Antidepressants for pain management in adults with chronic pain: a network meta-analysis.

BACKGROUND: Chronic pain is common in adults, and often has a detrimental impact upon physical ability, well-being, and quality of life. Previous reviews have shown that certain antidepressants may be effective in reducing pain with some benefit in improving patients' global impression of change for certain chronic pain conditions. However, there has not been a network meta-analysis (NMA) examining all antidepressants across all chronic pain conditions. OBJECTIVES: To assess the comparative efficacy and safety of antidepressants for adults with chronic pain (except headache). SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, AMED and PsycINFO databases, and clinical trials registries, for randomised controlled trials (RCTs) of antidepressants for chronic pain conditions in January 2022. SELECTION CRITERIA: We included RCTs that examined antidepressants for chronic pain against any comparator. If the comparator was placebo, another medication, another antidepressant, or the same antidepressant at different doses, then we required the study to be double-blind. We included RCTs with active comparators that were unable to be double-blinded (e.g. psychotherapy) but rated them as high risk of bias. We excluded RCTs where the follow-up was less than two weeks and those with fewer than 10 participants in each arm.  DATA COLLECTION AND ANALYSIS: Two review authors separately screened, data extracted, and judged risk of bias. We synthesised the data using Bayesian NMA and pairwise meta-analyses for each outcome and ranked the antidepressants in terms of their effectiveness using the surface under the cumulative ranking curve (SUCRA). We primarily used Confidence in Meta-Analysis (CINeMA) and Risk of Bias due to Missing Evidence in Network meta-analysis (ROB-MEN) to assess the certainty of the evidence. Where it was not possible to use CINeMA and ROB-MEN due to the complexity of the networks, we used GRADE to assess the certainty of the evidence. Our primary outcomes were substantial (50%) pain relief, pain intensity, mood, and adverse events. Our secondary outcomes were moderate pain relief (30%), physical function, sleep, quality of life, Patient Global Impression of Change (PGIC), serious adverse events, and withdrawal. MAIN RESULTS: This review and NMA included 176 studies with a total of 28,664 participants. The majority of studies were placebo-controlled (83), and parallel-armed (141). The most common pain conditions examined were fibromyalgia (59 studies); neuropathic pain (49 studies) and musculoskeletal pain (40 studies). The average length of RCTs was 10 weeks. Seven studies provided no useable data and were omitted from the NMA. The majority of studies measured short-term outcomes only and excluded people with low mood and other mental health conditions. Across efficacy outcomes, duloxetine was consistently the highest-ranked antidepressant with moderate- to high-certainty evidence. In duloxetine studies, standard dose was equally efficacious as high dose for the majority of outcomes. Milnacipran was often ranked as the next most efficacious antidepressant, although the certainty of evidence was lower than that of duloxetine. There was insufficient evidence to draw robust conclusions for the efficacy and safety of any other antidepressant for chronic pain.  Primary efficacy outcomes Duloxetine standard dose (60 mg) showed a small to moderate effect for substantial pain relief (odds ratio (OR) 1.91, 95% confidence interval (CI) 1.69 to 2.17; 16 studies, 4490 participants; moderate-certainty evidence) and continuous pain intensity (standardised mean difference (SMD) -0.31, 95% CI -0.39 to -0.24; 18 studies, 4959 participants; moderate-certainty evidence). For pain intensity, milnacipran standard dose (100 mg) also showed a small effect (SMD -0.22, 95% CI -0.39 to 0.06; 4 studies, 1866 participants; moderate-certainty evidence). Mirtazapine (30 mg) had a moderate effect on mood (SMD -0.5, 95% CI -0.78 to -0.22; 1 study, 406 participants; low-certainty evidence), while duloxetine showed a small effect (SMD -0.16, 95% CI -0.22 to -0.1; 26 studies, 7952 participants; moderate-certainty evidence); however it is important to note that most studies excluded participants with mental health conditions, and so average anxiety and depression scores tended to be in the 'normal' or 'subclinical' ranges at baseline already. Secondary efficacy outcomes Across all secondary efficacy outcomes (moderate pain relief, physical function, sleep, quality of life, and PGIC), duloxetine and milnacipran were the highest-ranked antidepressants with moderate-certainty evidence, although effects were small. For both duloxetine and milnacipran, standard doses were as efficacious as high doses. Safety There was very low-certainty evidence for all safety outcomes (adverse events, serious adverse events, and withdrawal) across all antidepressants. We cannot draw any reliable conclusions from the NMAs for these outcomes. AUTHORS' CONCLUSIONS: Our review and NMAs show that despite studies investigating 25 different antidepressants, the only antidepressant we are certain about for the treatment of chronic pain is duloxetine. Duloxetine was moderately efficacious across all outcomes at standard dose. There is also promising evidence for milnacipran, although further high-quality research is needed to be confident in these conclusions. Evidence for all other antidepressants was low certainty. As RCTs excluded people with low mood, we were unable to establish the effects of antidepressants for people with chronic pain and depression. There is currently no reliable evidence for the long-term efficacy of any antidepressant, and no reliable evidence for the safety of antidepressants for chronic pain at any time point.

