Beyond the Self-Reports: A Review on Objective Pain Measurement and Its Implications.

Current methods of pain measurement are inadequate in capturing the complexity of the pain experience. This limitation arises mainly because these methods tend to overlook the multiple dimensions of pain during assessment, heavily relying on self-reported measures, which inherently have their drawbacks. Self-reported measures aim to gauge the pain severity experienced by an individual, based solely on their perception of the most intense pain sensation. However, these measures are prone to various biases and may not accurately reflect the actual pain experienced. To overcome these limitations, a new system of pain assessment is necessary, which minimizes subjective involvement and provides a more accurate representation of pain. The 'Pain Calculator' is a newly developed tool that has demonstrated promising accuracy in measuring somatic pain in the low back region. This tool effectively overcomes the subjective biases characteristic of the self-reported measures and provides a reliable and clinically feasible alternative to the existing pain assessment tools.

Performance Evaluation of a Supervised Machine Learning Pain Classification Model Developed by Neonatal Nurses.

BACKGROUND: Early-life pain is associated with adverse neurodevelopmental consequences; and current pain assessment practices are discontinuous, inconsistent, and highly dependent on nurses' availability. Furthermore, facial expressions in commonly used pain assessment tools are not associated with brain-based evidence of pain. PURPOSE: To develop and validate a machine learning (ML) model to classify pain. METHODS: In this retrospective validation study, using a human-centered design for Embedded Machine Learning Solutions approach and the Neonatal Facial Coding System (NFCS), 6 experienced neonatal intensive care unit (NICU) nurses labeled data from randomly assigned iCOPEvid (infant Classification Of Pain Expression video) sequences of 49 neonates undergoing heel lance. NFCS is the only observational pain assessment tool associated with brain-based evidence of pain. A standard 70% training and 30% testing split of the data was used to train and test several ML models. NICU nurses' interrater reliability was evaluated, and NICU nurses' area under the receiver operating characteristic curve (AUC) was compared with the ML models' AUC. RESULTS: Nurses weighted mean interrater reliability was 68% (63%-79%) for NFCS tasks, 77.7% (74%-83%) for pain intensity, and 48.6% (15%-59%) for frame and 78.4% (64%-100%) for video pain classification, with AUC of 0.68. The best performing ML model had 97.7% precision, 98% accuracy, 98.5% recall, and AUC of 0.98. IMPLICATIONS FOR PRACTICE AND RESEARCH: The pain classification ML model AUC far exceeded that of NICU nurses for identifying neonatal pain. These findings will inform the development of a continuous, unbiased, brain-based, nurse-in-the-loop Pain Recognition Automated Monitoring System (PRAMS) for neonates and infants.

Oral and topical analgesia in pediatric electrodiagnostic studies.

INTRODUCTION/AIMS: Electrodiagnostic examinations, such as nerve conduction studies (NCS) and needle electromyography (EMG), are perceived as painful by children and their parents/guardians. Methods to reduce peri-procedural pain improve compliance and have neurocognitive and neuropsychiatric benefits. This study aimed to assess the efficacy of combined oral and topical analgesics (COTA), oral analgesics (OA), and placebo in reducing pain during NCS/EMG in children. METHODS: We performed a double-blind, randomized, placebo-controlled trial on children presenting to our neurophysiology lab. Patients were stratified into two age groups (6M-6Y and 7Y-18Y) and randomized into three arms: COTA, OA, and placebo. Pain scores post-NCS/EMG were assessed using the Modified Behavioral Pain Scale (MBPS) and Faces Pain Scale-Revised (FPS-R). RESULTS: One hundred thirteen participants were enrolled. A comparison of participants from both age groups combined revealed no significant differences in guardian FPS-R scores across all arms for NCS and EMG. A significant difference in the distribution of post-NCS FPS-R score severities in children aged 7Y-18Y was noted between OA and placebo (p = .007). EMG was more painful than NCS across all arms (p < .05). In children aged 6M-6Y undergoing at least 10 muscle samplings during EMG, those receiving COTA had significantly lower pain scores (p = .014). DISCUSSION: This study reveals the complexity of pediatric pain perception during NCS/EMG and highlights that other methods to reduce experienced pain are required. Our findings suggest that procedural characteristics, such as number of muscles sampled, may influence the effectiveness of analgesia and serve as a foundation for future research aimed at optimizing pain management strategies.

