Chronic Pain Research Research Articles

A MAPP Network Case-control Study of Urological Chronic Pelvic Pain Compared With Nonurological Pain Conditions.

Limited research suggests commonalities between urological chronic pelvic pain syndromes (UCPPS) and other nonurological chronic overlapping pain conditions (COPCs) including fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome. The goal of this case-control study was to examine similarities and differences between UCPPS and these other COPCs. As part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research (MAPP) Network, we examined 1039 individuals with UCPPS (n=424), nonurological COPCs (n=200), and healthy controls (HCs; n=415). Validated standardized measures were used to assess urological symptoms, nonurological pain symptoms, and psychosocial symptoms and traits. Participants with UCPPS had more urological symptoms than nonurological COPCs or HCs (P<0.001); nonurological COPC group also had significantly worse urological symptoms than HCs (P<0.001). Participants with nonurological COPCs reported more widespread pain than those with UCPPS (P<0.001), yet both groups had similarly increased symptoms of anxiety, depression, negative affect, perceived stress, neuroticism, and lower levels of extraversion than HCs (P<0.001). Participants with UCPPS with and without COPCs reported more catastrophizing than those with nonurological COPCs (P<0.001). Findings are consistent with the hypothesis of common underlying biopsychosocial mechanisms and can guide the comprehensive assessment and treatment of these conditions regardless of the primary site of pain or diagnosis. Heightened catastrophizing in UCPPS should be examined to inform psychosocial interventions and improve patient care.

Interpersonal problems as a predictor of pain catastrophizing in patients with chronic pain.

Background and aims Pain catastrophizing has consistently been related to a variety of negative outcomes within chronic pain conditions, but competing models exist explaining the role of catastrophizing. According to the fear-avoidance model (FAM), catastrophizing is primarily related to the appraisal of pain (i.e. "intrapersonal"), whereas the communal coping model (CCM) suggests that catastrophizing is a strategy to elicit support (i.e. "interpersonal"). In order to examine the interpersonal nature of catastrophizing, this cross-sectional study examined interpersonal problems as a predictor of pain catastrophizing in a sample of patients (n = 97) with chronic pain. Methods Self-report data was taken from patients entering a multidisciplinary, inpatient rehabilitation program. The four quadrants of the Inventory of Interpersonal Problems circumplex model (Hostile-Dominant, Hostile-Submissive, Friendly-Submissive, Friendly-Dominant) were used as predictors of pain catastrophizing in a series of separate, hierarchical regression analyses. Results After controlling for relevant confounding variables such as demographics (gender, age), pain severity, psychiatric symptoms (anxiety/depression, fatigue, insomnia), adverse life experiences and perceived social support, higher levels of Hostile-Dominant interpersonal problems predicted higher levels of pain catastrophizing (p ≤ 0.01, d = 0.56). Conclusions The results add support to the notion that pain catastrophizing may serve a communicative functioning, as predicted by the CCM, with cold, dominant and controlling behaviors as a maladaptive interpersonal strategy to elicit support. It may thus be useful to consider the broader interpersonal context of the individual, and not only the patient's appraisal of pain, when conceptualizing the role of pain catastrophizing in patients with chronic pain. Implications Future psychosocial research and treatment of chronic pain could be informed by including interpersonal theory as a useful theoretical framework, which may help shed more light on how interpersonal problems relates to pain catastrophizing.

Changes in whole body pain intensity and widespreadness during urologic chronic pelvic pain syndrome flares-Findings from one site of the MAPP study.

