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.

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.

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.

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.

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.

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.

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.

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.

Time Since Inciting Event Is Associated With Higher Centralized Pain Symptoms in Patients Diagnosed With Complex Regional Pain Syndrome.

BACKGROUND AND OBJECTIVES: We hypothesized that patients with complex regional pain syndrome (CRPS) with a longer time since their inciting event would demonstrate more symptoms of centralized pain. METHODS: We conducted a cross-sectional analysis of 160 patients with CRPS using validated measures of pain, negative mood, and functioning at the time of their new patient evaluation. The 2011 Fibromyalgia Survey Criteria is a validated self-report measure of widespread body pain and comorbid symptoms (eg, trouble thinking, headaches). The measure was used as a surrogate for centralized pain symptoms. Univariate analyses and multivariate linear regression models were used to assess the associations between patient characteristics and the duration of CRPS. RESULTS: The cohort was divided into tertiles based on the time since the inciting event (<12 months; 1-3 years; >3 years) for univariate comparisons. Unlike the other measures of pain, mood, and function, the fibromyalgia survey score was significantly associated with a longer duration of symptoms. In a multivariate model adjusting for age and sex, each year since the inciting event was associated with an increase of 0.28 in fibromyalgia survey score (Est 0.28; 95% confidence interval, 0.11-0.46; P = 0.002). The finding was distinct from self-reported spread of CRPS symptoms, which was not different based on time since the inciting event. CONCLUSIONS: Our findings suggest that the longer the patients have CRPS the more likely they are to report symptoms suggestive of centralized pain. These data may explain why some patients with a longer duration of CRPS do not respond to peripherally directed therapies.

The Association Between a History of Lifetime Traumatic Events and Pain Severity, Physical Function, and Affective Distress in Patients With Chronic Pain.

Evidence suggests that pain patients who report lifetime abuse experience greater psychological distress, have more severe pain and other physical symptoms, and greater functional disability. The aim of the present study was to determine the associations between a history of lifetime abuse and affective distress, fibromyalgianess (measured using the 2011 Fibromyalgia Survey), pain severity and interference, and physical functioning. A cross-sectional analysis of 3,081 individuals presenting with chronic pain was performed using validated measures and a history of abuse was assessed via patient self-report. Multivariate logistic regression showed that individuals with a history of abuse (n = 470; 15.25%) had greater depression, greater anxiety, worse physical functioning, greater pain severity, worse pain interference, higher catastrophizing, and higher scores on the Fibromyalgia Survey criteria (P < .001 for all comparisons). Mediation models showed that the Fibromyalgia Survey score and affective distress independently mediate the relationship between abuse and pain severity and physical functioning (Ps < .001). Our mediation models support a novel biopsychosocial paradigm wherein affective distress and fibromyalgianess interact to play significant roles in the association between abuse and pain. We posit that having a centralized pain phenotype underlies the mediation of increased pain morbidity in individuals with a history of abuse. PERSPECTIVE: This article examines the associations between a history of lifetime abuse and affective distress, fibromyalgianess, pain severity and interference, and physical functioning in chronic pain patients. Our findings support a novel biopsychosocial paradigm in which affective distress and fibromyalgianess interact to play roles in the association between abuse and pain.

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.

Preliminary validation of the Michigan Body Map.

We developed the Michigan Body Map (MBM) as a self-report measure to assess body areas where chronic pain is experienced and to specifically quantify the degree of widespread body pain when assessing for centralized pain features (eg, fibromyalgia-like presentation). A total of 402 patients completed the measure in 5 distinct studies to support the validation of the original and a revised version of the MBM. Administration is rapid 39 to 44 seconds, and errors for the original MBM were detected in only 7.2% of the possible body areas. Most errors underestimated the number of painful areas or represented confusion in determining the right vs left side. The MBM was preferred (P = 0.013) and felt to better depict pain location (P = 0.001) when compared with the Widespread Pain Index checklist of the 2011 Fibromyalgia Survey Criteria, but participants did not express any preference between the MBM and Brief Pain Inventory body map. Based on the data from the first 3 studies, a revised version of the MBM was created including a front and back body image and improved guidance on right-sidedness vs left. The revised MBM was preferred when compared with the original and was more accurate in depicting painful body areas (P = 0.004). Furthermore, the revised MBM showed convergent and discriminant validity with other self-report measures of pain, mood, and function. In conclusion, the MBM demonstrated utility, reliability, and construct validity. This new measure can be used to accurately assess the distribution of pain or widespread bodily pain as an element of the fibromyalgia survey score.

Affect and Low Back Pain: More to Consider Than the Influence of Negative Affect Alone.

