- Email: [email protected]
Prevalence of Prostatitis-Like Symptoms in a Managed Care Population
Prevalence of Prostatitis-Like Symptoms in a Managed Care Population J. Quentin Clemens,*,† Richard T. Meenan, Maureen C. O’Keeffe-Rosetti, Sara Y. Gao, Sheila O. Brown and Elizabeth A. Calhoun From the Department of Urology, Northwestern University, Feinberg School of Medicine (JQC, SOB), and Department of Health Policy Administration, University of Illinois, School of Public Health (EAC), Chicago, Illinois, and the Center for Health Research, Kaiser Permanente Northwest Division, Portland, Oregon (RTM, MCO, SYG)
Purpose: We calculated the prevalence of symptoms typically associated with chronic prostatitis/chronic pelvic pain syndrome in men in a managed care population in the Pacific Northwest. Materials and Methods: A questionnaire mailing to 5,000 male enrollees 25 to 80 years old in the Kaiser Permanente Northwest (Portland, Oregon) health plan was performed. The questionnaires included screening questions about the presence, duration and severity of pelvic pain, and the National Institutes of Health Chronic Prostatitis Symptom Index. Chronic prostatitis/chronic pelvic pain syndrome symptoms were defined in 2 ways: 1) presence of any of the following for a duration of 3 or more months: pain in the perineum, testicles, tip of penis, pubic or bladder area, dysuria, ejaculatory pain; and 2) perineal and/or ejaculatory pain, and a National Institutes of Health Chronic Prostatitis Symptom Index total pain score of 4 or more. Prevalence estimates were age adjusted to the total Kaiser Permanente Northwest male population. Results: A total of 1,550 questionnaires were returned. The prevalence of chronic prostatitis/chronic pelvic pain syndrome symptoms was 7.5% for definition 1 and 5.9% for definition 2. Mean National Institutes of Health Chronic Prostatitis Symptom Index scores were 17 for definitions 1 and 2. Of those with prostatitis-like symptoms, 30% met criteria for having both definitions present. The prevalence of prostatitis-like symptoms using either of the 2 diagnoses was 11.2%. Conclusions: This population based study indicates that approximately 1 in 9 men have prostatitis-like symptoms. Application of 2 different definitions for prostatitis-like symptoms identified unique groups of men, with limited overlap in the groups. Key Words: epidemiology, pelvic pain
The aim of this study was to assess the prevalence of prostatitis-like symptoms in men enrolled in a managed care health plan, and assess the differences in prevalence estimates that occur when various definitions for prostatitis-like symptoms are used. Administrative data from the health plan was used to apply typical CP/CPPS exclusion criteria to improve the specificity of the findings.
hronic prostatitis/chronic pelvic pain syndrome is a chronic disabling syndrome consisting of pelviperineal pain of unclear etiology, often accompanied by voiding and sexual symptoms. CP/CPPS is poorly understood, often inadequately treated, and extraordinarily bothersome in the men it afflicts.1 Since there is no objective marker for the presence of CP/CPPS, epidemiologic studies of the condition are difficult. Such studies can define the presence of CP/CPPS based on physician coded diagnoses, patient reported history, or assessment of the presence of CP/CPPS symptoms. Studies that focus on physician diagnoses require the patient to be seen and accurately diagnosed by a physician. Studies that use patient self-report may be inaccurate due to recall bias. Assessment of current symptoms may be nonspecific, as the symptoms could be due to conditions other than prostatitis. Furthermore, criteria used to define prostatitis-like symptoms are not standardized.
C
MATERIALS AND METHODS Study Population The EpicCare clinical database at Kaiser Permanente Northwest (KPNW) was used to define the study population. KPNW is based in the Portland, Oregon metropolitan area, which includes southwest Washington state. Specific details about the KPNW patient population and the EpicCare database search protocol have been previously published.2 An initial database search was performed to exclude subjects younger than 25 years or older than 80 years, those who were not current KPNW members at the time of the analysis (May 2002), those with dental coverage only, and those on the do not contact list for research studies. The age limits were chosen because previous epidemiological studies of this population have shown that members ages younger than 25 and older than 80 years are typically quite transient and very difficult to follow over time. After applying these initial demographic exclusions, 120,574 men were identified.
Submitted for publication September 21, 2005. Supported by National Institute of Diabetes and Digestive and Kidney Diseases Grant U01 DK060177-02. * Correspondence: Department of Urology, Northwestern University Feinberg School of Medicine, 303 E. Chicago Ave., Tarry 16, Chicago, Illinois 60611 (telephone: 312-695-6124; FAX: 312-6957030; e-mail: [email protected]). † Financial interest and/or other relationship with Merck, Pfizer, Medtronic, Allergan and Boehringer Ingelheim.
