Original Article: Clinical Investigation
Core Lower Urinary Tract Symptom Score (CLSS) questionnaire: A reliable tool in the overall assessment of lower urinary tract symptoms
Yukio Homma md, Department of Urology, Tokyo University Hospital, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-8655, Japan. Email: email@example.com
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.
Assessment of lower urinary tract symptoms (LUTS) is essential both for making a diagnosis and for evaluating the response of lower urinary tract disorders to treatment in men1 and women.2 LUTS are commonly assessed by asking patients to complete a symptom questionnaire. Examples of such questionnaires include the International Prostate Symptom Score (IPSS),3 the International Continence Society (ICS)-male4 and the short form of the ICS-male5 for patients with benign prostatic hyperplasia (BPH); the Incontinence Impact Questionnaire6 and the International Consultation on Incontinence Questionnaire (ICIQ)7 for patients with urinary incontinence; the Chronic Prostatitis Symptom Score for patients with chronic prostatitis8; O'Leary & Sant's Symptom Index9 ; the Pain Urgency Frequency score10 for patients with interstitial cystitis; and the Urgency Perception Scale,11 the Indevus Urgency Severity Scale,12 or the Overactive Bladder Symptom Score13 for patients with overactive bladder (OAB). The International Consultation on Incontinence Modular Questionnaire (ICIMQ) comprises multiple questionnaires that cover a wide range of diseases/conditions/symptoms of the lower urinary tract.14 These questionnaires have been confirmed as displaying face validity, reliability, internal consistency, criterion validity, and sensitivity to the effects of treatment.
Use of such questionnaires in the clinical setting is associated with various difficulties, however. First, the correct diagnosis may not be obvious initially. Applying a disease-specific questionnaire based on the physician's presumed diagnosis may lead to overlooking other important symptoms that are not included in the questionnaire. Second, patients often have more than one disease. How are the overall symptoms to be evaluated for patients with multiple diagnoses? Third, a new disease/condition may develop incidentally or as an adverse event related to therapy, but assessment using a questionnaire designed for the original disease may be unable to capture the overall impact of treatment. For example, a high score of IPSS (a specific questionnaire for BPH) in male LUTS patients would automatically indicate a diagnosis and treatment of BPH, ignoring possible coexisting incontinence or pain symptoms. IPSS alone could not evaluate LUTS properly because it includes no questions on incontinence and pain. Employing a symptom tool for OAB or prostatitis based on a suspicion of these diseases may be necessary. To overcome problems of current symptom questionnaires, a questionnaire that can allow overall assessment of LUTS is needed. The ICIQ-MLUTS and ICIQ-FLUTS were designed to assess a variety of LUTS in a non-disease-specific manner for men and women, respectively.14 However, these questionnaires may be too extensive and partly inconsistent with terminology defined by the ICS standardization committee.15 In the present study, we attempted to select important or core symptoms from the symptom panel of the ICS terminology report, and suggested a questionnaire for their assessment.
Questionnaire for ICS Symptom Panel
A comprehensive questionnaire was devised that covered the following 25 LUTS defined by the standardization report:15 increased daytime frequency, nocturia, urgency, urgency incontinence, stress incontinence, nocturnal enuresis, continuous incontinence, other types of incontinence, increased bladder sensation, reduced bladder sensation, absence of bladder sensation, slow stream, splitting or spraying of the stream, intermittency, hesitancy, straining, terminal dribble, feeling of incomplete emptying, post-micturition dribble, bladder pain, urethral pain, vulval pain, scrotal pain (for men only), perineal pain, and pelvic pain. Symptoms were scored according to their frequency (0: never, 1: rare, 2: sometimes, and 3: often) and their severity (0: none, 1: slight, 2: moderate, and 3: severe). The frequency of voiding was scored as follows: 0 (≤7 times), 1 (8–10 times), 2 (11–14 times), 3 (≥15 times) for the daytime, as well as 0 (0 times), 1 (1 time), 2 (2–3 times), and 3 (≥4 times) for the nighttime. Each subject was also asked to choose up to three symptoms that he/she considered to have a significant impact on daily life. The understandability and reproducibility of the questionnaire were confirmed by a preliminary study involving 15 male patients (mean age: 65.3 years) and 14 female patients (mean age: 68.4 years) who presented with LUTS.
Data collection and analysis
In study 1, the questionnaire was administered to unselected consecutive adult patients attending the authors' hospitals for the first time. Symptom scores were examined by basic statistics, including inter-symptom correlations (Spearman's r values) and intra-symptom symmetry of the frequency and severity scores (kappa analysis). Detection of significant asymmetry by kappa analysis (P < 0.05) suggested that a question about the frequency of a symptom could not be substituted for a question about its severity or vice versa. In study 2, additional patients were recruited to obtain a minimum sample size of 40 for each of nine common diseases (OAB, underactive bladder, interstitial cystitis, bacterial cystitis, BPH, chronic prostatitis, acute prostatitis, urethritis, and stress incontinence). The diagnosis was a clinical diagnosis. The subjects were asked to choose up to three symptoms that had a significant impact on daily life. Both the questionnaire for the significant symptoms and the quality of life (QOL) index of the IPSS3 were examined for reliability by repeating these assessments after a 2-week interval without treatment. This study was approved by the ethical committees of the participating institutions. Mr. Takashi Ando (Cronova, Tokyo) served as the statistical consultant.
