chronic pain

Tramadol versus placebo for chronic pain: a systematic review with meta-analysis and trial sequential analysis

Author/s: 
Jehad Ahmad Barkji, Mathias Maagaard, Johanne Juul Petersen, Yousef Ahmad Barakji, Emil Ørskov Ipsen, Christian Gluud, Ole Mathiesen, Janus Christian Jakobsen

Objectives The objective of our study was to assess the benefits and harms of tramadol vs placebo in adults with chronic pain.

Design The research method was a systematic review of randomised clinical trials with meta-analysis. The review followed the Trial Sequential Analysis and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Data sources The Cochrane Library, MEDLINE, Embase, Science Citation Index and BIOSIS were searched for trials published from inception to 6 February 2025.

Eligibility criteria for selecting studies Studies were eligible for inclusion if they were published and unpublished randomised clinical trials comparing tramadol vs placebo in adults with any type of chronic pain. Risk of bias was assessed according to the Cochrane Handbook for Systematic Reviews of Interventions.

Main outcome measures The main outcome measures were pain level, adverse events, quality of life, dependence, abuse and depressive symptoms.

Results We included 19 randomised placebo-controlled clinical trials enrolling 6506 participants. All outcome results were at high risk of bias. Meta-analysis and Trial Sequential Analysis showed evidence of a beneficial effect of tramadol on chronic pain (mean difference numerical rating scale (NRS) −0.93 points; 97.5% CI −1.26 to −0.60; p<0.0001; low certainty of evidence). However, the effect size was below our predefined minimal important difference of 1.0 point on NRS. Beta binomial regression showed evidence of a harmful effect of tramadol on serious adverse events (OR 2.13; 97.5% CI 1.29 to 3.51; p=0.001; moderate certainty of evidence), mainly driven by a higher proportion of cardiac events and neoplasms. It was not possible to conduct a meta-analysis of the quality of life due to a lack of data. Meta-analysis and Trial Sequential Analysis showed that tramadol increased the risk of several non-serious adverse events including nausea (number needed to harm (NNH) 7), dizziness (NNH 8), constipation (NNH 9), and somnolence (NNH 13) (all very low certainty of evidence).

Conclusion Tramadol may have a slight effect on reducing chronic pain levels (low certainty of evidence) while likely increasing the risk of both serious (moderate certainty of evidence) and non-serious adverse events (very low certainty of evidence). The potential harms associated with tramadol use for pain management likely outweigh its limited benefits.

Cognitive Behavioral Therapy for Insomnia in People With Chronic Disease: A Systematic Review and Meta-Analysis

Author/s: 
Amelia J. Scott, Ashleigh B. Correa, Madelyne A. Bisby

Importance: Insomnia is highly prevalent among individuals with chronic disease (eg, chronic pain, cardiovascular disease, and cancer) and results in poorer disease outcomes and quality of life. Cognitive behavioral therapy for insomnia (CBT-I) is recommended as first-line treatment for insomnia. However, concerns remain about its applicability and efficacy in people with chronic disease.

Objective: To evaluate the nature, efficacy, and acceptability of CBT-I in adults with chronic disease, and to identify moderators of treatment outcomes.

Data sources: Systematic searches were conducted in PsycINFO, Medline, Embase, and CENTRAL from database inception to June 5, 2025. Additional records were identified from reference lists of relevant reviews and studies.

Study selection: Eligible studies were randomized clinical trials (RCTs) involving adults (aged ≥18 years) with chronic disease and insomnia. Studies using CBT-I with measured sleep outcomes were included.

Data extraction and synthesis: Two assessors extracted data from RCTs. Hedges g was used to calculate effect sizes, and random effects meta-analyses were conducted. Heterogeneity was assessed via I2. Subgroup analyses examined whether outcomes varied by delivery format, chronic condition type, or control group.

Main outcomes and measures: Primary outcomes included insomnia severity, sleep efficiency, and sleep onset latency. Secondary outcomes included treatment acceptability and adverse effects.

