement of pain related science.

Compensatory biomechanics and spinal loading during dynamic maneuvers in patients with chronic low back pain.

PURPOSE: This study explores the biomechanics underlying the sit-to-stand (STS) functional maneuver in chronic LBP patients to understand how different spinal disorders and levels of pain severity relate to unique compensatory biomechanical behaviors. This work stands to further our understanding of the relationship between spinal loading and symptoms in LBP patients. METHODS: We collected in-clinic motion data from 44 non-specific LBP (NS-LBP) and 42 spinal deformity LBP (SD-LBP) patients during routine clinical visits. An RGB-depth camera tracked 3D joint positions from the frontal view during unassisted, repeated STS maneuvers. Patient-reported outcomes (PROs) for back pain (VAS) and low back disability (ODI) were collected during the same clinical visit. RESULTS: Between patient groups, SD-LBP patients had 14.3% greater dynamic sagittal vertical alignment (dSVA) and 10.1% greater peak spine torque compared to NS-LBP patients (p < 0.001). SD-LBP patients also had 11.8% greater hip torque (p < 0.001) and 86.7% greater knee torque (p = 0.04) compared to NS-LBP patients. There were no significant differences between patient groups in regard to anterior or vertical torso velocities, but anterior and vertical torso velocities correlated with both VAS (r = - 0.38, p < 0.001) and ODI (r = - 0.29, p = 0.01). PROs did not correlate with other variables. CONCLUSION: Patients with LBP differ in movement biomechanics during an STS transfer as severity of symptoms may relate to different compensatory strategies that affect spinal loading. Further research aims to establish relationships between movement and PROs and to inform targeted rehabilitation approaches.

Radiofrequency Ablation for Chronic Hip Pain: A Comprehensive, Narrative Review.

Chronic hip pain can be treated with physical therapy, oral medications, injections, and, definitively, total hip arthroplasty. Enough patients have contraindications to and refractory pain even after total hip arthroplasty, that there is a need to develop alternative managements for this disabling condition. This article examines the state of hip radiofrequency ablation literature including relevant anatomy, patient selection, and treatment outcomes.

Pain and Functional Outcomes After Sacroiliac Joint Injection with Anesthetic and Corticosteroid at Six Months, Stratified by Anesthetic Response and Physical Exam Maneuvers.

OBJECTIVE: To evaluate sacroiliac joint (SIJ) injection outcomes with local anesthetic and corticosteroid. DESIGN: Prospective cohort. SETTING: Single academic medical center. METHODS: Thirty-four patients referred for SIJ injection with a clinical diagnosis of SIJ pain underwent injections with 1:1 mixture of 2% lidocaine and triamcinolone 40 mg/mL. Pain provocation physical exam (PE) maneuvers were recorded immediately before and after injection. Outcome measures at two to four weeks and six months included pain numeric rating scale (NRS) and Oswestry Disability Index (ODI). RESULTS: For the analysis of outcomes by the overall group (not stratified by PE and/or anesthetic block), a 58.8% (95% confidence interval [CI] = +/-16.5%) ≥2 NRS reduction, a 32.4% (95% CI = +/-15.7%) ≥50% NRS reduction, and a 38.2% (95% CI = +/-16.3%) ≥30% ODI reduction were observed at two to four weeks, with similar improvements at six months. Outcomes stratified based on pre-injection PE did not reveal significant differences at either time point. The stratification based on the presence of 100% postinjection anesthetic response demonstrated a significant difference at two to four weeks for ≥50% NRS improvement. The true positive/true negative group (TP/TN) stratification demonstrated a significant difference for ≥50% NRS improvement at two to four weeks, whereas six-month outcomes for TP/TN demonstrated significant differences for ≥50% NRS and ≥30% ODI improvement. An increased injection response was observed with stratification of patients more likely to have true SIJ pain (i.e., TP), with TP/TN stratification demonstrating a 75% (95% CI = +/-30.0%) ≥2 NRS improvement and a 62.5% (95% CI = +/-33.5%) improvement of ≥50% NRS and ≥30% ODI for the TP group at two to four weeks, with similar results at six months. CONCLUSIONS: SIJ steroid injection based on referral clinical diagnosis is unlikely to demonstrate true injection efficacy, and more specific selection criteria are warranted.

