Predictors of Improvements in Pain Intensity in a National Cohort of Older Veterans With Chronic Pain

The Problem of Pain in Rheumatology: Variations in Case Definitions Derived From Chronic Pain Phenotyping Algorithms Using Electronic Health Records

OBJECTIVE

The aim of this study was to investigate and compare different case definitions for chronic pain to provide estimates of possible misclassification when researchers are limited by available electronic health record and administrative claims data, allowing for greater precision in case definitions.

METHODS

We compared the prevalence of different case definitions for chronic pain (N = 3042) in patients with autoimmune rheumatic diseases. We estimated the prevalence of chronic pain based on 15 unique combinations of pain scores, diagnostic codes, analgesic medications, and pain interventions.

RESULTS

Chronic pain prevalence was lowest in unimodal pain phenotyping algorithms: 15% using analgesic medications, 18% using pain scores, 21% using pain diagnostic codes, and 22% using pain interventions. In comparison, the prevalence using a well-validated phenotyping algorithm was 37%. The prevalence of chronic pain also increased with the increasing number (bimodal to quadrimodal) of phenotyping algorithms that comprised the multimodal phenotyping algorithms. The highest estimated chronic pain prevalence (47%) was the multimodal phenotyping algorithm that combined pain scores, diagnostic codes, analgesic medications, and pain interventions. However, this quadrimodal phenotyping algorithm yielded a 10% overestimation of chronic pain compared to the well-validated algorithm.

CONCLUSION

This is the first empirical study to our knowledge that shows that established common modes of phenotyping chronic pain can lead to substantially varying estimates of the number of patients with chronic pain. These findings can be a reference for biases in case definitions for chronic pain and could be used to estimate the extent of possible misclassifications or corrections in using datasets that cannot include specific data elements.

Bidirectional Associations Between Pain and Perceived Stress Among Veterans: Depressive Disorder as a Predisposing Factor

OBJECTIVE

Military veterans who were injured in combat very often report pain along with co-occurring perceived stress and preexisting depressive disorder. The systems model of pain is a theoretical model suggesting that pain and perceived stress are bidirectionally associated at the within-person level, and associations are heightened among those with depressive disorder. However, the systems model of pain has not been adequately tested. Testing the systems model of pain could illuminate salient treatment targets for combat-injured veterans with pain and co-occurring psychological problems.

METHODS

The present study empirically tests the systems model of pain among a sample of combat-injured veterans ( N = 902) surveyed five times during an 18-month period. We used a multigroup, autoregressive latent trajectory with structured residual statistical model to test the within-person associations between pain and perceived stress and determine whether associations differ between veterans with and without a positive screen for depressive disorder.

RESULTS

In line with the systems model of pain, pain and perceived stress were bidirectionally associated only among combat-injured veterans with depressive disorder. Among such veterans, perceived stress was positively associated with subsequent pain ( b = 0.12; 95% confidence interval = 0.06-0.17), and pain was positively associated with subsequent perceived stress ( b = 0.44; 95% CI = 0.11-0.77).

CONCLUSIONS

Our work highlights the interplay between pain and its psychological correlates among a particularly at-risk population. Clinicians addressing pain and perceived stress among combat-injured veterans should be prepared to identify and address depressive disorder.

Pattern of Cumulative Treatment Hours on Pain Impact and PROMIS Outcomes

INTRODUCTION

Participation in interdisciplinary treatments is associated with improvement in pain intensity, physical function, and additional pain-related outcome domains. However, the effect of cumulative treatment hours on outcomes remains unknown among military patients. The present analysis examined the relationship between cumulative interdisciplinary treatment hours and pain management outcomes at a single interdisciplinary pain management center (IPMC).

MATERIALS AND METHODS

This is a retrospective observational study of data previously collected as standard of care at the Madigan Army Medical Center, approved by the Institutional Review Board. We included patients who received treatment at the IPMC and completed at least two self-report assessment batteries: one at baseline and at least one between 90 and 180 days after baseline (n = 882). The primary outcome was pain impact. Secondary outcomes included fatigue, depression, anxiety, and sleep-related impairment.