To investigate changes in whole body pain during urologic chronic pelvic pain syndrome (UCPPS) flares. UCPPS participants at one site of the multidisciplinary approach to the study of chronic pelvic pain research network reported their daily flare status and pain levels in 7 pelvic/genital and 42 extrapelvic body areas (scale = 0-10) for 10 days at baseline and during their first flare. Linear mixed models and conditional logistic regression were used to investigate symptom changes during flares. Analyses were stratified by chronic overlapping pain condition (COPC) status. Fifty-five out of 60 participants completed the study, 27 of whom provided information on both nonflare (n = 281) and flare (n = 208) days. Pelvic/genital pain intensity (mean change = 3.20 of 10) and widespreadness (mean = 1.48) increased significantly during flares for all participants (all P interaction > .1), whereas extrapelvic pain intensity increased significantly only among participants with COPCs (mean = 2.09; P interaction < .0001). Pelvic/genital and extrapelvic pain also varied on nonflare days but symptom fluctuations were generally ≤1 point (80.0%-100% of participants). Increases of ≥2 points in pelvic/genital pain intensity (odds ratio (OR) = 22.0, 95% confidence interval (CI) = 4.0-118.6) and ≥1 point in urination-related pain (OR = 9.10, 95% CI = 1.74-47.7) were independently associated with flare onset for all participants. Our observations of extrapelvic pain increases during flares for patients with COPCs and our independent associations between pelvic/genital/urination-related pain intensity and flare onset may provide insight into mechanisms underlying flare development (eg, common biologic pathways between UCPPS phenotypes and flares), flare management (eg, local vs systemic therapies by COPC status), and patient flare definitions.

What Is New in Chronic Pelvic Pain Research?: Best Articles From the Past Year.

This month we focus on current research in chronic pelvic pain. Dr. El-Nashar discusses four recent publications, which are concluded with a "bottom-line" that is the take-home message. A complete reference for each can be found on on this page along with direct links to abstracts.

Survive or Thrive? Longitudinal Relation Between Chronic Pain and Well-Being.

The minimal literature on the relation between chronic pain and both eudaimonic (EWB) and hedonic well-being (HWB) examines the relation cross-sectionally, and most studies have examined chronic pain's effect only on psychopathology. Using a sample of 473 midlife and older adults with chronic pain, this study examined both the cross-sectional and longitudinal relations between chronic pain and EWB and HWB in addition to psychological distress. Multiple-group longitudinal structural equation modeling revealed that chronic pain was related significantly and negatively to EWB and HWB, and significantly and positively to distress among both men and women. When examined longitudinally, chronic pain at time 1 was associated significantly only with decreased EWB at time 2, suggesting chronic pain's risk to psychological functioning, especially because of its long-term effects on future EWB. Our study provides a comprehensive picture of the way chronic pain is associated both with EWB and HWB, in addition to psychological distress. Further, chronic pain may have a lasting influence on EWB, while it may have little predictive value for future HWB and psychological distress. Our study supports well-being's relevance to chronic pain research and has the potential to guide prevention strategies and treatment for chronic pain using a positive psychological framework.

Impact of early adverse life events and sex on functional brain networks in patients with urological chronic pelvic pain syndrome (UCPPS): A MAPP Research Network study.

Pain is a highly complex and individualized experience with biopsychosocial components. Neuroimaging research has shown evidence of the involvement of the central nervous system in the development and maintenance of chronic pain conditions, including urological chronic pelvic pain syndrome (UCPPS). Furthermore, a history of early adverse life events (EALs) has been shown to adversely impact symptoms throughout childhood and into adulthood. However, to date, the role of EAL’s in the central processes of chronic pain have not been adequately investigated. We studied 85 patients (56 females) with UCPPS along with 86 healthy controls (HCs) who had resting-state magnetic resonance imaging scans (59 females), and data on EALs as a part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network Study. We used graph theory methods in order to investigate the impact of EALs on measures of centrality, which characterize information flow, communication, influence, and integration in a priori selected regions of interest. Patients with UCPPS exhibited lower centrality in the right anterior insula compared to HCs, a key node in the salience network. Males with UCPPS exhibited lower centrality in the right anterior insula compared the HC males. Females with UCPPS exhibited greater centrality in the right caudate nucleus and left angular gyrus compared to HC females. Males with UCPPS exhibited lower centrality in the left posterior cingulate, angular gyrus, middle temporal gyrus, and superior temporal sulcus, but greater centrality in the precuneus and anterior mid-cingulate cortex (aMCC) compared to females with UCPPS. Higher reports of EALs was associated with greater centrality in the left precuneus and left aMCC in females with UCPPS. This study provides evidence for disease and sex-related alterations in the default mode, salience, and basal ganglia networks in patients with UCPPS, which are moderated by EALs, and associated with clinical symptoms and quality of life (QoL).

