Core Lower Urinary Tract Symptom Score (CLSS) questionnaire: A reliable tool in the overall assessment of lower urinary tract symptoms

Objectives: To identify the symptoms of higher relevance in patients complaining of lower urinary tract symptoms (LUTS). Methods: A questionnaire covering 25 LUTS as defined by the International Continence Society (ICS) terminology committee was administered to 1000 adults complaining of LUTS and 360 not complaining (controls). Symptoms were defined as 'highly relevant (core LUTS)' when indicated by at least 25% of symptomatic patients with nine common diseases/conditions as one of the three symptoms that had a significant impact on their daily life. Results: Ten symptoms (daytime frequency, nocturia, urgency, urgency incontinence, stress incontinence, slow urinary stream, straining, feeling of incomplete emptying, bladder pain, and urethral pain) were selected as being of high relevance. Core LUTS all showed significantly higher scores in the symptomatic patients than in the controls and they were not correlated with other more prevalent symptoms. The Core LUTS score (CLSS) questionnaire derived from these 10 symptoms was confirmed as showing test-retest reliability. Conclusions: Of 25 LUTS defined by the ICS committee, 10 symptoms were selected as core LUTS. The CLSS, a questionnaire for core LUTS, provides an overall assessment of relevant symptoms without significant omissions. It might be useful for new patients, those with multiple diseases, and those without a definite diagnosis, as well as before and after interventions that may cause other symptoms.