Association between pain interference and motoric cognitive risk syndrome in older adults: a population-based cohort study.

OBJECTIVES: Motoric cognitive risk syndrome (MCR) is a pre-dementia condition characterized by subjective complaints in cognition and slow gait. Pain interference has previously been linked with cognitive deterioration; however, its specific relationship with MCR remains unclear. We aimed to examine how pain interference is associated with concurrent and incident MCR. METHODS: This study included older adults aged ≥ 65 years without dementia from the Health and Retirement Study. We combined participants with MCR information in 2006 and 2008 as baseline, and the participants were followed up 4 and 8 years later. The states of pain interference were divided into 3 categories: interfering pain, non-interfering pain, and no pain. Logistic regression analysis was done at baseline to examine the associations between pain interference and concurrent MCR. During the 8-year follow-up, Cox regression analysis was done to investigate the associations between pain interference and incident MCR. RESULTS: The study included 7120 older adults (74.6 ± 6.7 years; 56.8% females) at baseline. The baseline prevalence of MCR was 5.7%. Individuals with interfering pain had a significantly increased risk of MCR (OR = 1.51, 95% CI = 1.17-1.95; p = 0.001). The longitudinal analysis included 4605 participants, and there were 284 (6.2%) MCR cases on follow-up. Participants with interfering pain at baseline had a higher risk for MCR at 8 years of follow-up (HR = 2.02, 95% CI = 1.52-2.69; p < 0.001). CONCLUSIONS: Older adults with interfering pain had a higher risk for MCR versus those with non-interfering pain or without pain. Timely and adequate management of interfering pain may contribute to the prevention and treatment of MCR and its associated adverse outcomes.

Foot and lower leg pain in children and adults with cerebral palsy: a population-based register study on 5,122 individuals.

BACKGROUND: Pain is common in individuals with cerebral palsy (CP) and the most reported pain site is the foot/lower leg. We analyzed the prevalence of pain in the foot/lower leg and the associations with age, sex, gross motor function, and clinical findings in individuals with CP. METHOD: This was a cross-sectional register-study, based on data reported to the Swedish Cerebral Palsy Follow-up Program (CPUP). All participants in CPUP, four years-of-age or older, were included. Pearson chi-square tests and logistic regression were used to analyze the prevalence and degree of pain in the foot/lower leg. RESULTS: In total, 5,122 individuals were included from the CPUP database: 58% were males and 66% were under 18 years-of-age. Overall, 1,077 (21%) reported pain in the foot/lower leg. The odds ratios (ORs) of pain were higher in females (OR 1.31, 95% confidence interval (CI) 1.13-1.53), individuals who could ambulate (Gross Motor Function Classification System Level I (OR 1.84, CI 1.32-2.57) and II (OR 2.01, CI 1.46-2.79) compared to level V), and in individuals with decreased range of motion of the ankle (dorsiflexion 1-10 degrees (OR 1.43, CI 1.13-1.83) and ≤ 0 degrees (OR 1.46, CI 1.10-1.93) compared to ≥ 20 degrees). With increasing age the OR of pain increased (OR 1.02, CI 1.01-1.03) as well as the reported pain intensity (p < 0.001). CONCLUSIONS: Pain in the foot and lower leg appears to be a significant problem in individuals with CP, particularly in those who walk. As with pain in general in this population, both pain intensity and frequency increase with age. The odds of pain in the foot and lower leg were increased in individuals with limited dorsiflexion of the ankle. Given the cross-sectional design causality cannot be inferred and it is unknown if pain causes decreased range of motion of the ankle or if decreased range of motion causes pain. Further research is needed on causal pathways and importantly on prevention.

Exploring Patient Pain Experiences during and after Conventional Red Light and Simulated Daylight Photodynamic Therapy for Actinic Keratosis: A Qualitative Interview Study.

