The Global Burden of Pain

Distributions of recorded pain in mental health records: a natural language processing based study

OBJECTIVE

The objective of this study is to determine demographic and diagnostic distributions of physical pain recorded in clinical notes of a mental health electronic health records database by using natural language processing and examine the overlap in recorded physical pain between primary and secondary care.

DESIGN, SETTING AND PARTICIPANTS

The data were extracted from an anonymised version of the electronic health records of a large secondary mental healthcare provider serving a catchment of 1.3 million residents in south London. These included patients under active referral, aged 18+ at the index date of 1 July 2018 and having at least one clinical document (≥30 characters) between 1 July 2017 and 1 July 2019. This cohort was compared with linked primary care records from one of the four local government areas.

OUTCOME

The primary outcome of interest was the presence of recorded physical pain within the clinical notes of the patients, not including psychological or metaphorical pain.

RESULTS

A total of 27 211 patients were retrieved. Of these, 52% (14,202) had narrative text containing relevant mentions of physical pain. Older patients (OR 1.17, 95% CI 1.15 to 1.19), females (OR 1.42, 95% CI 1.35 to 1.49), Asians (OR 1.30, 95% CI 1.16 to 1.45) or black (OR 1.49, 95% CI 1.40 to 1.59) ethnicities, living in deprived neighbourhoods (OR 1.64, 95% CI 1.55 to 1.73) showed higher odds of recorded pain. Patients with severe mental illnesses were found to be less likely to report pain (OR 0.43, 95% CI 0.41 to 0.46, p<0.001). 17% of the cohort from secondary care also had records from primary care.

CONCLUSION

The findings of this study show sociodemographic and diagnostic differences in recorded pain. Specifically, lower documentation across certain groups indicates the need for better screening protocols and training on recognising varied pain presentations. Additionally, targeting improved detection of pain for minority and disadvantaged groups by care providers can promote health equity.

Lidocaine-Liposomes-A Promising Frontier for Transdermal Pain Management

(1) Background: We aim to develop novel gel formulations for transdermal drug delivery systems in acute and inflammatory pain therapy. (2) Methods: We induced inflammation by the injection of λ-carrageenan on the hind paw of 80 Wistar male rats. The animals were randomized into eight groups of 10 rats each: C (placebo gel), E (EMLATM), L (lidocaine 2%), L-CD (lidocaine + cyclodextrin 2.5%), L-LP (lidocaine + liposomes 1.7%), L-CS (lidocaine + chitosan 4%), L-CSh (lidocaine + chitosan hydrochloride), and L-CS-LP (lidocaine + chitosan + liposomes). The behavior response was determined with a hot plate, cold plate, and algesimeter, each being performed at 30, 60, 120, 180, and 240 min after pain induction. At the end of the experiment, tissue samples were collected for histological assessment. (3) Results: L-LP had the greatest anesthetic effects, which was proven on the cold plate test compared to placebo and EMLATM (all p ≤ 0.001). L-CS-LP had a significant effect on cold plate evaluation compared to placebo (p ≤ 0.001) and on hot plate evaluation compared to EMLATM (p = 0.018). (4) Conclusions: L-LP is a new substance with a substantial analgesic effect demonstrated by the cold plate in the first 120 min. Further studies with more animals are needed to determine the maximum doses that can be applied for a better analgesia with minimum side effects.

Anti-inflammatory biomolecular activity of chlorinated-phenyldiazenyl-naphthalene-2-sulfonic acid derivatives: perception from DFT, molecular docking, and molecular dynamic simulation

