Use of a Medication Quantification Scale for Comparison of Pain Medication Usage in Patients with Complex Regional Pain Syndrome (CRPS)

Effect of an interdisciplinary inpatient program for patients with complex regional pain syndrome in reducing disease activity-a single-center prospective cohort study

OBJECTIVE

The aim of this study was to evaluate the benefit of inpatient treatment in reducing disease activity in patients with complex regional pain syndrome (CRPS) who have exhausted outpatient options. Furthermore, the study sought to identify patient-related outcome variables that predict a reduction in disease activity.

METHODS

The primary outcome was disease severity (CRPS Severity Score, range 0-16 points). Secondary outcomes included depression, anxiety, physical function, pain interference, fatigue, sleep disturbance, and the ability to participate in social roles and activities, all of which were assessed using the PROMIS-29. Furthermore, pain catastrophizing, neuropathic pain, quality of life, pain self-efficacy, medication intake, and the patient's global impression of change were examined in accordance with current international agreed recommendations, assessed at discharge, 3-month, and 6-month post-discharge. Mixed-effects models were conducted to identify baseline variables associated with CRPS severity.

RESULTS

Twenty-five patients completed the program (mean age 49.28 [SD 11.23] years, 92% females, mean symptom duration 8.5 [SD 6.5] months). Results showed a significant reduction between baseline and discharge of disease activity (CSS -2.36, P < .0001), pain (PROMIS-29 pain -0.88, P = .005), and emotional function (PROMIS-29 depression -5.05, P < .001; fatigue -4.63, P = .002). Moderate evidence for a reduction between baseline and discharge could be observed for pain interference (+2.27, P = .05), social participation (PROMIS-29 + 1.93, P = .05), anxiety (PROMIS-29 -3.32, P = .02) and physical function (PROMIS-29 + 1.3, P = .03). On discharge, 92% of patients (23 of 25) reported improvement in their overall condition. In the follow-up period, medication intake could be reduced after 3 (MQS -8.22, P = .002) and 6 months (MQS -8.69, P = .001), and there was further improvement in social participation after 3 months (PROMIS-29 + 1.72, 0.03) and sleep after 6 months (PROMIS-29 + 2.38, 0.008). In the mixed models, it was demonstrated that patients experiencing less pain at baseline also exhibited lower disease activity.

CONCLUSION

The results of this study confirm that inpatient interdisciplinary treatment of CRPS patients improves disease activity, pain, physical function, emotional function, and social participation. Most improvements were maintained for up to 6 months after discharge. The majority of patients reported that their overall condition had improved during the study period.

Large-scale real-world data on a multidisciplinary approach to spinal cord stimulation for persistent spinal pain syndromes: first evaluation of the Neuro-Pain® nationwide screening and follow-up interactive register

Introduction

Spinal cord stimulation is a common treatment option for neuropathic pain conditions. Despite its extensive use and multiple technological evolutions, long term efficacy of spinal cord stimulation is debated. Most studies on spinal cord stimulation include a rather limited number of patients and/or follow-ups over a limited period. Therefore, there is an urgent need for real-world, long-term data.

Methods

In 2018, the Belgian government initiated a nationwide secure platform for the follow-up of all new and existing spinal cord stimulation therapies. This is a unique approach used worldwide. Four years after the start of centralized recording, the first global extraction of data was performed.

Results

Herein, we present the findings, detailing the different steps in the centralized procedure, as well as the observed patient and treatment characteristics. Furthermore, we identified dropouts during the screening process, the reasons behind discontinuation, and the evolution of key indicators during the trial period. In addition, we obtained the first insights into the evolution of the clinical impact of permanent implants on the overall functioning and quality of life of patients in the long-term.

Discussion

Although these findings are the results of the first data extraction, some interesting conclusions can be drawn. The long-term outcomes of neuromodulation are complex and subject to many variables. Future data extraction will allow us to identify these confounding factors and the early predictors of success. In addition, we will propose further optimization of the current process.