Effective Connectivity of Beta Oscillations in Endometriosis-Related Chronic Pain During rest and Pain-Related Mental Imagery

Using the EEG recordings of patients with endometriosis-related chronic pelvic pain, we have examined the effective connectivity within the cortical pain-related network during rest and during pain-related imagery. During rest, an altered connectivity was hypothesized between cortical somatosensory pain areas and regions involved in emotional and cognitive modulation of pain. During pain-related imagery, alterations in prefrontal-temporal connectivity were expected. The effective connectivity was estimated using the Directed Transfer Function method. Differences between endometriosis patients and controls were found in the beta band (14–25 Hz). During rest, endometriosis was associated with an increased connectivity from the left dorsolateral prefrontal cortex to the left somatosensory cortex and also from the left somatosensory cortex to the orbitofrontal cortex and the right temporal cortex. These results might be related to sustained activation of the somatosensory pain system caused by the ongoing pain. During pain-related imagery, endometriosis patients showed an increased connectivity from the left dorsolateral prefrontal cortex to the right temporal cortex. This finding might point to impaired emotional regulation when processing pain-related stimuli, or it might be related to altered memorization of pain experiences. Results of this study open up new directions in chronic pain research aimed at exploring the beta band connectivity alterations. PerspectiveThis study examined the pain system's dynamics in endometriosis patients with chronic pelvic pain during resting-state and pain-related mental imagery. The results could contribute to the development of new therapies using guided mental imagery.

World Workshop in Oral Medicine VII: Reporting of IMMPACT‐recommended outcome domains in randomized controlled trials of burning mouth syndrome: A systematic review

To determine the frequency of use of the core outcome domains published by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) in burning mouth syndrome (BMS) randomized controlled trials (RCTs). This systematic review, conducted as part of the World Workshop on Oral Medicine VII (WWOM VII), was performed by searching the literature for studies published in PubMed, Web of Science, PsycINFO, Cochrane Database/Cochrane Central, and Google Scholar from January 1994 (when the first BMS definition came out) through October 2017. A total of 36 RCTs (n=2,175 study participants) were included and analyzed. The overall reporting of the IMMPACT core and supplemental outcome domains was low even after the publication of the IMMPACT consensus papers in 2003 and 2005 (mean before IMMPACT consensus publication=2.6 out of 6; mean after IMMPACT publication=3.8 out of 6). Use of validated assessment tools recommended by the IMMPACT consensus was scarce (1.9 out of 6). None of the RCTs reviewed cited the IMMPACT consensus papers. The underreporting of IMMPACT outcome domains in BMS RCTs is significant. Raising awareness regarding the existence of standardized outcome domains in chronic pain research is essential to ensure more accurate, comparable, and consistent interpretation of RCT findings that can be clinically translatable.

A longitudinal analysis of urological chronic pelvic pain syndrome flares in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network.

To describe the frequency, intensity and duration of urological chronic pelvic pain syndrome symptom exacerbations ('flares'), as well as risk factors for these features, in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Epidemiology and Phenotyping longitudinal study. Current flare status ('urological or pelvic pain symptoms that are much worse than usual') was ascertained at each bi-weekly assessment. Flare characteristics, including start date, and current intensity of pelvic pain, urgency and frequency (scales of 0-10), were assessed for participants' first three flares and at three randomly selected times when they did not report a flare. Generalized linear and mixed effects models were used to investigate flare risk factors. Of the 385 eligible participants, 24.2% reported no flares, 22.9% reported one flare, 28.3% reported 2-3 flares, and 24.6% reported ≥4 flares, up to a maximum of 18 during the 11-month follow-up (median incidence rate = 0.13/bi-weekly assessment, range = 0.00-1.00). Pelvic pain (mean = 2.63-point increase) and urological symptoms (mean = 1.72) were both significantly worse during most flares (60.6%), with considerable within-participant variability (26.2-37.8%). Flare duration varied from 1 to 150days (94.3% within-participant variability). In adjusted analyses, flares were more common, symptomatic, and/or longer-lasting in women and in those with worse non-flare symptoms, bladder hypersensitivity, and chronic overlapping pain conditions. In this foundational flare study, we found that pelvic pain and urological symptom flares were common, but variable in frequency and manifestation. We also identified subgroups of participants with more frequent, symptomatic, and/or longer-lasting flares for targeted flare management/prevention and further study.

