Reasons for Preoperative Opioid Use Are Associated with Persistent Use following Surgery Among Patients Undergoing Total Knee and Hip Arthroplasty.

OBJECTIVE: Most studies on preoperative opioid use only describe whether or not patients use opioids without characterizing reasons for use. Knowing why patients use opioids can help inform perioperative opioid management. The objective of this study was to explore pain specific reasons for preoperative opioid use prior to total hip and knee arthroplasty (THA and TKA) and their association with persistent use. METHODS: This is a prospective study of 197 patients undergoing THA (n = 99) or TKA (n = 98) enrolled in the Analgesic Outcomes Study between December 2015 and November 2018. All participants reported preoperative opioid use. RESULTS: Reasons for preoperative opioid use were categorized as surgical site pain only (81 [41.1%]); pain in other body areas only (22 [11.2%]); and combined pain (94 [47.7%]). Compared to patients taking opioids for surgical site pain, those with combined reasons for use had 1.24 (P = .40) and 2.28 (P = .16) greater odds of persistent use at 3 and 6 months postoperatively, adjusting for relevant covariates. CONCLUSIONS: This study provides novel insights into the heterogeneity of reasons for presurgical opioid use in patients undergoing a THA or TKA. One key take away is that not all preoperative opioid use is the same and many patients are taking opioids preoperatively for more than just pain at the surgical site. Combined reasons for use was associated with long-term use, suggesting nonsurgical pain, in part, drives persistent opioid use after surgery. Future directions in perioperative care should focus on pain and non-pain reasons for presurgical opioid use to create tailored postoperative opioid weaning plans.

Exploring various polygenic risk scores for skin cancer in the phenomes of the Michigan genomics initiative and the UK Biobank with a visual catalog: PRSWeb.

Polygenic risk scores (PRS) are designed to serve as single summary measures that are easy to construct, condensing information from a large number of genetic variants associated with a disease. They have been used for stratification and prediction of disease risk. The primary focus of this paper is to demonstrate how we can combine PRS and electronic health records data to better understand the shared and unique genetic architecture and etiology of disease subtypes that may be both related and heterogeneous. PRS construction strategies often depend on the purpose of the study, the available data/summary estimates, and the underlying genetic architecture of a disease. We consider several choices for constructing a PRS using data obtained from various publicly-available sources including the UK Biobank and evaluate their abilities to predict not just the primary phenotype but also secondary phenotypes derived from electronic health records (EHR). This study was conducted using data from 30,702 unrelated, genotyped patients of recent European descent from the Michigan Genomics Initiative (MGI), a longitudinal biorepository effort within Michigan Medicine. We examine the three most common skin cancer subtypes in the USA: basal cell carcinoma, cutaneous squamous cell carcinoma, and melanoma. Using these PRS for various skin cancer subtypes, we conduct a phenome-wide association study (PheWAS) within the MGI data to evaluate PRS associations with secondary traits. PheWAS results are then replicated using population-based UK Biobank data and compared across various PRS construction methods. We develop an accompanying visual catalog called PRSweb that provides detailed PheWAS results and allows users to directly compare different PRS construction methods.

Association of Polygenic Risk Scores for Multiple Cancers in a Phenome-wide Study: Results from The Michigan Genomics Initiative.

Health systems are stewards of patient electronic health record (EHR) data with extraordinarily rich depth and breadth, reflecting thousands of diagnoses and exposures. Measures of genomic variation integrated with EHRs offer a potential strategy to accurately stratify patients for risk profiling and discover new relationships between diagnoses and genomes. The objective of this study was to evaluate whether polygenic risk scores (PRS) for common cancers are associated with multiple phenotypes in a phenome-wide association study (PheWAS) conducted in 28,260 unrelated, genotyped patients of recent European ancestry who consented to participate in the Michigan Genomics Initiative, a longitudinal biorepository effort within Michigan Medicine. PRS for 12 cancer traits were calculated using summary statistics from the NHGRI-EBI catalog. A total of 1,711 synthetic case-control studies was used for PheWAS analyses. There were 13,490 (47.7%) patients with at least one cancer diagnosis in this study sample. PRS exhibited strong association for several cancer traits they were designed for, including female breast cancer, prostate cancer, melanoma, basal cell carcinoma, squamous cell carcinoma, and thyroid cancer. Phenome-wide significant associations were observed between PRS and many non-cancer diagnoses. To differentiate PRS associations driven by the primary trait from associations arising through shared genetic risk profiles, the idea of "exclusion PRS PheWAS" was introduced. Further analysis of temporal order of the diagnoses improved our understanding of these secondary associations. This comprehensive PheWAS used PRS instead of a single variant.