The Medication Quantification Scale 4.0: An Updated Index Based on Prescribers' Perceptions of the Risk Associated With Chronic Pain Medications

To quantify risks associated with drug utilization in the real world for the treatment of chronic pain (CP), an index called the Medication Quantification Scale (MQS) was developed in 1992 in the United States and last updated in 2003. This study aimed to update, adapt to the contemporary Canadian context, and validate a revised version of the MQS (the MQS-4.0). Step 1: An expert committee adapted the MQS to the Canadian clinical practice context. Step 2: An update of risk weights given to medication subclasses was achieved using a prescriber survey (weights were derived from median 0-10 scores given to each subclass). Step 3: Construct validity of the MQS-4.0 was assessed after applying risk weights to the medication use profile of persons living with CP covered by public drug insurance plan. Thirty-six medication subclasses were included in the MQS-4.0. A total of 207 prescribers (physicians, pharmacists, and nurse practitioners) participated in the perception survey; 10.63% identified as pain specialists. When risk weights were applied to prescription claims (n = 9,122), the MQS-4.0 score was associated (P < .05) with the MQS-III score and variables associated with polypharmacy (eg, Charlson Comorbidity Index, number of prescribers or health care visits). This study provides an updated index intended for adult populations based on prescribers' perceptions of the risk associated with CP medications that can be useful for clinical practice and research among persons living with CP in Canada. It will, however, be relevant to verify whether similar risk weights are obtained in future pain specialist surveys. PERSPECTIVE: The MQS-4.0 is an update of the MQS used for quantifying the risk associated with the use of analgesics/coanalgesics. Adequate psychometrics properties were found.

Considerations on the Obstacles That Lead to Slow Recruitment in a Pain Management Clinical Trial: Experiences from the Belgian PELICAN (PrEgabalin Lidocaine Capsaicin Neuropathic Pain) Pragmatic Study

Background

A qualitative evaluation study of the prematurely terminated PrEgabalin Lidocaine Capsaicin Neuropathic Pain (PELICAN) study was performed. The PELICAN study aimed to examine pain management for localized neuropathic pain (LNP), as epidemiological figures have shown a high percentage of LNP patients in Belgium. The study compared systemic and topical medications according to pain relief, adverse effects, and several measures of quality of life.

Objective

Achieving better study patient recruitment through qualitative research. To investigate and determine the causes of the observed recruitment problems in the PELICAN study, pain centers involved in the study as well as nonrecruiting pain centers were included. Furthermore, it aimed to highlight the positive and negative lessons learned from the conducted study and the number of obstacles the team had to overcome.

Methods

A qualitative study, using a mixed methods approach, was performed. Multiple pain centers in Belgium completed an online survey, after which a structured interview was conducted to elaborate the responses in more detail. The broad topics of these meetings were feedback about the study, reviewing survey answers, and actions undertaken to enhance recruitment.

Results

Different factors contributed to the low recruitment rate in the PELICAN study, such as limited and late referral from the general practitioners to the Belgian pain centers, insufficient internal referrals from nonpain specialists, lack of specific expertise on LNP in some centers, scarcity of staff, limited reimbursement to administer complex analgesic schemes, overestimation of the patient population, and the reluctance of patients to participate in pain research. Additionally, shortcomings in the implemented study design and the need for more logistical investments were identified.

Conclusion

The findings of the qualitative study demonstrate the need for further, more varied LNP research in Belgium, not limited to pharmacological studies. It also sheds important light on the recruitment obstacles that may be faced during these studies. Future studies could support this research by offering better proposals for feasibility and recruitment, for instance, by designing and conducting a compelling pilot study or applying social media during the recruitment phase. Clinical Trials. This trial is registered with NCT03348735. EUDRACT number 2018-003617-17.

Cross-Country Differences in Pain Medication Before and After Spinal Cord Stimulation: A Pooled Analysis of Individual Patient Data From Two Prospective Studies in the United Kingdom and Belgium

OBJECTIVES

Spinal cord stimulation (SCS) can reduce the need for opioids; however, the influence on the full spectrum of pain medication is less known. The aims of this study were to explore general prescription practices for patients scheduled for SCS, potential differences in prescriptions between Belgium and United Kingdom, and the influence of SCS on pain medication.