Simulated daylight photodynamic therapy is a relatively new and potentially less painful alternative to conventional red light photodynamic therapy for actinic keratosis. Qualitative research exploring patient experiences of pain and skin reactions during these treatments is scarce. To address this, semi-structured interviews were conducted of 10 patients aged 60-81 years with symmetrically distributed actinic keratoses 4 weeks after split-face treatment with conventional red light photodynamic therapy and simulated daylight photodynamic therapy. The participants were recruited from an ongoing clinical randomized trial. Interviews (median length 35 min) were conducted between June 2022 and January 2023, audio-recorded, transcribed verbatim, and analysed qualitatively using content analysis, as described by Graneheim and Lundman. Participants reported that conventional red light photodynamic therapy was very painful during illumination and transiently painful in the post-treatment period, while simulated daylight photodynamic therapy was almost painless during illumination and led to minor post-treatment pain. Also, skin reactions were more intense and longer-lasting with conventional red light photodynamic therapy than with simulated daylight photodynamic therapy. Most participants expressed a treatment preference for simulated daylight photodynamic therapy but had reservations about its unestablished long-term effectiveness. This study underscores the considerable pain associated with conventional red light photodynamic therapy, and the pivotal importance of shared decision-making when selecting the most appropriate treatment.

Nurses' perception of uncertainty regarding suspected pain in people with dementia: A qualitative descriptive study.

OBJECTIVES: This study aims to qualitatively examine nurses' perception of uncertainty regarding suspected pain in people with dementia (PWD). DESIGN: The study utilized a qualitative descriptive design. PARTICIPANTS: The participants in this study were nurses with a minimum of six months of experience caring for PWD and currently working in a university hospital in Irbid, Jordan. Twenty-five participants were selected using convenience sampling from the selected hospital. RESULTS: Four major themes and 12 subthemes relating to nurses' perceptions of uncertainty regarding suspected pain in PWD emerged. The main themes were (a) the culture-bound nature of uncertainty regarding suspected pain in PWD, (b) dimensions of uncertainty regarding suspected pain in PWD, (c) indicators of uncertainty regarding suspected pain in PWD, and (d) assessment methods of uncertainty to suspected pain in PWD. Moreover, for each major theme, different subthemes were developed. CONCLUSIONS: It is crucial to address factors influencing -nurses' uncertainty regarding suspected pain in PWD to improve pain assessment and management in PWD. Additionally, the study identified five indicators of uncertainty: complicated decision-making, knowledge deficit, bias, intuition, and misconceptions. Effective assessment methods, such as semi-structured interviews and simulated assessments, should be employed to evaluate uncertainty accurately. By addressing these issues and utilizing appropriate assessment approaches, healthcare professionals can enhance pain management for individuals with dementia.

Is the Central Sensitization Inventory (CSI) associated with quantitative sensory testing (QST)? A systematic review and meta-analysis.

Central sensitization (CS) involves an amplification of neural processing within the central nervous system that can result in widespread pain patterns and hypersensitivity to stimuli. The Central Sensitization Inventory (CSI) and various quantitative sensory testing (QST) methods purport to assess clinical markers of CS. The purpose of this systematic review and meta-analysis was to summarize and quantify the associations between total CSI scores and QST measures from previous studies. A systematic search identified 39 unique studies that were deemed eligible for the systematic review and 33 studies for meta-analyses (with 3314 subjects and 154 effect sizes), including five QST modalities: conditioned pain modulation, temporal summation, pressure pain threshold, heat pain threshold, and cold pain threshold. The meta-analysis yielded statistically significant CSI-QST correlations in total subject samples for all five QST modalities. The strongest associations were identified between CSI scores and pain threshold testing, especially pressure pain threshold, in which 51% of effects sizes, from 29 studies and 3071 subjects, were determined to be in a medium to large range.

Understanding the association between pain and delirium in older hospital inpatients: systematic review and meta-analysis.

