Introduction

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a prevalent, chronic pelvic pain condition largely unresponsive to medical interventions. Psychosocial risk factors are associated with poor outcomes in CP/CPPS, but have not been examined for their intervening roles between pain and reduced quality of life (QoL). This study aimed to determine if psychosocial risk factors (i.e., patient coping and catastrophizing) mediate the association between pain and QoL.

Methods

Using a cross sectional design, 175 men with CP/CPPS (mean age 46.83; SD 10.86) were recruited from tertiary care urology clinics and completed questionnaires on demographics, pain, QoL, pain coping, depression, and catastrophizing. An exploratory factor analysis was conducted and aggregate factor scores were examined to improve the amount of meaningful measurement to be used in multiple mediations. The models specified multiple risk factors as mechanisms between pain and both physical and mental QoL as the primary outcome measurements.

Results

Four aggregate psychosocial factor scores were produced from the psychosocial measures (i.e., illness and wellness-focused behavioural coping, depression and catastrophizing). Illness-focused coping partially mediated the relationship between pain and physical QoL. However, catastrophizing and illness-focused coping fully mediated the relation between pain and mental QoL, showing the association between pain and mental QoL was no longer significant when catastrophizing and illness-focused coping were in the model.

Conclusion

Psychosocial factors function as mechanisms between higher pain and they are associated diminished mental QoL. These results introduce illness-focused coping as an important biopsychosocial target in CP/CPPS management.

Urologic chronic pelvic pain syndrome (UCPPS), which encompasses interstitial cystitis/bladder pain syndrome and chronic prostatitis/chronic pelvic pain syndrome, is characterized by chronic pain in the pelvic region or genitalia that is often accompanied by urinary frequency and urgency. Despite considerable research, no definite aetiological risk factors or effective treatments have been identified. The Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network uses a novel integrated strategy to characterize UCPPS as a systemic disorder that potentially involves multiple aetiologies. The first phase, MAPP I, included >1,000 participants who completed an intensive baseline assessment followed by a 12-month observational follow-up period. MAPP I studies showed that UCPPS pain and urinary symptoms co-vary, with only moderate correlation, and should be evaluated separately and that symptom flares are common and can differ considerably in intensity, duration and influence on quality of life. Longitudinal clinical changes in UCPPS correlated with structural and functional brain changes, and many patients experienced global multisensory hypersensitivity. Additionally, UCPPS symptom profiles were distinguishable by biological correlates, such as immune factors. These findings indicate that patients with UCPPS have objective phenotypic abnormalities and distinct biological characteristics, providing a new foundation for the study and clinical management of UCPPS.

Chronic overlapping pain conditions (COPCs) are characterized by aberrant central nervous system processing of pain. This "centralized pain" phenotype has been described using a large and diverse set of symptom domains, including the spatial distribution of pain, pain intensity, fatigue, mood imbalances, cognitive dysfunction, altered somatic sensations, and hypersensitivity to external stimuli. Here, we used 3 cohorts, including patients with urologic chronic pelvic pain syndrome, a mixed pain cohort with other COPCs, and healthy individuals (total n = 1039) from the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network to explore the factor structure of symptoms of centralized pain. Using exploratory and confirmatory factor analysis, we identified 2 general factors in all 3 cohorts, one characterized by a broad increased sensitivity to internal somatic sensations,environmental stimuli, and diffuse pain, termed Generalized Sensory Sensitivity, and one characterized by constitutional symptoms-Sleep, Pain, Affect, Cognition, Energy (SPACE). Longitudinal analyses in the urologic chronic pelvic pain syndrome cohort found the same 2-factor structure at month 6 and 1 year, suggesting that the 2-factor structure is reproducible over time. In secondary analyses, we found that Generalized Sensory Sensitivity particularly is associated with the presence of comorbid COPCs, whereas SPACE shows modest associations with measures of disability and urinary symptoms. These factors may represent an important and distinct continuum of symptoms that are indicative of the centralized pain phenotype at high levels. Future research of COPCs should accommodate the measurement of each factor.

Purpose

The purpose of this study was to create symptom indexes, that is scores derived from questionnaires to accurately and efficiently measure symptoms of interstitial cystitis/bladder pain syndrome and chronic prostatitis/chronic pelvic pain syndrome, collectively referred to as urological chronic pelvic pain syndromes. We created these indexes empirically by investigating the structure of symptoms using exploratory factor analysis.