Advances in application of functional magnetic resonance imaging in patients with painful temporomandibular disorders

Temporomandibular disorders (TMD), characterized by pain and dysfunction of the temporomandibular joint, are the most common chronic orofacial pain. However, the etiologies and pathologies of TMD related chronic pain are poorly understood. Functional magnetic resonance imaging (fMRI) measures brain activity by detecting changes associated with blood flow without invasiveness, and has been widely used in chronic pain research. We reviewed recent fMRI studies exploring the brain changes of patients with painful TMD to investigate the role of central nervous system in abnormal pain perception and impaired pain modulation, and to summarize the effects of splint therapy, in the hope of facilitating the clinical diagnosis and treatment of TMD.

Chronic Pain and Etiology of Psychological Disturbances

Objective: The aim of this study was to review the impact of a possible association between self- efficacy, symptom severity, pain intensity, depression, anxiety and catastrophizing on health- related quality of life among chronic pain patients. Background: A large number of people experience and live with various types of physiological-oriented chronic pain (CP) diseases. Lives of individuals who suffer from CP may alter in various ways. Particularly, in terms of health-related quality of life after diagnosis. Even though, there has been significant increase in chronic pain research, this area of research continues to offer patients significant health repercussions. Findings: This research has discovered that, there still, is an urgent need for improvements in regard to treatment and quality of chronic pain management care. A range of literatures assessed several aspects in which CP alters the patients’ lives, as well as its potential repercussions in the workplace, on the dynamic of patients’ families, and their social environments. Methods: An exploratory review of literature alongside the implementation of a small exemplary pilot study that was solely undertaken to help further validate the results that were acquired via review of literature. The data presented in the pilot study were drawn from purposive sampling and structured survey questionnaires. Participants of the pilot study: Thirty adults (&gt;18 years) diagnosed and currently living with various kinds of chronic physical non-cancer pain.

Does Spinal Cord Stimulation Really Influence Sleep?

To date, clinical pain research has typically used subjective questionnaires to assess effectiveness of treatment. However, in the near future, new technologies may provide us objective outcome measures as an alternative to self-report. The goal of this study is to compare subjective and objective sleep assessments in a population of failed back surgery syndrome (FBSS) patients, treated with spinal cord stimulation (SCS). Twenty-two patients diagnosed with FBSS received SCS. Sleep data was collected at three time point: prior to SCS implantation (B), one month after SCS (T1), and two months after SCS (T2). Sleep data measured by actigraphy provided objective sleep data and were compared to Pittsburgh sleep quality index (PSQI) scores. Agreement between sleep parameters, total sleep time (TST), sleep efficiency (SE), and sleep onset latency (SOL), was examined. Nineteen out of 22 patients completed the study. We identified significant differences between objective and subjective measurements for TST and SE at baseline and after two months of SCS, with patients underestimating both parameters on the PSQI in comparison to objective measurements. For SOL no significant differences were found, although patients subjectively overestimated SOL at B. The results about sleep measurements shown in this population of chronic pain patients, suggest that the subjective ratings scored worse than the objective measurements. Second, short-term SCS mainly seems to affect subjectively measured sleep parameters, especially SOL. This study shows the discrepancies between objective and subjective assessments in chronic pain research. Objective tools are indispensable for a correct assessment and treatment of sleep parameters. They are also playing a role as a biofeedback tool and are supporting the rehabilitation process.