Results: Sixty-seven RCTs (5232 participants) met inclusion criteria, including chronic diseases such as cancer, chronic pain, irritable bowel syndrome, and stroke. CBT-I was associated with significantly improved outcomes for insomnia severity (g = 0.98; 95% CI, 0.81-1.16) and moderate effect sizes regarding sleep efficiency (g = 0.77; 95% CI, 0.63-0.91) and sleep onset latency (g = 0.64; 95% CI, 0.50-0.78). Subgroup analyses revealed some sample, treatment, and methodological moderators (eg, longer treatment yielded better outcomes for sleep efficiency and sleep onset latency). Satisfaction with CBT-I was high, with a mean dropout rate of 13.3%. Treatment-related adverse effects were rare.

Conclusions and relevance: This systematic review and meta-analysis showed that CBT-I demonstrated strong efficacy and acceptability in chronic disease populations, with moderate to large effect sizes that appear comparable to those in non-chronic disease populations. Efficacy of CBT-I was similar across a range of disease subgroups. Future research should explore the role and nature of treatment adaptations for specific populations and increase access to CBT-I in medical settings.

Review of systemic and syndromic complications of cannabis use: A review

Author/s: 
Shah, J., Fermo, O.

Purpose of review: Prescribed and non-prescribed cannabis use is common. Providers in specialties treating chronic pain – primary care, pain management, and neurology–will be coming across medical cannabis as a treatment for chronic pain, regardless of whether they are prescribers. It is important to be aware of the systemic and syndromic complications of acute and chronic cannabis use in the differential diagnosis of cardiac, cardiovascular, cerebrovascular, gastrointestinal, and psychiatric disorders.

Recent Findings: Medical cannabis is legal in 36 states. Studies have shown several potentially serious adverse effects associated with cannabis use.

Summary: Cannabis use has the potential to cause several complications that can be easily overlooked without a preexisting high index of suspicion.

Living Systematic Review on Cannabis and Other Plant-Based Treatments for Chronic Pain

Author/s: 
McDonagh, M. S., Wagner, J., Ahmed, A. Y., Fu, R., Morasco, B., Kansagara, D., Chou, R.

In an effort to address the opioid epidemic, a prominent goal of current research is to identify alternative treatments with equal or better benefits for pain while avoiding potential unintended consequences that could result in harms.

This 'living' systematic review assesses the effectiveness and harms of cannabis and other plant-based treatments for chronic pain conditions. For the purposes of this review, plant-based compounds (PBCs) included are those that are similar to opioids in effect and that have the potential for addiction, misuse, and serious adverse effects; other PBCs such as herbal treatments are not included. The intended audience includes policy and decision makers, funders and researchers of treatments for chronic pain, and clinicians who treat chronic pain.

The report will be updated on a quarterly basis.

Cannabis-Based Products for Chronic Pain : A Systematic Review

Author/s: 
McDonah, M. S., Morasco, B. J., Wagner, J., Ahmed, A. Y., Fu, R., Kansagara, D., Chou, R.

Background: Contemporary data are needed about the utility of cannabinoids in chronic pain.

Purpose: To evaluate the benefits and harms of cannabinoids for chronic pain.

Data sources: Ovid MEDLINE, PsycINFO, EMBASE, the Cochrane Library, and Scopus to January 2022.

Study selection: English-language, randomized, placebo-controlled trials and cohort studies (≥1 month duration) of cannabinoids for chronic pain.

Data extraction: Data abstraction, risk of bias, and strength of evidence assessments were dually reviewed. Cannabinoids were categorized by THC-to-CBD ratio (high, comparable, or low) and source (synthetic, extract or purified, or whole plant).

Data synthesis: Eighteen randomized, placebo-controlled trials (n = 1740) and 7 cohort studies (n = 13 095) assessed cannabinoids. Studies were primarily short term (1 to 6 months); 56% enrolled patients with neuropathic pain, with 3% to 89% female patients. Synthetic products with high THC-to-CBD ratios (>98% THC) may be associated with moderate improvement in pain severity and response (≥30% improvement) and an increased risk for sedation and are probably associated with a large increased risk for dizziness. Extracted products with high THC-to-CBD ratios (range, 3:1 to 47:1) may be associated with large increased risk for study withdrawal due to adverse events and dizziness. Sublingual spray with comparable THC-to-CBD ratio (1.1:1) probably is associated with small improvement in pain severity and overall function and may be associated with large increased risk for dizziness and sedation and moderate increased risk for nausea. Evidence for other products and outcomes, including longer-term harms, were not reported or were insufficient.