Digital Care for Chronic Musculoskeletal Pain: 10,000 Participant Longitudinal Cohort Study.

BACKGROUND: Chronic musculoskeletal pain has a vast global prevalence and economic burden. Conservative therapies are universally recommended but require patient engagement and self-management to be effective. OBJECTIVE: This study aimed to evaluate the efficacy of a 12-week digital care program (DCP) in a large population of patients with chronic knee and back pain. METHODS: A longitudinal observational study was conducted using a remote DCP available through a mobile app. Subjects participated in a 12-week multimodal DCP incorporating education, sensor-guided exercise therapy (ET), and behavioral health support with 1-on-1 remote health coaching. The primary outcome was pain measured by the visual analog scale (VAS). Secondary measures included engagement levels, program completion, program satisfaction, condition-specific pain measures, depression, anxiety, and work productivity. RESULTS: A total of 10,264 adults with either knee (n=3796) or low back (n=6468) pain for at least three months were included in the study. Participants experienced a 68.45% average improvement in VAS pain between baseline intake and 12 weeks. In all, 73.04% (7497/10,264) participants completed the DCP into the final month. In total, 78.60% (5893/7497) of program completers (7144/10,264, 69.60% of all participants) achieved minimally important change in pain. Furthermore, the number of ET sessions and coaching interactions were both positively associated with improvement in pain, suggesting that the amount of engagement influenced outcomes. Secondary outcomes included a 57.9% and 58.3% decrease in depression and anxiety scores, respectively, and 61.5% improvement in work productivity. Finally, 3 distinct clusters of pain response trajectories were identified, which could be predicted with a mean 76% accuracy using baseline measures. CONCLUSIONS: These results support the efficacy and scalability of a DCP for chronic low back and knee pain in a large, diverse, real-world population. Participants demonstrated high completion and engagement rates and a significant positive relationship between engagement and pain reduction was identified, a finding that has not been previously demonstrated in a DCP. Furthermore, the large sample size allowed for the identification of distinct pain response subgroups, which may prove beneficial in predicting recovery and tailoring future interventions. This is the first longitudinal digital health study to analyze pain outcomes in a sample of this magnitude, and it supports the prospect for DCPs to serve the overwhelming number of musculoskeletal pain sufferers worldwide.

Intra-articular Steroids vs Saline for Lumbar Z-Joint Pain: A Prospective, Randomized, Double-Blind Placebo-Controlled Trial.

OBJECTIVE: To determine if intra-articular (IA) injection of corticosteroids is effective in reducing the need for radiofrequency ablation (RFA) in those with dual comparative medial branch block (MBB)-confirmed lumbar z-joint pain. DESIGN: This was a randomized, double blind, placebo-controlled study. SETTING: Two academic medical centers. SUBJECTS: Fifty-six consecutive subjects who had ≥80% pain relief during an initial screening MBB were recruited. METHODS: Patients received a second confirmatory MBB and concurrent IA injection of either corticosteroid or saline per randomization. Twenty-nine of 56 received intra-articular corticosteroid (triamcinolone 20 mg), of whom 24 also had a positive confirmatory MBB per Spine Interventional Society guidelines, with ≥80% pain relief from both MBBs. Twenty-seven of 56 received IA saline into the z-joint during the confirmatory MBB, of whom 22 also had a positive confirmatory MBB. The primary outcome measure was the categorical need for RFA due to insufficient pain relief with intra-articular injection, and the secondary outcome was time to RFA. RESULTS: There was no statistically significant difference in the need for an RFA between the groups (16/24 steroid, 67%, 95% confidence interval [CI] = 47-82%) vs 15/22 saline (68%, 95% CI = 47-84%, P = 1.00). The average time to RFA was also not different, at 6.00 weeks for steroids vs 6.55 weeks for saline (P = 0.82). CONCLUSIONS: Intra-articular corticosteroids were not effective in reducing the need for or the time to a radiofrequency ablation of the medial branches in those with dual MBB-confirmed lumbar z-joint pain.