PD20-07 PREDICTORS OF FEMALE SEXUAL DYSFUNCTION IN INTERSTITIAL CYSTITIS/BLADDER PAIN SYNDROME, OTHER CHRONIC PAIN CONDITIONS AND HEALTHY CONTROLS IN THE MAPP RESEARCH NETWORK

INTRODUCTION AND OBJECTIVES:Female sexual dysfunction (FSD) is associated with lower quality of life (QoL) in interstitial cystitis/bladder pain syndrome (IC/BPS). Our objectives were to: 1) compare the prevalence of FSD among IC/BPS, other non-urologic chronic pain conditions (positive controls, PCs) and healthy controls (HCs); 2) evaluate the role of psychosocial and urologic factors in FSD in all three cohorts; 3) correlate longitudinal changes in FSD with changes in IC/BPS symptoms.METHODS:Cross sectional analysis was performed on female participants in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network. FSD was defined as a score <26 on the Female Sexual Function Index (FSFI). Baseline data were compared by ANOVA and chi-squared tests. Multivariate logistic regression was used to assess associations between psychosocial variables [Self Esteem and Relationship (SEAR); Perceived Stress Scale (PSS); Hospital Depression and Anxiety Scale (HADS), International Perso...

A Culture-Independent Analysis of the Microbiota of Female Interstitial Cystitis/Bladder Pain Syndrome Participants in the MAPP Research Network.

We surveyed urine microbiota of females diagnosed with interstitial cystitis/bladder pain syndrome (IC/BPS) and matched control participants enrolled in the National Institutes of Health (NIH) Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network using the culture-independent methodology. Midstream urine specimens were analyzed with the Plex-ID molecular diagnostic platform that utilizes polymerase chain reaction–electrospray ionization–time-of-flight–mass spectrometry (PCR-ESI-TOF MS) to provide a comprehensive identification of bacterial and select fungal species. IC/BPS and control participants were evaluated for differences (presence, diversity, and abundance) in species and genus. Urine specimens obtained from 181 female IC/BPS and 182 female control participants detected a total of 92 species (41 genera). Mean (SD) species count was 2.49 (1.48) and 2.30 (1.28) among IC/BPS and control participants, respectively. Overall species composition did not significantly differ between IC/BPS and control participants at any level (p = 0.726 species level, p = 0.222 genus level). IC/BPS participants urine trended to an overabundance of Lactobacillus gasseri (p = 0.09) detected but had a lower prevalence of Corynebacterium compared with control participants (p = 0.002). The relative abundance data analysis mirrored the prevalence data differences with no significant differences in most species or genus abundance other than Lactobacillus gasseri and Corynebacterium (p = 0.08 and p = 0.001, respectively). No cause and/or effect conclusion can be drawn from this observation, but it suggests that a more comprehensive evaluation (vaginal, bowel, catheterized bladder and/or tissue-based specimens) of the lower urinary tract microbiota in IC/BPS patients is warranted.

(266) Impact of Opioid Analgesics on the Dynamic Functional Connectivity of Resting-State Brain Networks in Patients with Chronic Low Back Pain

Growing body of research has described iatrogenic consequences of prescription opioid use in chronic pain including hyperalgesia and impaired executive function. While changes in pain and behavior have been noted, little is known about the brain mechanisms that change with prescription opioid use in chronic pain. Here, we examined whether long-term opioid therapy altered whole-brain functional connectivity in patients with chronic low back pain (CLBP). We focused on dynamic functional connectivity (DFC) because connectivity patterns can be time-varying, and as such it can better capture brain function. Furthermore, DFC approach may be well suited for chronic pain research because chronic pain can fluctuate over time, and the static connectivity measures may not capture the overall intensity or chronicity of the pain (i.e., state vs trait pain). Using resting-state fMRI data of 10 CLBP patients on opioid (CLBP+; 5 males, mean age ± SD = 48.5 ± 14.8 years) and 10 matched opioid-naive CLBP patients (CLBP-, 5 males, mean age ± SD = 43.6 ± 12.6 years), we performed high-dimensional group independent component analysis (GICA; N = 75) and extracted thirty-six components as intrinsic connectivity networks (ICNs). DFC analysis of ICNs was carried out in GIFT software (Medical Image Analysis Lab, USA) with sliding time-window method and k-means clustering algorithm to categorize DFC by matching the time-windowed connectivity patterns (cluster centroids) to features in a finite set of connectivity patterns (states). Different dwell times for cluster states were observed in CLBP- vs CLBP+. Two-sample t-test further revealed different non-stationary, time-varying connectivity patterns particularly involving the default-mode, salience (insula and anterior cingulate cortex), subcortical (amygdala and hippocampus), and sensorimotor networks (p