Patient Factors Associated With Opioid Consumption in the Month Following Major Surgery.

OBJECTIVE: The aim of this study was to determine preoperative patient characteristics associated with postoperative outpatient opioid use and assess the frequency of postoperative opioid overprescribing. SUMMARY BACKGROUND DATA: Although characteristics associated with inpatient opioid use have been described, data regarding patient factors associated with opioid use after discharge are lacking. This hampers the development of individualized approaches to postoperative prescribing. METHODS: We included opioid-naïve patients undergoing hysterectomy, thoracic surgery, and total knee and hip arthroplasty in a single-center prospective observational cohort study. Preoperative phenotyping included self-report measures to assess pain severity, fibromyalgia survey criteria score, pain catastrophizing, depression, anxiety, functional status, fatigue, and sleep disturbance. Our primary outcome measure was self-reported total opioid use in oral morphine equivalents. We constructed multivariable linear-regression models predicting opioids consumed in the first month following surgery. RESULTS: We enrolled 1181 patients; 1001 had complete primary outcome data and 913 had complete phenotype data. Younger age, non-white race, lack of a college degree, higher anxiety, greater sleep disturbance, heavy alcohol use, current tobacco use, and larger initial opioid prescription size were significantly associated with increased opioid consumption. Median total oral morphine equivalents prescribed was 600 mg (equivalent to one hundred twenty 5-mg hydrocodone pills), whereas median opioid consumption was 188 mg (38 pills). CONCLUSIONS: In this prospective cohort of opioid-naïve patients undergoing major surgery, we found a number of characteristics associated with greater opioid use in the first month after surgery. Future studies should address the use of non-opioid medications and behavioral therapies in the perioperative period for these higher risk patients.

Prescribing and Consumption of Opioids After Primary, Unilateral Total Hip and Knee Arthroplasty in Opioid-Naive Patients.

BACKGROUND: This cohort study was designed to determine the discrepancy between the quantity of opioid prescribed vs that which was consumed after total knee arthroplasty (TKA) and total hip arthroplasty (THA) in opioid-naive patients. METHODS: Seven hundred twenty-three opioid-naive patients (426 TKAs and 297 THAs) from 7 hospitals in Michigan were contacted within 3 months of their surgery. Opioid prescribing and self-reported consumption was calculated in oral morphine equivalents (OMEs). Secondary outcomes included opioid refill in the first 90 days, pain in the first 7 days post-operatively, and satisfaction with pain care. RESULTS: For TKA, the mean prescribing was 632 mg OME (±229), and the mean consumption was 416 mg (±279). For THA, the mean prescribing was 584 mg OME (±335), and the mean consumption was 285 mg (±301). There were no associations between the amount of opioid prescribed and the likelihood of refill, post-operative pain, or satisfaction with pain control. The amount of opioid prescribed was associated with increased consumption, such that each increase of 1 pill was associated with approximately an additional half pill consumed after adjusting for other covariates. Moreover, 48.2% felt that they received "More" or "Much more" opioid than they needed. CONCLUSION: We recommend no more than 50 tablets of 5 mg oxycodone or its equivalent after TKA and 30 tablets after THA. Although dose reductions in other surgeries have not resulted in harm, continued assessment is needed to ensure that there are no unintended effects of opioid reduction, including worsened pain, decreased satisfaction, emergency department visits, or hospital readmissions. LEVEL OF EVIDENCE: Level III; Retrospective, cohort study.

Discrepancies Between Perceived Benefit of Opioids and Self-Reported Patient Outcomes.