In this study, two novel derivatives of naphthalene-2-sulfonic acid: 6-(((1S,5R)-3,5-dichloro-2,4,6-triazabicyclo [z3.1.0]hex-3-en-1-yl)amino)-5-((E)-phenyldiazenyl)naphthalene-2-sulfonic acid (DTPS1) and (E)-6-((4,6-dichloro-1,3,5-triazine2-yl)amino)-4-hydroxy-3-(phenyldiazenyl)naphthalene-2-sulfonic acid (DTPS2) have been synthesized and characterized using FT-IR, UV-vis, and NMR spectroscopic techniques. Applying density functional theory (DFT) at the B3LYP, APFD, PBEPBE, HCTH, TPSSTPSS, and ωB97XD/aug-cc-pVDZ level of theories for the electronic structural properties. In-vitro analysis, molecular docking, molecular dynamic (MD) simulation of the compounds was conducted to investigate the anti-inflammatory potential using COXs enzymes. Docking indicates binding affinity of -9.57, -9.60, -6.77 and -7.37 kcal/mol for DTPS1, DTPS2, Ibuprofen and Diclofenac which agrees with in-vitro assay. Results of MD simulation, indicates sulphonic group in DTPS1 has > 30% interaction with the hydroxyl and oxygen atoms in amino acid residues, but > 35% interaction with the DTPS2. It can be said that the DTPS1 and DTPS2 can induce inhibitory effect on COXs to halt biosynthesis of prostaglandins (PGs), a chief mediator of inflammation and pain in mammals.Communicated by Ramaswamy H. Sarma.

Induced pain affects auricular and body biosignals: From cold stressor to deep breathing

Pain affects every fifth adult worldwide and is a significant health problem. From a physiological perspective, pain is a protective reaction that restricts physical functions and causes responses in physiological systems. These responses are accessible for evaluation via recorded biosignals and can be favorably used as feedback in active pain therapy via auricular vagus nerve stimulation (aVNS). The aim of this study is to assess the significance of diverse parameters of biosignals with respect to their deflection from cold stressor to deep breathing and their suitability for use as biofeedback in aVNS stimulator. Seventy-eight volunteers participated in two cold pressors and one deep breathing test. Three targeted physiological parameters (RR interval of electrocardiogram, cardiac deflection magnitude Z _AC of ear impedance signal, and cardiac deflection magnitude PPG _AC of finger photoplethysmogram) and two reference parameters (systolic and diastolic blood pressures BP _S and BP _D) were derived and monitored. The results show that the cold water decreases the medians of targeted parameters (by 5.6, 9.3%, and 8.0% of RR, Z _AC, and PPG _AC, respectively) and increases the medians of reference parameters (by 7.1% and 6.1% of BP _S and BP _D, respectively), with opposite changes in deep breathing. Increasing pain level from relatively mild to moderate/strong with cold stressor varies the medians of targeted and reference parameters in the range from 0.5% to 6.0% (e.g., 2.9% for RR, Z _AC and 6.0% for BP _D). The physiological footprints of painful cold stressor and relaxing deep breathing were shown for auricular and non-auricular biosignals. The investigated targeted parameters can be used as biofeedback to close the loop in aVNS to personalize the pain therapy and increase its compliance.

Association of pain and quality of life among middle-aged and older adults of India

BACKGROUND

India is passing through a phase of demographic and epidemiological transition where ageing and chronic morbidities are being more common. Though studies have examined the prevalence and risk factors of pain and other chronic morbidities, nationally representative research examining the association of pain and quality of life (QoL) is limited in India. This study examines the association between pain and QoL among middle-aged and older adults in India.

METHODS

This study uses the data from wave 1 of the Longitudinal Ageing Study in India (LASI) conducted in 2017-18. This study is restricted to 58,328 individuals from all states (except Sikkim), aged 45 years and above. The quality of life is measured in 6 domains (physical, psychological, social, environment, general health and life satisfaction) with 21 variables that range from 0 to 100. The principal component analysis was used to generate a composite score of QoL and the multiple linear regression was used to show the association between pain and quality of life.

RESULTS

It is estimated that approximately 37% of Indian middle-aged and older populations were often troubled with pain. Pain prevalence increase with age and is more common among older adults aged 75 + years (43.37%; 95% CI, 40.95-45.80), and female (41.38%; 95% CI, 39.36-43.39). The average QoL score among those with pain was 81.6 compared to 85.2 among those without pain. QoL was lower among elderly age 75 and above, females, rural residents and illiterates. Controlling for socio-demographic factors, pain reduces the QoL by 2.57 points (β= -2.57; 95% CI, -3.02 - -2.11).

CONCLUSION

Pain reduces the quality of life among middle-aged adults and older adults in India. This evidence could potentially help the policymakers to consider pain as a significant determinant of quality of life in India.