(301) Youth with Functional Abdominal Pain Disorders Experience a Reduction in Anxiety after CBT Despite the Presence of Maternal Anxiety

Pediatric functional abdominal pain disorders (FAPD) are associated with increased rates of anxiety in affected youth and in their parents and child anxiety has been shown to adversely impact response to cognitive behavioral therapy (CBT) for pain. Novel CBT approaches targeting both pain and anxiety have demonstrated effectiveness in reducing symptoms in youth with FAPD (i.e., Aim to Decrease Anxiety in Pain Treatment [ADAPT]), though it is unknown how parental anxiety may impact treatment response. Parental anxiety may warrant further study given that anxiety often aggregates in families. The current study explored how maternal anxiety impacted changes in child anxiety following ADAPT versus treatment as usual. A total of 74 mother-child dyads participated in the 6-session randomized trial, with 51% (n=38) completing ADAPT. Maternal report of anxiety symptoms at baseline (Differential Abilities Scale, Anxiety Subscale) and child report of anxiety symptoms at baseline and following the trial were collected (Screen for Child Anxiety and Related Emotional Disorders, Generalized Anxiety Subscale). The ADAPT intervention moderated the relation between maternal anxiety and change in the child's anxiety symptoms (b=4.34, SE=1.56, t=2.79, p=.007). Probing this interaction revealed that maternal anxiety tended to relate to greater decreases in child anxiety only for those families in the ADAPT condition. Children assigned to the control group with more anxious mothers actually demonstrated increases in their anxiety symptoms over the course of the trial. Results reveal the effectiveness of ADAPT for potentially disrupting the intergenerational transmission of anxiety, which in turn may improve pain-related outcomes for youth with chronic pain conditions. Funded by American Pain Society Sharon S Keller Chronic Pain Research Grant (2015-2017) and Cincinnati Children's Hospital Place Outcomes Research Award. (Campo, Arch Pediatr Adolesc Med, 2007; Cunningham, J Pediatr, 2016; Cunningham, J Pediatr Gastroenterol Nutr, 2018; Eley, Am J Psychiatry, 2015)

Altered mesocorticolimbic functional connectivity in chronic low back pain patients at rest and following sad mood induction.

Depressive symptoms are common among individuals with chronic pain. Previous work suggests that chronic pain patients have difficulty regulating emotional responses, which is a risk factor for the development of major depressive disorder (MDD). Function of the mesocorticolimbic system, a neural network associated with reward processing, contributes to emotion regulation. This network's dysfunction has been described in chronic pain and MDD research and potentially underlies the relationship among emotion dysregulation, chronic pain, and MDD development. Given that mood induction paradigms have been used to measure emotion regulation, the present study examined intrinsic mesocorticolimbic functional connectivity (FC) after induced sad mood in individuals with and without chronic low back pain (cLBP). Thirty-three MDD-free individuals (17 cLBP) underwent resting-state scanning before and after sad memory-evoked mood induction. A Group [cLBP, healthy control (HC)] x Mood (Neutral, Sadness) repeated measures ANCOVA was conducted on seed-based FC data using a mesolimbic a priori region of interest. Interaction effects were identified in the orbital frontal cortex and inferior frontal gyrus [F(2,29) = 21.07, pFDR < .05. hp2= .5]. Whereas cLBP showed significantly greater FC between these two regions and the mesolimbic seed under neutral mood, FC among these regions increased in HC and decreased in cLBP under sad mood. Exploratory graph theory analyses further describe between-group differences in mesocorticolimbic network properties. Findings support previous literature describing mesocorticolimbic dysfunction in cLBP and demonstrate aberrant function in emotion regulation. Mesocorticolimbic dysfunction during emotion regulation might contribute to the development of certain depressive phenotypes in chronic pain patients.

What Affects the Completion of Ecological Momentary Assessments in Chronic Pain Research? An Individual Patient Data Meta-Analysis.

