Indices of pain variability: a paradigm shift

Psychosocial Phenotypes of Older Adults With Pain and Their Associated Clinical Outcomes

A comprehensive understanding of the patterns of psychosocial characteristics in older adults with pain is needed. Our objectives were to (1) identify psychosocial phenotypes (comprising depression, anxiety, affect, self-realization, resilience, and social participation) among older adults with pain and (2) compare pain characteristics, physical health, and cognition among the identified phenotypes. Using cross-sectional 2021 data from the National Health and Aging Trends Study, we performed latent class analysis to identify four psychosocial phenotypes of older adults with pain (N = 1903): Favorable (best psychosocial characteristics, 67.7%), Adverse (worst psychosocial characteristics, 4.9%), Intermediate (moderate scores on psychosocial variables, 12.6%), and Compensated (moderate scores with relatively high self-realization and resilience, 14.9%). Phenotypes with less psychosocial adversity had generally better clinical outcomes. Future research should explore precision pain management interventions in older adults based on their psychosocial phenotypes, longitudinal trajectories of phenotypes, and technology-based, point-of-care clinical insights for pain management.

The role of pain trajectory and sex in predicting postoperative neck pain in patients after cervical spine surgery: A retrospective cohort study

BackgroundPostoperative neck pain is common after cervical spine surgery, with potential progression to chronic pain.ObjectiveTo assess the role of pain trajectory in predicting postoperative neck pain following cervical spine surgery and to discern sex-based differences in this relationship.MethodsA retrospective study was conducted on 133 patients (mean age:64.1 ± 11.9 years; 86 males, 47 females) undergoing cervical spine surgery. Pain trajectory, defined by Numerical Rating Scale scores on postoperative days 1, 3, 5, and 7, was analyzed using hierarchical multiple regression to evaluate its predictive value for neck pain at two weeks, with sex as a moderator.ResultsSex (B = 0.613; p < .05), slope (B = 1.528; p < .01), and intercept (B = 0.410; p < .01) were significant predictors. Pain trajectory had a stronger association with neck pain in females (B = 2.283; p < .01) than in males (B = 0.772; p = .03).ConclusionPain trajectory is a predictor of postoperative neck pain and highlights sex-based differences. Incorporating pain trajectory monitoring into clinical practice can enable the early identification of patients at higher risk for poor pain outcomes, facilitating more targeted and effective interventions.

Increased Pain Variability in Patients With Chronic Pain: A Role for Pain Catastrophizing

Pain is an inherently negative perceptual and affective experience that acts as a warning system to protect the body from injury and illness. Pain unfolds over time and is influenced by myriad factors, making it highly dynamic. Despite this, statistical measures often treat any intraindividual variability in pain ratings as noise or error. This is consequential, especially for research on chronic pain, because pain variability is associated with greater pain severity and depression. Yet, differences in pain variability between patients with chronic pain and controls in response to acute pain has not been fully examined-and it is unknown if dispositional factors such as pain catastrophizing (negative cognitive-affective response to potential or actual pain in which attention cannot be diverted away from pain) relate to pain variability. In the current study, we recruited chronic-pain patients (N = 30) and pain-free controls (N = 22) to complete a 30-second thermal pain task where they continually rated a painful thermal stimulus. To quantify pain variability and capture potential dynamics, we used both a traditional intraindividual standard deviation (iSD) metric of variability and a novel derivatives approach. For both metrics, patients with chronic pain had higher variability in their pain ratings over time, and pain catastrophizing significantly mediated this relationship. This suggests patients with chronic pain experience pain stimuli differently over time, and pain catastrophizing may account for this differential experience. PERSPECTIVE: The present study demonstrates (using multiple variability metrics) that chronic pain patients show more variability when rating experimental pain stimuli, and that pain catastrophizing helps explain this differential experience. These results provide preliminary evidence that short-term pain variability could have utility as a clinical marker in pain assessment and treatment.