Objective: There is little empirical evidence supporting the long-term use of opioid therapy for chronic pain, suggesting the need to reevaluate the role of opioids in chronic pain management. Few studies have considered opioid use and opioid cessation from the perspective of the patient. Methods: This prospective structured interview study included 150 new patients seeking treatment for chronic pain at an outpatient tertiary care pain clinic. Results: Of the 150 patients, 56% (N = 84) reported current opioid use. Opioids users reported higher pain severity (t(137) = -3.75, P < 0.001), worse physical functioning (t(136) = -3.82, P < 0.001), and more symptoms of depression (t(136) = -1.98, P = 0.050) than nonusers. Among opioid users, 45.6% reported high pain (>7), 60.8% reported low functioning (>7), and 71.4% reported less than a 30% reduction in pain severity since starting opioids, suggesting that many patients are unlikely to be receiving adequate benefit. Overall, 66.3% of current opioid users reported moderate to high opioid-related difficulties on the prescribed opioids difficulties scale, and patients with depression were more likely to report greater difficulties. There was no association between helpfulness of opioids over the past month and opioid-related difficulties (r(75) = -0.07, P = 0.559), current pain severity (r(72)=0.05, P = 0.705), or current pain interference (r(72) = 0.20, P = 0.095). Conclusions: Despite clinical indicators that question the benefit, patients may continue to report that their opioids are helpful. Such discrepancies in patients' perceptions will likely pose significant barriers for implementing opioid cessation guidelines in clinical practice.

Preoperative Opioid Use is Independently Associated With Increased Costs and Worse Outcomes After Major Abdominal Surgery.

OBJECTIVE: To explore the clinical and financial implications of preoperative opioid use in major abdominal surgery. BACKGROUND: Opioids are increasingly used to manage chronic pain, and chronic opioid users are challenging to care for perioperatively. Given the epidemic of opioid-related morbidity and mortality, it is critical to understand how preoperative opioid use impacts surgical outcomes. METHODS: This was an analysis of nonemergent, abdominopelvic surgeries from 2008 to 2014 from a single center within the Michigan Surgical Quality Collaborative clinical registry database. Preoperative opioid use (binary exposure variable) was retrospectively queried from the home medication list of the preoperative evaluation. Our primary outcome was 90-day total hospital costs. Secondary outcomes included hospital length of stay, 30-day major complication rates, discharge destination, and 30-day hospital readmission rates. Analyses were risk-adjusted for case complexity and patient-specific risk factors such as demographics, insurance, smoking, comorbidities, and concurrent medication use. RESULTS: In all, 2413 patients met the inclusion criteria. Among them, 502 patients (21%) used opioids preoperatively. After covariate adjustment, opioid users (compared with those who were opioid-naïve) had 9.2% higher costs [95% confidence interval (CI) 2.8%-15.6%; adjusted means $26,604 vs $24,263; P = 0.005), 12.4% longer length of stay (95% CI 2.3%-23.5%; adjusted means 5.9 vs 5.2 days; P = 0.015), more complications (odds ratio 1.36; 95% CI 1.04-1.78; adjusted rates 20% vs 16%; P = 0.023), more readmissions (odds ratio 1.57; 95% CI 1.08-2.29; adjusted rates 10% vs 6%; P = 0.018), and no difference in discharge destination (P = 0.11). CONCLUSIONS: Opioid use is common before abdominopelvic surgery, and is independently associated with increased postoperative healthcare utilization and morbidity. Preoperative opioids represent a potentially modifiable risk factor and a novel target to improve quality and value of surgical care.

Developing and Testing an Electronic Measure of Screening Colonoscopy Overuse in a Large Integrated Healthcare System.

