The Italian Version of the National Institutes of Health Chronic Prostatitis Symptom Index

Transcription

1 European Urology European Urology 47 (2005) The Italian Version of the National Institutes of Health Chronic Prostatitis Symptom Index Gianluca Giubilei a, *, Nicola Mondaini a, Alfonso Crisci a, Andrea Raugei a, Giuseppe Lombardi b, Fabrizio Travaglini a, Giulio Del Popolo b, Riccardo Bartoletti a a Department of Urology, University of Florence, Viale Pieraccini 18, Florence, Italy b Spinal Unit, Careggi Hospital, Florence, Italy Accepted 29 December 2004 Available online 24 March 2005 Abstract Objectives: To perform the Italian version of the National Institutes of Health Chronic Prostatitis Symptom Index (NHI-CPSI), and to study its linguistic validity and its correlations with the Visual Analogue Scale for pain (VAS) and the Italian version of International Prostatic Symptom Score (I-PSS) in men with chronic pelvic pain syndrome (CPPS) and healthy controls. Methods: A rigorous double-back translation of the original English NHI-CPSI was performed by a staff composed of 3 professional bilingual experts and 3 urologists. The study population consisted of 160 male CPPS patients and 125 healthy controls, who were asked to self complete the Italian version of the NHI-CPSI together with the VAS and the Italian I-PSS. The discriminatory power, psychometric properties, internal correlations and convergent validity of the questionnaire were tested. Results: Of the 285 enrolled patients, 223 patients (142 with CPPS and 81 healthy patients) were definitively considered for the study. The overall Italian NIH-CPSI scores and each subscale differed significantly (p < 0.001) between the two groups, and so that the index proved a good discriminant validity. High correlations were found between the VAS and the pain domain (0.88) and between I-PSS and void domain (0.94), suggesting a good convergent validity of the Italian version of the NIH-CPSI. The questionnaire proved to have a high internal consistency. Conclusions: The Italian NIH-CPSI is a reliable symptom index that can be self-administrated in about 5 minutes in daily clinical practice for the follow-up of the Italian patients with chronic prostatitis. # 2004 Elsevier B.V. All rights reserved. Keywords: Chronic prostatitis; Chronic pelvic pain symptoms; CPPS; Chronic prostatitis symptom index; NIH- CPSI; Italian version 1. Introduction Chronic non-bacterial prostatitis or CPPS are very common in everyday medical practice and their prevalence rate in the general population ranges from 5% to 14.2% [1,2]. A prospective-descriptive study conducted on 20 Italian centers reported a 12.8% as prevalence of a clinical diagnosis of prostatitis [3]. * Corresponding author. Tel ; Fax: +055/ address: gianluca.giubilei@libero.it (G. Giubilei). CPPS may cause morbidity through symptoms and quality of life (QoL) can be severely compromised. CPPS is still poorly understood, often inadequately treated and further studies are needed to clarify the relationships among its aspects [4]. To diagnose and treat patients with CPPS, we need accurate measurements of their symptoms and QoL at baseline and longitudinally with or without treatment. For the perceived need to develop a standardized prostatitis symptom index, to objectively measure symptoms for natural history studies and assess the outcome para /$ see front matter # 2004 Elsevier B.V. All rights reserved. doi: /j.eururo

2 806 G. Giubilei et al. / European Urology 47 (2005) meters for clinical trials, the National Institutes of Health (NIH) Chronic Prostatitis Collaborative Research Network developed and validated the NHI- CPSI [5]. This instrument is a 9-item questionnaire that measures the three most important domains in the chronic prostatitis patient s experience: pain, voiding symptoms and impact of the symptoms on the patient s quality of life. The previous literature about symptoms assessment and health related quality of life among men with CPPS primarily comprised studies that simply listed common symptoms and occasionally tried to define a set of disease-targeted items to create a rough symptom index [6 10]. Since its assessment, NIH- CPSI has been useful as a valid outcome measure in men with CPPS and it has provided a primary endpoint in clinical trials and in clinical practice [11]. Recently, the translation-validation of this questionnaire was performed into Spanish, Japanese, German, Finnish, Malay, Chinese and Korean [12 17]. Our aim is to create and validate a fluent and comprehensive Italian version of the NIH-CPSI. Furthermore, we studied the correlation of the Italian version of NIH-CPSI with two previous acknowledged outcome measures, the VAS [18] and the I-PSS [19]. Fig. 1. Italian prostatitis symptom index.