Demographic factors affect willingness to register as an organ donor more than a personal relationship with a transplant candidate.

BACKGROUND: Transplant candidate caregivers (TCCs) are an under-utilized but potentially devoted pool of advocates who themselves may be recruited to register for deceased organ donation. AIM: The purpose of this study was to assess and compare recruitment barriers to deceased donor registration efforts in TCCs and health fair attendees (HFAs). METHODS: A 42-item questionnaire assessing willingness to register as an organ donor and perceptions and knowledge about organ donation was administered to 452 participants (174 in Denver, 278 in San Francisco). Logistic regression, stratified by study site, was used to assess associations between explanatory variables and willingness to register as an organ donor. RESULTS: In Denver, 83 % of TCCs versus 68 % of HFAs indicated a willingness to register (p = 0.03). Controlling for study group (TCC vs HFA), predictors of willingness to register were female gender [odds ratio (OR) 2.4], Caucasian race (OR 2.3), college graduate (OR 11.1), married (OR 2.4) and higher positive perception of organ donation (OR 1.2), each p < 0.05. In San Francisco, 58 % of TCCs versus 70 % of HFAs indicated a willingness to register (p = 0.03). Controlling for study group (TCC vs HFA), predictors of willingness to register were Caucasian race (OR 3.5), college graduate (OR 2.2), married (OR 1.9), higher knowledge (OR 1.6) and higher positive perception of organ donation (OR 1.2), each p < 0.05. In both locales, Caucasians were more likely to have positive perceptions about organ donation and were more willing to register. CONCLUSIONS: Demographic characteristics, not personal connection to a transplant candidate, explain willingness to register as an organ donor.

Predictors of response in PROMIS-global in a chronic low back pain specialty clinic: STarTBack and chronic overlapping pain conditions.

BACKGROUND: Tools, such as the STarTBack Screening Tool (SBT), have been developed to identify risks of progressing to chronic disability in low back pain (LBP) patients in the primary care population. However, less is known about predictors of change in function after treatment in the specialty care population. OBJECTIVE: We pursued a retrospective observational cohort study involving LBP patients seen in a multidisciplinary specialty clinic to assess which features can predict change in function at follow-up. METHODS: The SBT was administered at initial visit, and a variety of patient characteristics were available in the chart including the presence of chronic overlapping pain conditions (COPCs). Patient Reported Outcomes Measurement Information System-10 (PROMIS-10) global physical health (PH) and global mental health (MH) were measured at baseline and at pragmatic time points during follow-up. Linear regression was used to estimate adjusted associations between available features and changes in PROMIS scores. RESULTS: 241 patients were followed for a mean of 17.0 ± 7.5 months. Mean baseline pain was 6.7 (SD 2.1), PROMIS-10 global MH score was 44.8 (SD 9.3), and PH score was 39.4 (SD 8.6). 29.7% were low-risk on the SBT, 41.8% were medium-risk, and 28.5% were high-risk. Mean change in MH and PH scores from baseline to the follow-up questionnaire were 0.86 (SD 8.11) and 2.39 (SD 7.52), respectively. Compared to low-risk patients, high-risk patients had a mean 4.35 points greater improvement in their MH score (p= 0.004) and a mean 3.54 points greater improvement in PH score (p= 0.006). Fewer COPCs also predicted greater improvement in MH and PH. CONCLUSIONS: SBT and the presence of COPC, which can be assessed at initial presentation to a specialty clinic, can predict change in PROMIS following treatment. Effort is needed to identify other factors that can help predict change in function after treatment in the specialty care setting.

FACTFINDERS for PATIENT SAFETY: Preventing procedure-related complications: Epidural lipomatosis and postpartum steroid exposure.

