The present population-based cross-sectional epidemiological survey of prostatitis in men aged 20–59 years in 1996–1997 gave an overall lifetime prevalence of 14.2% (261 with prostatitis out of 1832 respondents), and seems to be the first survey of the occurrence of prostatitis in an unselected, randomly chosen male population.
Earlier published studies have mainly derived data from questionnaire results combined with retrospective reviews of physicians’ charts, giving prevalences from 4% to 11% (Moon et al. 1997, McNaughton-Collins et al. 1998b, Roberts et al. 1998, Nickel et al. 2001), or based on data concerning urological outpatient visits, giving estimates between 19% and 25% (Roberts et al. 1997, Pavone et al. 2000) or even up to 35% (de la Rosette et al. 1992a). These major differences between the figures have been explained in terms of study design, the ages of the patients and the indeterminate definition of prostatitis. Such reports must therefore be regarded as indicating the prevalence of prostatitis in particular series of patients seen by physicians and do not reflect its prevalence in the general population (Nickel et al. 2001).
The survey performed by Alexander and Trissel (1996) has also been regarded as a population-based one, although it is impossible give the prevalence of prostatitis, because the respondents were all prostatitis patients. The population was also highly selected, since it included only men having access to the Internet.
A recently published survey by Nickel et al. (2001) is similar in its basic setting to the present one and arrives at a prevalence of 9.7%. It must be mentioned in connection with this result, however, that their response rate was only 29%, which leaves behind a large measure of uncertainty and missing information. Also, the older respondents, those over 60 years (age range 20–74 years), may have been greatly influenced by possible BPE or prostate cancer (Bennett et al. 1993). Men over 60 years were excluded from the present series.
The explanatory power of the present findings relies on the high response rate (75%) and the demographically balanced distribution of the respondents (socio-economic background) over the whole area surveyed (rural and suburban aspects equally represented) and also on the number of preliminary age groups counted, to minimize the influence of sample size on the results.
The prevalence of prostatitis in northern Finland may in reality be even higher, as there were 265 men (14.5% of the 1832), who were uncertain about their symptoms. If it had been possible to interview this uncertain group personally after the survey, the prevalence might have been even higher.
27% of the men with prostatitis symptoms in the present randomly chosen population in northern Finland had prostatitis symptoms repeatedly at least once a year, which is also highly comparable with the results of up to 35% given by de la Rosette et al. (1992a).
Moreover, every population includes ”silent” sufferers, who do not visit a doctor and will be missed if the survey is based only on health care registers or notes (McNaughton-Collins et al. 1998a, Roberts et al. 1998). It must be remembered, however, that the present survey also included men who had had only one prostatitis attack, whereas all the other published reports deal with cases of chronic prostatitis. The definition and diagnosis of prostatitis has not been uniform, however, and it is difficult to distinguish by questioning between its acute and chronic forms.
One explanation for the relatively high prevalence of prostatitis in the present survey could be the cold climate in northern Finland. The possible influence of climatic factors has not been extensively discussed, a special section of questions in the present survey was devoted to collecting data especially on this topic. Clear evidence of a seasonal influence on the initiation and worsening of symptoms of prostatitis was obtained, in that 63% of the men reported having their most severe symptoms in wintertime (November–March) and 53% considered that the cold climate was the main reason for their illness. It must remembered, however, that the summer is short in Finland, people are on vacation and health care centres and hospitals are partially closed, all factors causing a decrease in the seeking of medical help and in its availability during the summertime.
Although it is a common belief that prostatitis is a disease of young males, the present results showed that the oldest group of men had prostatitis symptoms most often, and are in accordance with those of Roberts et al. (1997) and McNaughton-Collins et al. (1998b), whereas Nickel et al. (2001) found a slightly higher prevalence of prostatitis in the age group below 50 years than among men over 50 (11.5% vs 8.5%). There are studies supporting the latter finding, but these were performed on younger, selected populations, e.g. military personnel, (Drabick et al. 1997, Moon et al. 1997) and the results cannot be taken as a basis for general comparisons.
The explanation for the over-representation of prostatitis in older men may be the co-existence of BPE, as it is known that increased detrusor pressure is needed to empty the bladder in obstructive voiding, which can predispose the subject to a reflux of urine into the prostate gland (Kirby et al. 1982). Anyway, older men also have a longer time to develop the disease than their younger counterparts. Histopathological evidence of prostatitis has been confirmed in up to 98% of prostatitis patients (Kohnen & Drach 1979, Doble et al. 1989b, Nickel et al. 1999a, True et al. 1999), and Schatteman et al. (2001) have reported figures of up to 100%.
Divorced and single men were found here to have a lower risk of prostatitis than their married counterparts, which is difficult to explain, but the difference could be due to married men having a higher exposure to bacterial vaginosis in their wives ( Stamey 1973, Drach 1976, Worm & Peterson 1987, Berger et al. 1989). On the other hand, single and divorced men may have a higher frequency of random intercourse and numerous sexual partners, with a possible increased risk of sexually transmitted disease (Worm & Petersen 1989), or else they can experience only sexual excitement (Kretschmer 1937) without physiological expulsion of semen and release of intraductal pressure.
One interesting finding in the survey showed that 48% of men with prostatitis symptoms in Finland have at least one male relative with the same symptoms, while Alexander and Trissel (1996), in their data on 161 men with prostatitis, reported that about 12% had relatives with similar symptoms of prostatitis. This can be explained by the possession of similar hobbies, jobs and outdoor activities (mainly hunting in autumn and fishing around the year), along with the exposure to the influence of the cold northern climate.