3 G. Giubilei et al. / European Urology 47 (2005) Fig. 1. (Continued). 2. Materials and methods 2.1. Translation procedure The NIH-CPSI was initially translated into the Italian language by three urologists (G.G, R.B, G.D.P.), while a professional translator who was a bilingual, Italian born made a second Italian version of the questionnaire. The four translators made the two Italian versions trying to use very simple language, easy to understand, also for patients with a low education level. The two versions resulted very similar and a few differences were solved by a fifth translator (a bilingual Italian) obtaining a third reconciled version. The third version was then translated back into English by another (the sixth) independent professional translator who was fully bilingual. The back-translated version and the original NIH-CPSI were compared by the three urologists and the fifth translator who found an identical idiomatic content and no inconsistencies between the two versions except for one question. The inconsistencies found in the ninth question of the reconciled version were reviewed and back-translated again into a new English version (using the same method and staff), which was confirmed to be consistent with the original version in wording and meaning. Finally, the corrected Italian version was reviewed for grammar and spelling by an Italian teacher, resulting in the final Italian version of NIH-CPSI (Fig. 1). During a pre-test of 5 weeks in daily clinical practice no corrections were made Validation step The population of this study consisted of 160 male patients affected by CPPS and 125 healthy controls. Patients with a diagnosis consistent with the NIH definition of the CPPS [20] were enrolled at Florence University by experienced urologists. All men complained of recurrent symptoms related to prostatitis from at least 3 years and they were very poor responders to the conventional treatments. Exclusion criteria for this group were history of tumor, major psychiatric disorders, inflammatory bowel diseases, benign prostatic hyperplasia and neurological diseases. Healthy men working at Florence University who were not affected by chronic prostatitis composed the control group. They had no previous urological history or other significant diseases that can reproduce prostatitis-like symptoms. All enrolled patients were fully informed about the procedure and the aims of the investigation, and every man signed a written informed consent. All patients affected by prostatitis were examined at least twice in the last 6 months. Both control and prostatitis patients self-completed a short questionnaire about their personal details (age, education level, affections, use of drugs, etc.) plus the Italian version of NIH-CPSI.

4 808 G. Giubilei et al. / European Urology 47 (2005) To evaluate the test-retest reliability they were asked to fill out again the NIH-CPSI 1 week later. The time of compilation was noted for each individual. Then they were interviewed by two authors (B.R. and G.G.) to determine whether any question was found difficult to understand or irrelevant for their conditions, and their comments were taken down for an eventual rearrangement of the questionnaire. In addition, every patient self completed the VAS and the Italian version of I-PSS Statistical analysis Mann-Whitney U-test was used to compare the differences in the distribution between the two groups. Pearson product moment correlation was used to study item associations and test-retest reliability. Internal consistency of the total score (Italian NHI- CPSI) and its three subscales were evaluated using Cronbach s coefficient a [21]. 3. Results Of the 285 enrolled patients, 223 patients (142 with CPPS and 81 healthy patients) were definitively selected for the study. A total of 62 patients (44 of the control group and 18 of the CPPS patients) were excluded from the study because they only partially filled in the questionnaires. The general characteristics of the enrolled patients are shown in Table 1. The mean age of the CPPS patients plus or minus standard deviation (SD) was 50.2 (11.6) and their compliance in completing the questionnaire was 88.7%. In contrast healthy patients were younger and their compliance in filling in questionnaires was lower (Table 1). The mean time to complete the questionnaire for the prostatitis group was 6 minutes (range 3 9 minutes) and 23 patients of this group (16.2%) required explanation of one or more item. The Italian NIH-CPSI, the I-PSS and the VAS scores resulted significantly different in the two groups (p < 0.001). It also showed a significant difference for each NIH-CPSI domain (p < 0.001). The total mean Italian NIH-CPSI score plus or minus standard deviation in the CPPS group was 21.8 (8.5) while in the control group was 2.0 (2.8). The results of the groups performance in each score and the groups differences studied with Mann-Whitney U-test are presented in Table 1. Statistical analysis with Pearson s test demonstrated that the domains of the Italian NIH-CPSI correlated well with each other. The best correlations were found between Void domain and the