Construct validity of an instrument to measure neuropathic pain in women with bladder pain syndrome.

ABSTRACT

AIMS: To determine the construct validity of an instrument to measure neuropathic pain in women with bladder pain syndrome (BPS). Our hypothesis is that neuropathic, bladder, and bowel pain represent different constructs in women with BPS. METHODS: Secondary planned analysis of a prospective cross-sectional study of 150 women with BPS. The relationship between neuropathic pain, urinary, and bowel symptoms was assessed. RESULTS: The correlation of the total neuropathic pain score with total urinary and bowel symptom scores was low to moderate (r = 0.28-0.49). The correlation of specific neuropathic pain items with bladder and bowel pain was also low to moderate (r = 0.12-0.36). Women with neuropathic pain had significantly higher scores for urinary urgency, bladder pain, abdominal pain, diarrhea, and constipation than women with non-neuropathic pain (all P < 0.0001). CONCLUSION: Somatosensory neuropathic pain and "visceral" bladder and bowel pain represent separate but related constructs in women with BPS.