Limitation: Variation in interventions; lack of study details, including unclear availability in the United States; and inadequate evidence for some products.

Conclusion: Oral, synthetic cannabis products with high THC-to-CBD ratios and sublingual, extracted cannabis products with comparable THC-to-CBD ratios may be associated with short-term improvements in chronic pain and increased risk for dizziness and sedation. Studies are needed on long-term outcomes and further evaluation of product formulation effects.

Living Systematic Review on Cannabis and Other Plant-Based Treatments for Chronic Pain

Author/s: 
McDonagh, M. S., Wagner, J., Ahmed, A. Y., Morasco, B., Kansagara, D., Chou, R.

Objectives. To evaluate the evidence on benefits and harms of cannabinoids and similar plant-based compounds to treat chronic pain.

Data sources. Ovid® MEDLINE®, PsycINFO®, Embase®, the Cochrane Library, and SCOPUS® databases, reference lists of included studies, submissions received after Federal Register request were searched to July 2021.

Review methods. Using dual review, we screened search results for randomized controlled trials (RCTs) and observational studies of patients with chronic pain evaluating cannabis, kratom, and similar compounds with any comparison group and at least 1 month of treatment or followup. Dual review was used to abstract study data, assess study-level risk of bias, and rate the strength of evidence. Prioritized outcomes included pain, overall function, and adverse events. We grouped studies that assessed tetrahydrocannabinol (THC) and/or cannabidiol (CBD) based on their THC to CBD ratio and categorized them as high-THC to CBD ratio, comparable THC to CBD ratio, and low-THC to CBD ratio. We also grouped studies by whether the product was a whole-plant product (cannabis), cannabinoids extracted or purified from a whole plant, or synthetic. We conducted meta-analyses using the profile likelihood random effects model and assessed between-study heterogeneity using Cochran’s Q statistic chi square and the I2 test for inconsistency. Magnitude of benefit was categorized into no effect or small, moderate, and large effects.

Results. From 2,850 abstracts, 20 RCTs (N=1,776) and 7 observational studies (N=13,095) assessing different cannabinoids were included; none of kratom. Studies were primarily short term, and 75 percent enrolled patients with a variety of neuropathic pain. Comparators were primarily placebo or usual care. The strength of evidence (SOE) was low, unless otherwise noted. Compared with placebo, comparable THC to CBD ratio oral spray was associated with a small benefit in change in pain severity (7 RCTs, N=632, 0 to10 scale, mean difference [MD] −0.54, 95% confidence interval [CI] −0.95 to −0.19, I2=28%; SOE: moderate) and overall function (6 RCTs, N=616, 0 to 10 scale, MD −0.42, 95% CI −0.73 to −0.16, I2=24%). There was no effect on study withdrawals due to adverse events. There was a large increased risk of dizziness and sedation and a moderate increased risk of nausea (dizziness: 6 RCTs, N=866, 30% vs. 8%, relative risk [RR] 3.57, 95% CI 2.42 to 5.60, I2=0%; sedation: 6 RCTs, N=866, 22% vs. 16%, RR 5.04, 95% CI 2.10 to 11.89, I2=0%; and nausea: 6 RCTs, N=866, 13% vs. 7.5%, RR 1.79, 95% CI 1.20 to 2.78, I2=0%). Synthetic products with high-THC to CBD ratios were associated with a moderate improvement in pain severity, a moderate increase in sedation, and a large increase in nausea (pain: 6 RCTs, N=390 to 10 scale, MD −1.15, 95% CI −1.99 to −0.54, I2=39%; sedation: 3 RCTs, N=335, 19% vs. 10%, RR 1.73, 95% CI 1.03 to 4.63, I2=0%; nausea: 2 RCTs, N=302, 12% vs. 6%, RR 2.19, 95% CI 0.77 to 5.39; I²=0%). We found moderate SOE for a large increased risk of dizziness (2 RCTs, 32% vs. 11%, RR 2.74, 95% CI 1.47 to 6.86, I2=0%). Extracted whole-plant products with high-THC to CBD ratios (oral) were associated with a large increased risk of study withdrawal due to adverse events (1 RCT, 13.9% vs. 5.7%, RR 3.12, 95% CI 1.54 to 6.33) and dizziness (1 RCT, 62.2% vs. 7.5%, RR 8.34, 95% CI 4.53 to 15.34). We observed a moderate improvement in pain severity when combining all studies of high-THC to CBD ratio (8 RCTs, N=684, MD −1.25, 95% CI −2.09 to −0.71, I2=50%; SOE: moderate). Evidence on whole-plant cannabis, topical CBD, low-THC to CBD, other cannabinoids, comparisons with active products, and impact on use of opioids was insufficient to draw conclusions. Other important harms (psychosis, cannabis use disorder, and cognitive effects) were not reported.

