Individuals with chronic obstructive pulmonary disease (COPD) experience pain at levels similar to or greater than levels reported in the general population, report authors of a new study.
However, findings from this UK research groups’ systematic literature review suggest that nonpharmacologic and noninvasive interventions that have been investigated to date “do not currently improve chronic pain for people with COPD to a level that is clinically meaningful.”
Further, studies into the impact of these interventions are fundamentally flawed, according to lead author Leah Avery, PhD, professor of applied health psychology in the School of Health and Life Sciences, Teesside University, Middlesbrough, UK, and colleagues.
Current national and international COPD guidelines do not address chronic pain, write Avery et al in the journal Respiratory Medicine, nor are specific pain measures commonly used in persons with COPD. Pharmacologic treatment, while often the prescribed approach, is commonly ineffective, they add.
With evidence accumulating that indicates the high prevalence of pain in this already vulnerable group, the investigators set out specifically to evaluate the efficacy of existing nonpharmacologic and noninvasive interventions for addressing chronic pain in those with COPD.
The team conducted a search of 14 databases from May to June 2020, with an updated search for May to August 2022. Eligible studies were any nonpharmacologic, noninvasive intervention-based studies, with both randomized and nonrandomized controlled designs, that included patients with a confirmed diagnosis of stable COPD (ie, Global Initiative for Chronic Obstructive Lung Disease stages 1-4). Outcomes of interest were pain measures or pain subscale scores. Chronic pain was defined as pain occurring for at least 3 months with no underlying tissue damage in its etiology.
From an original yield of 95 302 potentially relevant studies, Avery et al assessed 223 for eligibility, with 29 studies (n=3228) included in the final review. Of the studies, 25 were randomized controlled trials (RCT) and 4 had non-RCT designs, 1 with a mixed methods approach.
A wide range of interventions were reported including physical rehabilitation (PR), education, various forms of exercise, breathing management techniques, self-management, and psychotherapeutic interventions; most of the interventions were not targeted specifically at pain.
A clinically meaningful change in pain outcomes (minimal clinically important difference of ≥1) from pre-intervention to postintervention was reported in 7 studies, although results were statistically significant (P<.001) in only 2 studies, according to results. A third study did not find a clinically meaningful improvement but did show statistical significance (P =.0273).
When Avery and team looked to identify specific behavior change techniques (BCT) associated with an effective intervention, they found very few studies reported descriptions of the interventions. In studies where descriptions were included, the BCT was reported to include “instructions on how to perform the behaviour,” “pulmonary rehabilitation,” or “goal setting” behaviour.
The researchers emphasized that study interventions did not specifically focus on pain in COPD, but rather on a range of primary outcomes. Specific BCTs, therefore, were often targeting increased physical activity or improved emotional state.
Mean pain scores ranged from 8.15 to 77.50 with an overall weighted mean of 54.53. The weighted mean SF-36 Physical Component and Mental Component scores were 33.34 and 42.43, respectively.
Regarding the quality of evidence, 5 RCTs had a low risk of bias, 8 had a moderate risk of bias, 12 indicated a high risk of bias, and the 4 non-RCTs had a moderate risk of bias.
Avery et al cite several limitations to the research, a significant one involving BCTs. BCT protocols require that interventions be coded only when the BCT is explicitly reported in the intervention description, and this process was limited by the detail of intervention methodology reported within each study.
They add that “Intervention heterogeneity and methodological quality limit current knowledge about effectiveness of previously trialed non-pharmacological and non-invasive interventions on pain symptoms in people with COPD,” thus they could not use the data to recommend a specific intervention. “Future research should describe interventions in detail and more frequently assess pain in this population to inform the development of an intervention targeting pain management for people with COPD,” they concluded.
Reference: Morris JR, Harrison SL, Robinson J, Martin D, Avery L. Non-pharmacological and non-invasive interventions for chronic pain in people with chronic obstructive pulmonary disease: a systematic review without meta-analysis. Respir Med. Published online March 6, 2023. doi:10.1016/j.rmed.2023.107191