0022-5347/06/1762-0593/0 THE JOURNAL OF UROLOGY® Copyright © 2006 by AMERICAN UROLOGICAL ASSOCIATION
593
Vol. 176, 593-596, August 2006 Printed in U.S.A. DOI:10.1016/j.juro.2006.03.089
594
PROSTATITIS-LIKE SYMPTOMS IN MANAGED CARE POPULATION
Database Queries ICD-9 based queries of the KPNW database were used to identify subjects with CP/CPPS exclusion criteria based on those used in the National Institutes of Health Chronic Prostatitis Collaborative Research Network.3 Exclusion criteria included lower urinary tract cancer, neurological disease, radiation cystitis, urethral stricture, and dementia. Men with these exclusion criteria were excluded from further analysis, but were included in the population denominator for prevalence estimates. Subsequent ICD-9 based queries were used to identify those with codes indicating the presence of irritative or painful urological symptoms (referred to as irritative/painful urological conditions). These conditions included chronic prostatitis (ICD-9 601.1), prostatitis not otherwise specified (601.9), interstitial cystitis (595.1), bladder pain (788.9), dysuria (788.1), frequency (788.41), chronic cystitis (595.2), unspecified cystitis (595.9), unspecified disorder of male genital organs (608.9) and unspecified abdominal pain (789.0). Sampling Strategy From the database queries a total of 18,011 men were identified with at least 1 of the ICD-9 coded irritative/painful urological conditions and none of the exclusion criteria. A total of 3,099 questionnaires were mailed to a random sample of these individuals, who were identified as cases for purposes of the study. An additional 1,901 questionnaires were mailed to male subjects with none of the coded irritative/painful urological conditions, for a total mailing of 5,000. These men were labeled controls. The questionnaires included demographic data (date of birth, race, gender, education, income), screening questions to identify the presence, duration and severity of urgency, frequency and pelvic pain, and the NIH-CPSI. The NIHCPSI was modified slightly from its original version to reflect a time period of 1 month (rather than 1 week as in the original). Prevalence estimates were adjusted to the age distribution of the KPNW population and then weighted based on the proportion of the 2 groups (those with and
TABLE 2 Pain Symptoms
No. With Symptoms (% of respondents)
Pubic/bladder area Testicles Dysuria Perineum Ejaculatory Tip of penis
161 (10.3) 128 (8.3) 109 (7.0) 120 (7.7) 114 (7.3) 71 (4.5)
without coded irritative/painful urological diagnoses) in the entire KPNW population. Definitions of Prostatitis-Like Symptoms Two definitions for prostatitis-like symptoms were used. These definitions are identical to those used in previous surveys that assessed the prevalence of prostatitis symptoms.4,5 Definition 1 is the presence of any of the following for 3 or more months: pain in the perineum, testicles, tip of penis, below waist, dysuria, ejaculatory pain.4 Definition 2 is perineal and/or ejaculatory pain/discomfort, and a total NIH-CPSI pain subscale score (range 0 to 21) of 4 or greater.5 RESULTS A total of 1,550 completed questionnaires were returned, for a response rate of 31%. Of the 1,550, 999 (cases) had 1 or more coded irritative/painful urological diagnosis, and 551 (controls) had none. The study population was 88% white race with a mean age of 59, and 64% had some college or postgraduate education. Demographics are presented in table 1. A previous comparison indicated no apparent clinically meaningful differences in the prevalence of ICD-9 diagnoses (using major ICD-9 diagnostic categories) between respondents and nonrespondents, thereby reducing the likelihood of nonresponse bias.6 The prevalence of prostatitis-like symptoms was 7.5% for definition 1 (95% CI 6.2%– 8.8%), and 5.9% for definition 2 (95% CI 4.7%–7.1%). The prevalence of prostatitislike symptoms using either of the 2 diagnoses was 11.2% (95% CI 9.6%–12.8%). Mean NIH-CPSI score for all sub-
TABLE 1 Pt age: Mean Standard deviation Range No. education (%): Less than 12 yrs 12 yrs or high school graduate Post-high school training other than college Some college College graduate Postgraduate No. pre-tax income (%): Less than $30,000 $30,000–$49,999 $50,000–$79,999 $80,000 or More No. race (%): American Indian or Alaskan Native Asian Black Native Hawaiian Other Pacific Islander White Other Hispanic
59 12.29 25–80 104 (0.7) 231 (14.9) 147 (9.5) 400 (25.8) 278 (17.9) 313 (20.2) 246 (15.9) 384 (24.8) 386 (24.9) 281 (18.1) 16 (1) 31 (2) 18 (1.2) 1 (0.1) 3 (0.2) 1,363 (87.9) 118 (7.6) 43 (2.8)
FIG. 1. Patients meeting criteria for definitions of CP/CPPS
PROSTATITIS-LIKE SYMPTOMS IN MANAGED CARE POPULATION
595
TABLE 3 Diagnosis
No. Pts
Mean NIH-CPSI Score (range)
% Definition 1
% Definition 2
Chronic prostatitis Prostatitis not otherwise specified Dysuria Frequency No diagnosis (controls)