Conclusions. Low to moderate strength evidence suggests small to moderate improvements in pain (mostly neuropathic), and moderate to large increases in common adverse events (dizziness, sedation, nausea) and study withdrawal due to adverse events with high- and comparable THC to CBD ratio extracted cannabinoids and synthetic products in short-term treatment (1 to 6 months). Evidence for whole-plant cannabis, and other comparisons, outcomes, and PBCs were unavailable or insufficient to draw conclusions. Small sample sizes, lack of evidence for moderate and long-term use and other key outcomes, such as other adverse events and impact on use of opioids during treatment, indicate that more research is needed.

Interventional Treatments for Acute and Chronic Pain: Systematic Review

Author/s: 
Chou, R., Fu, R., Dana, T., Pappas, M., Hart, E., Mauer, K. M.

Objective. To evaluate the benefits and harms of selected interventional procedures for acute and chronic pain that are not currently covered by the Centers for Medicare & Medicaid Services (CMS) but are relevant for and have potential utility for use in the Medicare population, or that are covered by CMS but for which there is important uncertainty or controversy regarding use.

Data sources. Electronic databases (Ovid® MEDLINE®, PsycINFO®, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews) to April 12, 2021, reference lists, and submissions in response to a Federal Register notice.

Review methods. Using predefined criteria and dual review, we selected randomized controlled trials (RCTs) for 10 interventional procedures and conditions that evaluated pain, function, health status, quality of life, medication use, and harms. Random effects meta-analysis was conducted for vertebral compression fracture; otherwise, outcomes were synthesized qualitatively. Effects were classified as small, moderate, or large using previously defined criteria.

Results. Thirty-seven randomized trials (in 48 publications) were included. Vertebroplasty (13 trials) is probably more effective at reducing pain and improving function in older (>65 years of age) patients, but benefits are small (less than 1 point on a 10-point pain scale). Benefits appear smaller (but still present) in sham-controlled (5 trials) compared with usual care controlled trials (8 trials) and larger in trials of patients with more acute symptoms; however, testing for subgroup effects was limited by imprecision. Vertebroplasty is probably not associated with increased risk of incident vertebral fracture (10 trials). Kyphoplasty (2 trials) is probably more effective than usual care for pain and function in older patients with vertebral compression fracture at up to 1 month (moderate to large benefits) and may be more effective at >1 month to ≥1 year (small to moderate benefits) but has not been compared against sham therapy. Evidence on kyphoplasty and risk of incident fracture was conflicting. In younger (below age for Medicare eligibility) populations, cooled radiofrequency denervation for sacroiliac pain (2 trials) is probably more effective for pain and function versus sham at 1 and 3 months (moderate to large benefits). Cooled radiofrequency for presumed facet joint pain may be similarly effective versus conventional radiofrequency, and piriformis injection with corticosteroid for piriformis syndrome may be more effective than sham injection for pain. For the other interventional procedures and conditions addressed, evidence was too limited to determine benefits and harms.

Conclusions. Vertebroplasty is probably effective at reducing pain and improving function in older patients with vertebral compression fractures; benefits are small but similar to other therapies recommended for pain. Evidence was too limited to separate effects of control type and symptom acuity on effectiveness of vertebroplasty. Kyphoplasty has not been compared against sham but is probably more effective than usual care for vertebral compression fractures in older patients. In younger populations, cooled radiofrequency denervation is probably more effective than sham for sacroiliac pain. Research is needed to determine the benefits and harms of the other interventional procedures and conditions addressed in this review.