Development of a spontaneous pain indicator based on brain cellular calcium using deep learning

Chronic pain remains an intractable condition in millions of patients worldwide. Spontaneous ongoing pain is a major clinical problem of chronic pain and is extremely challenging to diagnose and treat compared to stimulus-evoked pain. Although extensive efforts have been made in preclinical studies, there still exists a mismatch in pain type between the animal model and humans (i.e., evoked vs. spontaneous), which obstructs the translation of knowledge from preclinical animal models into objective diagnosis and effective new treatments. Here, we developed a deep learning algorithm, designated AI-bRNN (Average training, Individual test-bidirectional Recurrent Neural Network), to detect spontaneous pain information from brain cellular Ca²⁺ activity recorded by two-photon microscopy imaging in awake, head-fixed mice. AI-bRNN robustly determines the intensity and time points of spontaneous pain even in chronic pain models and evaluates the efficacy of analgesics in real time. Furthermore, AI-bRNN can be applied to various cell types (neurons and glia), brain areas (cerebral cortex and cerebellum) and forms of somatosensory input (itch and pain), proving its versatile performance. These results suggest that our approach offers a clinically relevant, quantitative, real-time preclinical evaluation platform for pain medicine, thereby accelerating the development of new methods for diagnosing and treating human patients with chronic pain.

A microscopy technique coupled with an artificial intelligence (AI) platform could help researchers discover new types of pain-relief medicines. A team from South Korea led by Sun Kwang Kim of Kyung Hee University and Sang Jeong Kim of Seoul National University created a machine-learning algorithm that converts calcium signaling data in the brain, as estimated via imaging on genetically engineered mice, into a measurement of pain intensity. The researchers applied the technique to several mouse models of chronic pain and showed that it accurately captured the analgesic effects of known painkillers. They also extended the system to multiple brain regions, cell types and another brain-controlled sensory process, itch. The researchers propose using the AI-based tool to evaluate candidate anti-pain and anti-itch medicines ahead of human trials.

Virtual reality and its use in post-operative pain following laparoscopy: a feasibility study

Pain following laparoscopic surgery remains a neglected healthcare issue. Virtual reality-mediated therapy’s (VRT) analgesic potential could address this. However, its effect in this setting remains unexplored. We aimed to establish the feasibility and safety of VRT as an adjunct analgesic following gynaecological laparoscopy and explore differences between active distraction and passive meditation content. 35 women were enrolled into an open crossover pilot and randomised to either intervention group 1 (active then passive content) or intervention group 2 (passive then active content) following surgery. VRT was administered in two 10-min segments with a 10-min washout period in between. Pain scores, opioid requirements and side effects were recorded before and after each segment whilst questionnaires evaluated acceptability. We observed a significant reduction in pain over time for the entire study population (F = 8.63, p < 0.0005) but no differences between intervention groups, in contrast to many studies demonstrating an increase in pain during this time. During segment one, intervention group 1 (n = 18) were administered significantly less opioid than intervention group 2 (n = 17) [0.0 (0.0–7.5) vs. 3.0(0.0–10.0), p = 0.04]. Intervention group 1 rated the VRT experience significantly higher than intervention group 2 (7.97 vs. 6.62. p = 0.017). 97.1% (n = 34) would recommend VRT to a friend and use it as the standard-of-care in future procedures. These results demonstrate that post-operative VRT is feasible and safe. However, adequately powered studies are needed to appropriately determine its efficacy.

Prevalence and correlates of pain and associated depression among community-dwelling older adults: Cross-sectional findings from LASI, 2017-2018

BACKGROUND

Health practitioners often meet older persons suffering both from pain and depression. The study aimed to examine the factors associated with pain among older individuals and its association with major depression. In addition, the interaction between self-rated health (SRH), wealth status, and pain that is associated with depression are explored.

METHODS

We used data from the Longitudinal Aging Study in India (LASI). Participants included 15,098 male and 16,366 female adults aged 60 years or older. Univariate and bivariate analyses along with χ² tests were conducted in the initial stage. Binary logistic regression analyses were performed to fulfill the objectives. Major depression was calculated using Short Form Composite International Diagnostic Interview.