OBJECTIVE: Delirium and pain are common in older adults admitted to hospital. The relationship between these is unclear, but clinically important. We aimed to systematically review the association between pain (at rest, movement, pain severity) and delirium in this population. METHODS: PubMed, EMBASE, CINAHL, PsycINFO, Cochrane and Web of Science were searched (January 1982-November 2022) for Medical Subject Heading terms and synonyms ('Pain', 'Analgesic', 'Delirium'). Study eligibility: (1) validated pain measure as exposure, (2) validated delirium tool as an outcome; participant eligibility: (1) medical or surgical (planned/unplanned) inpatients, (2) admission length ≥ 48 h and (3) median cohort age over 65 years. Study quality was assessed with the Newcastle Ottawa Scale. We collected/calculated odds ratios (ORs) for categorical data and standard mean differences (SMDs) for continuous data and conducted multi-level random-intercepts meta-regression models. This review was prospectively registered with PROSPERO [18/5/2020] (CRD42020181346). RESULTS: Thirty studies were selected: 14 reported categorical data; 16 reported continuous data. Delirium prevalence ranged from 2.2 to 55%. In the multi-level analysis, pain at rest (OR 2.14; 95% confidence interval [CI] 1.39-3.30), movement (OR 1.30; 95% CI 0.66-2.56), pain categorised as 'severe' (OR 3.42; 95% CI 2.09-5.59) and increased pain severity when measured continuously (SMD 0.33; 95% CI 0.08-0.59) were associated with an increased delirium risk. There was substantial heterogeneity in both categorical (I2 = 0%-77%) and continuous analyses (I2 = 85%). CONCLUSION: An increase in pain was associated with a higher risk of developing delirium. Adequate pain management with appropriate analgesia may reduce incidence and severity of delirium.

The association of fatigue severity with pain level, obesity indices and functional performances in women with knee osteoarthritis.

INTRODUCTION: Knee osteoarthritis is most common among women with obesity. It may lead to physical inactivity that, in turn, causes fatigue or lack of physical enthusiasm to perform meaningful daily activities. Hence, this study aimed to examine whether pain level, obesity indices and functional performances are associated with fatigue severity in women with knee osteoarthritis (KOA). MATERIALS AND METHODS: This cross-sectional study recruited women referred to physiotherapy to manage OA. The measurements included fatigue severity (fatigue severity scale); pain level (numerical rating scale); obesity indices (body mass index, fat %, waist circumference); functional performances (upper limb strength, lower limb strength, mobility, exercise capacity and quality of life). A simple linear regression analysis was used to determine which independent variable may be associated with fatigue severity. RESULTS: Ninety-six women with unilateral KOA participated in this study (Mean age, 55.70, Standard Deviation, SD 6.90) years; Mean fatigue severity, 34.51, SD 14.03). The simple linear regression analysis showed that pain level (ß=4.089, p<0.001), fat % (ß=0.825, p<0.001) and QoL (ß=0.304, p<0.001) were significantly associated with fatigue. After controlling for pain level, only fat % was significantly associated with fatigue (ß=0.581, p=0.005). CONCLUSION: Pain level, fat %, and QoL appear to be associated with fatigue severity in women with KOA. In addition, pain symptoms may interact with factors associated with fatigue severity.

Pain trajectories and their associations with cognition among older adults: a 10-year cohort study from network perspective.

BACKGROUND: Few studies have examined the associations between pain trajectories and cognitive function in older adults. This study explored the associations between pain trajectories and different cognitive domains in older adults from a network perspective. METHODS: Data on pain trajectories were derived from the Health and Retirement Study between 2010 and 2020 using latent class growth analyses. Measurements of key cognition domains, including memory, attention, calculation, orientation and language, were included. Linear regression and network analysis were performed to evaluate the associations between different pain trajectories and cognition. RESULTS: A total of 9,551 older adults were included in this study and three trajectories of pain were identified. After controlling for the covariates, persistent severe pain trajectory was associated with poorer overall cognition, memory and calculation ability when compared to mild or non-persistent pain trajectory. In the pain and cognition network model, memory (expected influence (EI) = 0.62), language (EI = 0.58) and calculation (EI = 0.41) were the most central domains. CONCLUSIONS: Pain trajectories appeared stable over time among older adults in this study. Severity of persistent pain was an important risk factor for poor cognition, especially in relation to memory and calculation domains. Interventions targeting memory, language and calculation domains might be useful in addressing cognitive decline in older adults with persistent pain.

Painful differences between different pain scale assessments: The outcome of assessed pain is a matter of the choices of scale and statistics.