Materials and methods

As part of the MAPP (Multi-Disciplinary Approach to the Study of Chronic Pelvic Pain) Research Network 424 participants completed questionnaires, including GUPI (Genitourinary Pain Index), ICSI (Interstitial Cystitis Symptom Index) and ICPI (Interstitial Cystitis Problem Index). Individual items from questionnaires about bladder and pain symptoms were evaluated by principal component and exploratory factor analyses to identify indexes with fewer questions to comprehensively quantify symptom severity. Additional analyses included correlating symptom indexes with symptoms of depression, which is a known comorbidity of patients with pelvic pain.

Results and conclusions

Exploratory factor analyses suggested that the 2 factors pain severity and urinary severity provided the best psychometric description of items in GUPI, ICSI and ICPI. These factors were used to create 2 symptom indexes for pain and urinary symptoms. Pain, but not urinary symptoms, was associated with symptoms of depression on multiple regression analysis, suggesting that these symptoms may impact patients with urological chronic pelvic pain syndromes differently (B ± SE for pain severity = 0.24 ± 0.04, 95% CI 0.16-0.32, β = 0.32, p <0.001). Our results suggest that pain and urinary symptoms should be assessed separately rather than combined into 1 total score. Total scores that combine the separate factors of pain and urinary symptoms into 1 score may be limited for clinical and research purposes.

Three categories of pain mechanisms are recognized as contributing to pain perception: nociceptive, neuropathic, and nociplastic (ie, central nervous system augmented pain processing). We use validated questionnaires to identify pain mechanisms in Urologic Chronic Pelvic Pain Syndrome (UCCPS) patients (n = 568, female = 378, male = 190) taking part in the Symptom Patterns Study of the Multidisciplinary Approach to the study of chronic Pelvic Pain Research Network. A cutoff score of 12 on the painDETECT questionnaire (-1 to 38) was used to classify patients into the neuropathic category while the median score of 7 on the fibromyalgia survey criteria (0-31) was used to classify patients into the nociplastic category. Categories were compared on demographic, clinical, psychosocial, psychophysical and medication variables. At baseline, 43% of UCPPS patients were classified as nociceptive-only, 8% as neuropathic only, 27% as nociceptive+nociplastic, and 22% as neuropathic+nociplastic. Across outcomes nociceptive-only patients had the least severe symptoms and neuropathic+nociplastic patients the most severe. Neuropathic pain was associated with genital pain and/or sensitivity on pelvic exam, while nociplastic pain was associated with comorbid pain conditions, psychosocial difficulties, and increased pressure pain sensitivity outside the pelvis. A self-report method classifying individuals on pain mechanisms reveals clinical differences that could inform clinical trials and novel targets for treatment. PERSPECTIVE: This article presents differences in clinical characteristics based on a simple self-report method of classifying pain mechanisms for Urologic Chronic Pelvic Pain Syndrome patients. This method can be easily applied to other chronic pain conditions and may be useful for exploring pathophysiology in pain subtypes.

Background

The "Multidisciplinary Approach to the Study of Chronic Pelvic Pain" (MAPP) Research Network was established by the NIDDK to better understand the pathophysiology of urologic chronic pelvic pain syndromes (UCPPS), to inform future clinical trials and improve clinical care. The evolution, organization, and scientific scope of the MAPP Research Network, and the unique approach of the network's central study and common data elements are described.

Methods

The primary scientific protocol for the Trans-MAPP Epidemiology/Phenotyping (EP) Study comprises a multi-site, longitudinal observational study, including bi-weekly internet-based symptom assessments, following a comprehensive in-clinic deep-phenotyping array of urological symptoms, non-urological symptoms and psychosocial factors to evaluate men and women with UCPPS. Healthy controls, matched on sex and age, as well as "positive" controls meeting the non-urologic associated syndromes (NUAS) criteria for one or more of the target conditions of Fibromyalgia (FM), Chronic Fatigue Syndrome (CFS) or Irritable Bowel Syndrome (IBS), were also evaluated. Additional, complementary studies addressing diverse hypotheses are integrated into the Trans-MAPP EP Study to provide a systemic characterization of study participants, including biomarker discovery studies of infectious agents, quantitative sensory testing, and structural and resting state neuroimaging and functional neurobiology studies. A highly novel effort to develop and assess clinically relevant animal models of UCPPS was also undertaken to allow improved translation between clinical and mechanistic studies. Recruitment into the central study occurred at six Discovery Sites in the United States, resulting in a total of 1,039 enrolled participants, exceeding the original targets. The biospecimen collection rate at baseline visits reached nearly 100%, and 279 participants underwent common neuroimaging through a standardized protocol. An extended follow-up study for 161 of the UCPPS participants is ongoing.