BackgroundEcological momentary assessment (EMA) involves repeated sampling of people’s current experiences in real time in their natural environments, which offers a granular perspective on patients’ experience of pain and other symptoms. However, EMA can be burdensome to patients, and its benefits depend upon patients’ engagement in the assessments.ObjectiveThe goal of this study was to investigate factors affecting EMA-completion rates among patients with chronic pain.MethodsThis individual patient data meta-analysis was based on 12 EMA datasets that examined patients with chronic noncancer-related pain (n=701). The EMA-completion rates were calculated on a daily basis for each patient. Multilevel models were used to test the following predictors of completion rates at different levels: within-patient factors (days into the study and daily pain level), between-patient factors (age, sex, pain diagnosis, and average pain level per person), and between-study EMA design factors (study duration, sampling density, and survey length).ResultsAcross datasets, an EMA-completion rate of 85% was observed. The strongest results were found for the between-patient factor age: Younger respondents reported lower completion rates than older respondents (P=.002). One within-patient factor, study day, was associated with completion rates (P<.001): over the course of the studies, the completion rates declined. The two abovementioned factors interacted with each other (P=.02) in that younger participants showed a more rapid decline in EMA completion over time. In addition, none of the other hypothesized factors including gender, chronic pain diagnoses, pain intensity levels, or measures of study burden showed any significant effects.ConclusionMany factors thought to influence the EMA-completion rates in chronic pain studies were not confirmed. However, future EMA research in chronic pain should note that study length and young age can impact the quality of the momentary data and devise strategies to maximize completion rates across different age groups and study days.

Quantitative assessment of nonpelvic pressure pain sensitivity in urologic chronic pelvic pain syndrome: a MAPP Research Network study.

Experimental pain sensitivity was assessed in individuals with urologic chronic pelvic pain syndrome (UCPPS) as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network. A series of computer-controlled pressure stimuli were delivered to the thumbnail bed, an asymptomatic site distant from the area of UCPPS pain that is considered to be indicative of overall body pain threshold. Stimuli were rated according to a standardized magnitude estimation protocol. Pain sensitivity in participants with UCPPS was compared with healthy controls and a mixed pain group composed of individuals with other chronic overlapping pain conditions, including fibromyalgia, chronic fatigue, and irritable bowel syndromes. Data from 6 participating MAPP testing sites were pooled for analysis. Participants with UCPPS (n = 153) exhibited an intermediate pain sensitivity phenotype: they were less sensitive relative to the mixed pain group (n = 35) but significantly more sensitive than healthy controls (n = 100). Increased pain sensitivity in patients with UCPPS was associated with both higher levels of clinical pain severity and more painful body areas outside the pelvic region. Exploratory analyses in participants with UCPPS revealed that pain sensitivity increased during periods of urologic symptom flare and that less pressure pain sensitivity at baseline was associated with a greater likelihood of subsequent genitourinary pain improvement 1 year later. The finding that individuals with UCPPS demonstrate nonpelvic pain hypersensitivity that is related to clinical symptoms suggests that central nervous system mechanisms of pain amplification contribute to UCPPS.

A narrative review of data collection and analysis guidelines for comparative effectiveness research in chronic pain using patient-reported outcomes and electronic health records.

Chronic pain is a widespread and complex set of conditions that are often difficult and expensive to treat. Comparative effectiveness research (CER) is an evolving research method that is useful in determining which treatments are most effective for medical conditions such as chronic pain. An underutilized mechanism for conducting CER in pain medicine involves combining patient-reported outcomes (PROs) with electronic health records (EHRs). Patient-reported pain and mental and physical health outcomes are increasingly collected during clinic visits, and these data can be linked to EHR data that are relevant to the treatment of a patient’s pain, such as diagnoses, medications ordered, and medical comorbidities. When aggregated, this information forms a data repository that can be used for high-quality CER. This review provides a blueprint for conducting CER using PROs combined with EHRs. As an example, the University of Pittsburgh’s patient outcomes repository for treatment is described. This system includes PROs collected via the Collaborative Health Outcomes Information Registry software and cross-linked data from the University of Pittsburgh Medical Center EHR. The requirements, best practice guidelines, statistical considerations, and caveats for performing CER with this type of data repository are also discussed.