The association of Incontinence Symptom Index scores with urethral function and support

Objective: The objective of this study was to establish categories of symptom severity based on Incontinence Symptom Index (ISI) scores and to show how these categories are associated with urethral function and support. Study Design: Women with stress incontinence (n = 97) and asymptomatic controls (n = 98) completed the ISI. Asymptomatic women's scores were between 0 and 6; this range was designated as absent/mild (n = 104). The median score for symptomatic women was 16; scores from 7 to 16 (n = 50) were designated as moderate, and scores of 17 or greater (n = 40) were designated as severe. Results: Urethral function differed in women with mild, moderate, and severe scores: Valsalva leak point pressure (162.3 vs 123.5 vs 101.9 cm H₂O; P = .001), cough leak point pressure (202.0 vs 163.0 vs 134.3 cm H₂O; P = .001), and maximum urethral closure pressure (69.1 vs 44.1 vs 35.3 cm H₂O; P = .001). Loss of urethrovesical support (point Aa: -1.0 vs -0.6 vs -0.5 cm; P = .004) was found in women with moderate and severe symptoms, compared with those with mild symptoms. Conclusion: Categories of symptom severity assessed by the ISI are associated with urethral function and support.