This series of FactFinders presents a brief summary of the evidence and outlines recommendations to improve our understanding and management of potential procedure-related complications. Evidence in support of the following facts is presented. (1) Epidural Steroid injections for Radicular Pain Due to Spinal Stenosis Caused by Lipomatosis -- There is low-level evidence of an association between epidural steroid injections (ESIs) and the development and/or worsening of spinal epidural lipomatosis (SEL). However, there is insufficient evidence to establish whether ESIs independently result in an increase in spinal stenosis with neurological compromise in individuals with pre-existing SEL. (2) Steroid Exposure Postpartum -- There is no absolute contraindication to steroid injections based on postpartum or lactating status, but there may be disruption of both maternal and breastfed child hypothalamic-pituitary-adrenal (HPA) axis response to steroid administration. For the duration of breastfeeding, milk production may be affected after steroid exposure, and withholding breast milk produced for several hours after exposure minimizes infant exposure.

FactFinders for patient safety: Delaying epidural steroid injections: Infection and safe platelet cutoff.

This series of FactFinders presents a brief summary of the evidence and outlines recommendations to improve our understanding and management of patients with potential contraindications to epidural steroid injections.

Design of the COMEBACK and BACKHOME Studies, Longitudinal Cohorts for Comprehensive Deep Phenotyping of Adults with Chronic Low-Back Pain (cLBP): a part of the BACPAC Research Program.

Objective: The University of California, San Francisco (UCSF) Core Center for Patient-centric, Mechanistic Phenotyping in Chronic Low Back Pain (REACH) is one of the three NIH Back Pain Consortium (BACPAC) Research Programs Mechanistic Research Centers (MRCs). The goal of UCSF REACH is to define cLBP phenotypes and pain mechanisms that can lead to effective, personalized treatments for patients across the population. The primary objective of this research project is to address the critical need for new diagnostic and prognostic markers, and associated patient classification protocols for chronic low back pain (cLBP) treatment. Design: To meet this objective, REACH is conducting two large investigator-initiated translational research cohort studies called: The Longitudinal Clinical Cohort for Comprehensive Deep Phenotyping of Chronic Low-Back Pain (cLBP) Adults Study (comeBACK) and the Chronic Low-Back Pain (cLBP) in Adults Study (BACKHOME). Setting: comeBACK is a longitudinal multicenter in-person observational study of 450 adults with chronic low back pain designed to perform comprehensive deep phenotyping. While, the BACKHOME study is a site-less longitudinal observational e-cohort of approximately 3000 U.S. adults with cLBP. To our knowledge, BACKHOME is the largest prospective remote registry of nationwide adults with cLBP. Methods: Both the comeBACK and BACKHOME studies are collecting a robust and comprehensive set of risk factors, outcomes, and covariates in order to perform deep phenotyping of cLBP patients based on combined biopsychosocial variables to: define cLBP subtypes, establish phenotyping tools for routine clinical evaluation, and lead to improved cLBP outcomes in the future. The data from both studies will be used to establish techniques to develop a patient-centric definition of treatment success and to analyze cLBP patient traits to define clinically useful cLBP phenotypes, using a combination of traditional data analyses and deep learning methods. Conclusions: These 2 pivotal studies, in conjunction with the ancillary studies being performed in both comeBACK and BACKHOME, and the other BACPAC-consortium research projects, we will be able to address a number of diagnostic and therapeutic issues in this complex and diverse patient population with cLBP. These studies will help clarify biopsychosocial mechanisms of cLBP with the aim to provide a foundation to improve the evaluation of treatment effectiveness and to spur new avenues of therapeutic research, including personalized outcome measures that constitute a clinically meaningful treatment effect for individual cLBP patients.

Chronic Low Back Pain Causal Risk Factors Identified by Mendelian Randomization: a Cross-Sectional Cohort Analysis.