I-PSS (0.94), and between the total NIH-CPSI score and the VAS (0.91), while Void domain was positively but not quite as highly correlated both with pain and with quality of life domain. Cross tabulation with correlations among the VAS, I-PSS, NHI-CPSI and its three domains is shown in Fig. 2. Test-retest reliability was performed on a selected group of 64 patients with CPPS and on 32 control patients. Score s distributions for the three domains were similar in test and retest, and the correlation of the total scores was as high as 0.90 (Table 2). Psychometric analysis indicated an excellent internal consistency with high a Table 1 Baseline characteristics of the enrolled patients and the differences of CPSI-NIH score and its domains between the two groups Total sample CPPS Controls No. pts Mean age (SD) 47.6 (11.1) 50.2 (11.6) (8.7) No. (%) Origin (area of Italy) North 49 (22) 35 (24.6) 14 (17.3) Center 150 (67.3) 94 (66.2) 56 (69.1) South 24 (10.7) 13 (9.2) 11(13.6) Education level, school degree (%) Primary school 37 (16.6) 24 (16.9) 13 (16.1) High school 72 (32.3) 47 (33.1) 25 (30.9) Up grade school 65 (29.1) 49 (34.5) 16 (19.7) University graduated 49 (22.0) 22 (15.5) 27 (33.3) Duration of symptoms, years (SD) 5.2 (7.3) Questionnaire compliance % NHI-CPSI compiling time (minutes) 6 (3 9) 4 (2 9) Mean score (SD) NHI-CPSI (0 43) 21.8 (8.5) * 2.0 (2.8) * Pain domain (0 21) 10.5 (4.5) * 0.5 (1.2) * Void domain (0 10) 4.5 (2.9) * 0.9 (1.2) * Quality of life impact (0 12) 6.8 (3.1) * 0.6 (1.0) * VAS 4.9 (2.0) * 0.3 (0.5) * I-PSS 14.7 (9.9) * 3.2 (4.5) * * p < with Mann-Whitney U-test.

5 G. Giubilei et al. / European Urology 47 (2005) Table 2 Reliability of the test-retest analysis (Pearson product moment correlation) and Internal consistency (Cronbach s a coefficient) of the present study a Chronic prostatitis Correlation Controls Correlation No. pts Mean age (SD) 41,4 (9.6) 48.4 (10.8) Domain (range) Test Re-test Test Re-test Overall Nih-CPSI (19.23, 23.79) 20.9 (18.44, 22.61) (1.03, 3.09) 2.1 (1.62, 3.25) 0.87 Pain (8.97, 11.36) 9.8 (8.28, 10.61) (0.90, 0.03) 0.7 (1.14, 0.22) 0.79 Urinary symptoms (4.08, 5.60) 4.8 (4.08, 5.47) (1.33, 0.47) 1.1 (1.51, 0.67) 0.73 Life quality impact (5.63, 7.37) 6.3 (5.51, 7.08) (1.11, 0.23) 0.8 (1.19, 0.36) 0.94 Data for test and retest presented as the mean with the 95% confidence interval in parentheses. Fig. 2. Correlation between the void subscale (US) and IPSS (a) and between pain domain (PD) and the VAS (b) presented as a scatter plot. (c) Correlations of VAS, I-PSS and NIH-CPSI and its subscales among patients affected by CPPS. coefficients both for the overall index (0.95) and for its subscales. 4. Comment The study described the translation and validation of the Italian version of the NHI-CPSI in a sample of relatively large size. A rigorous double-back translation, which is a widely accepted method [12 15], was performed using a procedure similar to that used by the Spanish NHI-CPSI validation [12]. The medium NHI-CPSI score obtained in the CPPS group (21.8) and in the pain domain (10.5) were slightly higher than the correspondent values in the original validation. Anyway, our data are consistent with the scores of the other validation studies. Moreover two years of German experience with NIH-CPSI showed total and a pain domain scores higher than those in the present study [22]. These light discrepancies may be due, apart from the different profile of the selected patients, to a different way of perceiving and expressing symptoms of the Italian population. The Italian version of the NIH-CPSI proved to have high discriminative power between CPPS patients and controls, in fact, the differences in pain, urinary symptoms, quality of life and total NIH-CPSI score were all significantly different (p < 0,001 U-test). In the prostatitis group the correlation between total score and pain (0.91) was higher than those reported in Finnish (0.89) and German (0.85) experiences. Conversely the Spanish validation reported a very high correlation (0.97) but, as Leskinen remarked [15], the study was performed on a group of only 47 patients [12]. Our correlations data, that are somewhat higher than the results obtained in the original English version, support the construct validity of the present tool. Using the I-PSS and the VAS, that have never been somministred together in precedent linguistic validation [11 17], we examined the convergent validity of the Italian NIH-CPSI. VAS and IPSS are well-accepted and validated measures of pain [23] and lower urinary tract symptoms respectively that have been largely used in clinical trials and in day by day practice. I- PSS is more frequently used in assessing benign prostatic hyperplasia symptoms and it was translated into Italian in 1997 [19]. The correlations between VAS and NIH-CPSI (0.80) and between VAS and pain (0.88) were higher than the correspondent results of the Finnish validation [15]. I-PSS correlated well with the urinary symptoms domain (0.94), while the correlations with some other items were positive but not so