Patient-centered consultations for persons with musculoskeletal conditions.

Consultations between practitioners and patients are more than a hypothesis-chasing exploration, especially when uncertainty about etiology and prognosis are high. In this article we describe a single individual's account of their lived experience of pain and long journey of consultations. This personal account includes challenges as well as opportunities, and ultimately led to self-awareness, clarity, and living well with pain. We follow each section of this narrative with a short description of the emerging scientific evidence informing on specific aspects of the consultation. Using this novel structure, we portray a framework for understanding consultations for persistent musculoskeletal pain from a position of patient-centered research to inform practice.

Risk-based stratified primary care for common musculoskeletal pain presentations: qualitative findings from the STarT MSK cluster randomised controlled trial.

BACKGROUND: The STarT MSK cluster randomised controlled trial (RCT) investigated the clinical- and cost-effectiveness of risk-based stratified primary care versus usual care for patients with back, neck, shoulder, knee or multi-site pain. Trial quantitative results showed risk-based stratified care was not superior to usual care for patients' clinical outcomes, but the intervention led to some changes in GP clinical decision-making. This paper reports a linked qualitative study exploring how risk-based stratified care was perceived and used in the trial, from the perspectives of clinicians and patients. METHODS: Semi-structured interviews were conducted with 27 patients, and focus groups and interviews with 20 clinicians (GPs and physiotherapists) in the intervention arm of the trial. Data were analysed thematically and findings explored using Normalisation Process Theory (NPT) and the COM-B model. MAIN FINDINGS: Risk-based stratified care (subgrouping and matching treatments) was found to have 'coherence' (i.e. made sense) to several clinicians and patients, in that it was well-integrated in practice, and supported clinical decision-making. However, for some GPs stratified care was less 'meaningful', as the risk-stratification tool did not fit with usual ways of consulting and added to already time-pressured consultations. GPs reported giving more patients written information/advice due to easier access to electronic information leaflets through the trial template and were motivated to refer patients to physiotherapy as they believed the trial resulted in faster physiotherapy access (although this was not the case). Patients and clinicians reported that risk-based stratified care influenced conversations in the consultation, prompting greater attention to psychosocial factors, and facilitating negotiation of treatment options. Physiotherapists saw benefits in receiving information about patients' risk subgroup on referral forms. CONCLUSION: These findings provide context for interpreting some of the trial outcomes, particularly in relation to changes in clinical decision-making when risk-based stratified care was used. Findings also indicate potential reasons for lack of GP engagement with risk-based stratified care. Positive outcomes were identified that were not captured in the quantitative data, specifically that risk-based stratified care positively influenced some GP-patient conversations and facilitated negotiation of treatment options. TRIAL REGISTRATION: ISRCTN15366334 (26/04/2016).

Risk-based stratified primary care for common musculoskeletal pain presentations (STarT MSK): a cluster-randomised, controlled trial.

Background: Risk-based stratified care shows clinical effectiveness and cost-effectiveness versus usual primary care for non-specific low back pain but is untested for other common musculoskeletal disorders. We aimed to test the clinical effectiveness and cost-effectiveness of point-of-care risk stratification (using Keele's STarT MSK Tool and risk-matched treatments) versus usual care for the five most common musculoskeletal presentations (back, neck, knee, shoulder, and multi-site pain). Methods: In this cluster-randomised, controlled trial in UK primary care with embedded qualitative and health economic studies we recruited patients from 24 general practices in the West Midlands region of England. Eligible patients were those aged 18 years or older whose general practitioner (GP) confirmed a consultation for a musculoskeletal presentation. General practices that consented to participate via a representative of the cluster were randomly assigned (1:1) to intervention or usual care, using stratified block randomisation. Researchers involved in data collection, outcome data entry, and statistical analysis were masked at both the cluster and individual participant level. Participating patients were told the study was examining GP treatment of common aches and pains and were not aware they were in a randomised trial. GPs in practices allocated to the intervention group were supported to deliver risk-based stratified care using a bespoke computer-based template, including the risk-stratification tool, and risk-matched treatment options for patients at low, medium, or high risk of poor disability or pain outcomes. There were 15 risk-matched treatment options. In the usual care group, patients with musculoskeletal pain consulting their GP received treatment as usual, typically including advice and education, medication, referral for investigations or tests, or referral to other services. The primary outcome was time-averaged pain intensity over 6 months. All analyses were done by intention to treat. The trial is registered with ISRCTN, ISRCTN15366334. Results: Between May 1, 2018, and April 30, 2019, 104 GPs from 24 practices (12 per study group) identified 2494 patients with musculoskeletal pain. 1211 (49%) participants consented to questionnaires (534 in the intervention group and 677 in the usual care group), with 1070 (88%) completing the follow-up questionnaire at 6 months. We found no significant difference in time-averaged pain intensity (mean(SD) mean 4·4 [SD 2·3] in the intervention group vs 4·6 [2·5] in the control group; adjusted mean difference -0·16, 95% CI -0·65 to 0·34) or in standardised function score (mean -0·06 [SD 0·94] in the intervention group vs 0·05 [1·04]; adjusted mean difference -0·07, 95% CI -0·22 to 0·08). No serious adverse events or adverse events were reported. Risk stratification received positive patient and clinician feedback. Interpretation: Risk stratification for patients in primary care with common musculoskeletal presentations did not lead to significant improvements in pain or function, although some aspects of GP decision making were affected, and GP and patients had positive experiences. The costs of risk-based stratified care were similar to usual care, and such a strategy only offers marginal changes in cost-effectiveness outcomes. The clinical implications from this trial are largely inconclusive. Funding: National Institute for Health Research.

