Aims
of study
Epidemiological studies on female urinary incontinence
are seldom performed, because
embarrassment and fatalism make
difficult quantifying the true
prevalence of symptoms in general
population ( 1). Instruments used
for definition and quantification
are highly variable and therefore
not comparable. Rates are varying
from 4 to 52% in relationship
to the methods of investigation
and the age of
females examined ( 2-3).
This large study was completed
in a sanitary district in Northern
Italy, by mail or directly to
people referred to public outpatient
offices for gynecological pathologies.
Methods
A self administered questionnaire ( SQ) was
submitted by mail to 4440 females,
aged 18 - 65, in the district
named VA: questions investigated
circumstances of urinary leakage,
urgency /frequency syndrome, difficulties
in bladder emptying, quality of
life and fecal incontinence: it
was coupled with an additional
form (HF) that investigated history,
social, economical and obstetric
factors. In another district of
the same region named DE, all
patients referred to a public
gynecological outpatient office
for benign conditions from Nov.
97 to July 98 were answered to
fill the same questionnaire and
the additional form (HF) : 1989
patients were recruited after
they have received by physicians
explanations about the aims of
the study and the importance for
them to seek aid for the problem
of urinary incontinence: pts.
were then left free to fill the
form SQ or
not.
Results
1558 HF and 1491 SQ were collected from the
VA group and 1989 HF and 1512
SQ from the DE one, which represents
a response rate for SQ of 33.6
% and 76% respectively. The modality
of administration of the questionnaire
represents a significant factor
in response rates: a questionnaire
send only by mail is poorly
understood and taken into
account, even if at the beginning
of the study all G.P. of the district
were alerted about it and informed
their patients. On the other hand,
if a questionnaire is well explained
and administered by a physician,
patients are available to answer
the interview and to fill
in a questionnaire regarding their
condition.
About pts’ age, the relationship between female
population and enrolled patients
is shown in table 1: curves of
distribution are similar, but
not completely overlapping in
the sample, while a perfect similarity
is observed in VA group: this
is due to a small prevalence of
middle-aged people referred to
public outpatient office in DE
district. The similarity between
VA group and general population
demonstrates that there hasn’t been any selective factor
in the response rate for each
age.
Conclusions
This large epidemiological study has been performed
by means of 2 different ways of
administration of a disease-specific
questionnaire and an historical
form, which is very useful for analyzing socio-economical, obstetrical and
medical factors influencing the
prevalence of urinary incontinence
( see part two).
The response rate was obviously
highly different between females
contacted only by mail and those
interviewed directly
by physicians and this fact represents a major bias in the analysis of data eventually collected
only by means of the first method
.
Table 1.
Age distribution in the region and in the 2
groups
|
Age
|
Population %
|
Pts.%
|
VA group%
|
DE group%
|
|
18-30
31-40
41-50
51-60
61-65
|
25.8
24.3
21.5
19.5
8.9
|
21.6
25.3
25.3
20.7
7.1
|
26.4
24.2
23
19.3
7.1
|
17.4
25.3
26.3
21.3
7.1
|
References
1)
Br .Med. J. 281:1242-45, 1980
2)
J.Urol.136: 1022-30,1986
3)
J. Gerontol. 45: 67-72, 1990.