Evaluation of a Chronic Pain Screening Program Implemented in Primary Care

Author/s: 
Bifulco, L., Anderson, D. R., Blankson, M. L, Channamsetty, V., Blaz, J. W., Nguyen-Louie, T., Scholle, S. H.

Importance: Although pain is among the most common symptoms reported by patients, primary care practitioners (PCPs) face substantial challenges identifying and assessing pain.

Objective: To evaluate a 2-step process for chronic pain screening and follow-up in primary care.

Design, setting, and participants: A cross-sectional study of patients with a primary care visit between July 2, 2018, and June 1, 2019, was conducted at a statewide, multisite federally qualified health center. Participants included 68 PCPs and 58 medical assistants from 13 sites who implemented the screening process in primary care, and 38 866 patients aged 18 years or older with a primary care visit during that time.

Exposures: Single-question assessment of pain frequency, followed by a 3-question PEG (pain, enjoyment of life, general activity) functional assessment for patients with chronic pain.

Main outcomes and measures: Adherence to a 2-step chronic pain screening and PEG process, proportion of patients with positive screening results, mean PEG pain severity greater than or equal to 7, and documented chronic painful condition diagnosis in patient's electronic health record between 1 year before and 90 days after screening.

Results: Of 38 866 patients with a primary care visit, 31 600 patients (81.3%) underwent screening. Mean (SD) age was 46.2 (15.4) years, and most were aged 35 to 54 years (12 987 [41.1%]), female (18 436 [58.3%]), Hispanic (14 809 [46.9%]), and English-speaking (22 519 [71.3%]), and had Medicaid insurance (18 442 [58.4%]). A total of 10 262 participants (32.5%) screened positive and, of these, 9701 (94.5%) completed the PEG questionnaire. PEG responses indicated severe pain interference with activities of daily living (PEG ≥7) in 5735 (59.1%) participants. A chronic painful condition had not been diagnosed in 4257 (43.9%) patients in the year before screening. A new chronic painful condition was diagnosed at screening or within 90 days in 2250 (52.9%) patients. Care teams found the workflow acceptable, but cited lengthy administration time, challenges with comprehension of the PEG questions, and limited comprehensiveness as implementation barriers.

Conclusions and relevance: A systematic, 2-step process for chronic pain screening and functional assessment in primary care appeared to identify patients with previously undocumented chronic pain and was feasible to implement. Patient-provided information on the frequency of pain, pain level, and pain interference can help improve the assessment and monitoring of pain in primary care.

Living Systematic Review on Cannabis and Other Plant-Based Treatments for Chronic Pain - Quarterly Progress Report: May 2021

Author/s: 
M. S., Wagner, J., Ahmed, A. Y., Morasco, B., Kansagara, D., Chou, R.

This is the third quarterly progress report for an ongoing living systematic review on
cannabis and other plant-based treatments for chronic pain. The first progress report was
published in January 2021 and the second in March 2021. The draft systematic review was
available for public comment from May 19 through June 15, 2021, on the Agency for Healthcare
Research and Quality (AHRQ) Effective Health Care website. The systematic review synthesizes
evidence on the benefits and harms of plant-based compounds (PBCs), such as cannabinoids and
kratom, used to treat chronic pain, addressing concerns about severe adverse effects, abuse,
misuse, dependence, and addiction.
The purpose of this progress report is to describe the cumulative literature identified thus far.
This report will be periodically updated with new studies as they are published and identified,
culminating in an annual systematic review that provides a synthesis of the accumulated
evidence.

Living Systematic Review on Cannabis and Other Plant-Based Treatments for Chronic Pain - Quarterly Progress Report: December 2020

Author/s: 
McDonagh, M. S., Wagner, J., Ahmed, A. Y., Morasco, B., Kansagara, D., Chou, R.

This is the first progress report for an ongoing living systematic review on plant-based
treatments for chronic pain. The systematic review will synthesize evidence on the benefits and
harms of plant-based compounds (PBCs) such as cannabinoids and kratom used to treat chronic
pain, addressing concerns about severe adverse effects, abuse, misuse, dependence, and
addiction.
The purpose of this progress report is to describe the body of literature identified thus far.
This report will be periodically updated with new studies as they are published and identified,
culminating in a systematic review that provides a synthesis of the accumulated evidence.

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