MATERIALS AND METHODS

Individual patient data from the TRIAL-STIM study in the United Kingdom and DISCOVER in Belgium were pooled. Medication use was collected before SCS and three months after SCS from 180 chronic pain patients. The Medication Quantification Scale III (MQS) was used to calculate a total score for medication use, as well as subscores for several classes. Differences in prescription practices between United Kingdom and Belgium were evaluated with two-sided Wilcoxon tests. To evaluate differences in medication use after three months of SCS between United Kingdom and Belgium, Tweedie-generalized linear models were calculated.

RESULTS

There was a statistically significant difference (-6.40 [95% CI from -3.40 to -9.10]) between the median total MQS score in United Kingdom and Belgium before SCS. Additionally, a significant difference was found for nonsteroidal anti-inflammatory drugs (NSAIDs) (-3.40 [95% CI -3.40 to -6.80]), neuropathic agents (-2.30 [95% CI -0.40 to -3.80]), and benzodiazepines (1.83e-05 [95% CI 2.64-05 to 7.45-05]) between United Kingdom and Belgium, before SCS. Tweedie-generalized models revealed a statistically significant interaction between country and time for MQS, neuropathic agents, and opioids.

CONCLUSIONS

Our combined analysis revealed differences in prescription practice in patients scheduled for SCS implantation between Belgium and United Kingdom. NSAIDs and neuropathic mood agents are more frequently used in the United Kingdom, presumably due to easier access to repeat prescriptions and over the counter medications. After three months of SCS, a decrease in medication use is observed in both countries, with higher reductions in Belgium, presumably due to strict regulations concerning reimbursement criteria.

Pain, disability, and lifestyle: Patients with complex regional pain syndrome compared to chronic musculoskeletal pain - a retrospective analysis

BACKGROUND

Complex regional pain syndrome (CRPS) is an orphan disease occurring as a complication after trauma. Due to its acute onset and the typical clinical presentation of the inflammatory and autonomous signs, it is an eye-catching chronic pain disease affecting also young and working people. In social media and the internet, high pain severity and unfavorable prognosis is often empathized.

METHODS

Here, we compared epidemiological, pain and lifestyle factors of 223 CPRS patients from the "ncRNAPain" cohort with 255 patients with chronic musculoskeletal pain (MSK). MSK patients were recruited at the beginning of a multimodal pain therapy program. We searched for factors predicting pain intensity.

RESULTS

Both chronic pain diseases affected women in middle age. Patients with MSK were more obese, drank more alcohol and were less educated (Pearson Chi-square Test or Mann-Whitney/U-Test). Both groups smoked more than healthy people in the OECD (Organization for Economic Cooperation and Development). Mann-Whitney/U-Test confirmed that CRPS patients did not have more severe pain and did not suffer more from pain-related disability than patients with MSK. CRPS patients also had less psychiatric comorbidities. Multiple linear regression analysis revealed that group assignment, depressive characteristics, body mass index, average alcohol consumption and smoking predicted higher pain ratings, while disease duration, anxiety symptoms or gender had no influence on pain intensity.

CONCLUSION

In summary our study supports a more optimistic view on pain in CRPS patients in comparison to MSK and identifies lifestyle factors which might contribute to the pathophysiology like smoking and drinking. Important next steps are the identification of CRPS patients at risk for chronification or - vice versa - with protective factors for pain resolution.

Effectiveness of high dose spinal cord stimulation for non-surgical intractable lumbar radiculopathy - HIDENS Study

OBJECTIVES

Spinal cord stimulation (SCS) is being increasingly used in non-surgical intractable low back pain. This study was designed to evaluate the efficacy of high-dose (HD) SCS utilizing sub-perception stimulation with higher frequency and pulse width in non-surgical predominant low-back pain population at 12 months.

MATERIALS AND METHODS

A total of 20 patients were recruited (280 screened between March 2017 and July 2018) to undergo percutaneous fluoroscopic-guided SCS (Medtronic 8 contact standard leads and Restore^R IPG), with T8 and T9 midline anatomical parallel placement. Sixteen patients completed 12 months follow-up (500 Hz frequency, 500 μs pulse width, and 25% pulse density). Differences in patients' clinical outcome (NRS back, NRS leg, ODI, PGIC, and PSQ) and medication usage (MQS) at 1, 3, and 12 months from the baseline were assessed using non-parametric Wilcoxon paired test.