Background Context: There are a number of risk factors- from biological, psychological, and social domains- for non-specific chronic low back pain (cLBP). Many cLBP treatments target risk factors on the assumption that the targeted factor is not just associated with cLBP but is also a cause (i.e, a causal risk factor). In most cases this is a strong assumption, primarily due to the possibility of confounding variables. False assumptions about the causal relationships between risk factors and cLBP likely contribute to the generally marginal results from cLBP treatments. Purpose: The objectives of this study were to a) using rigorous confounding control compare associations between modifiable causal risk factors identified by Mendelian randomization (MR) studies with associations in a cLBP population and b) estimate the association of these risk factors with cLBP outcomes. Study Design/Setting: Cross sectional analysis of a longitudinal, online, observational study. Patient Sample: 1,376 participants in BACKHOME, a longitudinal observational e-Cohort of U.S. adults with cLBP that is part of the NIH Back Pain Consortium (BACPAC) Research Program. Outcome Measures: Pain, Enjoyment of Life, and General Activity (PEG) Scale. Methods: Five risk factors were selected based on evidence from MR randomization studies: sleep disturbance, depression, BMI, alcohol use, and smoking status. Confounders were identified using the ESC-DAG approach, a rigorous method for building directed acyclic graphs based on causal criteria. Strong evidence for confounding was found for age, female sex, education, relationship status, financial strain, anxiety, fear avoidance and catastrophizing. These variables were used to determine the adjustment sets for the primary analysis. Potential confounders with weaker evidence were used for a sensitivity analysis. Results: Participants had the following characteristics: age 54.9 ± 14.4 years, 67.4% female, 60% never smokers, 29.9% overweight, 39.5% obese, PROMIS sleep disturbance T-score 54.8 ± 8.0, PROMIS depression T-score 52.6 ± 10.1, Fear-avoidance Beliefs Questionnaire 11.6 ± 5.9, Patient Catastrophizing Scale 4.5 ± 2.6, PEG 4.4 ± 2.2. In the adjusted models alcohol use, sleep disturbance, depression, and obesity were associated with PEG, after adjusting for confounding variables identified via a DAG constructed using a rigorous protocol. The adjusted effect estimates- the expected change in the PEG outcome for every standard deviation increase or decrease in the exposure (or category shift for categorical exposures) were the largest for sleep disturbance and obesity. Each SD increase in the PROMIS sleep disturbance T-score resulted in a mean 0.77 (95% CI: 0.66, 0.88) point increase in baseline PEG score. Compared to participants with normal BMI, adjusted mean PEG score was slightly higher by 0.37 points (95% CI: 0.09, 0.65) for overweight participants, about 0.8 to 0.9 points higher for those in obesity classes I and II, and 1.39 (95% CI: 0.98, 1.80) points higher for the most obese participants. Each SD increase in the PROMIS depression T-score was associated with a mean 0.28 (95% CI: 0.17, 0.40) point increase in baseline PEG score, while each SD decrease in number of alcoholic drinks per week resulted in a mean 0.12 (95%CI: 0.01, 0.23) increase in baseline PEG score in the adjusted model. Conclusions: Several modifiable causal risk factors for cLBP - alcohol use, sleep disturbance, depression, and obesity- are associated with PEG, after adjusting for confounding variables identified via a DAG constructed using a rigorous protocol. Convergence of our findings for sleep disturbance, depression, and obesity with the results from MR studies, which have different designs and biases, strengthens the evidence for causal relationships between these risk factors and cLBP (1). The estimated effect of change in a risk factors on change in PEG were the largest for sleep disturbance and obesity. Future analyses will evaluate these relationships with longitudinal data.

Preferences for risks and benefits of treatment outcomes for chronic low back pain: Choice-based conjoint measure development and discrete choice experiment.

INTRODUCTION: Understanding individual patient preferences for chronic low back pain (cLBP) outcomes is essential for targeting available therapeutic options; yet tools to elicit patient outcome preferences are limited. OBJECTIVE: To develop and test a choice-based conjoint (CBC) measure, commonly used in behavioral economics research, to elicit what outcomes patients with cLBP want to achieve and avoid. DESIGN: We developed a survey-based CBC measure to allow patients to make risk/benefit trade-off choices between possible treatment outcomes. After extensive literature, clinician, and patient input, our measure included seven attributes: fatigue, anxiety/depression, difficulty thinking/making decisions, pain intensity, physical abilities, change in pain, and ability to enjoy life despite pain. Random-parameters logit models were used to estimate strength of preferences, and latent class analysis was used to identify patient characteristics associated with distinct preference. SETTING: Online study using the Sawtooth web-based platform. PARTICIPANTS: Two hundred eleven individuals with cLBP recruited from online advertising as well as at clinical sites across multiple academic and private institutions. INTERVENTIONS: Not applicable. RESULTS: The most valued outcome was the highest level of physical activity (ß = 1.6-1.98; p < .001), followed by avoiding cognitive difficulties (ß = -1.48; p < .001). Avoidance of severe pain was comparable to avoiding constant fatigue and near-constant depression/anxiety (ß = -0.99, -1.02); p < .001). There was an association between preferences and current pain/disability status; patients with higher pain had a stronger preference to avoid severe pain, whereas those with higher disability have stronger preferences for achieving physical activity. The latent class analysis identified two distinct groups: (1) more risk-seeking and willing to accept worse outcomes (56%); and (2) more risk-averse with a stronger preference for achieving maximum benefits (44%). CONCLUSIONS: Our study illuminated cLBP patient preferences for treatment outcomes and heterogeneity in these preferences. Patients stressed the importance of reaching high physical activity and avoiding cognitive declines, even over a desire to avoid pain. More work is needed to understand patient preferences to aid informed, shared decisions.