140 658 119 128 551
10 (0–35) 10 (0–36) 11 (0–33) 11 (0–33) 4 (0–32)
28.6 24.6 31.1 21.1 4.4
15.7 14.4 18.5 10.2 3.1
jects was 7 (SD 6.9, range 0 to 36). Mean score for men with definition 1 symptoms was 17 and for definition 2 was also 17 (p ⫽ not significant). Table 2 shows the distribution of pain symptoms reported by all respondents. The most commonly reported symptom was pain in the suprapubic/bladder region. A total of 293 unique individuals (256 cases and 37 controls) had prostatitis-like symptoms. Of these 293, 87 (30%) met criteria for both definitions (fig. 1). Table 3 presents symptoms stratified by ICD-9 diagnoses ‘chronic prostatitis’, ‘prostatitis not otherwise specified’, ‘dysuria’ and ‘frequency’. These data indicate that the majority of men (approximately 75%) with these coded diagnoses did not meet criteria for having prostatitis-like symptoms. However, the prevalence of prostatitis-like symptoms was significantly higher in men with these diagnoses than in men with no coded diagnosis (controls). Age specific prevalence rates of prostatitis-like symptoms (either definition) are presented in figure 2. Prostatitis-like symptoms were more common in men greater than 50 years of age, peaking at age 56 to 60. Approximately 76% of the men with symptoms were over age 50, while 24% were 50 years of age or less. DISCUSSION Using 2 different previously described definitions for prostatitis-like symptoms, we found the prevalence of such symptoms to be 11.2% in men aged 25 and above. These results can be compared with similar studies that used the same definitions. Using definition 1 Cheah et al reported the prevalence of prostatitis-like symptoms to be 8.7% in a sample of 3,147 Malaysian men 20 to 50 years old.4 This estimate is similar to our findings of 7.5%. It is possible that ethnic and/or age differences in the populations studied could account for some of the difference in the estimates.
FIG. 2. Age specific prevalence rates of prostatitis-like symptoms (either definition).
Nickel et al used definition 2 to define prostatitis symptoms, and found a prevalence of 9.7% in 868 Canadian men 20 to 74 years old who responded to a postal survey.5 Subsequently, Roberts applied the same definition to the Olmsted County, Minnesota male population, and identified symptoms in 2.3% of 1,541 men age 40 or older.7 Therefore, our prevalence rate of 5.9% is in between the rates reported in these 2 previous studies using this definition. Differences in the ages of the studied populations, and differences in the method of questionnaire administration could explain some of this discrepancy. In addition, the response rates in our study and the Nickel study were low (each approximately 30%, compared with greater than 80% for the Roberts study). This could artificially inflate the prevalence estimates due to response bias. Finally, there could be real differences in the prevalence of these symptoms in the studied populations. The extensive KPNW administrative database allows for a comparison to be made between patient self-reported symptoms and coded diagnoses. The results show that the majority of men with coded irritative/painful urological conditions did not report prostatitis-like symptoms. This may reflect the transient nature of these symptoms or perhaps the response of the symptoms to treatment. In men with any of these coded conditions, however, prostatitis-like symptoms were reported much more commonly than in men with no such coded diagnosis. It is of interest to note that prostatitis-like symptoms were reported by 3% to 4% of controls. Possible explanations for this could be the use of other codes (eg benign prostatic hyperplasia) to document these symptoms, lack of reporting of the symptoms by patients, or lack of coding of symptoms by health care providers. There are limitations to this study that must be recognized. First, the questionnaire response rate was only 31%, which raises the possibility for nonresponse bias. Although our review of major ICD-9 codes indicated relatively small differences between respondents and nonrespondents, it is still likely that subjects with prostatitis-like symptoms were more likely to complete the questionnaire than those without such symptoms. This response bias would erroneously increase our prevalence estimate. Second, no clinical evaluations of subjects with symptoms were performed. Therefore, it is possible that some of the symptoms identified were due to a discrete but unrecognized cause. However, using ICD-9 codes in the KPNW database, we did apply many of the typical exclusion criteria used for NIDDK studies of chronic prostatitis. Finally, since the respondents were predominantly white and educated, these findings may not be generalizable to populations with different ethnic or demographic characteristics.