RESULTS

The mean NRS scores for back pain (baseline 7.53) improved significantly at 1, 3, and 12 months; 2.78 (p < 0.001), 4.45 (p = 0.002), and 3.85 (p = 0.002), respectively. The mean NRS score for leg pain (baseline 6.09) improved significantly at 1 and 3 months; 1.86 (p < 0.001) and 3.13 (p = 0.010), respectively. Mean NRS for leg pain at 12 months was 3.85 (p = 0.057). ODI and sleep demonstrated significant improvement as there was consistent improvement in medication particularly opioid usage (MQS) at 12 months.

CONCLUSIONS

This study demonstrates that anatomical placement of leads with sub-perception HD stimulation could provide effective pain relief in patients who are not candidates for spinal surgery.

Neural substrates for poststroke complex regional pain syndrome type I: a retrospective case-control study using voxel-based lesion symptom mapping analysis

Poststroke complex regional pain syndrome (CRPS) is characterized by swelling, pain, and changes in the skin that appear on the affected wrist and hand. In this retrospective study, we analyzed the relationship between poststroke CRPS and the location of stroke lesion. From all patients admitted to our hospital from 2009 to 2019, we recruited 80 patients affected by their first unilateral stroke who met the inclusion/exclusion criteria. Thirty-eight patients diagnosed with CRPS after stroke were assigned to the experimental group according to the "Budapest criteria" adopted by the International Association for the Study of Pain, and 42 patients without CRPS were included as controls. Regions of interest were manually drawn on T1-weighted magnetic resonance images, and data were normalized to a standard brain template. In the poststroke CRPS group, the relationship between the location of brain lesion and pain severity was analyzed using Freedman-Lane multivariable regression adjusting for Medication Quantification Scale rating, which was the only parameter to show a statistically significant correlation with pain intensity. A threshold of P < 0.01 was considered statistically significant for all voxel-based lesion symptom mapping tests, corrected for multiple comparisons with 5000 permutations. Analyses using voxel-wise subtraction and Liebermeister statistics indicated that the corticospinal tract (CST) was associated with the development of poststroke CRPS. Statistically significant correlations were found between pain intensity and the CST and the adjacent lentiform nucleus. Our results suggest that the CST may be a relevant neural structure for development of poststroke CRPS and the intensity of pain caused by the syndrome.

High-Dose Spinal Cord Stimulation Reduces Long-Term Pain Medication Use in Patients With Failed Back Surgery Syndrome Who Obtained at Least 50% Pain Intensity and Medication Reduction During a Trial Period: A Registry-Based Cohort Study

OBJECTIVES

High-dose spinal cord stimulation (HD-SCS) revealed positive results for obtaining pain relief in patients with failed back surgery syndrome (FBSS). However, it is less clear whether HD-SCS also is able to reduce pain medication use. The aim of this registry-based cohort study is to explore the impact of HD-SCS on pain medication use in FBSS patients.

MATERIALS AND METHODS

Data from the Discover registry was used in which the effectiveness of HD-SCS was explored in neurostimulation-naïve FBSS patients as well as in rescue patients. All neurostimulation-naïve FBSS patients positively responded to a four-week SCS trial period in which at least 50% pain relief and 50% medication reduction were obtained. Medication use was measured with the Medication Quantification Scale III (MQS) in 259 patients at baseline and at 1, 3, and 12 months of HD-SCS. Additionally, defined daily doses (DDD) and morphine milligram equivalents (MME) were calculated as well.

RESULTS

One hundred thirty patients reached the visit at 12 months. In neurostimulation-naïve patients, a statistically significant decrease in MQS (χ² = 62.92, p < 0.001), DDD (χ² = 11.47, p = 0.009), and MME (χ² = 21.55, p < 0.001) was found. In rescue patients, no statistically significant improvements were found. In both patient groups, statistically significant reductions in the proportion of patients on high-risk MME doses ≥90 were found over time. At the intraindividual level, positive correlations were found between MSQ scores and pain intensity for back (r = 0.56, r = 0.31, p < 0.001) and leg pain (r = 0.61, r = 0.22, p < 0.001) in neurostimulation-naïve and rescue patients, respectively.