The special fears and personality features of prostatitis patients have not been studied extensively. Men with prostatitis have considerable psychic stress, and some degree of psychic difficulty (anxiety, depression, affect lability, weak masculine identity) has been discovered earlier in 80% of patients with chronic prostatitis, while signs of severe psychic disturbance have been reported in 20 to 50% of cases (Keltikangas-Järvinen et al. 1981, Keltikangas-Järvinen et al. 1982, Keltikangas-Järvinen et al. 1989, de la Rosette et al. 1992a, de la Rosette et al. 1993b, Berghuis et al. 1996).
Young et al. (1906) already mentioned their patients´ concern over the possibility of undetected prostate cancer, and 17% of the present men reported a constant fear of prostate cancer despite proper investigations performed to exclude this possibility. McNaughton-Collins et al. (1998a) also reported that 22% of men were worried about their genito-urinary symptoms, which might be due to prostate cancer.
Similarly, a fear of untreated sexually transmitted disease was reported by Kretschmer (1937). This seemed not to be a problem in the present survey, however, as only 2.2% of the respondents reported such fear.
Chronic pain syndromes, including chronic prostatitis can cause psychological and physiological disability, involving depression, anxiety, sexual disorders (decreased libido and impotence) and difficulties in personal or social relationships (Kretschmer 1937, Keltikangas-Järvinen et al. 1981, Berghuis et al. 1996).
Sexual disturbances can place a great burden on human behaviour. Young et al. (1906) pointed out that erectile disturbances were present in 11% of cases and libido problems in 9%, and they pointed especially to premature ejaculation or sexual hypersensitivity in 20% of cases related to prostatitis. Kretschmer (1937) reported a decrease in libido in 16% of cases and total loss or decreased potency in 8% and 14%, respectively.
As reported by Keltikangas-Järvinen et al. (1981), sexual disturbances are common in men with chronic prostatitis, so that 52% of their prostatitis patients interviewed by a psychologist reported suffering from periodic or total impotence or decreased libido. Berghuis et al. (1996) reported that chronic prostatitis reduced the frequency of sexual contacts in 85% of cases, interfered with or ended ongoing sexual relationships in 67% and prevented or inhibited establishing new sexual relationships in 43%.
Alexander and Trissel (1996) nevertheless reported the prevalence of sexual disturbances to be only 6.6% (erectile dysfunctions and premature ejaculation taken together), whereas they did not ask about libido problems. In the present series, 43% of the respondents had erectile dysfunction and 24% decreased libido, which is consistent with the earlier findings of Keltikangas-Järvinen et al. (1981), while Pavone-Macaluso et al. (1991) reported reduced sexuality in 32% of cases without any further specification.
Prostatitis symptoms are mostly recurrent, causing considerable psychic stress. All this can reflect on the behaviour of patients in the long run. The importance of psychic stress, related to the chronic pain caused by prostatitis, was already mentioned by Young et al. (1906) and later confirmed by Kretschmer (1937). Chronic pain complaints and voiding dysfunctions were accompanied by neurasthenia and sexual disturbances, developing a burden on the social well-being and marital relationships of patients (Kretschmer 1937). Unrecognized chronic prostatitis with sexual disturbances can be a reason for suicide. The retrospective critical analysis of 1000 cases presented by Kretschmer (1937) nevertheless contained only one case of suicide after severe melancholy (0.1%). In the present survey 3.2% of the patients had some tendency for suicidal thinking, while Alexander and Trissel (1996) reported such behaviour in 5% of cases.
The personality features of men with prostatitis have been tested in a few selected contexts, and at least four pathologies have been found, i.e. psychosomatic personality, alexithymic personality, borderline personality and narssistic personality (Keltikangas-Järvinen et al. 1982). De la Rosette et al. (1993a) suggest that it is difficult to arrive at the conclusion that there are personality features typical of men with chronic prostatitis symptoms. The personality features of prostatitis patients have not been compared earlier with those of symptomless men using a self-assessment approach, and the present results based on information given by the respondents in an unselected population-based survey rather than in a specific psychological test showed men suffering from prostatitis to be 2 to 4 times more busy, nervous and meticulous than those without this disorder. A self-administered questionnaire filled in at home may give more accurate and truthful results in this group of men, as it is easier to elicit answers concerninig depression, anxiety or other mental symptoms at home, where the respondents can read and think about the questions in privacy (Rhodes et al. 1995, Roberts et al. 1996).
Keltikangas-Järvinen et al. (1989) showed that prostatitis patients become less cooperative with time and that their illness behaviour may be problematic, so that intensive psychic support is recommended for these men. Sometimes psychiatrists or psychologists are also consulted by urologists who feel that hidden psychological factors may play a role in the symptomatology of prostatitis patients for whom treatment has been unsuccessful (Kretschmer 1937, Keltikangas-Järvinen et al. 1981, Keltikangas-Järvinen et al. 1989, Egan & Krieger 1994).
Chronic psychic stress may cause organic changes in certain biological systems, and these may in turn influence the individual’s emotional-psychological set-up (Keltikangas-Järvinen et al. 1981, Addison 1984, Keltikangas-Järvinen et al. 1989, Berghuis et al. 1996, Wenniger et al. 1996). A new and unexpected finding of the present study never before discussed in connection with prostatitis symptoms was the need to be alone in a public urinal, a symptom generally connected with functional bladder neck dysfunction (Turner-Warwick et al. 1973, Barbalias et al. 1983, Hellstrom et al. 1987).
Whatever lies behind the fears of prostatitis symptoms, 69.2% of the present men wanted to have regular medical check-ups, compared with 60% of the cases reported by Nickel et al. (2001). Educational background and social well-being did not correlate with the degree to which the patients suffered from their prostatitis symptoms. This finding was also confirmed by Nickel et al. (2001).