Supporting people with pain-related distress in primary care consultations: a qualitative study.

BACKGROUND: Low mood and distress are commonly reported by people who have persistent musculoskeletal (MSK) pain, which may be labelled as 'depression'. It is important to understand how pain-related distress is conceptualised and managed in primary care consultations. AIM: To explore understanding of pain-related distress and depression from the perspectives of people with persistent MSK pain and GPs. DESIGN AND SETTING: Qualitative study with people with persistent MSK pain and GPs from different parts of the UK. METHOD: Semi-structured interviews conducted remotely and data analysed thematically. RESULTS: Most participants reported challenges in distinguishing between distress and depression in the context of persistent MSK pain, but also described strategies to make this distinction. Some people described how acceptance of their situation was key and involved optimism about the future and creation of a new identity. Some GPs expressed 'therapeutic nihilism', with uncertainty about the cause of pain and how to manage people with both persistent MSK pain and distress in primary care consultations, while GPs who could identify and build on optimism with patients described how to help the patient to move forwards. CONCLUSION: This study offers a framework for the primary care consultation with patients presenting with pain-related distress. GPs should recognise the impact of persistent MSK pain on the patient and support the person in coming to terms with their pain, explore how the person feels about the future, encourage optimism, and support self-management strategies.

Computer-Based Stratified Primary Care for Musculoskeletal Consultations Compared With Usual Care: Study Protocol for the STarT MSK Cluster Randomized Controlled Trial.

BACKGROUND: Musculoskeletal (MSK) pain is a major cause of pain and disability. We previously developed a prognostic tool (Start Back Tool) with demonstrated effectiveness in guiding primary care low back pain management by supporting decision making using matched treatments. A logical next step is to determine whether prognostic stratified care has benefits for a broader range of common MSK pain presentations. OBJECTIVE: This study seeks to determine, in patients with 1 of the 5 most common MSK presentations (back, neck, knee, shoulder, and multisite pain), whether stratified care involving the use of the Keele Start MSK Tool to allocate individuals into low-, medium-, and high-risk subgroups, and matching these subgroups to recommended matched clinical management options, is clinical and cost-effective compared with usual nonstratified primary care. METHODS: This is a pragmatic, two-arm parallel (stratified vs nonstratified care), cluster randomized controlled trial, with a health economic analysis and mixed methods process evaluation. The setting is UK primary care, involving 24 average-sized general practices randomized (stratified by practice size) in a 1:1 ratio (12 per arm) with blinding of trial statistician and outcome data collectors. Randomization units are general practices, and units of observation are adult MSK consulters without indicators of serious pathologies, urgent medical needs, or vulnerabilities. Potential participant records are tagged and individuals invited using a general practitioner (GP) point-of-consultation electronic medical record (EMR) template. The intervention is supported by an EMR template (computer-based) housing the Keele Start MSK Tool (to stratify into prognostic subgroups) and the recommended matched treatment options. The primary outcome using intention-to-treat analysis is pain intensity, measured monthly over 6 months. Secondary outcomes include physical function and quality of life, and an anonymized EMR audit to capture clinician decision making. The economic evaluation is focused on the estimation of incremental quality-adjusted life years and MSK pain-related health care costs. The process evaluation is exploring a range of potential factors influencing the intervention and understanding how it is perceived by patients and clinicians, with quantitative analyses focusing on a priori hypothesized intervention targets and qualitative approaches using focus groups and interviews. The target sample size is 1200 patients from 24 general practices, with >5000 MSK consultations available for anonymized medical record data comparisons. RESULTS: Trial recruitment commenced on May 18, 2018, and ended on July 15, 2019, after a 14-month recruitment period in 24 GP practices. Follow-up and interview data collection was completed in February 2020. CONCLUSIONS: This trial is the first attempt, as far as we know, at testing a prognostic stratified care approach for primary care patients with MSK pain. The results of this trial should be available by the summer of 2020. TRIAL REGISTRATION: ISRCTN Registry ISRCTN15366334; http://www.isrctn.com/ISRCTN15366334. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/17939.