6 810 G. Giubilei et al. / European Urology 47 (2005) high. These presented data support the good convergent validity of the Italian NIH-CPSI. In addition our results confirmed the very high internal consistency of the Italian NIH-CPSI (0.95 with Cronbach) and its subscales ( ), which is similar or higher than the original English version [5]. In a report of the year 2002 was estimated that 57,715,625 people approximately made up the Italian population, and that 19,334,208 of these were male between 15 and 64 years old. The Italian language, apart from Italy, is also spoken in by all inhabitants of S. Marino, by the 7.6% of those living in Switzerland (Canton Ticino) and by a consistent part of the population living in other countries in the world such as Slovenia, Albania, Argentina, Venezuela and the U.S.A. [24]. These data combined with the high prevalence of chronic prostatitis detected among Italian population highlights the importance of an Italian questionnaire to improve investigating this entity. The NIH-CPSI was initially developed with an evaluative objective instead of a discriminative one [5]. Nevertheless, validation studies determined that the index and its translated versions have a significant discriminatory power and can identify men with prostatitis-like symptoms [5,12 17]. Since its development, the constant and recommended [27] use of the NIH-CPSI, both in clinical trial and in epidemiological-prevalence studies for CPPS [25 30], enhanced the power of this tool. NIH-CPSI is likely to function best if adopted widely as a standard instrument in the evaluation of CPPS [5,11]. The constant arising of questionnaire linguistic validations permits to bring near the optimization of its use. The present study has two main limitations. First, the majority of patients came from the center of Italy (67.3%); a minority of them was of southern Italian origin, where many different dialects are spoken and the level of education is low. Second, most of the patients enrolled had a medium-high level of education that is not able to represent truly the standard of Italian patients. A similar situation was found on patients of the original English study, where Caucasian outnumbered the others, and the level of education was too high [5,11]. 5. Conclusions The present study provides the Italian version of the NIH-CPSI and demonstrates its validity in assessing the different clinical aspects of CPPS. Our experience shows that the Italian NIH-CPSI can be easily selfcompleted in less than 5 minutes. We found it important to remark our agreement with previous authors, particularly Litwin, Kunishima and Schneider [11,13,22] on the necessity of new validated translations of the NIH-CPSI to promote a universal language, comparison of major results and a better care for the patient. Acknowledgements To Fabio Rigat for statistical supervision, to Anna Calzolai for data entry and to Giampaolo Chiari for linguistic support. References [1] Moon TD, Hagen L, Heisey DM. Urinary symptomatology in younger men. Urology 1997;50: [2] Anthony J. Schaeffer: Epidemiology and Demographics of Prostatitis. Eur Urol Supp 2003;2:5 10. [3] Rizzo M, Marchetti F, Travaglini F, Trinchieri A, Nickel JC. Prevalence, diagnosis and treatment of prostatitis in Italy: a prospective urology outpatient practice study. BJU Int 2003;92: [4] Turner JA, Hauge S, Von Korff M, Saunders K, Lowe M, Berger R. Primary care and urology patients with the male pelvic pain syndrome: symptoms and quality of life. J Urol 2002;167: [5] Litwin MS, McNaughton-Collins M, Fowler Jr FJ, Nickel JC, Calhoun EA, Pontari MA, et al. The National Institutes of Health chronic prostatitis symptom index: development and validation of a new outcome measure. Chronic Prostatitis Collaborative Research Network. J Urol 1999;162: [6] Keltikagas-Jarvinen L, Jarvinen H, Lehtonen T. Psychic disturbances in patient with chronic prostatitis. Ann Clin Res 1981;13:45 9. [7] Wenninger K, Heiman JR, Rothman I, Berghuis JP, Berger RE. Sickness impact of chronic non bacterial prostatitis and its correlates. J Urol 1996;155: [8] Neal Jr DE, Moon TD. Use of terazosin in prostatodynia and validation of a symptom score questionnaire. Urology 1994;43: [9] Nickel JC, Sorensen R. Transurethral microwave thermotherapy for non bacterial prostatitis: a randomized double-blind sham controlled study using new prostatitis specific assessment questionnaires. J Urol 1996;155: [10] Braheler E, Wurz J, Unger U. The Giessen Prostatitis Symptom Index (GPSS): Standardization of the questionnaire and prevalence of symptoms [Abstract]. J Urol 1997;157:239A. [11] Litwin MS. A review of the development and validation of the National Institute of Health Chronic Prostatitis Symptom Index. Urology 2002;60(Suppl 6A):14 9. [12] Collins MM, O Leary MP, Calhoun EA, Pontari MA, Adler A, Eremenco S, et al. Chronic Prostatitis Collaborative Research Network: The Spanish National Institutes of Health-Chronic Prostatitis Symptom Index: translation and linguistic validation. J Urol 2001; 166: [13] Kunishima Y, Matsukawa M, Takahashi S, Itoh N, Hirose T, Furuya S, et al. National Institutes of Health Chronic Prostatitis Symptom Index for Japanese men. Urology 2002;60:74 7.