SOMAScience: A Novel Platform for Multidimensional, Longitudinal Pain Assessment

Chronic pain is one of the most significant health issues in the United States, affecting more than 20% of the population. Despite its contribution to the increasing health crisis, reliable predictors of disease development, progression, or treatment outcomes are lacking. Self-report remains the most effective way to assess pain, but measures are often acquired in sparse settings over short time windows, limiting their predictive ability. In this paper, we present a new mobile health platform called SOMAScience. SOMAScience serves as an easy-to-use research tool for scientists and clinicians, enabling the collection of large-scale pain datasets in single- and multicenter studies by facilitating the acquisition, transfer, and analysis of longitudinal, multidimensional, self-report pain data. Data acquisition for SOMAScience is done through a user-friendly smartphone app, SOMA, that uses experience sampling methodology to capture momentary and daily assessments of pain intensity, unpleasantness, interference, location, mood, activities, and predictions about the next day that provide personal insights into daily pain dynamics. The visualization of data and its trends over time is meant to empower individual users' self-management of their pain. This paper outlines the scientific, clinical, technological, and user considerations involved in the development of SOMAScience and how it can be used in clinical studies or for pain self-management purposes. Our goal is for SOMAScience to provide a much-needed platform for individual users to gain insight into the multidimensional features of their pain while lowering the barrier for researchers and clinicians to obtain the type of pain data that will ultimately lead to improved prevention, diagnosis, and treatment of chronic pain.

Exploring visual pain trajectories in neck pain patients, using clinical course, SMS-based patterns, and patient characteristics: a cohort study

Background

The dynamic nature of neck pain has so far been identified through longitudinal studies with frequent measures, a method which is time-consuming and impractical. Pictures illustrating different courses of pain may be an alternative solution, usable in both clinical work and research, but it is unknown how well they capture the clinical course. The aim of this study was to explore and describe self-reported visual trajectories in terms of details of patients’ prospectively reported clinical course, their SMS-based pattern classification of neck pain, and patient’s characteristics.

Methods

Prospective cohort study including 888 neck pain patients from chiropractic practice, responding to weekly SMS-questions about pain intensity for 1 year from 2015 to 2017. Patients were classified into one of three clinical course patterns using definitions based on previously published descriptors. At 1-year follow-up, patients selected a visual trajectory that best represented their retrospective 1-year course of pain: single episode, episodic, mild ongoing, fluctuating and severe ongoing.

Results

The visual trajectories generally resembled the 1-year clinical course characteristics on group level, but there were large individual variations. Patients selecting Episodic and Mild ongoing visual trajectories were similar on most parameters. The visual trajectories generally resembled more the clinical course of the last quarter.

Discussion

The visual trajectories reflected the descriptors of the clinical course of pain captured by weekly SMS measures on a group level and formed groups of patients that differed on symptoms and characteristics. However, there were large variations in symptoms and characteristics within, as well as overlap between, each visual trajectory. In particular, patients with mild pain seemed predisposed to recall bias. Although the visual trajectories and SMS-based classifications appear related, visual trajectories likely capture more elements of the pain experience than just the course of pain. Therefore, they cannot be seen as a proxy for SMS-tracking of pain over 1 year.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12998-022-00443-3.

Anxiety sensitivity and Pain Experience: a prospective investigation among World Trade Center Responders

Chronic pain is a significant public health problem and is exacerbated by stress. The World Trade Center (WTC) Disaster represents a unique stressor, and responders to the WTC disaster are at increased risk for pain and other health complaints. Therefore, there is a significant need to identify vulnerability factors for exacerbated pain experience among this high-risk population. Anxiety sensitivity (AS), defined as fear of anxiety-related sensations, is one such vulnerability factor associated with pain intensity and disability. Yet, no work has tested the predictive effects of AS on pain, limiting conclusions regarding the predictive utility and direction of associations. Therefore, the current study examined the prospective associations of AS, pain intensity, and pain interference among 452 (M_age = 55.22, SD = 8.73, 89.4% male) responders to the WTC disaster completing a 2-week daily diary study. Using multi-level modeling, AS total score was positively associated with both pain intensity and pain interference, and that AS cognitive concerns, but not social or physical concerns, were associated with increased pain. These results highlight the importance of AS as a predictor of pain complaints among WTC responders and provide initial empirical evidence to support AS as a clinical target for treating pain complaints among WTC responders.