RESULTS

A proportion of 39.6% older individuals (n = 12,686) reported pain and 8.7% older adults (n = 2657) suffered from depression. Older adults who suffered from pain frequently were more likely to be depressed than those who never suffered from pain (adjusted odds ratio [AOR]: 1.70; confidence interval [CI]: 1.38-2.09). The interaction of pain, SRH, and household wealth status on depression found that older adults with pain who reported poor SRH (AOR: 4.18; CI: 3.50-5.00) or belonged to rich households (AOR: 2.27; CI: 1.84-2.80) had higher odds of suffering from depression, compared to older adults with no pain and good SRH or no pain and belonged to poor households.

CONCLUSION

It is highlighted that pain is quite common in older people, and is linked to depression especially among older people with poor SRH. Thus, routine evaluation of pain and associated symptoms of mental illnesses should be performed for ensuring healthy aging.

Nanotechnology for Pain Management: Current and Future Therapeutic Interventions

Pain is one of the most common medical conditions and affects more Americans than diabetes, heart disease, and cancer combined. Current pain treatments mainly rely on opioid analgesics and remain unsatisfactory. The life-threatening side effects and addictive properties of opioids demand new therapeutic approaches. Nanomedicine may be able to address these challenges as it allows for sensitive and targeted treatments without some of the burdens associated with current clinical pain therapies. This review discusses the physiology of pain, the current landscape of pain treatment, novel targets for pain treatment, and recent and ongoing efforts to effectively treat pain using nanotechnology-based approaches. We highl ight advances in nanoparticle-based drug delivery to reduce side effects, gene therapy to tackle the source of pain, and nanomaterials-based scavenging to proactively mediate pain signaling.

The value of interdisciplinary treatment for sickness absence in chronic pain: A nationwide register-based cohort study

BACKGROUND

Interdisciplinary treatment (IDT) is an internationally recommended intervention for chronic pain, despite inconclusive evidence of its effects on sickness absence.

METHODS

With data from 25,613 patients in Swedish specialist healthcare, we compared sickness absence, in the form of both sick leave and disability pensions, over a 5-year period between patients either allocated to an IDT programme or to other/no interventions (controls). To obtain population-average estimates, a Markov multistate model with theory-based inverse probability weights was used to compute both the proportion of patients on sickness absence and the total sickness absence duration.

RESULTS

IDT patients were more likely than controls to receive sickness absence benefits at any given time (baseline: 49% vs. 46%; 5-year follow-up: 36% vs. 35%), and thereby also had a higher total duration, with a mean (95% CI) of 67 (87, 48) more days than controls over the 5-year period. Intriguingly, sick leave was higher in IDT patients (563 [552, 573] vs. 478 [466, 490] days), whereas disability pension was higher in controls (152 [144, 160] vs. 169 [161, 178] days).

CONCLUSION

Although sickness absence decreased over the study period in both IDT patients and controls, we found no support for IDT decreasing sickness absence more than other/no interventions in chronic pain patients.

SIGNIFICANCE

In this large study of chronic pain patients in specialist healthcare, sickness absence is compared over a 5-year period between patients in an interdisciplinary treatment programme and other/no interventions. Sickness absence decreased over the study period in bothgroups; however, there was no support forthat it decreased more with interdisciplinary treatment than alternative interventions.

Quantification of selected analgesics and their metabolites in influent wastewater by liquid chromatography tandem mass spectrometry

Wastewater-based epidemiology (WBE) is an established tool to analyse patterns of community drug use. In recent times, monitoring the use of analgesics has become a public health priority. An analytical method was developed, optimised and validated for a broad range of common analgesics (non-steroidal anti-inflammatories and opioids) and their metabolites at trace concentrations in wastewater influent. Samples were analysed via liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) with an electrospray ionization source (ESI) in both positive and negative ion multiple reaction monitoring modes. Fifteen of the thirty-five biomarkers were validated for LC-MS/MS analysis by direct injection, while the other 20 biomarkers were present in wastewater at lower concentrations, requiring extraction by solid phase extraction (SPE) using Oasis HLB cartridges. The limit of quantification (LOQ) ranged between 17 ng/L - 191 ng/L and 13 ng/L -110 ng/L for direct injection and SPE, respectively. Recoveries for SPE ranged between 80% and 120%. Following validation, the method was applied to 28 wastewater samples from four municipal wastewater treatment plants. Twenty-eight of the thirty-five analgesic biomarkers were detected in the samples at concentrations of between 0.03 and 289 μg/L. Population normalised mass loads ranged from 10 mg/day/1000 (meperidine) to 72,000 mg/day/1000 (paracetamol) among all investigated compounds. The described method is a suitable analytical tool for wastewater-based epidemiology applications to estimate analgesics consumption.