BACKGROUND: Most existing performance measures focus on underuse of care, but there is growing interest in identifying and reducing overuse. OBJECTIVE: We aimed to develop a valid and reliable electronic performance measure of overuse of screening colonoscopy in the Veterans Affairs Health Care System (VA), and to quantify overuse in VA. DESIGN: This was a cross-sectional study with multiple cross-sections. SUBJECTS: U.S. Veterans who underwent screening colonoscopy between 2011 and 2013. MAIN MEASURES: Overuse of screening colonoscopy, using a validated electronic measure developed by an expert workgroup. KEY RESULTS: Compared to results obtained from manual record review, the electronic measure was highly specific (97 %) for overuse, but not sensitive (20 %). After exclusion of diagnostic and high-risk screening or surveillance procedures, the validated electronic measure identified 88,754 average-risk screening colonoscopies performed in VA during 2013. Of these, 20,530 (23 %) met the definition for probable (17 %) or possible (6 %) overuse. Substantial variation in colonoscopy overuse was noted between Veterans Integrated Care Networks (VISNs) and between facilities, with a nearly twofold difference between the maximum and minimum rates of overuse at the VISN level and a nearly eightfold difference at the facility level. Overuse at the VISN and facility level was relatively stable over time. CONCLUSIONS: Overuse of screening colonoscopy can be measured reliably and with high specificity using electronic data, and is common in a large integrated healthcare system. Overuse measures, such as those we have specified through a consensus workgroup process, could be combined with underuse measures to improve the appropriateness of colorectal cancer screening.

Fibromyalgia survey criteria are associated with increased postoperative opioid consumption in women undergoing hysterectomy.

BACKGROUND: The current study was designed to test the hypothesis that the fibromyalgia survey criteria would be directly associated with increased opioid consumption after hysterectomy even when accounting for other factors previously described as being predictive for acute postoperative pain. METHODS: Two hundred eight adult patients undergoing hysterectomy between October 2011 and December 2013 were phenotyped preoperatively with the use of validated self-reported questionnaires including the 2011 fibromyalgia survey criteria, measures of pain severity and descriptors, psychological measures, preoperative opioid use, and health information. The primary outcome was the total postoperative opioid consumption converted to oral morphine equivalents. RESULTS: Higher fibromyalgia survey scores were significantly associated with worse preoperative pain characteristics, including higher pain severity, more neuropathic pain, greater psychological distress, and more preoperative opioid use. In a multivariate linear regression model, the fibromyalgia survey score was independently associated with increased postoperative opioid consumption, with an increase of 7-mg oral morphine equivalents for every 1-point increase on the 31-point measure (Estimate, 7.0; Standard Error, 1.7; P < 0.0001). In addition to the fibromyalgia survey score, multivariate analysis showed that more severe medical comorbidity, catastrophizing, laparotomy surgical approach, and preoperative opioid use were also predictive of increased postoperative opioid consumption. CONCLUSIONS: As was previously demonstrated in a total knee and hip arthroplasty cohort, this study demonstrated that increased fibromyalgia survey scores were predictive of postoperative opioid consumption in the posthysterectomy surgical population during their hospital stay. By demonstrating the generalizability in a second surgical cohort, these data suggest that patients with fibromyalgia-like characteristics may require a tailored perioperative analgesic regimen.

Associations Between Pain, Current Tobacco Smoking, Depression, and Fibromyalgia Status Among Treatment-Seeking Chronic Pain Patients.

OBJECTIVE: As smoking impacts physiological pathways in the central nervous system, it is important to consider the association between smoking and fibromyalgia, a pain condition caused predominantly by central nervous system dysfunction. The objectives were to assess the prevalence of current smoking among treatment-seeking chronic pain patients with (FM+) and without (FM-) a fibromyalgia-like phenotype; test the individual and combined influence of smoking and fibromyalgia on pain severity and interference; and examine depression as a mediator of these processes. METHODS: Questionnaire data from 1566 patients evaluated for a range of conditions at an outpatient pain clinic were used. The 2011 Survey Criteria for Fibromyalgia were used to assess the presence of symptoms associated with fibromyalgia. RESULTS: Current smoking was reported by 38.7% of FM+ patients compared to 24.7% of FM- patients. FM+ smokers reported higher pain and greater interference compared to FM+ nonsmokers, FM- smokers, and FM- nonsmokers. There was no interaction between smoking and fibromyalgia. Significant indirect effects of fibromyalgia and smoking via greater depression were observed for pain severity and interference. CONCLUSIONS: Current smoking and positive fibromyalgia status were associated with greater pain and impairment among chronic pain patients, possibly as a function of depression. Although FM+ smokers report the most negative clinical symptomatology (i.e., high pain, greater interference) smoking does not appear to have a unique association with pain or functioning in FM+ patients, rather the effect is additive. The 38.7% smoking rate in FM+ patients is high, suggesting FM+ smokers present a significant clinical challenge.

