Validation of a quality-of-life scale for women with bladder pain syndrome/interstitial cystitis

Purpose To validate a disease-specific scale to measure the impact of symptoms of bladder pain syndrome/interstitial cystitis (BPS/IC), a condition that affects up to 6.5% of US women. Methods Participants were drawn from the RAND Interstitial Cystitis Epidemiology (RICE) Study, a telephone probability survey of 146,231 US households. Women who met RICE BPS/IC symptom criteria (n = 3,397) completed the 6-item RAND Bladder Symptom Impact scale (RICE BSI-6). The RICE BSI-6 was adapted from a scale used to assess the impact of diabetes on life and sexuality and modified based on expert input on face validity and focus group work; items specific to diabetic symptoms were eliminated. Validated scales of symptom severity, mental-and physical-health-related quality of life (QoL), depression, coping, and perceived control were used to assess convergent validity. Results The RICE BSI-6 (α = 0.92) was significantly related to greater symptom severity, worse general mentaland physical-health-related QoL, more severe depression symptoms, and lower perceived control over life in general and over BPS/IC symptoms (P values < .05). It was also associated with less use of distancing coping (P < .05). Conclusion The RICE BSI-6 shows excellent internal consistency and strong convergent validity. It can be used to examine the effects of psychosocial and treatment interventions on QoL among women with BPS/IC.