RESULTS

Generalized additive models indicated that cumulative treatment hours were significantly associated with improvement in pain impact, fatigue, and depression. Patients who had higher baseline pain impact, who had mild or no depressive symptoms, and who were >40 years of age had greater improvements in pain impact following treatment, relative to those with lower pain impact, moderate-to-severe depressive symptoms, and were 40 years of age or younger, respectively. Additional research is needed to elucidate the effect of different therapies and additional patient factors in understanding the "therapeutic dose" of interdisciplinary pain management.

CONCLUSIONS

A higher number of cumulative treatment hours was associated with improvement of pain impact, fatigue, and depression among military personnel receiving interdisciplinary pain treatment. At least 30 hours of sustained interdisciplinary treatment appears to be the threshold for improvement in pain impact and related outcomes.

Effects of veterans' mental health service-connections on patient-reported outcomes following total joint arthroplasty

Background

Studies report poor outcomes of elective orthopaedic surgeries among civilian patients receiving Workers' Compensation (WC). However, little is known about surgical outcomes in veterans receiving similar benefits through the Veterans Affairs (VA) service-connected (SC) disability compensation program.

Methods

Veterans undergoing primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) at a VA Medical Center between 07/2019-12/2021 were analyzed by SC status. Outcomes were evaluated using Hip disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS-JR) and Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) scores collected preoperatively and at 2- and 12-months postoperatively. Repeated measures mixed models were used to test for the effect of SC on HOOS-JR/KOOS-JR scores, controlling for baseline age, sex, and Charlson Comorbidity Index (CCI). SC and baseline joint function (stratified into quartiles using baseline HOOS-JR/KOOS-JR scores) were analyzed for effects on achieving substantial clinical benefit (SCB) at 12-month follow-up.

Results

The analysis included 67 hips and 142 knees. SC and non-SC (NSC) veterans had similar baseline HOOS-JR/KOOS-JR and CCI. HOOS-JR remained similar between groups through 12 months (79.9 ± 19.2 vs. 82.7 ± 18.8) as did KOOS-JR (70.4 ± 15.6 vs. 74.6 ± 15.3). The designation of any SC and mental health SC reached significance for KOOS-JR (P = 0.034 and P = 0.032, respectively). For HOOS-JR and KOOS-JR, baseline function score quartile significantly influenced final score (P < 0.001), with patients in the lowest quartiles (i.e., worst baseline function) exhibiting significantly greater improvements than patients in higher quartiles.

Conclusions

Mental health SC and high preoperative functional status are variables that may have unfavorable influences on self-reported outcomes of TKA in veteran patients. SC status does not appear to influence the outcomes of THA or the likelihood of achieving SCB after either THA or TKA. Regardless of SC status, most veterans can expect significant clinical improvements after total joint arthroplasty.

Influence of comorbidities on pain intensity in patients with chronic low back pain

OBJECTIVES

Chronic pain is a complex process that can vary depending on factors such as time evolution, mood, or even previous experiences. Our objective is to describe patient's characteristics from those who were referred with a diagnosis of low back pain in their first Pain Unit (PU) visit, and identify those factors that may interfere with their pain perception.

METHODS

Inferential analysis was carried out from data recorded in the PU database of the Hospital de la Santa Creu y Sant Pau in Barcelona, from November 2012 to November 2018. The average pain intensity during the last 24 hours (EVN24) was quantified using data from the BPI (Brief Pain Inventory) questionnaire. Using multiple linear regression, the independent predictive factors related to pain intensity (EVN24) were assessed.

RESULTS

Mood disorders (Degree of depresión acording HAD_D level) was the variable with the highest impact in pain perception. Using binary logistic regression for multivariate analysis, a model of variables related to pain intensity (EVN24) was obtained (R = 0.354, P < 0.001).

CONCLUSIONS

The specialized treatment of low back pain in PUs must take into account the patient's profile and especially the affective disorders and associated comorbidities since they predict a greater intensity of pain. Consequently, the associated comorbidity not only affects the greater intensity of pain, but the physical characteristics that accompany the patient throughout the process can influence or even compromise treatment.