OBJECTIVES: Perceived pain is a multi-factorial subjective variable, commonly measured by numeric rating scales, verbal descriptive scales (VDS), or by a position on an analogue line (VAS). A major question is whether an individual's VAS and VDS pain assessments, on the same occasion, could be comparable. The aim was to compare continuous and discretized VAS pain data with verbal descriptive pain datasets from the Oswestry Disability Index (ODI) and the European Quality of Life Scale (EQ-5D) in paired pain datasets. METHODS: The measurement level of data from any type of scale assessments is ordinal, having rank-invariant properties only. Non-parametric statistical methods were used. Two ways of discretizing the VAS-line to VAS-intervals to fit the number of the comparing VDS-categories were used: the commonly used (equidistant VAS,VDS)-pairs and the (unbiased VAS,VDS)-pairs of pain data. The comparability of the (VAS,VDS)-pairs of data of perceived pain was studied by the bivariate ranking approach. Hence, each pair will be regarded as ordered, disordered, or tied with respect to the other pairs of data. The percentage agreement, PA, the measures of disorder, D, and of order consistency, MA, were calculated. Total interchangeability requires PA = 1 and MA = 1. RESULTS: The wide range of overlapping of (VAS,VDS)-pairs indicated that the continuous VAS data were not comparable to any of the VDS pain datasets. The percentage of agreement, PA; in the (equidistant VAS,ODI) and (equidistant VAS, EQ-5D) pairs were 38 and 49%, and the order consistency, MA, was 0.70 and 0.80, respectively. Corresponding results for the (unbiased VAS,VDS)-pairs of pain data were PA: 54 and 100%, and MA: 0.77 and 1.0. CONCLUSION: Our results confirmed that perceived pain is the individual's subjective experience, and possible scale-interchangeability is only study-specific. The pain experience is not possible to be measured univocally, but is possible for the individual to rate on a scale.

Change in number of pain sites - which factors are important? A 12-year prospective cohort study.

BACKGROUND: Pain in multiple body sites is common and often persistent. The purpose of this prospective study was to examine the change in the number of pain sites (NPS) over time and to evaluate to which extent clinical, demographic, lifestyle and health-related factors predict a change in NPS. METHODS: This was a population-based longitudinal cohort study of adults (n = 2,357). Data on pain, demographic, lifestyle, and health-related variables were collected by questionnaires in 2008 and 2020 and register data from 2006 to 2017. Data was analysed with linear regression. RESULTS: We found a mean decrease in NPS over the 12-year follow-up period (-0.36 (95% CI; -0.44; -0.27) and 56% of this sample reported no change or only one pain site increase/decrease over 12 years. While participants reporting pain for less than 3 months at baseline had almost no change in NPS (-0.04 (95% CI; -0.18; 0.10)), participants with pain for longer than 3 months decreased by -0.51 (95% CI; -0.62; -0.41). Age at baseline (20-49 years), pain intensity, and obesity (BMI ≥ 30) were associated with an increase in NPS over the follow-up period. CONCLUSIONS: NPS is relatively stable over time. We found a small mean decrease in NPS over 12 years varying between participants with pain for longer than 3 months and pain for less than 3 months respectively. The results also indicate that pain intensity, age, and obesity could be relevant factors to consider when predicting change in NPS.

A guide to pain assessment and management in adults.

Pain is universally experienced and extremely complex, involving the mind as well as the body. It is activated by a variety of stimuli, including biological, physical and psychological. This article seeks to provide a deeper understanding of the physiology of pain and the various classifications used in clinical practice. It also aims to raise awareness of the skills that nurses require for the assessment and management of an individual patient's pain. It explores the tools available to assist with the assessment of pain and provides an introduction to some of the management strategies that can be used to manage pain. Some of the barriers to effective pain assessment and management are also examined.

Prevalence of prehospital pain and pain assessment difference between patients and paramedics: a prospective cross-sectional observational study.

Adequate analgesia is one of the most important interventions in emergency medicine. However, studies suggest that many patients are undertreated for pain. There can be many reasons why patients assess their pain differently to the paramedics. This study aimed to assess the differences in pain ratings between patients and paramedics and factors influencing them in prehospital emergencies. This prospective cross-sectional observational study included patients treated and transported by paramedics or paramedics and emergency physicians of the German Red Cross in Reutlingen, Germany. This study included 6,365 patients. The prevalence of pain was 49.7%. Among patients with a self-reported numerical rating scale (NRS) > 0, the mean patient pain rating was NRS 4.2 ± 2.7, while the mean paramedic pain rating was NRS 3.6 ± 2.4 (p < 0.001). Approximately 11.8% (n = 751) of patients reported subjectively unbearable pain. Patients reported a mean NRS of 7.7 ± 1.8 for unbearable pain, but a mean NRS of 3.3 ± 2.0 for bearable pain (p < 0.001). The difference in pain ratings between patients and paramedics increased with pain severity. Univariate analysis showed that there were no gender differences, but the difference in pain rating was influenced by patient age (p < 0.001) and paramedic age (p = 0.042). The differences in pain ratings were particularly pronounced for abdominal diseases (p < 0.001) and trauma (p < 0.001). There is a difference in pain ratings between patients and paramedics, which increases with pain severity and appears to be associated with the patient's age and the paramedic's age. To determine the desire and need for analgesics, the question about unbearable pain is a good addition to the NRS.