Reliabilities of Intra-Individual Mean and Intra-Individual Variability of Self-Reported Pain Derived From Ecological Momentary Assessments: Results From the Einstein Aging Study

An individual's pain experiences vary substantially over time. Though variability in pain may be an important metric which usually predicts health consequences, research on the measurement of pain variability estimates is lacking among older adults. We aimed to examine the reliabilities of both intra-individual mean (IIM) and intra-individual variability (IIV) of pain assessed using ecological momentary assessments (EMA) among racially diverse, systematically recruited community dwelling cohort of older adults. Participants (N = 311, age = 70-91) completed a 14-day EMA protocol which included self-reports of pain intensity, pain interference with activities, and pain interference with concentration multiple times a day. Over a 2-week period, we found excellent reliabilities for both pain IIM (.99), and pain IIV (≥.90). We also found that we need 5 to 6 days to achieve good reliability (.8) for pain IIV, suggesting that a shorter protocol may be used to reduce participants' burden among the current sample, although caution is required when using this result to determine EMA study designs among different samples. Future studies are required to examine the associations of various EMA pain metrics with different health outcomes among older adults to facilitate the detection of underlying mechanisms linking pain to health as a prelude to interventions. PERSPECTIVE: Mean levels and variability in pain intensity, pain interference with activities, and pain interference with concentration can be reliably measured to be linked with various health outcomes in older adults. Future studies including these pain metrics will assess the natural history, the consequences, and effects of intervention of pain.

The Effectiveness of Thermal Neuromodulation Using Precise Heat in the Treatment of Chronic Low Back Pain Over 60 Days: An In-Home User Trial

PURPOSE

Two previous independent double-blind randomized studies demonstrated that thermal neuromodulation using high temperature pulsed heat reduced pain in subjects with chronic low back pain. The present study examined the effects of high temperature pulsed heat via an experimental device in a real-world In-Home Use Trial (IHUT) over a sixty-day period.

MATERIALS AND METHODS

This in-home study recruited 34 subjects with chronic low back pain, provided them with an experimental device that delivered treatment session of high temperature pulsed heat up to 45°C, and followed them for eight weeks. Subjects were allowed to use the device as needed. Primary outcome was pain rating as measured by the 11-point Numeric Pain Scale at baseline, four and eight weeks of treatment. The secondary outcome measures were the interference with daily living components of the Brief Pain Inventory at baseline versus eight weeks of treatment.

RESULTS

Thirty-two subjects completed the study. Pain levels were 5.81 at baseline, 2.79 at four weeks and 2.25 at eight weeks. All changes in pain levels between baseline and four weeks, baseline, and eight weeks and between four and eight weeks were statistically significant (p < 0.05). At eight weeks, the seven components of pain interference with activities of daily living and pain interference with walking were statistically reduced (P < 0.05). About 72% of subjects reported a single 30-minute treatment session produced over 3 hours of pain relief.

CONCLUSION

An eight-week in-home trial of high-temperature thermal modulation devices produced significant reductions in pain and pain interference with activities of daily living, an important measure of function. Efforts were made to control and reduce study contamination. This study provides important initial data for long-term outcome studies of thermal neuromodulation using high temperature pulsed heat to treat low back pain and to improve subject function and demonstrated that individuals with chronic pain can effectively self-manage pain.

Beyond Average: Providers' Assessments of Indices for Measuring Pain Intensity in Patients With Chronic Pain

Introduction: Effective clinical care for chronic pain requires accurate, comprehensive, meaningful pain assessment. This study investigated healthcare providers' perspectives on seven pain measurement indices for capturing pain intensity.

Methods: Semi-structured telephone interviews were conducted with a purposeful sample from four US regions of 20 healthcare providers who treat patients with chronic pain. The qualitative interview guide included open-ended questions to address perspectives on pain measurement, and included quantitative ratings of the importance of seven indices [average pain, worst pain, least pain, time in no/low pain, time in high pain, fluctuating pain, unpredictable pain]. Qualitative interview data were read, coded and analyzed for themes and final interpretation. Standard quantitative methods were used to analyze index importance ratings.