596
PROSTATITIS-LIKE SYMPTOMS IN MANAGED CARE POPULATION
CONCLUSIONS
EDITORIAL COMMENT
This population based study indicates that approximately 1 in 9 men have prostatitis-like symptoms. These symptoms were identified in subjects without evidence of CP/CPPS exclusion criteria in the medical record. Application of 2 different definitions for prostatitis-like symptoms identified unique groups of men, with limited overlap in the 2 groups. Further research of this type would benefit from the adoption of a standardized, uniform definition to define the presence of symptoms.
Prostatitis is a common condition. The authors have estimated the prevalence of men in the community with these symptoms. Perineal and/or ejaculatory pain (definition number 2) are the main symptoms that distinguish men with a clinical diagnosis of prostatitis from asymptomatic men or men with benign prostatic hyperplasia.1 Ejaculatory pain or discomfort, while not only one of the most prevalent symptoms, is also one of the most bothersome.2 Our group had previously reported a 9.7% prevalence of prostatitis-like symptoms using this same definition and a 6.6% prevalence using a more rigid definition in community men in Canada (reference 5 in article). However, our study, like this reported study, was hampered by a low responder rate and no subsequent clinical confirmation. But both of these studies do confirm that many men of all ages have prostatitis-like symptoms which likely impact their activities and/or quality of life, but fail to report these to their physician. For urologists, that is probably a good thing, since we do not have truly effective evidence based therapies to offer these men. The National Institutes of Health Chronic Prostatitis Collaborative Research Network is currently recruiting patients with chronic prostatitis into an early intervention trial to determine if newly diagnosed men will respond to ␣-blocker therapy (alfuzosin). Being able to prevent progression into the more familiar condition physicians recognize as the difficult to manage chronic prostatitis/chronic pelvic pain syndrome will then provide us with the impetus to actively seek out men with prostatitis-like symptoms. Until then it is perhaps best for the majority of those men identified by Clemens et al to stay hidden in the community.
Abbreviations and Acronyms CP/CPPS ⫽ chronic prostatitis/chronic pelvic pain syndrome ICD-9 ⫽ International Classification of Diseases, 9th edition KPNW ⫽ Kaiser Permanente Northwest NIDDK ⫽ National Institute of Diabetes and Digestive and Kidney Diseases NIH-CPSI ⫽ National Institutes of Health Chronic Prostatitis Symptom Index REFERENCES 1.
2.
3.
4.
5.
6.
7.
Collins, M. M., O’Leary, M. P. and Barry, M. J.: Prevalence of bothersome genitourinary symptoms and diagnoses in younger men on routine primary care visits. Urology, 52: 422, 1998 Clemens, J. Q., Meenan, R. T., Rosetti, M. C. O., Gao, S. and Calhoun, E. A.: Prevalence and incidence of interstitial cystitis in a managed care population. J Urol, 173: 98, 2005 Schaeffer, A. J., Landis, J. R., Knauss, J. S., Propert, K. J., Alexander, R. B., Litwin, M. S. et al: Demographic and clinical characteristics of men with chronic prostatitis: the National Institutes of Health Chronic Prostatitis Cohort study. J Urol, 168: 593, 2002 Cheah, P. Y., Liong, M. L., Yuen, K. H., The, C. L., Khor, T., Yang, J. R. et al: Chronic prostatitis: symptom survey with follow-up clinical evaluation. Urology, 61: 60, 2003 Nickel, J. C., Downey, J., Hunter, D. and Clark, J.: Prevalence of prostatitis-like symptoms in a population based study using the National Institutes of Health Chronic Prostatitis Symptom Index. J Urol, 165: 842, 2001 Clemens, J. Q., Meenan, R. T., Rosetti, M. C. O., Brown, S. O., Gao, S. and Calhoun, E. A.: Prevalence of interstitial cystitis symptoms in a managed care population. J Urol, 174: 576, 2005 Roberts, R. O., Lieber, M. M., Rhodes, T., Girman, C. J., Bostwick, D. G. and Jacobsen, S. J.: Prevalence of a physician-assigned diagnosis of prostatitis: the Olmsted County Study of Urinary Symptoms and Health Status Among Men. Urology, 51: 578, 1998
J. Curtis Nickel Department of Urology Queen’s University Kingston, Ontario, Canada
1.
2.