Behavioral pain scale may not be reliable in awake non-verbal intensive care patients: a case control study.

BACKGROUND: The evaluation of pain in patients, unable of oral communication, often relies on behavioral assessment. However, some critically ill patients, while non-verbal, are awake and have some potential for self-reporting. The objective was to compare the results of a behavioral pain assessment with self-reporting in awake, non-verbal, critically ill patients unable to use low-tech augmentative and alternative communication tools. METHODS: Prospective cohort study of intubated or tracheotomized adult, ventilated patients with a RASS (Richmond Agitation Sedation Scale) of -1 to + 1 and inadequate non-verbal communication skills in a surgical intensive care unit of a tertiary care university hospital. For pain assessment, the Behavioral Pain Scale (BPS) was used. Self-reporting of pain was achieved by using an eye tracking device to evaluate the Numeric Rating Scale (NRS) and the pain/discomfort item of the EuroQol EQ-5D-5 L (EQ-Pain). All measurements were taken at rest. RESULTS: Data was collected from 75 patients. Neither the NRS nor the EQ-Pain (r < .15) correlated with the BPS. However, NRS and EQ-Pain were significantly correlated (r = .78, p = < 0.001), indicating the reliability of the self-reporting by these patients. Neither the duration of intubation/tracheostomy, nor cause for ICU treatment, nor BPS subcategories had an influence on these results. CONCLUSIONS: Behavioral pain assessment tools in non-verbal patients who are awake and not in delirium appear unreliable in estimating pain during rest. Before a behavioral assessment tool such as the BPS is used, the application of high-tech AACs should be strongly considered. TRIAL REGISTRATION: German Clinical Trials Register, Registration number: DRKS00021233. Registered 23 April 2020 - Retrospectively registered, https://drks.de/search/en/trial/DRKS00021233 .

Impact of Pain on Symptom Burden in Chemotherapy-Induced Peripheral Neurotoxicity.

BACKGROUND: Chemotherapy-induced peripheral neurotoxicity (CIPN) affects the quality of life of cancer survivors. However, the impact of pain on symptom burden remains undefined. This study aimed to define differences in the clinical symptom profile of patients with painful and nonpainful CIPN. PATIENTS AND METHODS: A total of 579 participants (median age, 59 years [IQR, 19 years]; F=66%) were assessed cross-sectionally 6 months posttreatment. CIPN severity was graded using multiple methods, including patient-reported outcome measures, a clinically graded scale (NCI-CTCAE), and a neurologic examination score. Participants were classified into subgroups based on patient symptom report, with painful CIPN characterized by the presence of shooting/burning pain, and nonpainful CIPN characterized by the presence of numbness or tingling without shooting/burning pain. Behavioral changes were assessed via structured patient interview regarding symptom impact on sleep, exercise, and treatment-seeking. RESULTS: Among 579 participants, 24% (n=140) reported painful CIPN, 48% (n=280) reported nonpainful CIPN, and 28% (n=159) had no CIPN. Participants with painful CIPN demonstrated higher CIPN severity than those with nonpainful CIPN across multiple measures, including NCI-CTCAE, neurologic grading, and patient report (all P<.05). Participants with painful CIPN were more likely to report that their symptoms affected their ability to exercise (P=.007), produced sleep impairment, and increased treatment-seeking behavior due to their symptoms (both P<.001) compared with participants with nonpainful CIPN. CONCLUSIONS: Overall, participants with painful CIPN reported higher scores across all CIPN severity measures, including behavioral changes. This study underlines the need for accurate identification of different CIPN subgroups in hopes of informing better treatment and rehabilitation options for cancer survivors with painful CIPN.