Results: Despite concerns regarding 10-point visual analog and numeric rating scales, almost all providers used them. Providers most commonly asked about average pain, although they expressed misgivings about patient reporting and the index's informational value. Some supplemented average with worst and least pain, and most believed pain intensity is best understood within the context of patient functioning. Worst pain received the highest mean importance rating (7.60), average pain the second lowest rating (5.65), and unpredictable pain the lowest rating (5.20).

Discussion: Assessing average pain intensity obviates obtaining clinical insight into daily contextual factors relating to pain and functioning. Pain index use, together with timing, functionality and disability, may be most effective for understanding the meaning to patients of high pain, how pain affects their life, how life affects their pain, and how pain changes and responds to treatment.

AN EXAMINATION OF DAY-TO-DAY AND INTRAINDIVIDUAL PAIN VARIABILITY IN LOW BACK PAIN

OBJECTIVE

This study aimed to capture day-to-day changes in pain intensity in individuals with low back pain (LBP), which may be indicative of patients' ability to modulate their pain levels. A secondary aim was to explore the presence of latent subgroups characterized by pain level, intraindividual pain variability, and change in pain over a 14-day period.

SUBJECTS

Participants were 54 adults with self-reported low back pain recruited from outpatient Physical Therapy clinics and the community.

METHODS

Over the course of 14 days, participants completed daily measures of pain intensity, catastrophizing, pain self-efficacy, and negative affect. Change in pain intensity as well as total amount of intraindividual pain variability were also calculated.

RESULTS

Daily increases in maladaptive coping and affective responses (i.e., higher catastrophizing, higher negative affect, lower pain self-efficacy) were associated with increases in pain intensity. A hierarchical cluster analysis revealed three subgroups: (1) moderate pain intensity, moderate pain variability, increase in pain over time; (2) low pain intensity, low pain variability, no change in pain over time; and (3) moderate pain intensity, high pain variability, decrease in pain over time. Cluster 2 demonstrated more adaptive coping and affective responses at baseline and during the 14-day period, and Cluster 1 and 3 did not differ in their coping nor affective responses.

CONCLUSIONS

These findings provide support that day-to-day changes in pain, coping and affective responses are meaningful and provide additional evidence of pain variability as a potential phenotypic characteristic.

Self-Regulatory Processes, Motivation to Conserve Resources and Activity Levels in People With Chronic Pain: A Series of Digital N-of-1 Observational Studies

Objectives

Motivational and self-regulatory processes during goal pursuit may account for activity patterns in people with chronic pain. This article describes a series of N-of-1 observational studies designed to investigate the influence of goal-related factors on fluctuations in motivation to conserve resources and objectively measured activity levels.

Methods

Four participants with chronic pain who attended a formal pain management program (PMP; 41–59 years old; three female) were recruited and completed digital daily diaries for 11–12 weeks. The daily dairies, delivered via text message, measured self-regulatory fatigue, goal self-efficacy, goal striving, perceived demands, pain, and motivation to conserve resources. Continuously worn accelerometers measured physical activity and sedentary time. Analyses were conducted individually for each participant. The effects of self-regulatory fatigue, goal self-efficacy, goal striving, perceived demands, and pain on motivation to conserve resources, physical activity and sedentary time were assessed with dynamic regression modeling.

Results

Different patterns of associations between the predictors and outcomes were observed across participants. Most associations occurred concurrently (e.g., on the same day). Perceived demand was the only variable to predict motivation to conserve resources, physical activity, and sedentary time. Motivation to conserve resources and sedentary time were most frequently predicted by goal striving and perceived demand. Self-regulatory fatigue and pain intensity both predicted motivation to conserve resources in two participants and sedentary time in one participant. Motivation to conserve resources predicted sedentary time in two participants.

Conclusion

This study was the first to examine the impact of fluctuations in self-regulatory processes on motivation to conserve resources and objective activity levels within individuals with chronic pain. The results generally supported recent affective-motivational views of goal pursuit in chronic pain. This study demonstrated that N-of-1 observational studies can be conducted with patients during a PMP using digital technologies. The use of these approaches may facilitate the application of personalized medicine.