Association Between Pain Intensity and Discontinuing Opioid Therapy or Transitioning to Intermittent Opioid Therapy After Initial Long-Term Opioid Therapy: A Retrospective Cohort Study

The purpose of this study was to evaluate changes in pain intensity among Veterans transitioning from long-term opioid therapy (LTOT) to either intermittent therapy or discontinuation compared to continued LTOT. Pain intensity was assessed using the Numeric Rating Scale in 90-day increments starting in the 90-day period prior to potential opioid transitions and the two ensuing 90-day periods after transition. Primary analyses used a 1:1 greedy propensity matched sample. A total of 29,293 Veterans switching to intermittent opioids and 5,972 discontinuing opioids were matched to Veterans continuing LTOT. Covariates were well balanced after matching except minor differences in baseline mean pain scores. Pain scores were lower in the follow up periods for those switching to intermittent opioids and discontinuing opioids compared to those continuing LTOT (0-90 days: Intermittent: 3.79, 95%CI: 3.76, 3.82; LTOT: 4.09, 95%CI: 4.06, 4.12, P < .0001; Discontinuation: 3.06, 95%CI: 2.99, 3.13; LTOT: 3.86, 95%CI: 3.79, 3.94, P = <.0001; 91-180 days: Intermittent: 3.76, 95%CI: 3.73, 3.79; LTOT: 3.99, 95%CI: 3.96, 4.02, P < .0001; Discontinuation: 3.01, 95%CI: 2.94, 3.09; LTOT: 3.80, 95%CI: 3.73, 3.87, P = <.0001). Sensitivity analyses found similar results. Discontinuing opioid therapy or switching to intermittent opioid therapy was not associated with increased pain intensity. PERSPECTIVE: This article evaluates the association of switching to intermittent opioid therapy or discontinuing opioids with pain intensity after using opioids long-term. Pain intensity decreased after switching to intermittent therapy or discontinuing opioids, but remained relatively stable for those continuing long-term opioid therapy. Switching to intermittent opioids or discontinuing opioids was not associated with increased pain intensity.

Impact of opioid dose escalation on pain intensity: a retrospective cohort study

Prescribers are often confronted with the decision to escalate opioid doses to achieve adequate analgesia. Understanding the impact of dose escalation on pain intensity is warranted. Using a retrospective cohort study design, Veterans with chronic pain and chronic opioid therapy were identified. Opioid dose escalators (>20% increase in average morphine milligram equivalent daily dose) were compared with dose maintainers (±20% change in average morphine milligram equivalent daily dose) assessed over 2 consecutive 6-month windows. Pain intensity was measured by the Numeric Rating Scale. The primary analyses used linear repeated-measures models among a 1:1 matched sample of escalators and maintainers matched on propensity score and within ±180 days of the index date. Sensitivity analyses were conducted using adjusted linear repeated-measures models with and without incorporating stabilized inverse probability of treatment weighting. There were 32,420 dose maintainers and 20,767 dose escalators identified with 19,358 (93%) matched pairs. Pain scores were persistently higher among dose escalators at each 90-day period after the index date (0-90 days after index date: dose escalators: 4.68, 95% confidence interval [CI]: 4.64-4.72 dose maintainers: 4.32, 95% CI: 4.28-4.36, P < 0.0001; 91-180 days after index date: dose escalators: 4.53, 95% CI: 4.49-4.57; dose maintainers: 4.25, 95% CI: 4.22-4.29, P < 0.0001) but were not different in the 90 days before the index date (dose escalators: 4.64, 95% CI: 4.61-4.68; dose maintainers: 4.59, 95% CI: 4.55-4.63, P = 0.0551). Sensitivity analyses provided similar results as the primary analyses. Opioid dose escalation among patients with chronic pain is not associated with improvements in Numeric Rating Scale pain scores.

Associations of Pain Numeric Rating Scale Scores Collected during Usual Care with Research Administered Patient Reported Pain Outcomes

OBJECTIVE

The purpose of this study is to examine the extent to which numeric rating scale (NRS) scores collected during usual care are associated with more robust and validated measures of pain, disability, mental health, and health-related quality of life (HRQOL).

DESIGN

We conducted a secondary analysis of data from a prospective cohort study.

SUBJECTS

We included 186 patients with musculoskeletal pain who were prescribed long-term opioid therapy.

SETTING

VA Portland Health Care System outpatient clinic.

METHODS

All patients had been screened with the 0-10 NRS during routine outpatient visits. They also completed research visits that assessed pain, mental health and HRQOL every 6 months for 2 years. Accounting for nonindependence of repeated measures data, we examined associations of NRS data obtained from the medical record with scores on standardized measures of pain and its related outcomes.

