Mapping of Pain Phenotypes in Female Patients with Bladder Pain Syndrome/Interstitial Cystitis and Controls.

Abstract

BACKGROUND: Many bladder pain syndrome/interstitial cystitis (BPS/IC) patients report multiple pain locations outside the pelvis. No research has examined pain using a whole-body diagram, pain-associated adjustment factors, or the impact of pain in multiple body areas on patients' quality of life (QoL). OBJECTIVE: Compare and contrast pain in BPS/IC patients and controls using a whole-body diagram (visible body areas). Examine the association between patient adjustment factors and greater number of body pain areas (pain phenotypes). DESIGN, SETTING, AND PARTICIPANTS: Validated questionnaires were collected from diagnosed, tertiary-care, outpatient, female BPS/IC patients (n=193) and age-matched controls (n=115). Scales included a body pain area diagram, demographics/history, pain severity, BPS/IC symptoms, pain, depression, catastrophizing, and QoL. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Cross-tabulation and analysis of variance models addressed the patient and control differences. RESULTS AND LIMITATIONS: Patients reported more pain than controls in all reported body areas. Four pain phenotypes were created based on increasing counts of body locations (BPS/IC only, BPS/IC+plus 1-3 additional locations, BPS/IC plus 4-9, BPS/IC ≥10). Patients reported more body pain locations, pain, urinary symptoms, depression, catastrophizing, and diminished QoL than controls. The increased-pain phenotype was associated with poorer psychosocial adjustment and diminished physical QoL, but catastrophizing and low scores for mental QoL remained stable across all patient groups. This study was cross-sectional, relying on correlation-based analyses, thus causality cannot be established. CONCLUSIONS: Patients reported numerous systemic pain symptoms outside the areas associated with the bladder/pelvic region, and increased numbers of body pain sites were associated with poorer patient outcomes (ie, pain severity, depression). This study illustrates the significant negative impact of pain on patient adjustment in BPS/IC. These findings suggest that clinicians carefully consider pain location distributions and the potential impact of body pain phenotypes during patient evaluation and treatment planning.