Prevalence of clinically confirmed interstitial cystitis in women: a population based study in Finland.
OBJECTIVE
Interstitial cystitis (IC) is a clinical condition occurring predominantly in women that is characterized by irritative voiding symptoms, including urinary frequency, urgency and pain. To our knowledge its etiology is unknown and little is known about its occurrence. We evaluated the prevalence of IC in women in Finland.


METHODS
A total of 2,000 participants were randomly selected from the Finnish population register. Urinary symptoms were evaluated using the validated O'Leary-Sant IC symptom and problem index questionnaire. Women with moderate or severe symptom scores (7 or higher) without any urinary tract infection during the last month were invited to undergo clinical examination.


RESULTS
Of the 1,331 respondents 32 had moderate or severe symptoms involving a suspicion of IC, of whom 21 underwent clinical evaluation. Three women were found to have probable IC and 4 had possible IC. Thus, the prevalence of clinically confirmed probable IC in women was 230/100.000 (95% CI 100 to 360) and that of possible/probable IC was 530/100.000 (95% CI 140 to 910). Considering the lack of information on 8 patients with urinary symptoms the corrected estimates were 300/100,000 (95% CI 120 to 770) and 680/100,000 women (95% CI 360 to 1,300), respectively.


CONCLUSIONS
Our results based on a large and representative population, and clinically confirmed diagnoses indicate that IC is substantially more common than previously thought.
Leppilahti
Mikael
M
Division of Urology, Seinäjoki Central Hospital, Seinäjoki, Department of Urology, Helsinki University Hospital, Helsinki, Finland. mikael.leppilahti@epshp.fi
Sairanen
Jukka
J
Tammela
Teuvo L J
TL
Aaltomaa
Sirpa
S
Lehtoranta
Kari
K
Auvinen
Anssi
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D018856:Cystitis, Interstitial / Q000453:epidemiology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D015995:Prevalence; D011795:Surveys and Questionnaires