RESULTS

NRS scores obtained in clinical practice were moderately associated with pain intensity scores (B's = 0.53-0.59) and modestly associated with pain disability scores (B's = 0.33-0.36) obtained by researchers. Associations between pain NRS scores and validated measures of depression, anxiety, and health related HRQOL were low (B's = 0.09-0.26, with the preponderance of B's < .20).

CONCLUSIONS

Standardized assessments of pain during usual care are moderately associated with research-administered measures of pain intensity and would be improved from the inclusion of more robust measures of pain-related function, mental health, and HRQOL.

Opioid Prescribing in the Elderly: A Systematic Review

Objective: To characterize the literature describing the therapeutic use of opioids in the elderly. Data Sources: Two electronic databases, EMBASE and MEDLINE, were searched from years 1990 to September 5, 2018. Relevant reference lists were reviewed. Searches were restricted to English language. Study Selection and Data Extraction: Two reviewers independently screened 827 citations to identify observational studies, population-based cohort studies, retrospective analyses, and control trials looking at the management of persistent pain in patients aged ≥65 years and/or frail patients. Data Synthesis: Thirty-nine articles were included in the systematic review. More specifically, 17 observational studies, 7 population-based cohort studies, 10 retrospective analyses, and 4 controlled trials. The most common etiology of persistent pain was musculoskeletal (50%), and the most often adverse effects reported were central nervous system related (41%) and falls/fractures (39%). Relevance to Patient Care and Clinical Practice: As there is a lack of strong evidence-based recommendations for opioid use in the elderly, this review aims to evaluate opioid use in the elderly and compare their efficacy and safety among this population. Conclusions: Overall, central nervous system adverse effects were most commonly seen in the elderly. However, higher quality evidence is required to further appreciate the dose-related effects on efficacy and safety of opioids in the elderly.

Genetic Contribution in Low Back Pain: A Prospective Genetic Association Study

OBJECTIVES

Chronic pain is one of the most common reasons individuals seek medical attention. It is a major issue because of the wide interindividual variability in the analgesic response. This might be partly explained by the presence of variants in genes encoding molecules involved in pharmacodynamics and pharmacokinetics. The aim was to analyze opioid effectiveness in chronic low back pain (CLBP) relief after opioid titration, unveiling the impact of pharmacogenetics.

METHODS

The study included 231 opioid-naïve patients from the Spine Unit; age 63 ± 14 years, 64% female, body mass index 29 ± 6 kg/m² , visual analog scale pain intensity score 73 ± 16 mm. Clinical data were collected at baseline, 3 months after opioid titration, and after 2 to 4 years of follow-up concerning pain (intensity and relief), quality of life, disability, comorbidities, and drug prescription (opioid dose, rotations, and adverse events). The genotype influence of OPRM1, COMT, UGT2B7, ABCB1, KCNJ6, and CYP3A5*3A in analgesic response was analyzed by reverse-transcription polymerase chain reaction genotyping.

RESULTS

Patients with the COMT G472A-AA genotype (rs4680) and KCNJ6 A1032G-A allele (rs2070995) CLBP responded differently to opioid titration, with higher pain intensity requiring higher dosing. Furthermore, GG- genotypes of A118G (OPRM1, rs1799971) and A854G (UGT2B7, rs776746) influenced the neuropathic component. After opioid titration, CLBP intensity, neuropathic component, low back pain disability, anxiety, and depression significantly decreased, while quality of life improved.

CONCLUSION

Single-nucleotide polymorphisms in genes involved in pain transmission and opioid metabolism might predispose to exaggerated sensitivity and differences in the opioid analgesic effect in patients with CLBP. We encourage clinical trials for their clinical application in chronic pain management.

Impact of hepatitis C treatment on pain intensity, prescription opioid use and arthritis

OBJECTIVE

To assess the impact of direct acting anti-viral (DAA) therapy for hepatitis C virus (HCV) infection on changes in pain intensity and prescription opioid use among Veterans.