In study 1, a total of 800 subjects were assessed, including 440 patients complaining of LUTS and 360 controls who presented to hospital for reasons unrelated to LUTS (Table 1). The mean scores for all symptoms were higher in the patients with LUTS than the controls, but the difference was not significant (P > 0.05) for seven symptoms (nocturnal enuresis, other types of incontinence, continuous incontinence, absence of bladder sensation, spraying, terminal dribble, and post-micturition dribble). The frequency scores of seven pairs of symptoms (nocturnal enuresis + continuous incontinence, other types of incontinence + continuous incontinence, absence of bladder sensation + reduced bladder sensation, hesitancy + straining, terminal dribble + intermittency, scrotal pain + perineal pain, and pelvic pain + bladder pain; the scores for latter symptoms were higher) were significantly correlated with the Spearman's r > 0.5. Only increased bladder sensation showed asymmetry between the responses with regard to frequency and severity.
Table 1. Demographic data for the subjects
|Control||360 (266/94)||52.7 (52.7/52.5)||360 (266/94)||52.7 (52.7/52.5)|
|Overactive bladder||101 (35/66)||64.4 (67.1/63.0)||253 (104/149)||64.7 (67.9/62.5)|
|Underactive bladder||17 (10/7)||58.2 (55.8/61.7)||58 (30/28)||58.2 (57.4/59.0)|
|Interstitial cystitis||13 (1/12)||56.3||51 (5/46)||57.6 (53.2/58.1)|
|Bacterial cystitis||68 (2/66)||42.0||144 (5/139)||44.1 (52.4/43.8)|
|Benign prostatic hyperplasia||144||70.0||261||70.4|
|Prostatic cancer||24||71.4|| || |
|Urethritis||22 (21/1)||30.6||46 (46/0)||32.1|
|Stress urinary incontinence||19 (1/18)||55.9||83 (3/80)||57.9 (65.9/57.6)|
Study 2 involved 1000 symptomatic subjects and 360 controls (Table 1). Ten symptoms (increased daytime frequency, nocturia, urgency, urgency incontinence, stress incontinence, slow urinary stream, straining, feeling of incomplete emptying, bladder pain, and urethral pain) were chosen as having a significant impact by >25% of the patients with nine common urinary tract diseases (Table 2). These 10 symptoms (core LUTS) were used to create the Core Lower urinary tract Symptom Score (CLSS) questionnaire (Table 3). Because none of the 10 core LUTS showed significant asymmetry between the responses to questions about frequency and severity, only frequency questions were included to simplify the questionnaire. Test-retest reliability was examined in 45 patients (12 with OAB, six with underactive bladder, four with interstitial cystitis, 12 with BPH, five with chronic prostatitis, and six with stress incontinence). The weighted kappa coefficient was 0.75 to 0.90 for the individual scores and 0.82 for the total score of the CLSS. It was 0.81 for the QOL index of the IPSS.
Table 2. Symptoms chosen as having a significant impact on daily life by patients with nine common diseases (%)
Table 3. Core Lower urinary tract Symptom Score (CLSS) Questionnaire : Please circle the number that applies best to your urinary condition during the last week.
|How many times do you typically urinate from waking in the morning until sleeping at night?||0||1||2||3|
|How many times do you typically urinate from sleeping at night until waking in the morning?||0||1||2||3|
|A sudden strong desire to urinate, which is difficult to postpone||0||1||2||3|
|Leaking of urine because you cannot hold it||0||1||2||3|
|Leaking of urine, when you cough, sneeze, or strain||0||1||2||3|
|Slow urinary stream||0||1||2||3|
|Need to strain when urinating||0||1||2||3|
|Feeling of incomplete emptying of the bladder after urination||0||1||2||3|
|Pain in the bladder||0||1||2||3|
|Pain in the urethra||0||1||2||3|
| ||CLSS (Sum of Q1-10) ______|
A number of questionnaires are now available to assess LUTS in various diseases/conditions.3–13 Most of these questionnaires have been tailored for a specific disease, however, and may overlook other important symptoms that are not to be evaluated for that disease. In the present study, we attempted to identify the LUTS of high relevance for various diseases/conditions (core LUTS) and then devised a questionnaire for their assessment.