OBJECTIVES: Affect balance style, a measure of trait positive affect (PA) and negative affect (NA), is predictive of pain and functioning in fibromyalgia and healthy individuals. The purpose of this study was to evaluate the distribution of affect balance styles and the relationship between these styles and clinical factors in low back pain. METHODS: In this cross-sectional study, patients with low back pain (N=443) completed questionnaires and were categorized as having 1 of 4 distinct affect balance styles: Healthy (high levels of PA and low levels of NA), Low (low PA/low NA), Reactive (high PA/high NA), and Depressive (low PA/high NA). Comparisons between groups were made in regard to pain, functioning, and psychiatric comorbidity. RESULTS: High NA was observed in 63% (n=281), whereas low PA was present in 81% (n=359). We found that having a Depressive style was associated with greater pain severity, increased odds for comorbid fibromyalgia, and worse functioning compared with having a Healthy or Low style. Yet, those with a Low style were at increased risk for depression compared with a Healthy style, whereas patients with a Reactive style had similar levels of pain, functioning, and depression as those with a Healthy affective style. CONCLUSIONS: Our study revealed that there are important differences between trait affect balance styles in regard to pain, mood, and functioning in low back pain. Findings related to Reactive and Low affective styles suggest that relationships between affect, pain, and disability in low back pain extend beyond considering NA alone.

Trends and predictors of opioid use after total knee and total hip arthroplasty.

Few studies have assessed postoperative trends in opioid cessation and predictors of persistent opioid use after total knee arthroplasty (TKA) and total hip arthroplasty (THA). Preoperatively, 574 TKA and THA patients completed validated, self-report measures of pain, functioning, and mood and were longitudinally assessed for 6 months after surgery. Among patients who were opioid naive the day of surgery, 8.2% of TKA and 4.3% of THA patients were using opioids at 6 months. In comparison, 53.3% of TKA and 34.7% of THA patients who reported opioid use the day of surgery continued to use opioids at 6 months. Patients taking >60 mg oral morphine equivalents preoperatively had an 80% likelihood of persistent use postoperatively. Day of surgery predictors for 6-month opioid use by opioid-naive patients included greater overall body pain (P = 0.002), greater affected joint pain (knee/hip) (P = 0.034), and greater catastrophizing (P = 0.010). For both opioid-naive and opioid users on the day of surgery, decreases in overall body pain from baseline to 6 months were associated with decreased odds of being on opioids at 6 months (adjusted odds ratio [aOR] = 0.72, P = 0.050; aOR = 0.62, P = 0.001); however, change in affected joint pain (knee/hip) was not predictive of opioid use (aOR = 0.99, P = 0.939; aOR = 1.00, P = 0.963). In conclusion, many patients taking opioids before surgery continue to use opioids after arthroplasty and some opioid-naive patients remained on opioids; however, persistent opioid use was not associated with change in joint pain. Given the growing concerns about chronic opioid use, the reasons for persistent opioid use and perioperative prescribing of opioids deserve further study.

Classifying the Indication for Colonoscopy Procedures: A Comparison of NLP Approaches in a Diverse National Healthcare System.

In order to measure the level of utilization of colonoscopy procedures, identifying the primary indication for the procedure is required. Colonoscopies may be utilized not only for screening, but also for diagnostic or therapeutic purposes. To determine whether a colonoscopy was performed for screening, we created a natural language processing system to identify colonoscopy reports in the electronic medical record system and extract indications for the procedure. A rule-based model and three machine-learning models were created using 2,000 manually annotated clinical notes of patients cared for in the Department of Veterans Affairs. Performance of the models was measured and compared. Analysis of the models on a test set of 1,000 documents indicates that the rule-based system performance stays fairly constant as evaluated on training and testing sets. However, the machine learning model without feature selection showed significant decrease in performance. Therefore, rule-based classification system appears to be more robust than a machine-learning system in cases when no feature selection is performed.

Aberrant analgesic response to medial branch blocks in patients with characteristics of fibromyalgia.

BACKGROUND AND OBJECTIVES: Facet interventions for spine pain have high failure rates, and preprocedural prediction of response is nearly impossible. A potential explanation may be aberrant central pain processing as that existing in conditions like fibromyalgia. To test this hypothesis, we conducted a retrospective study investigating the impact of having characteristics of fibromyalgia on the acute analgesic response to a first diagnostic medial branch block (MBB). METHODS: We evaluated the analgesic responses of 187 patients that underwent MBB. Patients were categorized as "fibromyalgia-positive" or "fibromyalgia-negative" using the 2011 fibromyalgia survey criteria. Preprocedural and postprocedural pain scores and patient-completed pain diaries up to 24 hours postprocedure were collected. A linear mixed model was used to study longitudinal effects of MBB on pain responses. RESULTS: Fibromyalgia-positive patients had a worse preprocedural pain phenotype (ie, greater pain severity, higher levels of depressive and anxiety symptoms, reduced function). Binary categorization of fibromyalgia status was not associated with a difference in immediate postprocedural pain relief; however, the longitudinal analgesic response across time varied significantly between groups (P = 0.0005). Fibromyalgia-negative subjects showed the expected steep decline in pain scores, followed by gradual return to baseline, whereas a more aberrant pattern was noted in the fibromyalgia-positive group. Pain scores for fibromyalgia-negative patients were also lower by -1.07 (SE = 0.37) on average after the MBB (P = 0.005). CONCLUSIONS: Characteristics of fibromyalgia may indicate pain that is more centralized in nature, a factor that may explain the aberrant analgesic response to this peripheral intervention. This may have implications for future prediction of treatment response, although prospective studies are needed.