Establishing measurement invariance: English and Spanish Paediatric Asthma Quality of Life Questionnaire.

BACKGROUND: Registered nurses and nurse researchers often use questionnaires to measure patient outcomes. When questionnaires or other multiple-item instruments have been developed using a relatively homogeneous sample, the suitability of even a psychometrically well-developed instrument for the new population comes into question. Bias or lack of equivalence can be introduced into instruments through differences in perceptions of the meaning of the measured items, constructs, or both in the two groups. OBJECTIVE: To explain measurement invariance and illustrate how it can be tested using the English and Spanish versions of the Paediatric Asthma Quality of Life Questionnaire (PAQLQ). METHODS: A sample of 607 children from the Phoenix Children's Hospital Breathmobile was selected for this analysis. The children were of ages 6-18 years; 61.2% completed the PAQLQ in Spanish. Testing measurement invariance using multiple-group confirmatory factor analysis, a series of hierarchical nested models, is demonstrated. In assessing the adequacy of the fit of each model at each stage, both χ2 tests and goodness-of-fit indexes were used. RESULTS: The test of measurement invariance for the one-factor model showed that the English and Spanish versions of the scale met the criteria for measurement invariance. The level of strict invariance (equal factor loadings, intercepts, and residual variances between groups) was achieved. DISCUSSION: Confirmatory factor analysis is used to evaluate the structural integrity of a measurement instrument; multiple confirmatory factor analyses are used to assess measurement invariance across different groups and to stamp the data as valid or invalid. The PAQLQ, a widely used instrument having evidence to support reliability and validity was used separately in English- and Spanish-speaking groups. Traditional methods for evaluating measurement instruments have been less than thorough, and this article demonstrates a well-developed approach, allowing for confident comparisons between populations.

Trajectories of Math and Reading Achievement in Low Achieving Children in Elementary School: Effects of Early and Later Retention in Grade.

This study investigated the effects of retention or promotion in first grade on growth trajectories in mathematics and reading achievement over the elementary school years (grades 1-5). From a large multiethnic sample (n = 784) of children who were below the median in literacy at school entrance, 363 children who were either promoted (n = 251) or retained (n = 112) in first grade could be successfully matched on 72 background variables. Achievement was measured annually using Woodcock-Johnson W scores; scores of retained children were shifted back one year to permit same-grade comparisons. Using longitudinal growth curve analysis, trajectories of math and reading scores for promoted and retained children were compared. Retained children received a one year boost in achievement; this boost fully dissipated by the end of elementary school. The pattern of subsequent retention in grades 2, 3 and 4 and placement in special education of the sample during the elementary school years is also described and their effects are explored. Policy implications for interventions for low achieving children are considered.

Does attending a college with more heavy drinking peers increase risk of heavy drinking and consequences? A prospective national analysis.

Heavy drinking in college increases risk for negative consequences. Among a national sample of high school abstainers and moderate drinkers, we hypothesized that the extent of heavy drinking among students on campus would be among the strongest predictors of first semester heavy drinking and consequences, relative to personal approval of alcohol use and sociability and impairment outcome expectancies. We expected these psychological factors to moderate effects of campus heavy drinking. Data from 90,455 abstainers and 97,168 moderate drinkers matriculating at 245 and 242 universities, respectively, were drawn from AlcoholEdu (EverFi, 2013), a web-based intervention completed by most first-year students at participating universities. Students reported alcohol use, approval, expectancies, and covariates prior to enrollment (Time 1). During the first semester (Time 2), abstinence, moderate drinking, or heavy drinking, and negative consequences experienced were reassessed. Campus heavy drinking reflected the percentage of other students attending the same school who engaged in heavy drinking at Time 2. In multilevel multinomial logistic regression models, campus heavy drinking was consistently among the strongest predictors of heavy drinking and consequences: It predicted an 83% and 82% increase in risk of heavy drinking and a 106% and 91% increase in risk of consequences among students who were abstainers and moderate drinkers at Time 1, respectively. There were few interactions among campus heavy drinking and psychological factors. Post hoc analyses supported that students did not self-select into heavier drinking environments. Campus heavy drinking is a key predictor of first semester alcohol use and an important intervention target. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Heritability of the Fibromyalgia Phenotype Varies by Age.

