Steven Zachary George

Background: Conditioning and positive expectations are potential mechanisms for pain relief. However, there is a gap in the literature on the isolated or combined impact of these factors for decreasing pain intensity. Methods: This study investigated whether a hidden conditioning procedure with a hidden lowering of the thermal noxious stimulus during a conditioning session combined with positive expectation would result in greater low back pain intensity reduction compared to positive and neutral expectations alone. All groups participating in the study received six sessions of spinal manipulative therapy (SMT). Patients ( n = 264) with nonspecific chronic low back pain (CLBP), aged between 18 and 65 years, were randomly allocated to three groups: hidden conditioning with positive expectations (C‐PEG), positive expectations alone (PEG), or neutral expectations alone (NEUG). Participants were submitted to a conditioning test pre‐ and post‐first session of SMT, where heat pain stimuli were surreptitiously lowered only in the C‐PEG group. The primary outcomes were low back pain intensity and global perceived effect (GPE) of improvement assessed post‐first SMT session and at 6‐week (primary endpoint) and 3‐month follow‐ups. Linear mixed‐effects models were used to assess group and time effects. Results: No significant difference was found between the three groups at any of the follow‐ups for pain intensity or GPE. Positive expectations (pre‐treatment) and psychosocial variables partially mediated the relationship between baseline low back pain and disability outcomes. All groups showed a within‐group reduction in low back pain and disability at follow‐ups. Significance Statement: Conditioning and positive expectation with SMT did not improve pain intensity or GPE outcomes for participants with low back pain, when compared to positive or neutral expectations alone. These findings suggest that patients did not generalize learned associations during conditioning to low back pain intensity outcome. Regardless of treatment assignment, positive expectations and psychosocial factors played a mediating role in pain intensity, GPE, and disability outcomes. Trial Registration: ClinicalTrials.gov identifier: NCT05202704

Describe baseline characteristics and representativeness of AIM-Back trial participants relative to Veterans with low back pain at participating clinics. Veterans were referred to AIM-Back randomized care pathways and included 1) enrolled participants with data collected in the Electronic Health Record (EHR) by clinical staff with no consent required and 2) survey participants who provided informed consent with data collected via surveys by research staff. Descriptive statistics were reported. Participation to prevalence ratios (PPRs) were calculated for sex, age, race, and ethnicity by clinic to describe representativeness. Across 17 primary care clinics, the Referral cohort included 2767 unique Veterans with n = 1817 enrolled (attended initial evaluation visit), n = 996 were survey participants; n = 799 of enrolled participants (44%) were also survey participants. More than 59% of Veterans of enrolled and survey participants had High Impact Chronic Pain and approximately 10% of enrolled participants had documented opioid use in the preceding year. Older Veterans (≥65 years) were underrepresented in the Referral cohort compared to those with LBP visits at clinics (PPRs < 0.8). These findings provide detailed insights for participants that will be included in future analyses of care pathway effectiveness. NCT04411420.

