To prospectively validate the chronic orchialgia symptom index (COSI), a newly created instrument with 12 questions in 3 domains (pain, sexual symptoms and quality of life).

The COSI was given to 170 men with chronic orchialgia at 2 institutions. Seventy-eight men repeated the COSI before therapy and 42 repeated it after surgical therapy. Data was analyzed for test/retest internal reliability, internal consistency, floor and ceiling effects, construct validity, responsiveness and linear regression of all questions including age, duration, and prior surgeries.

The 170 men had a mean age of 44.3 (range 18-82) and median symptom duration of 24 months (3-420). About 22.4% had prior vasectomy, 12.4% had hernia repair, and 12.9% had other prior surgery. Mean total COSI was 20.0±7.7 (range 1-37) with subscores of pain 9.1±3.5 (0-17), sexual symptoms 1.82±1.5 (0-5) and quality of life 9.0±4.0 (0-15). Test/retest reliability was high with mean retest total score of 21.2±7.9 and intraclass correlation coefficient of 0.82. Internal consistency by Cronbach's alpha was 0.86. There were no floor or ceiling effects for total score. Construct validity showed all items contributed to a good fit model (P = .001). Patient age, duration, and prior surgeries did not influence COSI. Finally, the COSI was responsive to improvement after therapy (mean after treatment 13.5±9.8, P = .00001).

COSI is a valid and clinically relevant symptom index to assess severity of orchialgia symptoms and response to therapy in this challenging patient population.