OBJECTIVE: Many studies suggest a strong familial component to fibromyalgia (FM). However, those studies have nearly all been confined to individuals with primary FM, i.e., FM without any other accompanying disorder. The current 2011 and 2016 criteria for diagnosing FM construct a score using a combination of the number of painful body sites and the severity of somatic symptoms (FM score). This study was undertaken to estimate the genetic heritability of the FM score across sex and age groups to identify subgroups of individuals with greater heritability, which may help in the design of future genetic studies. METHODS: We collected data on 26,749 individuals of European ancestry undergoing elective surgery at the University of Michigan (Michigan Genomics Initiative study). We estimated the single-nucleotide polymorphism-based heritability of FM score by age and sex categories using genome-wide association study data and a linear mixed-effects model. RESULTS: Overall, the FM score had an estimated heritability of 13.9% (SE 2.9%) (P = 1.6 × 10-7 ). Estimated FM score heritability was highest in individuals ≤50 years of age (23.5%; SE 7.9%) (P = 3.0 ×10-4 ) and lowest in individuals >60 years of age (7.5%; SE 8.1%) (P = 0.41). These patterns remained the same when we analyzed FM as a case-control phenotype. Even though women had an ~30% higher average FM score than men across age categories, FM score heritability did not differ significantly by sex. CONCLUSION: Younger individuals appear to have a much stronger genetic component to the FM score than older individuals. Older individuals may be more likely to have what was previously called "secondary FM." Regardless of the cause, these results have implications for future genetic studies of FM and associated conditions.

Fluoroscopically Guided Lateral Approach Hip Injection.

A retrospective comparison study of the anterior-oblique and lateral approach to hip injection procedures suggests that the lateral approach may be a valuable interventional skill for those performing hip injections.

Medial branch radiofrequency ablation outcomes in patients with centralized pain.

BACKGROUND AND OBJECTIVES: We hypothesized that patients with characteristics of centralized pain (fibromyalgia (FM)-like phenotype) would be less likely to respond to radiofrequency ablation (RFA), which may explain some of the failures of this peripherally directed therapy. METHODS: We conducted a prospective, observational study of patients undergoing RFA using a number of validated self-report measures of pain, mood and function. The 2011 Fibromyalgia Survey Criteria were used to assess for symptoms of centralized pain and was the primary predictor of interest. We constructed multivariable linear regression models to evaluate covariates independently associated with change in pain 3 months after RFA. RESULTS: 141 patients scheduled for medial branch blocks were enrolled in the study; 55 underwent RFA (51 with complete 3 months' follow-up). Patients with higher FM scores had less improvement in overall body pain; however, this was not statistically significant (adjusted mean change in pain FM+0.41, FM-1.11, p=0.396). In a secondary analysis, the FM score was not associated with change in back pain (p=0.720), with both groups improving equally. This cohort also reported significant improvement in anxiety, physical function, catastrophizing, and sleep disturbance at 3 months after RFA. CONCLUSIONS: Although patients with high baseline centralized pain exhibited less improvement in overall pain, this trend was not statistically significant, possibly due to insufficient power. The same trend was not seen with change in spine pain with both groups improving equally. Centralized pain patients may have less improvement in overall pain but may have equal improvement in their site-specific pain levels after localized interventions.

Phenotypic features of patients with complex regional pain syndrome compared with those with neuropathic pain.