Importance: Low back pain (LBP) is a leading cause of disability, and there is limited evidence from clinical practice to support the effectiveness of alternative care models. Objective: To compare a sequenced care pathway (SCP) with a pain navigator pathway (PNP) for patients with LBP. Design, Setting, and Participants: In this embedded cluster randomized clinical trial, 19 primary care clinics in the Veterans Health Administration were randomized to deliver 1 of 2 multimodal guideline-supported care pathways, with primary outcomes assessed in their electronic health records (EHRs) at 3 months. Between February 8, 2021 (first enrolled), and January 31, 2024 (last enrolled), 1817 participants were referred by primary care clinicians and attended an initial AIM-Back trial visit. A subset of 799 participants consented to complete additional questionnaires for secondary analyses (March 8, 2021 [first survey collected], to January 10, 2025 [final secondary outcome collected by survey]). Interventions: The SCP included pain education and modulation, physical activity coaching, risk stratification, and psychologically informed physical therapy. The PNP included shared decision-making and facilitated referrals to nondrug treatments. Main Outcomes and Measures: Pain interference and physical function were coprimary outcomes, assessed with the Patient-Reported Outcomes Measurement Information Systems 4-item Short Forms (PROMIS-SF; potential score range for pain interference, 41.6-75.6, where lower scores indicated less interference with daily activities due to pain; and potential score range for physical function, 22.5-57.0, where higher scores indicated higher physical functioning during daily activities). Secondary EHR outcomes included sleep disturbance and National Institutes of Health pain intensity, and survey outcomes included the coprimary outcomes and additional measures of pain, function, and quality of life. Analysis was performed in the intent-to-treat population. Results: There were 1817 enrolled participants (SCP, 811; PNP, 1006; mean [SD] age, 53.0 [15.7] years; 1597 men [87.9%]). At 3 months, 461 of 811 patients (56.8%) in the SCP group and 537 of 1006 (53.4%) in the PNP group had analyzable primary outcomes. The estimated baseline mean PROMIS-SF score was 63.2 points (97.5% CI, 62.7-63.6 points) for pain interference and 37.1 points (97.5% CI, 36.7-37.4 points) for physical function. The 3-month mean PROMIS-SF score for pain interference was 60.5 points (97.5% CI, 59.7-61.3 points) in the SCP group and 61.1 points (97.5% CI, 60.4-61.8 points) in the PNP group. The 3-month mean PROMIS-SF score for physical function was 39.1 points (97.5% CI, 38.4-39.7 points) in the SCP group and 38.5 points (97.5% CI, 37.8-39.1 points) in the PNP group. There was no SCP superiority, with estimated 3-month differences of −0.6 points (97.5% CI, −1.6 to 0.4 points) for pain interference and 0.6 points (97.5% CI, −0.3 to 1.5 points) for physical function. There were no pathway differences in secondary outcomes. Conclusion and Relevance: In this cluster randomized trial, the SCP was not superior for the primary outcomes of pain interference and physical function. Future research should consider designs that optimize pathway adherence, assess the effectiveness in other settings, and investigate patient-level factors indicative of a favorable response to the SCP or PNP. Trial Registration: ClinicalTrials.gov Identifier: NCT04411420

Introduction: High-impact chronic pain (HICP) is associated with impaired function, diminished quality of life, and greater healthcare utilization. Although total joint arthroplasty (TJA) is effective for osteoarthritis, up to 20% of patients report persistent pain and limitations. Objective: To examine transitions in HICP status and identify predictors of postoperative HICP following TJA. Methods: This was a retrospective longitudinal cohort study of 6631 patients who underwent total knee (46.6%), hip (31.2%), or shoulder (22.2%) arthroplasty at a large US academic medical center between January 2018 and August 2024. Transitions in HICP status were described, and multivariable logistic regression was used to evaluate predictors of postoperative HICP. Results were reported as odds ratios (OR) with 95% confidence intervals (CI). Model performance was assessed using classification accuracy, receiver operating characteristic analysis, and the area under the curve. Results: Preoperatively, 45.3% of patients reported HICP, which declined to 15.2% after surgery. However, 4.8% developed new-onset HICP, yielding an overall postoperative prevalence of 20.0%. Preoperative HICP (OR = 2.50, 95% CI: 2.10–2.94), lower physical function (OR = 0.95, 95% CI: 0.93–0.96), higher pain intensity (OR = 1.07, 95% CI: 1.04–1.10), and postoperative opioid exposure (OR = 1.83, 95% CI: 1.59–2.11) were the strongest predictors. Additional factors included younger age, sex, alcohol use, revision surgery, and comorbidity burden. Conclusion: Although TJA substantially reduces HICP prevalence, 1 in 5 patients continues to experience significant postoperative pain. Early identification of at-risk individuals and the integration of targeted perioperative interventions are critical to optimize recovery and long-term outcomes.