Litwin, M. S., McNaughton-Collins, M., Fowler, F. J., Jr., Nickel, J. C., Calhoun, E. A., Pontari, M. A. et al: The National Institutes of Health Chronic Prostatitis Symptom Index: development and validation of a new outcomes measure. J Urol, 162: 369, 1999 Shoskes, D. A., Landis, J. R., Wang, Y., Nickel, J. C., Zeitlin, S. I., Nadler, R. et al: Impact of post-ejaculatory pain in men with category III chronic prostatitis/chronic pelvic pain syndrome. J Urol, 172: 542, 2004
Purpose: We calculated the prevalence of symptoms typically associated with chronic prostatitis/chronic pelvic pain syndrome in men in a managed care population in the Pacific Northwest. Materials and Methods: A questionnaire mailing to 5,000 male enrollees 25 to 80 years old in the Kaiser Permanente Northwest (Portland, Oregon) health plan was performed. The questionnaires included screening questions about the presence, duration and severity of pelvic pain, and the National Institutes of Health Chronic Prostatitis Symptom Index. Chronic prostatitis/chronic pelvic pain syndrome symptoms were defined in 2 ways: 1) presence of any of the following for a duration of 3 or more months: pain in the perineum, testicles, tip of penis, pubic or bladder area, dysuria, ejaculatory pain; and 2) perineal and/or ejaculatory pain, and a National Institutes of Health Chronic Prostatitis Symptom Index total pain score of 4 or more. Prevalence estimates were age adjusted to the total Kaiser Permanente Northwest male population. Results: A total of 1,550 questionnaires were returned. The prevalence of chronic prostatitis/chronic pelvic pain syndrome symptoms was 7.5% for definition 1 and 5.9% for definition 2. Mean National Institutes of Health Chronic Prostatitis Symptom Index scores were 17 for definitions 1 and 2. Of those with prostatitis-like symptoms, 30% met criteria for having both definitions present. The prevalence of prostatitis-like symptoms using either of the 2 diagnoses was 11.2%. Conclusions: This population based study indicates that approximately 1 in 9 men have prostatitis-like symptoms. Application of 2 different definitions for prostatitis-like symptoms identified unique groups of men, with limited overlap in the groups. Key Words: epidemiology, pelvic pain
The aim of this study was to assess the prevalence of prostatitis-like symptoms in men enrolled in a managed care health plan, and assess the differences in prevalence estimates that occur when various definitions for prostatitis-like symptoms are used. Administrative data from the health plan was used to apply typical CP/CPPS exclusion criteria to improve the specificity of the findings.
hronic prostatitis/chronic pelvic pain syndrome is a chronic disabling syndrome consisting of pelviperineal pain of unclear etiology, often accompanied by voiding and sexual symptoms. CP/CPPS is poorly understood, often inadequately treated, and extraordinarily bothersome in the men it afflicts.1 Since there is no objective marker for the presence of CP/CPPS, epidemiologic studies of the condition are difficult. Such studies can define the presence of CP/CPPS based on physician coded diagnoses, patient reported history, or assessment of the presence of CP/CPPS symptoms. Studies that focus on physician diagnoses require the patient to be seen and accurately diagnosed by a physician. Studies that use patient self-report may be inaccurate due to recall bias. Assessment of current symptoms may be nonspecific, as the symptoms could be due to conditions other than prostatitis. Furthermore, criteria used to define prostatitis-like symptoms are not standardized.
C
MATERIALS AND METHODS Study Population The EpicCare clinical database at Kaiser Permanente Northwest (KPNW) was used to define the study population. KPNW is based in the Portland, Oregon metropolitan area, which includes southwest Washington state. Specific details about the KPNW patient population and the EpicCare database search protocol have been previously published.2 An initial database search was performed to exclude subjects younger than 25 years or older than 80 years, those who were not current KPNW members at the time of the analysis (May 2002), those with dental coverage only, and those on the do not contact list for research studies. The age limits were chosen because previous epidemiological studies of this population have shown that members ages younger than 25 and older than 80 years are typically quite transient and very difficult to follow over time. After applying these initial demographic exclusions, 120,574 men were identified.
Submitted for publication September 21, 2005. Supported by National Institute of Diabetes and Digestive and Kidney Diseases Grant U01 DK060177-02. * Correspondence: Department of Urology, Northwestern University Feinberg School of Medicine, 303 E. Chicago Ave., Tarry 16, Chicago, Illinois 60611 (telephone: 312-695-6124; FAX: 312-6957030; e-mail: [email protected]). † Financial interest and/or other relationship with Merck, Pfizer, Medtronic, Allergan and Boehringer Ingelheim.
