Hypothesis / aims of study
Chronic pelvic pain (CPP) patients have been shown to have a mean of 2.4 associated co-morbid painful conditions such as gastroesophageal reflux disease (GERD), migraine, irritable bowel syndrome (IBS), lower back pain, and fibromyalgia (FM) . It is unclear exactly which patient factors, such as patient demographics, or the presence or absence or number of comorbid conditions, contribute to the development of refractory chronic pain. Catastrophizing, an individual's predisposition to amplify perceived risk or sensation of pain, has been demonstrated to prolong and increase sensitivity and severity to pain, cause depression and anxiety, be associated with greater health care costs and contribute to worse outcomes including, potentially, early mortality [2-3]. This study seeks to elucidate the role of catastrophization on pain perception in CPP patients.
Study design, materials and methods
Pelvic pain referrals across 11 specialties were screened by a nurse navigator at our institution. Patients completed full histories, symptom screeners, and standardized questionnaires including genitourinary pain index (GUPI), patient health questionnaire (PHQ-4) for anxiety and depression, interstitial cystitis symptom index (ICSI), and pelvic floor distress inventory (PFDI-20). Scores, number of comorbidities, and our simple intake screener were compared to the pain catastrophizing scale (PCS) by linear regression. “Extreme catastrophizing” (score >=30), which is associated with worse outcomes, was also analyzed.
188 patients mean age of 41.7, 23 males. Mean of 4 comorbidities. Higher number of pain comorbidities correlated to PCS (p<0.001) as did more affirmative responses on the intake symptom screener (p<0.001). Mean scores at intake were: GUPI 29.1, PHQ-4 anxiety 2.5 and depression 2.2, ICSI 7.7, and PFDI-20 102.5. Higher scores on GUPI (p<0.001), PFDI-20 (p<0.001), ICSI (p<0.001), anxiety (p<0.001), and depression (p<0.001) all had positive correlations with the PCS.
81/184 (44%) were extreme catastrophizers, who scored significantly worse on all standardized measures when compared to non-extreme catastrophizers. Mean scores for non-extreme versus extreme catastrophizers respectively: GUPI (M=25.7 SD=6.8 v M=32.7 SD=7.5 p<0.001), ICSI (M=6.5, SD=4.7 v M=9.4, SD=5.8 p<0.001), PFDI (M=88.8, SD 52 v M=121.1, SD=62.8 p<0.0001), PHQ4 anxiety (M=1.7, SD=2.0 v M=3.6, SD=2.1 p<0.001) and depression (M=1.4 SD=1.6 v M=3.3, SD=2.0, p<0.001). The number of pain comorbidities was not significant predictor of extreme catastrophization (3.5 v 3.7 p=0.22).
Interpretation of results
Our study agrees with the growing body of literature correlating higher catastrophization with worse outcomes. Higher scores on pelvic symptoms, anxiety, and depression (GUPI, PFD10, ICSI, and PHQ-4) standardized measures predict more catastrophizing in pelvic pain patients. The more comorbidities, the higher the amount of catastrophization. In our study, for every 1 comorbidity there is an increase in PCS score by 2.3 points, which is a 15% of the total score on the PCS (2.3/52 points). These measures, as well as characterization of the number of pelvic symptoms on clinical screener and historic pain comorbidities help identify patients with catastrophizing.
When compared to non-extreme catastrophizers, extreme catastrophizers score significantly higher on all standardized measures suggesting that CPP patients who are extreme catastrophizers have worse outcomes and experience higher levels of pain. Catastrophizing is higher in those with more comorbid diagnoses by patient-reported history but this association is not maintained in extreme catastrophizing. Explanations could include a threshold over which increasing comorbidities have no additional effect, or the lack of further effects could be related to the fact that the historical data collection was patient reported and not as well controlled as the validated symptom scores.
Higher standardized scores on GUPI, PFDI-20, ICSI, PHQ-4 and number of comorbidities measures more catastrophizing in pelvic pain patients and may help predict patients who catastrophize. As clinicians, it is important to screen patients for catastrophizing and recognize that these pelvic pain patients tend to have worse symptoms, quality of life, more depression and anxiety, and to experience more pain. It is important to recognize when pain extends beyond the bladder, engaging collaborators in a multidisciplinary approach and including counseling and adjunctive therapies.