CONCLUSIONS

Registry data on HD-SCS in FBSS patients revealed a statistically significant and sustained decrease in pain medication use, not only on opioids, but also on anti-neuropathic agents in neurostimulation-naïve patients, who positively responded to an SCS trial period with at least 50% pain relief and 50% pain medication decrease, but not in rescue patients.

Botulinum toxin infiltrations versus local anaesthetic infiltrations in pelvic floor myofascial pain: Multicentre, randomized, double-blind study

BACKGROUND

Many studies have demonstrated a link between pelvic floor myofascial syndromes and chronic pelvic pain. Botulinum toxin has been extensively used for several years in the field of pain, especially due to its action on muscle spasm. However, the efficacy of botulinum toxin in the context of chronic pelvic pain remains controversial.

OBJECTIVES

This multicentre, randomized, controlled, double-blind study was designed to compare the efficacy of botulinum toxin and local anaesthetic (LA) injection versus LA injection alone for pelvic floor myofascial syndrome and chronic pelvic pain.

METHODS

According to the number of painful trigger points detected on physical examination, patients received from 1 to 4 injections of botulinum toxin with LA (BTX) or LA alone. The primary endpoint was Patient Global Impression of Improvement (PGI-I) score on day 60 after infiltration. Secondary endpoints were pain intensity, number of painful trigger points on palpation, analgesic drug consumption and quality of life.

RESULTS

We included 80 patients, 40 in each group. This study failed to demonstrate a significant difference between the 2 groups on day 60 in the primary endpoint or secondary endpoints (PGI-I score≤2=20% [LA] versus 27.5% [BTX], P=0.43). However, both groups showed significant alleviation of global pain.

CONCLUSION

This study does not justify the use of botulinum toxin in the context of chronic pelvic pain with myofascial syndrome but does justify muscle injections with LA alone. ClinicalTrials.gov: NCT01967524.

Posttraumatic stress disorder and chronic pain are associated with opioid use disorder: Results from a 2012-2013 American nationally representative survey

BACKGROUND

Chronic pain conditions and posttraumatic stress disorder (PTSD) commonly co-occur and are associated with opioid use disorder (OUD). The aims of this paper were to identify prevalence estimates of OUD among individuals with and without PTSD and assess independent and combined contributions of PTSD and chronic pain conditions on OUD in a nationally representative sample.

METHODS

Data were extracted from 36,309 individuals from the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions. Past-year PTSD and OUD were assessed using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-5 edition. Respondents reported physician-confirmed, past-year chronic pain conditions, categorized into musculoskeletal pain (e.g., arthritis), digestive pain (e.g., pancreatitis), and nerve pain (e.g., reflex sympathetic dystrophy). We examined the weighted prevalence of OUD among those with and without PTSD. Multiple logistic regressions examined the association between PTSD and chronic pain conditions on OUD.

RESULTS

The prevalence of OUD was higher among those with PTSD than those without. Comorbid PTSD/musculoskeletal pain and PTSD/nerve pain conditions were associated with increased odds of OUD, compared to those with neither PTSD nor chronic pain conditions. Digestive pain conditions were not associated with OUD. Comorbid PTSD/musculoskeletal pain conditions demonstrated an additive relationship on OUD compared to musculoskeletal pain conditions and PTSD alone.

CONCLUSIONS

Results reveal that musculoskeletal pain and nerve pain conditions are associated with increased odds of OUD, but only musculoskeletal pain conditions display an additive relationship on OUD when combined with PTSD. These findings have implications for opioid management and screening among those with comorbid conditions.

Validation of the 4 week recall version of the Uterine Fibroid Symptom and Health-related Quality of Life (UFS-QOL) Questionnaire

OBJECTIVE

To assess the psychometric performance of the 4 week recall version of the Uterine Fibroid Symptom and Health-related Quality of Life Questionnaire (UFS-QoL), a patient measure of the severity of uterine fibroid (UF) symptoms and their impact on health-related quality of life (HRQL).

METHODS

This was a retrospective analysis of phase 2a data from pre-menopausal women with heavy menstrual bleeding associated with UF. Participants completed the UFS-QoL at Baseline, Treatment Month 3, and Follow-up Month 3 and a daily diary with a Menstrual Bleeding Scale and the UF Daily Symptom Scale throughout the study duration. Descriptive statistics were performed on patient demographic characteristics; analyses were conducted to assess the internal consistency reliability, validity, and responsiveness of the UFS-QoL 4 week recall version.