0022-5347/06/1762-0593/0 THE JOURNAL OF UROLOGY® Copyright © 2006 by AMERICAN UROLOGICAL ASSOCIATION
593
Vol. 176, 593-596, August 2006 Printed in U.S.A. DOI:10.1016/j.juro.2006.03.089
594
PROSTATITIS-LIKE SYMPTOMS IN MANAGED CARE POPULATION
Database Queries ICD-9 based queries of the KPNW database were used to identify subjects with CP/CPPS exclusion criteria based on those used in the National Institutes of Health Chronic Prostatitis Collaborative Research Network.3 Exclusion criteria included lower urinary tract cancer, neurological disease, radiation cystitis, urethral stricture, and dementia. Men with these exclusion criteria were excluded from further analysis, but were included in the population denominator for prevalence estimates. Subsequent ICD-9 based queries were used to identify those with codes indicating the presence of irritative or painful urological symptoms (referred to as irritative/painful urological conditions). These conditions included chronic prostatitis (ICD-9 601.1), prostatitis not otherwise specified (601.9), interstitial cystitis (595.1), bladder pain (788.9), dysuria (788.1), frequency (788.41), chronic cystitis (595.2), unspecified cystitis (595.9), unspecified disorder of male genital organs (608.9) and unspecified abdominal pain (789.0). Sampling Strategy From the database queries a total of 18,011 men were identified with at least 1 of the ICD-9 coded irritative/painful urological conditions and none of the exclusion criteria. A total of 3,099 questionnaires were mailed to a random sample of these individuals, who were identified as cases for purposes of the study. An additional 1,901 questionnaires were mailed to male subjects with none of the coded irritative/painful urological conditions, for a total mailing of 5,000. These men were labeled controls. The questionnaires included demographic data (date of birth, race, gender, education, income), screening questions to identify the presence, duration and severity of urgency, frequency and pelvic pain, and the NIH-CPSI. The NIHCPSI was modified slightly from its original version to reflect a time period of 1 month (rather than 1 week as in the original). Prevalence estimates were adjusted to the age distribution of the KPNW population and then weighted based on the proportion of the 2 groups (those with and
TABLE 2 Pain Symptoms
No. With Symptoms (% of respondents)
Pubic/bladder area Testicles Dysuria Perineum Ejaculatory Tip of penis
161 (10.3) 128 (8.3) 109 (7.0) 120 (7.7) 114 (7.3) 71 (4.5)
without coded irritative/painful urological diagnoses) in the entire KPNW population. Definitions of Prostatitis-Like Symptoms Two definitions for prostatitis-like symptoms were used. These definitions are identical to those used in previous surveys that assessed the prevalence of prostatitis symptoms.4,5 Definition 1 is the presence of any of the following for 3 or more months: pain in the perineum, testicles, tip of penis, below waist, dysuria, ejaculatory pain.4 Definition 2 is perineal and/or ejaculatory pain/discomfort, and a total NIH-CPSI pain subscale score (range 0 to 21) of 4 or greater.5 RESULTS A total of 1,550 completed questionnaires were returned, for a response rate of 31%. Of the 1,550, 999 (cases) had 1 or more coded irritative/painful urological diagnosis, and 551 (controls) had none. The study population was 88% white race with a mean age of 59, and 64% had some college or postgraduate education. Demographics are presented in table 1. A previous comparison indicated no apparent clinically meaningful differences in the prevalence of ICD-9 diagnoses (using major ICD-9 diagnostic categories) between respondents and nonrespondents, thereby reducing the likelihood of nonresponse bias.6 The prevalence of prostatitis-like symptoms was 7.5% for definition 1 (95% CI 6.2%– 8.8%), and 5.9% for definition 2 (95% CI 4.7%–7.1%). The prevalence of prostatitislike symptoms using either of the 2 diagnoses was 11.2% (95% CI 9.6%–12.8%). Mean NIH-CPSI score for all sub-
TABLE 1 Pt age: Mean Standard deviation Range No. education (%): Less than 12 yrs 12 yrs or high school graduate Post-high school training other than college Some college College graduate Postgraduate No. pre-tax income (%): Less than $30,000 $30,000–$49,999 $50,000–$79,999 $80,000 or More No. race (%): American Indian or Alaskan Native Asian Black Native Hawaiian Other Pacific Islander White Other Hispanic
59 12.29 25–80 104 (0.7) 231 (14.9) 147 (9.5) 400 (25.8) 278 (17.9) 313 (20.2) 246 (15.9) 384 (24.8) 386 (24.9) 281 (18.1) 16 (1) 31 (2) 18 (1.2) 1 (0.1) 3 (0.2) 1,363 (87.9) 118 (7.6) 43 (2.8)
FIG. 1. Patients meeting criteria for definitions of CP/CPPS
PROSTATITIS-LIKE SYMPTOMS IN MANAGED CARE POPULATION
595
TABLE 3 Diagnosis
No. Pts
Mean NIH-CPSI Score (range)
% Definition 1
% Definition 2
Chronic prostatitis Prostatitis not otherwise specified Dysuria Frequency No diagnosis (controls)