METHODS

We conducted a retrospective cohort study of Veterans with HCV who were seen in a rheumatology clinic at least once while receiving DAA therapy between January 1, 2010 and December 31st 2016. Demographic characteristics, HCV status, HCV treatment characteristics, numeric rating scale (NRS) pain scores and opioid prescription data were extracted from the electronic medical record. Pain scores were averaged over 6 months prior to HCV treatment and 6 months after completion of treatment. Prescription opioid dose was converted to a morphine equivalent daily dose (MEDD) and averaged across the two 6-month intervals. Generalized estimating equations were used to model the change in average pain and MEDD from pre- to post-HCV treatment. Effect size was assessed using Cohen's d.

RESULTS

A total of 121 Veterans, 91% male with average age of 59 were included. Average pre-treatment pain was 4.4 (SD 2.4). The average reduction in pain scores was 0.6 points (P = 0.02, Cohen's d = 0.22) after treatment. Among 67 patients prescribed chronic opioid therapy at baseline, average pre-treatment MEDD was 52.4 mg (SD = 62.5 mg) and post-DAA treatment average MEDD was 49.5 mg (SD = 69.3 mg), representing a decrease by 2.9 mg (P < 0.01, Cohen's d = 0.14). Opioid dose reduction was seen in 43/67 patients and 12 patients discontinued opioids entirely.

CONCLUSION

Among US Veterans, subjective pain scores had modest improvement and opioid prescriptions were mildly reduced following treatment with DAA.

Evaluation of opioid use among patients with back disorders and arthritis

PURPOSE

Long-term opioid use for chronic pain has increased, but limited evidence exists on its benefits. Evaluation of long-term benefits in pain is based on patient-reported measures such as health-related quality of life (HRQoL). This study examined the long-term effects of opioid use on HRQoL and its subdomains in patients with back pain or arthritis by comparing opioid users to non-opioid users for three metrics: (1) any opioid use, (2) duration of opioid use, and (3) average daily morphine equivalent dose.

METHODS

A nationally representative sample of cancer-free adults with chronic back pain or arthritis was selected. Using the 12-Item Short Form Survey, HRQoL measures of Mental Component Score (MCS), Physical Component Score (PCS), and individual subdomains were assessed at baseline and 1 year later. Opioid users were matched to non-opioid users in a 1:1 greedy match using propensity scores estimated based on many patient demographics and baseline HRQoL measures.

RESULTS

At year one, PCS was significantly lower among opioid users, mostly driven by bodily pain subdomain; MCS was not different. Short-term opioid users (< 1 month) had higher MCS while long-term users (≥ 1 month) had lower PCS. Low-dose [< 20 morphine milligram equivalents (MME)/day] opioid use was associated with lower PCS, while no difference was found between high dose (≥ 20 MME/day) and non-opioid users. However, most differences were not clinically significant.

CONCLUSIONS

Long-term opioid use is not associated with improvements in HRQoL. Clinicians should carefully evaluate the need for opioid use, especially long-term use in managing chronic back pain and arthritis.

Acupuncture for Cancer Pain and Symptom Management in a Palliative Medicine Clinic

OBJECTIVE:

Studies suggest acupuncture improves cancer-related symptoms; however, it is unclear whether patient characteristics predict pain response. This study determined acupuncture's effect on cancer-related pain and identified variables associated with pain response.

METHODS:

A retrospective chart review included adult patients with cancer referred to palliative medicine and received acupuncture for pain management. Paired t tests compared differences in pain scores from pre- to postacupuncture. Clinically meaningful pain improvement was defined as ≥2-point reduction in pain score. Logistic regression was used to evaluate associations between patient characteristics and pain improvement.

RESULTS:

One hundred seventy acupuncture treatments from 68 individual patients were studied. Significant reductions in mean pain scores were observed after the first treatment (-1.9 ± 1.8; P < .001) and across all treatments (-1.7 ± 1.9; P < .001). Multivariable analysis demonstrated clinically meaningful pain improvement with higher baseline pain scores (odds ratio [OR]: 1.79, 95% confidence interval [CI]: 1.44-2.22; P < .001) and stage III/IV disease (OR: 3.23, 95% CI: 1.11-9.40; P < .001). There were significant improvements in anxiety, depression, drowsiness, dyspnea, fatigue, nausea, and well-being after the first treatment and across all treatments ( P < .001).