RESULTS

A total of 271 women were enrolled with a mean age of 41.8 years; 74% were black. The UFS-QoL demonstrated excellent internal consistency reliability, with Cronbach's alpha coefficient values >0.70 for each subscale at each study visit. Results indicated good concurrent validity with the UF Daily Symptom Scale items. The women with amenorrhea at Treatment Month 3 had significantly better scores on all UFS-QoL subscales and HRQL Total than women with menstrual bleeding, indicating acceptable discriminant validity. Mean subscale change scores from Baseline to Treatment Month 3 were 19.2 to 39.8. Effect sizes were moderate to large (0.53 to 1.86), demonstrating responsiveness to change.

LIMITATIONS

As this study is a post hoc validation of the 4 week recall UFS-QOL, it is limited to the clinical trial data available and does not include a direct comparison to the 3 month recall version of UFS-QOL.

CONCLUSIONS

The 4 week recall version of the UFS-QoL demonstrated good internal consistency reliability, concurrent validity, and responsiveness and is psychometrically comparable to the original 3 month recall UFS-QoL.

CLINICAL TRIAL REGISTRATION

Data from a phase 2a, cohort design proof of concept study (trial M12-663); ClinicalTrials.gov identifier NCT01441635. Date of Registration: 6 September 2011.

Polypharmacy, Opioid Use, and Fibromyalgia: A Secondary Analysis of Clinical Trial Data

The major therapeutic approach for treating fibromyalgia (FM), a chronic widespread pain syndrome, is pharmacotherapy-centered symptom management. Complexity of treatment often leads to multiple medication prescriptions. While there is no current alternative to the probable need for polypharmacy in this patient population, there remains concern related to potential side effects and adverse drug events. In this secondary analysis of data on medications taken collected from two parent studies, all medications were broken down into the following categories: opioid, nonopioid, antidepressant, anticonvulsant, muscle relaxant, and benzodiazepine. The impact on pain severity and pain interference of these medication categories as well as perceived stress, fatigue, and depression scores was assessed. Baseline pain severity ( p = .0106) and pain interference ( p = .0002) were significantly correlated with opioid use as compared to nonopioid use. A multivariate regression with backward elimination resulted in a model for pain severity with one significant predictor variable, fatigue ( p < .0001); pain interference had three significant predictor variables: opioid use ( p = .04), fatigue ( p < .0001), and depression ( p = .04). While future studies should further address the utility of opioids and examine the role of polypharmacy as part of symptom management strategies for individuals with FM, study findings suggest that, for those who suffer chronic widespread pain as the predominant symptom experience, a challenge equally as perplexing for nurses and nursing research alike as managing the pain lies in addressing the fatigue and depression in this patient population.

Incidence of Complex Regional Pain Syndrome I Following Foot and Ankle Fractures Using the Budapest Criteria

OBJECTIVE : Fractures are a well-recognized inciting event in the development of complex regional pain syndrome. This study aimed to prospectively determine the incidence of complex regional pain syndrome following foot and ankle fractures. METHODS : A prospective study was conducted of patients presenting to two metropolitan hospitals with plain radiograph diagnosis of fractures to the foot or ankle. Patients were initially screened by phone 3 months after injury using the validated International Association for the Study of Pain Budapest criteria. Patients who fulfilled the screening criteria were then physically examined by a pain specialist to assess clinical signs as part of the Budapest criteria. RESULTS : A total of 306 consecutive eligible patients were included. One hundred and ten patients reported at least one symptom of complex regional pain syndrome; however, only three fulfilled the minimum requirements to necessitate clinical review. Of these three, only one patient fulfilled the combination of symptom and sign criteria for a positive diagnosis according to the validated Budapest criteria. The incidence of complex regional pain syndrome following foot and ankle fracture in this study was 0.3%. CONCLUSION : Although many patients may experience vasomotor, sensory, and sudomotor disturbance following a fracture to the foot and ankle, the observed incidence of complex regional pain syndrome using a prospectively collected validated criteria is significantly lower than previously published.