Impact of preclinical exposure to organ donation on knowledge and attitudes of medical students.

CONTEXT: Medical students receive little exposure to organ donation and procurement programs. OBJECTIVE: To describe a student-run elective and its effect on participants' knowledge about and attitudes toward organ donation. INTERVENTION: Preclinical students interacted directly with donor families, organ recipients, and donation representatives; many participated in an organ procurement with the surgical team. DESIGN: Between 2005 and 2007, 13 students who participated in the elective and a procurement were compared with 72 students who took the elective but did not participate in a procurement and with 22 control students. Students who participated in a procurement wrote reflections about their experience. In 2010, 15 first-year students who participated in the elective and a procurement and 59 randomly selected control students completed a previously validated measure. OUTCOME: Themes included awe, surgical procedures, learning opportunities, and brain death. Regardless of procurement participation, the elective participants from 2005 to 2007 reported higher 4-item knowledge scores (P<.001) than control students reported, but their 4-item attitude scores did not differ (P = .21). The 2010 students did not differ from control students in their number of correct responses to the 20 knowledge questions (P = .48) or their individual responses to each of the 14 attitude questions (all P>.05). RESULTS: Although elective participants reflected positively on their experiences and professed greater knowledge than control students via a researcher-made tool, these results were not sustained with a previously validated measure. These results point to the need for careful elective design and the need for more accurate measures to study the effectiveness of such interventions.

What does the patient with back pain want? A comparison of patient preferences and physician assumptions.

BACKGROUD CONTEXT: Low back pain can be difficult to diagnose, leaving patients frustrated and confused after medical visits. PURPOSE: To evaluate the importance of reasons for seeking care in patients with back pain, and to compare this to physicians' assumptions about these patients' reasons. STUDY DESIGN/SETTING: Prospective survey study carried out at two academic spine centers. PATIENT SAMPLE: A sum of 419 patients with back pain upon initial presentation to a spine clinic, and 198 physicians; all volunteered to complete a survey. OUTCOME MEASURES: Variance in mean values between patient and physician responders with significance determined by non-overlapping 95% confidence intervals. METHODS: Patients were asked to "rate each of the following with regard to their importance to you" (answering between 0 "not important" to 4 "extremely important"): improvement in level of pain, improvement in ability to perform daily tasks, explanation of what is causing your problem, thorough physical examination, diagnostic testing, medication, physical therapy, surgery. Physicians were asked to rate each of these "with regard to their importance to your patients." RESULTS: Patients indicated the following items were the most important (mean values): explanation of what is causing your problem (3.27), improvement in level of pain (3.48) and improvement in ability to perform daily tasks (3.31). Patients attributed the least importance and lowest scores to: surgery (1.07) and medication (1.89). Comparing the mean values to each item by patient and physician responders revealed statistically significant differences in certain items. Specifically, physicians underestimated the importance of an explanation of what is causing the problem (2.78±0.119 vs. 3.28±0.098, 95% CI) and overvalued diagnostic tests (2.64±0.120 vs. 2.30±0.147, 95% CI), medications (2.38±0.118 vs. 1.89± 0.143, 95% CI) and surgery (1.60±0.126 vs. 1.07±0.140, 95% CI). CONCLUSION: Patients did not place as much importance on diagnostic tests, medications and surgery as the physicians assumed. Physicians understand that back pain patients want improvement in both pain and function, but they underestimate the importance of an explanation for the pain.