7 G. Giubilei et al. / European Urology 47 (2005) [14] Henning Schneider, Elmar Brahler, Martin Ludwig, Werner Hochreiter, Severin Lenk, Win fried Vahlensieck Werner Hochreiter, et al. The German version of the NIH-CPSI. Evaluation of the internal consistency and median scores in 137 patients with CPPS-NHI III A and B. J Urol 2002;167(Suppl 4):27, A110. [15] Leskinen MJ, Mehik A, Sarpola A, Tammela TLJ, Jarvelin MR. The Finnish version of The National Institutes of Health Chronic Prostatitis Symptom Index correlates well with the visual pain scale. BJU Int 2003;92: [16] Chea PY, Liong MC, Yuen KH. Chronic symptoms survey with follow-up, clinical evaluation. Urology 2002;61:60 4. [17] Chong CH, Ryu DS, Oh TH. The Korean version of NIH-chronic prostatitis symptom index (NIH-CPSI): validation study and characteristics on chronic prostatitis. Korean J Urol 2001;42: [18] Price DD, McGrath PA, Rafii A, Buckingham B. The validation of visual analogue scales as ratio scales measures for chronic and experimental pain. Pain 1983;17: [19] Badia X, Garcia-Losa M, Dal-Re R. Ten-language translation and harmonization of the International Prostate Symptom Score: developing a methodology for multinational clinical trials. Eur Urol 1997; 31(2): [20] Krieger JN, Nyberg LM, Nickel JC. NIH consensus definition and classification of prostatitis. JAMA 1999;282:236. [21] Cronbach L. Coefficient alpha and the internal structure of tests. Psychometrika 1951; [22] Schneider H, Brahler E, Ludwig M, Hochreiter W, McNaughton CM, Eremenco S, et al. Two-year experience with the German-translated version of the NIH-CPSI in patients with CP/CPPS. Urology 2004;63: [23] Price DD, McGrath PA, Rafii A, Buckingham B. The validation of visual analogue scales as ratio scale measures for chronic and experimental pain. Pain 1983;17:45 6. [24] The world fact book. [25] Nickel JC, Nymberg LM, Hennenfent M. Research guidelines for chronic prostatitis: Consensus report from the first National Institutes of Health International Prostatitis Collaborative Network. Urology 1999;54: [26] Ku JH, Kim ME, Lee NK, Park YH. The prevalence of chronic prostatitis-like symptoms in young men: a community-based survey. Urol Res 2001;29(2): [27] Nickel JK. Recommendations for the evaluation of patients with prostatitis. World J Urol 2003;21: [28] Liang CZ, Zhang XJ, Hao ZY, Yang S, Wang DB, Shi HQ, et al. An epidemiological study of patients with chronic prostatitis. BJU Int 2004;94(4): [29] Alexander RB, Propert KJ, Schaeffer AJ, Landis JR, Nickel JC, O Leary MP, et al. Chronic Prostatitis Collaborative Research Network. Ciprofloxacin or tamsulosin in men with chronic prostatitis/ chronic pelvic pain syndrome: a randomized, double-blind trial. Ann Intern Med 2004;141(8): [30] Nickel JC, Downey J, Hunter D, Clark J. Prevalence of prostatitislike symptoms in a population based study using the National Institutes of Health chronic prostatitis symptom index. J Urol 2001;165(3):