INTRODUCTION: We hypothesized that patients with complex regional pain syndrome (CRPS) would describe a more negative pain phenotype including higher pain severity, more neuropathic pain descriptors, more centralized pain symptoms, poorer physical function, and more affective distress when compared with patients with neuropathic pain of the extremities not meeting CRPS criteria. MATERIALS AND METHODS: This was a retrospective cross-sectional study conducted at a tertiary pain center. The sample included 212 patients who met Budapest Criteria for CRPS and 175 patients with neuropathic pain of the extremities who did not meet criteria. All patients completed a packet of questionnaires before their initial visit containing validated outcome measures assessing pain severity, pain interference, physical functioning, depression, anxiety, and catastrophizing. RESULTS: Patients with CRPS reported higher physical disability (p=0.022) and more neuropathic pain symptoms (p=0.002) than patients not meeting CRPS criteria, but the groups did not otherwise differ significantly. There were no significant differences in pain severity or affective distress, despite power analyses suggesting the ability to detect small to medium effect sizes (d=0.29; w=0.14). Subanalyses of differences in neuropathic pain symptoms revealed that patients with CRPS, compared with patients not meeting CRPS criteria, were more likely to report pain with light touch (p=0.003), sudden pain attacks (p=0.003), pain with cold or heat (p=0.002), sensation of numbness (p=0.042), and pain with slight pressure (p=0.018). DISCUSSION: Counter to our hypothesis, the present study suggests that patients with CRPS do not have a worse clinical phenotype compared with patients not meeting CRPS criteria, with the exception of higher physical disability and more neuropathic pain symptoms. This corresponds to recent evidence that patients with CRPS are similar to other patient populations with chronic pain.

Association Between the 2011 Fibromyalgia Survey Criteria and Multisite Pain Sensitivity in Knee Osteoarthritis.

OBJECTIVES: The present study evaluated the relationship between the 2011 American College of Rheumatology fibromyalgia (FM) survey criteria and quantitative sensory testing (QST). MATERIALS AND METHODS: Patients with knee osteoarthritis scheduled to undergo knee arthroplasty completed the FM survey criteria and self-report measures assessing clinical symptoms. Patients also underwent a battery of QST procedures at the surgical knee and remote body sites, including pressure algometry, conditioned pain modulation, and temporal summation. All assessments were completed before surgery. FM survey criteria were used to calculate a continuous FM score indicating FM severity. RESULTS: A total of 129 patients were analyzed. Of these, 52.7% were female, 93.8% were Caucasian, and 3.8% met the FM survey criteria for FM classification. Mean age for females (63.6 y) and males (64.7 y) was similar. Females and males differed significantly in nearly every outcome, including FM severity, clinical pain, anxiety, depression, and pressure pain sensitivity. In females, FM scores significantly correlated with pressure pain sensitivity, but not conditioned pain modulation or temporal summation, such that increased sensitivity was associated with greater FM severity at all body sites examined. In addition, as FM scores increased, the association between pain sensitivity at the surgical knee and pain sensitivity at remote body sites also increased. No relationship between FM score and QST was observed in males. DISCUSSION: We demonstrated an association between diffuse hyperalgesia as measured by QST and FM severity in females with knee osteoarthritis. These results suggest that the FM survey criteria may represent a marker of pain centralization in females with potential utility in clinical decision making.

Pressure sensitivity and phenotypic changes in patients with suspected opioid-induced hyperalgesia being withdrawn from full mu agonists.

OBJECTIVES: To assess changes in phenotype and pressure sensitivity in patients with suspected opioid-induced-hyperalgesia (OIH) after transitioning to buprenorphine. METHODS: Twenty patients with suspected OIH were enrolled to transition to buprenorphine therapy. Patients completed validated self-report measures at baseline and at 1, 4, 8 weeks, and 6 months after initiation of buprenorphine along with quantitative sensory testing including measures of pressure pain threshold, pain tolerance and Pain 50 (a pain intensity rating). RESULTS: 20 patients were enrolled, 17 were treated with buprenorphine and 11 completed all assessment points. We found that after transitioning to buprenorphine, patients on higher opioid doses (≥100mg oral morphine equivalents) had significant improvements for some measures including decreased pain severity and fibromyalgia survey scores, fewer neuropathic pain features, less catastrophizing, fewer depressive symptoms, and improved functioning 1-week after transitioning to buprenorphine with an eventual return back to baseline. Although not statistically significant, patients on high dose opioids (≥100mg OME) also showed a trend of decreased pressure sensitivity 1-week after transitioning to buprenorphine with a gradual return back to baseline. CONCLUSIONS: Our study is the first to look at pressure pain sensitivity in patients who were taking opioids and transitioned to buprenorphine. These results suggest that the patients most likely to benefit from buprenorphine therapy are those on higher doses. In addition, the eventual return back to baseline on measures of pain phenotype and pressure sensitivity suggests that buprenorphine may over time result in a return of the hyperalgesic effects of a full mu agonist.