140 658 119 128 551
10 (0–35) 10 (0–36) 11 (0–33) 11 (0–33) 4 (0–32)
28.6 24.6 31.1 21.1 4.4
15.7 14.4 18.5 10.2 3.1
jects was 7 (SD 6.9, range 0 to 36). Mean score for men with definition 1 symptoms was 17 and for definition 2 was also 17 (p ⫽ not significant). Table 2 shows the distribution of pain symptoms reported by all respondents. The most commonly reported symptom was pain in the suprapubic/bladder region. A total of 293 unique individuals (256 cases and 37 controls) had prostatitis-like symptoms. Of these 293, 87 (30%) met criteria for both definitions (fig. 1). Table 3 presents symptoms stratified by ICD-9 diagnoses ‘chronic prostatitis’, ‘prostatitis not otherwise specified’, ‘dysuria’ and ‘frequency’. These data indicate that the majority of men (approximately 75%) with these coded diagnoses did not meet criteria for having prostatitis-like symptoms. However, the prevalence of prostatitis-like symptoms was significantly higher in men with these diagnoses than in men with no coded diagnosis (controls). Age specific prevalence rates of prostatitis-like symptoms (either definition) are presented in figure 2. Prostatitis-like symptoms were more common in men greater than 50 years of age, peaking at age 56 to 60. Approximately 76% of the men with symptoms were over age 50, while 24% were 50 years of age or less. DISCUSSION Using 2 different previously described definitions for prostatitis-like symptoms, we found the prevalence of such symptoms to be 11.2% in men aged 25 and above. These results can be compared with similar studies that used the same definitions. Using definition 1 Cheah et al reported the prevalence of prostatitis-like symptoms to be 8.7% in a sample of 3,147 Malaysian men 20 to 50 years old.4 This estimate is similar to our findings of 7.5%. It is possible that ethnic and/or age differences in the populations studied could account for some of the difference in the estimates.
FIG. 2. Age specific prevalence rates of prostatitis-like symptoms (either definition).
Nickel et al used definition 2 to define prostatitis symptoms, and found a prevalence of 9.7% in 868 Canadian men 20 to 74 years old who responded to a postal survey.5 Subsequently, Roberts applied the same definition to the Olmsted County, Minnesota male population, and identified symptoms in 2.3% of 1,541 men age 40 or older.7 Therefore, our prevalence rate of 5.9% is in between the rates reported in these 2 previous studies using this definition. Differences in the ages of the studied populations, and differences in the method of questionnaire administration could explain some of this discrepancy. In addition, the response rates in our study and the Nickel study were low (each approximately 30%, compared with greater than 80% for the Roberts study). This could artificially inflate the prevalence estimates due to response bias. Finally, there could be real differences in the prevalence of these symptoms in the studied populations. The extensive KPNW administrative database allows for a comparison to be made between patient self-reported symptoms and coded diagnoses. The results show that the majority of men with coded irritative/painful urological conditions did not report prostatitis-like symptoms. This may reflect the transient nature of these symptoms or perhaps the response of the symptoms to treatment. In men with any of these coded conditions, however, prostatitis-like symptoms were reported much more commonly than in men with no such coded diagnosis. It is of interest to note that prostatitis-like symptoms were reported by 3% to 4% of controls. Possible explanations for this could be the use of other codes (eg benign prostatic hyperplasia) to document these symptoms, lack of reporting of the symptoms by patients, or lack of coding of symptoms by health care providers. There are limitations to this study that must be recognized. First, the questionnaire response rate was only 31%, which raises the possibility for nonresponse bias. Although our review of major ICD-9 codes indicated relatively small differences between respondents and nonrespondents, it is still likely that subjects with prostatitis-like symptoms were more likely to complete the questionnaire than those without such symptoms. This response bias would erroneously increase our prevalence estimate. Second, no clinical evaluations of subjects with symptoms were performed. Therefore, it is possible that some of the symptoms identified were due to a discrete but unrecognized cause. However, using ICD-9 codes in the KPNW database, we did apply many of the typical exclusion criteria used for NIDDK studies of chronic prostatitis. Finally, since the respondents were predominantly white and educated, these findings may not be generalizable to populations with different ethnic or demographic characteristics.