Objective features of sedentary time and light activity differentiate people with low back pain from healthy controls: a pilot study.

BACKGROUND CONTEXT: Physical inactivity has been described as both a cause and a consequence of low back pain (LBP) largely based on self-reported measures of daily activity. A better understanding of the connections between routine physical activity and LBP may improve LBP interventions. PURPOSE: In this study, we aim to objectively characterize the free-living physical activity of people with low back pain in comparison to healthy controls using accelerometers, and we aim to derive a set of LBP-specific physical activity minutes thresholds that may be used as targets for future physical activity interventions. STUDY DESIGN: Cross-sectional. PATIENT SAMPLE: A total of 22 low back pain patients and 155 controls. OUTCOME MEASURES: Accelerometry derived physical activity measures. METHODS: Twenty-two people with LBP were compared to 155 age and gender-matched healthy controls. All subjects wore an ActiGraph accelerometer on the right hip for 7 consecutive days. Accelerometry-based physical activity features (count-per-minute CPM) were derived using Freedson's intervals and physical performance intervals. A random forest machine learning classifier was trained to classify LBP status using a leave-one-out cross-validation procedure. An interpretation algorithm, the SHapley Additive exPlanations (SHAP) algorithm was subsequently applied to assess the feature importance and to establish LBP-specific physical activity thresholds. RESULTS: The LBP group reported mild to moderate disability (average ODI=18.5). The random forest classifier identified a set of 8 features (digital biomarkers) that achieved 88.1% accuracy for distinguishing LBP from controls. All of the top distinguishing features were related to differences in the sedentary and light activity ranges (<800 CPM), whereas moderate to vigorous physical activity was not discriminative. In addition, we identified and ranked physical activity thresholds that are associated with LBP prediction that can be used in future studies of physical activity interventions for LBP. CONCLUSIONS: We describe a set of physical activity features from accelerometry data associated with LBP. All of the discriminating features were derived from the sedentary and light activity range. We also identified specific activity intensity minutes thresholds that distinguished LBP subjects from healthy controls. Future examination on the digital markers and thresholds identified through this work can be used to improve physical activity interventions for LBP treatment and prevention by allowing the development of LBP-specific physical activity guidelines.

Patient-perceived duration of effect of lidocaine and bupivacaine following diagnostic medial branch blocks; a multicenter study.

Objective: To quantify the duration of pain relief reported in association with lidocaine and bupivacaine in patients suffering from axial back pain, who reported a response of ≥80% relief lasting at least 30 â€‹min following medial branch blocks(MBB). Design: A retrospective review. Methods: Setting & Subjects: Four academic medical centers utilized a uniform pain diary. It was administered to consecutive patients after undergoing MBB. This pain diary included NRS pain score and percentage of pain relief (PPR) at 12 designated time points. Results: One hundred and fifty pain diaries were collected and analyzed. 42 blocks were performed in the cervical spine, 7 in the thoracic spine, and 101 in the lumbar spine. By NRS, 32% of pain diaries indicated that the patient experienced ≥80% pain relief at the 30-min and 42.7% (64/150) did so by PPR. Mean duration of ≥80% pain relief as measured by NRS in the bupivacaine subgroup was 3.5 â€‹h (SD 8.7, 95% CI 0.6-6.5) versus mean duration of 16.4 â€‹h (SD 19.6, 95% CI 5.4-27.4) in the lidocaine subgroup. Mean duration of ≥80% pain relief as measured by PPR in the bupivacaine subgroup was 19.2 â€‹h (SD 19.2, 95% CI 13.3-25.1) versus mean duration of 12.2 â€‹h (SD 15.9, 95% CI 5.6-18.8) in the lidocaine subgroup. Conclusions: This study demonstrates that there is no discernable or statistically significant difference in the duration of effect when comparing lidocaine to bupivacaine in patients that experience 80% or more relief following a medial branch block. This data suggests any emphasis on concordant duration of relief from specific anesthetics utilized for diagnostic medial branch blocks should be reconsidered.