Low quality of life in men with chronic prostatitis-like symptoms | Prostate Cancer and Prostatic Diseases

These results show that many cases of CP are not diagnosed. CPS was more than twice as prevalent as DCP (3.7% vs 1.4%). Furthermore, the QOL of men with CP was much lower than the national norm in all domains. QOL was particularly low in the RP, SF, RE, and MH domains.

Nickel et al. reported a prevalence of “chronic prostatitis like symptoms” of 9.7% from a survey done in Canada (n = 868) using the NIH-CPSI [5]. Subsequently, in several small studies done in limited geographical areas, the prevalence of CP has been estimated to be between 2.7% and 5.9% [6,7,8]. Liang et al. reported a prevalence of 8.7% for “prostatitis-like symptoms” in 12,743 people in five regions of China [9]. The sample in that study was large, but the sampling method is unclear and all of the participants were under 60 years of age. Suskind et al. estimated that the prevalence of “chronic prostatitis/chronic pelvic pain syndrome” was 1.8% (95% CI 0.9–2.7), based on data from 149 respondents after eligibility screening of 6072 randomly sampled families from across the USA [10]. The participants in our study were representative of men in Japan, given that we used quota sampling by age and place of residence, a relatively large sample size (5 010), and a wide age range (20 to 84 years). The prevalence of 5.1% (sum of DCP and CPS) in the present study is within the range reported in almost all previous studies (1.8% to 9.7%). We note that references 5 through 10 cited in this paragraph all use Nickel’s definition [5], which is likely to cover both DCP and CPS (i.e., they did not distinguish between DCP and CPS). Roberts et al. found a prevalence of DCP of 1.7% by self-report in 1543 randomly sampled residents of Olmsted County, Minnesota, USA (ages 47–90 years) [11]. That result is similar to the result of our study, although the men studied by Roberts et al. were older. Liang et al. also reported a prevalence of DCP of 4.5% [9]. Their report suggests that undiagnosed CP exists, but it was not their focus. Also, the participants in Liang’s study ranged in age from 15 to 60, while those in the present study ranged in age from 20 to 84.

The QOL of participants with CP, whether that CP had been diagnosed or was only suspected, was lower than that of the adult population of Japan as a whole. Also, on all eight domains of QOL except GH, the participants with CP had lower QOL than did those with BPH. It is noteworthy that with regard to role functioning and social functioning (i.e., RP, SF, and RE), the impact of CP on QOL was as strong as the impact of dialysis, and the impact of CP on MH scores was even stronger than the impact of dialysis [26]. These results show that men with CP have impaired physical and mental health, and that they have difficulty in their daily activities including work and socializing.

CP and depression have been reported to coexist [27]. In the present study, CP-like symptoms were associated with depression, and the prevalence of depression and of depressive symptoms was as high in the CPS group as in the DCP group (Table 1). Since this was a cross-sectional study, we could not determine whether CP caused depression, depression caused CP, or the two were independently caused by some other factor. However, it has been suggested that anxiety-like behavior may increase with CP [28], and early diagnosis and treatment of CP may help prevent depression. Participants with DCP had more comorbid conditions than did those who had CPS and those who had no CP (Table 1). This is partly attributable to age, because having DCP, having a chronic comorbid condition, being a patient, and receiving any diagnosis, are all more likely in older people. We also note that (1) participants in the CPS and the no-CP groups were similar with regard to comorbid conditions, but QOL was substantially lower in the CPS group, and (2) QOL was quite low in both the DCP and CPS groups, even though comorbidities were more common in the DCP group. Therefore, independent of comorbidities, the presence of CP itself is associated with a poor QOL.

Considering that more than 5% of the total adult male population may have CP, and that its impact on QOL appears to be substantial, CP imposes a serious health burden at the societal level. In relatively young, working-age men, CP’s largest effect on QOL is to impair their mental health and their role functioning. That is, CP lowers their productivity, which is to say that in addition to individual effects on individual patients CP also has a substantial economic impact on society [29]. This emphasizes the need to focus not only on patients in whom CP has already been diagnosed but also on men in whom CP is suspected, and particularly on younger men.

More than half of the participants with CPS were under 60 years old, and the largest gap between the prevalence of DCP and that of CPS was among men in their 30 s (Fig. 1). That is, CP seems to be seriously underdiagnosed in young men. There are several possible reasons for this finding: One is that these younger men may simply be too busy with full-time work to seek medical attention. As expected from the age distributions, full-time employment was more common among participants with CPS than among those with DCP (Table 1). Another possible explanation is that CP is not well known, especially among young people, so they may be less likely to know that they might benefit from medical attention. Furthermore, even those who do seek medical attention may not receive the correct diagnosis if they go to a clinic that does not specialize in urology [30]. Even consulting a urologist might not be enough. Liu et al. stated that urologists themselves may be confused and frustrated when treating patients who have CP. Their difficulties interpreting their patients’ complaints can lead to a lack of confidence in their diagnoses and treatments [31]. To overcome this situation, it is necessary to develop screening tools for CP in the general population, and then to provide referrals for consultation to men who test positive and thus are likely to have undiagnosed CP. Additionally, we believe that there is an urgent need to develop better tools to assist in diagnosing CP in primary care and in urology clinics. Such tools might incorporate quantitative prediction rules that use information both from patients and from physicians. This study has several limitations. First, the sample was not drawn at random. However, even with random sampling, the influence of non-respondents cannot be excluded, as the participation rate in previous studies was about 30%. We believe that the method employed in this study to allocate the number of respondents by age group and by geographic information resulted in a sample that is reasonably representative. Second, there may be misclassification of DCP because this study uses only self-reported information from the participants. It is possible that patients with a diagnosis of a similar disease, such as acute prostatitis, answered that they had received a CP diagnosis. Furthermore, since this study is based on a questionnaire survey, we cannot be sure of the accuracy of the CP diagnosis at each clinic. Third, there may also be misclassification due to the use of Nickel’s criteria for CPS. It is possible that those assigned to the CPS group were in fact affected by other diseases with similar symptoms. Specifically, some participants were at a relatively high risk for BPH because of their age, and thus the CPS group may have included men with BPH as well as men with undiagnosed CP. However, Nickel’s criteria provide the only tool that can be used in epidemiological studies, and they have been used in several previous studies. Also, the results of the two sensitivity analyses indicate that assignment to the CPS group in this study was robust to the use of definitions of CPS other than Nickel’s criteria.