To select core symptoms from 25 LUTS defined by the ICS standardization committee,15 we performed study 1 to exclude symptoms that were strongly correlated with other symptoms of more importance. However, the symptom scores were uniformly higher in patients complaining of LUTS than in the controls, which suggested that each symptom was relevant to the patients to some extent. In study 2, we identified 10 symptoms that were considered to have a significant impact by >25% of patients with any of nine common lower urinary tract diseases, and defined these 10 symptoms as core LUTS. Study 1 also indicated that these 10 core symptoms yielded significantly higher scores in patients with LUTS than in the controls, and were not correlated with other symptoms with higher frequency scores (Spearman's r < 0.5). The core LUTS score (CLSS) questionnaire was confirmed for reliability.
For comprehensive evaluation of LUTS, a pair of questionnaires (ICIQ-MLUTS and ICIQ-FLUTS) is available for male and female patients, respectively.14 The ICIQ-MLUTS includes questions about the frequency (score: 0–4) of 13 symptoms including daytime frequency, nocturia, urgency, urgency incontinence, stress incontinence, nocturnal enuresis, incontinence of unknown cause, poor stream, hesitancy, intermittency, straining, sensation of incomplete emptying, and terminal dribble. It allows the calculation of sub-scores for voiding symptoms (0–20) and incontinence symptoms (0–24). The impact on QOL is evaluated by scoring the impact severity for each symptom from 0 to 10. The ICIQ-FLUTS contains 12 questions about daytime frequency, nocturia, urgency, urgency incontinence, stress incontinence, nocturnal incontinence, incontinence of unknown cause, incontinence for any reason, hesitancy, intermittency, straining, and bladder pain. Symptoms are scored by using three sub-scales, filling symptoms (0–15), voiding symptoms (0–12), and incontinence symptoms (0–20), while QOL is evaluated in the same manner as with the ICIQ-MLUTS. Both the ICIQ-MLUTS and ICIQ-FLUTS have been validated and are recommended by the ICS. The CLSS questionnaire shares eight and seven symptoms with ICIQ-MLUTS and ICIQ-FLUTS, respectively, with the missing symptoms being nocturnal enuresis, incontinence of unknown cause, incontinence for any reason, hesitancy, intermittency, and terminal dribble. In our evaluation, we found that the scores for nocturnal enuresis, other types of incontinence, continuous incontinence, and terminal dribble showed no significant difference between LUTS patients and controls. In addition, hesitancy was correlated with straining, which is incorporated in the CLSS questionnaire, while intermittency was seldom selected as a symptom with significant impact. Incontinence of unknown cause is neither defined nor described in the ICS terminology.15 Conversely, bladder pain and urethral pain are not covered by ICIQ-MLUTS but were included in the CLSS, because they were symptoms with significant impact among symptomatic men in our study. Bladder pain was found to be a relatively common symptom in men with BPH.16 Thus, the CLSS questionnaire seems to cover LUTS of high clinical significance with a limited number of questions. The questionnaire may be useful when an overall symptom profile is to be assessed without omissions; for example, for new patients, patients with multiple diseases, and patients without a definite diagnosis, as well as before and after interventions that may cause other symptoms.
Limitations of the CLSS questionnaire and our study design include the following. First, the questionnaire only addresses 10 LUTS. For more comprehensive evaluation of LUTS, all 25 symptoms should be assessed. Second, the CLSS questionnaire cannot replace specific questionnaires for patients with a definite diagnosis. Furthermore, the CLSS questionnaire may be misleading if we compare symptom severity among different diseases on the basis of the total score. For instance, in a patient with stress incontinence, the score may only be high for stress incontinence and very low for other symptoms, yielding a low total score. Thus, the profile of individual symptoms should be examined rather than the total score. The advantage of this questionnaire is that it provides an overall review of LUTS without overlooking other important symptoms. Third, the selection of core symptoms was based on an arbitrary cut-off impact rate of 25%, which excluded increased sensation (the highest impact rate: 24%), pelvic pain (20%), and hesitancy (19%). However, increased sensation was almost specific to interstitial cystitis and bacterial cystitis, and these diseases were characterized by other symptoms with higher impact rates. Pelvic pain and hesitancy were significantly correlated with bladder pain and straining, respectively, and the latter symptoms (bladder pain and straining) were more common and included in the CLSS questionnaire. Therefore, these three symptoms near the cut-off value may be reasonably excluded from the core symptoms. Fourth, the diagnosis of each disease was made clinically rather than from urodynamic data. Accurate diagnosis was not required in this study, however, because we did not intend to compare the symptom profiles among diseases but instead wished to identify symptoms that were relevant to patients with common diseases/conditions. The symptom profiles of patients with a urodynamically confirmed diagnosis should be explored further. Finally, our patient population was Japanese; confirmatory studies of patients with different racial and/or cultural backgrounds are warranted.
Ten LUTS (increased daytime frequency, nocturia, urgency, urgency incontinence, stress incontinence, slow urinary stream, straining, feeling of incomplete emptying, bladder pain, and urethral pain) were selected as core LUTS. A questionnaire for the core LUTS provides overall assessment of relevant symptoms without omissions and may be useful for new patients, patients with multiple diseases, and patients without a definite diagnosis, as well as before and after interventions that may cause other symptoms.