Discussion

The MAPP Research Network represents a novel, comprehensive approach to the study of UCPPS, as well as other concomitant NUAS. Findings are expected to provide significant advances in understanding UCPPS pathophysiology that will ultimately inform future clinical trials and lead to improvements in patient care. Furthermore, the structure and methodologies developed by the MAPP Network provide the foundation upon which future studies of other urologic or non-urologic disorders can be based.

Trial registration

ClinicalTrials.gov identifier: NCT01098279 "Chronic Pelvic Pain Study of Individuals with Diagnoses or Symptoms of Interstitial Cystitis and/or Chronic Prostatitis (MAPP-EP)". http://clinicaltrials.gov/show/NCT01098279.

Purpose

We used MAPP data to identify participants with urological chronic pelvic pain syndromes only or a chronic functional nonurological associated somatic syndrome in addition to urological chronic pelvic pain syndromes. We characterized these 2 subgroups and explored them using 3 criteria, including 1) MAPP eligibility criteria, 2) self-reported medical history or 3) RICE criteria.

Materials and methods

Self-reported cross-sectional data were collected on men and women with urological chronic pelvic pain syndromes, including predominant symptoms, symptom duration and severity, nonurological associated somatic syndrome symptoms and psychosocial factors.

Results

Of 424 participants with urological chronic pelvic pain syndromes 162 (38%) had a nonurological associated somatic syndrome, including irritable bowel syndrome in 93 (22%), fibromyalgia in 15 (4%), chronic fatigue syndrome in 13 (3%) and multiple syndromes in 41 (10%). Of 233 females 103 (44%) had a nonurological associated somatic syndrome compared to 59 of 191 males (31%) (p = 0.006). Participants with a nonurological associated somatic syndrome had more severe urological symptoms and more frequent depression and anxiety. Of 424 participants 228 (54%) met RICE criteria. Of 228 RICE positive participants 108 (47%) had a nonurological associated somatic syndrome compared to 54 of 203 RICE negative patients (28%) with a nonurological associated somatic syndrome (p < 0.001).

Conclusions

Nonurological associated somatic syndromes represent important clinical characteristics of urological chronic pelvic pain syndromes. Participants with a nonurological associated somatic syndrome have more severe symptoms, longer duration and higher rates of depression and anxiety. RICE positive patients are more likely to have a nonurological associated somatic syndrome and more severe symptoms. Because nonurological associated somatic syndromes are more common in women, future studies must account for this potential confounding factor in urological chronic pelvic pain syndromes.

Purpose

We examined symptom variability in men and women with urological chronic pelvic pain syndrome. We describe symptom fluctuations as related to early symptom regression and its effect on estimated 1-year symptom change. We also describe a method to quantify patient specific symptom variability.

Materials and methods

Symptoms were assessed biweekly in 424 subjects with urological chronic pelvic pain syndrome during 1 year. To evaluate the impact of early symptom regression subjects were classified as improved, no change or worse according to the rate of change using 1) all data, 2) excluding week 0 and 3) excluding weeks 0 and 2. Patient specific, time varying variability was calculated at each interval using a sliding window approach. Patients were classified as high, medium or low variability at each time and ultimately as high or low variability overall based on the variability for the majority of contacts.

Results

Prior to excluding early weeks to adjust for early symptom regression 25% to 38% and 5% to 6% of patients were classified as improved and worse, respectively. After adjustment the percent of patients who were improved or worse ranged from 15% to 25% and 6% to 9%, respectively. High and low variability phenotypes were each identified in 25% to 30% of participants.

Conclusions

Patients with urological chronic pelvic pain syndrome show symptom variability. At study enrollment patients had worse symptoms on average, resulting in a regression effect that influenced the estimated proportion of those who were improved or worse. Prospective studies should include a run-in period to account for regression to the mean and other causes of early symptom regression. Further, symptom variability may be quantified and used to characterize longitudinal symptom profiles of urological chronic pelvic pain syndrome.