596
PROSTATITIS-LIKE SYMPTOMS IN MANAGED CARE POPULATION
CONCLUSIONS
EDITORIAL COMMENT
This population based study indicates that approximately 1 in 9 men have prostatitis-like symptoms. These symptoms were identified in subjects without evidence of CP/CPPS exclusion criteria in the medical record. Application of 2 different definitions for prostatitis-like symptoms identified unique groups of men, with limited overlap in the 2 groups. Further research of this type would benefit from the adoption of a standardized, uniform definition to define the presence of symptoms.
Prostatitis is a common condition. The authors have estimated the prevalence of men in the community with these symptoms. Perineal and/or ejaculatory pain (definition number 2) are the main symptoms that distinguish men with a clinical diagnosis of prostatitis from asymptomatic men or men with benign prostatic hyperplasia.1 Ejaculatory pain or discomfort, while not only one of the most prevalent symptoms, is also one of the most bothersome.2 Our group had previously reported a 9.7% prevalence of prostatitis-like symptoms using this same definition and a 6.6% prevalence using a more rigid definition in community men in Canada (reference 5 in article). However, our study, like this reported study, was hampered by a low responder rate and no subsequent clinical confirmation. But both of these studies do confirm that many men of all ages have prostatitis-like symptoms which likely impact their activities and/or quality of life, but fail to report these to their physician. For urologists, that is probably a good thing, since we do not have truly effective evidence based therapies to offer these men. The National Institutes of Health Chronic Prostatitis Collaborative Research Network is currently recruiting patients with chronic prostatitis into an early intervention trial to determine if newly diagnosed men will respond to ␣-blocker therapy (alfuzosin). Being able to prevent progression into the more familiar condition physicians recognize as the difficult to manage chronic prostatitis/chronic pelvic pain syndrome will then provide us with the impetus to actively seek out men with prostatitis-like symptoms. Until then it is perhaps best for the majority of those men identified by Clemens et al to stay hidden in the community.
Abbreviations and Acronyms CP/CPPS ⫽ chronic prostatitis/chronic pelvic pain syndrome ICD-9 ⫽ International Classification of Diseases, 9th edition KPNW ⫽ Kaiser Permanente Northwest NIDDK ⫽ National Institute of Diabetes and Digestive and Kidney Diseases NIH-CPSI ⫽ National Institutes of Health Chronic Prostatitis Symptom Index REFERENCES 1.
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Collins, M. M., O’Leary, M. P. and Barry, M. J.: Prevalence of bothersome genitourinary symptoms and diagnoses in younger men on routine primary care visits. Urology, 52: 422, 1998 Clemens, J. Q., Meenan, R. T., Rosetti, M. C. O., Gao, S. and Calhoun, E. A.: Prevalence and incidence of interstitial cystitis in a managed care population. J Urol, 173: 98, 2005 Schaeffer, A. J., Landis, J. R., Knauss, J. S., Propert, K. J., Alexander, R. B., Litwin, M. S. et al: Demographic and clinical characteristics of men with chronic prostatitis: the National Institutes of Health Chronic Prostatitis Cohort study. J Urol, 168: 593, 2002 Cheah, P. Y., Liong, M. L., Yuen, K. H., The, C. L., Khor, T., Yang, J. R. et al: Chronic prostatitis: symptom survey with follow-up clinical evaluation. Urology, 61: 60, 2003 Nickel, J. C., Downey, J., Hunter, D. and Clark, J.: Prevalence of prostatitis-like symptoms in a population based study using the National Institutes of Health Chronic Prostatitis Symptom Index. J Urol, 165: 842, 2001 Clemens, J. Q., Meenan, R. T., Rosetti, M. C. O., Brown, S. O., Gao, S. and Calhoun, E. A.: Prevalence of interstitial cystitis symptoms in a managed care population. J Urol, 174: 576, 2005 Roberts, R. O., Lieber, M. M., Rhodes, T., Girman, C. J., Bostwick, D. G. and Jacobsen, S. J.: Prevalence of a physician-assigned diagnosis of prostatitis: the Olmsted County Study of Urinary Symptoms and Health Status Among Men. Urology, 51: 578, 1998
J. Curtis Nickel Department of Urology Queen’s University Kingston, Ontario, Canada
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Litwin, M. S., McNaughton-Collins, M., Fowler, F. J., Jr., Nickel, J. C., Calhoun, E. A., Pontari, M. A. et al: The National Institutes of Health Chronic Prostatitis Symptom Index: development and validation of a new outcomes measure. J Urol, 162: 369, 1999 Shoskes, D. A., Landis, J. R., Wang, Y., Nickel, J. C., Zeitlin, S. I., Nadler, R. et al: Impact of post-ejaculatory pain in men with category III chronic prostatitis/chronic pelvic pain syndrome. J Urol, 172: 542, 2004