Biological Evaluation of Aegle marmelos Fruit Extract and Isolated Aegeline in Alleviating PainDepression Dyad: In Silico Analysis of Aegeline on MAO-A and iNOS

Pain and depression have been assessed to co-occur in up to 80% of patients, and this comorbidity is more debilitating and pricier for the patients as compared to either of these disorders alone. Aegle marmelos is a well-known medicinal plant with a broad spectrum of pharmacological activities. Aegeline is a relatively unexplored molecule present in Aegle marmelos. Therefore, the current investigation aims to explore the potential of Aegle marmelos fruit extract (AMFE) and isolated aegeline against the reserpine-induced pain-depression dyad. In the current investigation, aegeline was isolated from AMFE, followed by spectroscopic characterization, i.e., using NMR and mass analyses. AMFE (200 mg kg^-1 p.o) and aegeline (10 mg kg^-1 p.o.) were administered to reserpinized (0.5 mg kg^-1 s.c.) mice, and clorgyline (3 mg kg^-1 i.p.) was taken as the standard drug. AMFE and aegeline significantly alleviated the reserpine-induced reduction in a pain threshold and an increase in immobility as observed in behavioral tests of pain and depression, respectively. In silico molecular docking studies of aegeline showed a good binding interaction at the active sites of MAO-A and iNOS. The in vivo analysis showed that AMFE and aegeline treatment significantly decreased the monoamine oxidase-A (MAO-A) activity, serum interleukin-6 (IL-6) level, and lipid peroxidation, along with an increase in the reduced glutathione level in comparison to the reserpine-treated group. Immunofluorescence studies also showed that AMFE and aegeline abrogated the reserpine-induced increase in iNOS expression. Conclusively, the results delineate that AMFE and aegeline might exert a protective effect via downregulating the MAO-A hyperactivity, IL-6 level, oxidative and nitrosative stress.

A survey of postoperative pain treatments and unmet needs

More than 300 million patients undergo surgery worldwide each year. Pain associated with these procedures is associated with short- and long-term negative sequelae for patients, healthcare providers, and healthcare systems. The following chapter is a review of the reality of postoperative pain management in everyday clinical routine based on survey- and registry-derived data with a focus on care in adults. Between 30% and up to 80% of patients report moderate to severe pain in the days after surgery. Structures, processes, and outcomes vary widely between hospitals and indicate gaps between evidence-based findings and practice. Pain assessment is not effectively implemented in many hospitals and should consider cultural differences. Few data exist on the situation of pain management in low- and middle-income countries, indicating lack of resources and available medication in many of these areas. Certain types of surgery as well as demographic and clinical factors are associated with increased risk of severe postoperative pain.

Genetic correlations between pain phenotypes and depression and neuroticism

Correlations between pain phenotypes and psychiatric traits such as depression and the personality trait of neuroticism are not fully understood. In this study, we estimated the genetic correlations of eight pain phenotypes (defined by the UK Biobank, n = 151,922–226,683) with depressive symptoms, major depressive disorders and neuroticism using the the cross-trait linkage disequilibrium score regression (LDSC) method integrated in the LD Hub. We also used the LDSC software to calculate the genetic correlations among pain phenotypes. All pain phenotypes, except hip pain and knee pain, had significant and positive genetic correlations with depressive symptoms, major depressive disorders and neuroticism. All pain phenotypes were heritable, with pain all over the body showing the highest heritability (h² = 0.31, standard error = 0.072). Many pain phenotypes had positive and significant genetic correlations with each other indicating shared genetic mechanisms. Our results suggest that pain, neuroticism and depression share partially overlapping genetic risk factors.

Trends in adverse drug reaction-related hospitalisations over 13 years in New South Wales, Australia

BACKGROUND

Adverse drug reactions (ADR) are severe problems in global public health, and result in high mortality and morbidity. Various trends of ADR-related hospitalisations have been studied in many countries, while estimates of the trends in Australia are limited.

AIM

To examine trends in ADR-related hospitalisations in New South Wales (NSW).