CONCLUSIONS:

Acupuncture improved cancer-related pain and other symptoms. Those with higher baseline pain scores and advanced disease were more likely to achieve significant pain reduction. Improved depression and fatigue were closely related to pain reduction. Further studies are needed to confirm pain response variables, establish durability, and develop a personalized approach to acupuncture.

Health-Related Quality of Life among Chronic Opioid Users, Nonchronic Opioid Users, and Nonopioid Users with Chronic Noncancer Pain

OBJECTIVE

Evaluate the association between opioid therapy and health-related quality of life (HRQoL) in participants with chronic, noncancer pain (CNCP).

DATA SOURCES

Medical Expenditure Panel Survey Longitudinal, Medical Conditions, and Prescription Files.

STUDY DESIGN

Using a retrospective cohort study design, the Mental Health Component (MCS12) and Physical Health Component (PCS12) scores of the Short Form-12 Version 2 were assessed to measure mental and physical HRQoL.

DATA COLLECTION

Chronic, noncancer pain participants were classified as chronic, nonchronic, and nonopioid users. One-to-one propensity score matching was employed to match chronic opioid users to nonchronic opioid users plus nonchronic opioid users and chronic opioid users to nonopioid users.

PRINCIPAL FINDINGS

A total of 5,876 participants were identified. After matching, PCS12 was not significantly different between nonchronic versus nonopioid users (LSM Diff = -0.98, 95% CI: -2.07, 0.10), chronic versus nonopioid users (LSM Diff = -2.24, 95% CI: -4.58, 0.10), or chronic versus nonchronic opioid users (LSM Diff = -2.23, 95% CI: -4.53, 0.05). Similarly, MCS12 was not significantly different between nonchronic versus nonopioid users (LSM Diff = 0.76, 95% CI: -0.46, 1.98), chronic versus nonopioid users (LSM Diff = 1.08, 95% CI: -1.26, 3.42), or chronic versus nonchronic opioid users (LSM Diff = -0.57, 95% CI: -2.90, 1.77).

CONCLUSIONS

Clinicians should evaluate opioid use in participants with CNCP as opioid use is not correlated with better HRQoL.

A Model of the Intersection of Pain and Opioid Misuse in Children and Adolescents

Despite being a significant public health concern, the role of opioid prescriptions in potentiating risk of opioid misuse in the context of pediatric pain has been under-investigated. To address this gap, the present review identifies theory-based hypotheses about these associations, reviews the extant literature on opioid prescriptions that supports these hypotheses, and provides routes for future empirical studies. A multi-level model of mechanisms through which opioid prescriptions may impact pain and other negative outcomes in youth, including risk for opioid misuse and related problems, is proposed with particular attention paid to the role that psychologists can play in informing policies and developing preventative interventions in healthcare settings.

Characterizing the demographics of chronic pain patients in the state of Maine using the Maine all payer claims database

BACKGROUND

Chronic pain is currently a significant health problem in the United States. A comprehensive strategy is needed to increase prevention of chronic pain and to improve care for chronic pain patients. However, development of a successful strategy relies, in part, on a better understanding of the demographics and socioeconomics of patients living with chronic pain conditions. The current study was designed to understand the burden of chronic pain in the state of Maine by identifying the prevalence of chronic pain and its relationship with selected demographic and socioeconomic factors in Maine.

METHODS

The Maine All Payer Claims Database (MEAPCD) (2006-2011) was used in the secondary data analysis to assess the demographic characteristics (such as age, sex, insurance type, and county of residence) of chronic pain patients in Maine. Chronic pain patients were identified based on the presence of pre-identified chronic pain-associated ICD-9 code(s) and opioid prescription information. Potential associations between the prevalence of chronic pain and a number of socioeconomic factors were determined by comparisons to Maine Census data.

RESULTS

More women in the state were identified as having chronic pain across all counties and all age groups (> 10 years old). Surprisingly, the majority of chronic pain patients were identified based on the diagnostic code criteria and not the opioid prescription criteria. A greater utilization of public health insurance was seen within the chronic pain patients. At the county level, although neither education level nor income were associated with the prevalence of chronic pain, these factors significantly correlated with the usage of public health insurance.

CONCLUSIONS

Further detailed characterization of the chronic pain patient population in the state of Maine, using multiple data sources, can help design population-targeted strategies to prevent and manage chronic pain.