Validation of the Spanish version of the Bladder Pain/Interstitial Cystitis-Symptom Score (BPIC-SS) questionnaire. A useful tool for the diagnosis of bladder pain syndrome.

OBJECTIVES: Validation of the Spanish version of the Bladder Pain/Interstitial Cystitis-Symptom Score (BPIC-SS) questionnaire to evaluate its utility for the diagnosis of Bladder Pain Syndrome (BPS) patients in the Female and Urodynamics Urology Functional Units in Spain.

MATERIAL AND METHODS: The Spanish adaptation of the BPIC-SS questionnaire was evaluated in 243 BPS patients. EQ-5D-5L, Patient Perception of Bladder Condition (PPBC) and global impression questionnaire (CGI-S) were collected. Consistency, test-retest reliability in patients without clinical changes at 15 days, criterion validity and sensitivity to change were assessed in BPS patients with clinical changes at 6 months. The cut-off point for discriminating BPS patients from other similar pathologies (Hyperactive Bladder or other urinary pathologies) was analysed using ROC curve.

RESULTS: Mean (SD) BPIC-SS score (0-38) was 16.2 (12.0) points. Cronbach's alpha was 0.92 and intraclass coefficient correlation (ICC) was 0.82, ranging from 0.5-0.9 per item. Convergent validity determined a Spearman correlation of 0.63 with PPBC and -0.40 with EQ-5D-5L Visual Analogue Scale (VAS) and the effect size obtained in patients who improved their clinical status was 1.9. A score greater than or equal to 12 points in the BPIC-SS has been established as the best cut-off point for the diagnosis of BPS (87.5% sensitivity and 91.9% specificity).

CONCLUSIONS: The Spanish version of the BPIC-SS is a valid and reliable instrument for the diagnosis and follow-up of patients with BPS in Spain.