METHODS

Data were extracted from the Admitted Patient Data Collection, a census of hospital separations in NSW. We estimated age-adjusted rates of ADR-related hospitalisation between 1 July 2001 and 30 June 2014 and rates by patient characteristics, main therapeutic medication groups and clinical condition groups that warranted the hospitalisation. We used the percentage change annualised estimator to evaluate rates over time.

RESULTS

A total of 315 274 NSW residents admitted for urgent care of ADR was identified. The age-adjusted rates of ADR-related hospitalisations nearly doubled and increased by 5.8% (95% CI: 5.0-6.6%) per annum, with an in-hospital death rate increase of 2.4% (1.6-3.3%). Agranulocytosis (2.7%), nausea and vomiting (2.4%) and heart failure (2.4%) were the most common conditions that led to ADR-related hospitalisations over 13 years, with acute renal failure (1.4%) recently emerging as the leading adverse condition. Participants aged between 65 and 84 years accounted for nearly half of ADR hospitalisations (45.6%), with age-adjusted rate increasing from 103.9 in 2001-2002 to 189.0 per 100 000 NSW residents in 2013-2014. Anticoagulants (13.5%) were the most common medications contributing to ADR-related hospitalisation, followed by opioid analgesics (9.6%).

CONCLUSION

ADR-related hospitalisation remains a population health burden, with significant increase over time. The findings call for continuing efforts to prevent ADR, especially among high-risk populations, such as older people.

Barriers and facilitators to postoperative pain management in Rwanda from the perspective of health care providers: A contextualization of the theory of planned behavior

AIMS

Identify opportunities to improve knowledge translation for post-operative pain management in Rwanda by exploring clinician and environmental factors affecting this practice.

METHODS

The theory of planned behavior (TPB) guided development of a questionnaire to measure intent to assess and treat postoperative pain. Focus groups and individual interviews were used to contextualize the final questionnaire and generate questions related to pain management practice. Health care providers from two Rwandan teaching hospitals involved in postoperative pain management completed the TPB questionnaire in May 2015. TPB subscale scores were analyzed to identify demographic and practice characteristics associated with intention to treat pain. The general linear model was used to test effect of attitudes, subjective norms, and perceived control on behavioral intent to treat pain.

RESULTS

Forty-six percent of participants (N = 131) had training in acute pain management, 56% used a pain protocol, and 74% used pain scales. Tramadol (78%), morphine (79%), and paracetamol (75%) were used most often to treat pain. Drug availability was the most frequently reported barrier to treating pain. Though intention to treat pain was high, only attitudes and perceived control about assessing pain were associated with intention to treat pain. The theme of fear of the adverse effects of pain medications was consistent across focus groups and interviews in both sites.

CONCLUSIONS

System and knowledge barriers exist: interventions to address these barriers may lead to improved postoperative pain care. Further validation of the TPB questionnaire is required to address cultural and language factors specific to the Rwandan context.

The Prevalence of Chronic Pain among Adults in India

Background

The prevalence of chronic pain (CP) is well described in Europe, America, and Australia. However, little knowledge is available of the prevalence of CP within Asia or Southeast Asia. Given the cultural and genetic variation in pain causation, manifestation, and reporting, the findings of previous western studies cannot be extrapolated to Asian countries. A prevalence study was needed to be carried out to quantify the magnitude and impact of CP in the adult population in India.

Methods

Two sets of questionnaires were designed. The first, a screening questionnaire was used telephonically to identify the prevalence of CP, and should there be CP; the second, a detailed questionnaire was administered, to characterize the features and impact of pain. The interviews were carried out face-to-face.

Results

A total of 4326 Indian patients were screened, and 836 completed a detailed pain questionnaire during 2006. The prevalence of CP was found to be 19.3% (n = 836). There was a higher prevalence in females (25.2%). Pain prevalence increased steeply beyond the age of 65 years old. There was a significant impact of CP on work and daily function.

Conclusion

This Indian adults' population survey about CP found a higher prevalence of CP as compared to other Asian pain prevalence studies; however, the impact of pain was just as significant. In a rapidly aging population, CP is emerging as a significant healthcare problem which may likely to exert an increasing toll on the existing social infrastructure within the next two decades.