- Email: [email protected]
Clinical and Cystometric Characteristics of Continent and Incontinent Noninstitutionalized Elderly
0022-5347 /88/1403-0567$02.00/0 VoL 140, September
'THE JCUR~!AL OF UROLOGY
Printed in U.S.A.
Copyright© 1988 by The Williams & Wilkins Co.
CLINICAL AND CYSTOMETRIC CHARACTERISTICS OF CONTINENT AND INCONTINENT NONINSTITUTIONALIZED ELDERLY ANANIAS C. DIOKNO, * MORTON B. BROWN, BRUCE M. BROCK, A. REGULA HERZOG DANIEL P. NORMOLLE
AND
From the Department of Surgery-Urology, Medical School, University of Michigan, Ann Arbor and Department of Urology, William Beaumont Hospital, Royal Oak, Michigan
ABSTRACT
A survey of the clinical and cystometric characteristics of continent and incontinent elderly subjects living in a community has not been reported previously. Household respondents identified initially from a random probability sample were invited to undergo a free clinic evaluation followed by an invitation to free urodynamic testing. Of the 1,955 household respondents 456 women and 298 men attended the clinic. From this group 169 women and 94 men accepted the urodynamic invitation. Cystometric studies reveal a significant difference between the over-all prevalence of uninhibited detrusor contraction between genders, 7.9 per cent for women and 35 per cent for men. The occurrence of uninhibited detrusor contractions is more prevalent among incontinent than continent subjects and this difference is marginally significant. There is no significant association between uninhibited detrusor contractions and symptoms of difficult bladder emptying, irritative symptoms, voiding frequency, nocturia and urodynamic diagnosis of outlet obstruction (normal or high pressure and poor flow) but there were significant associations with responses to questions about the delay in getting to a toilet. The mean bladder capacities of men and women do not differ significantly between the different age groups but the capacity is significantly smaller for those with uninhibited detrusor contractions. The post-void residual urine volume shows no association with the continence status. These findings raise questions regarding our conventional thinking as to the etiology of uninhibited detrusor contractions, especially in men, and of urinary incontinence in general. (J. Ural., 140: 567-571, 1988) Urodynamic characteristics of incontinent elderly patients have been reported in recent years. 1- 3 Major discrepancies exist in the results of the urodynamic characteristics among the different reports, which may be owing to differences in the urodynamic protocols and the types of subjects examined. Most subjects were a mixture of incontinent inpatients or outpatients referred to an incontinence clinic setting and, therefore, they may not be representative of the incontinent person living in the community. Information also is lacking on the urodynamic characteristics of the continent noninstitutionalized elderly. To define the urodynamic characteristics of the continent and incontinent elderly living in a community, a prospective study was done under the sponsorship of the National Institute on Aging. Estimates of the prevalences of urinary incontinence and related urological symptoms obtained by this study have been reported previously.' MATERIALS AND METHODS
The subjects included in this report consisted of 1,953 respondents 60 years and older who were identified and consented to be interviewed in their home from a random probability sampling of 13,912 households in the county of Washtenaw, Michigan.4 (Two additional subjects who refused to give their ages are omitted from the analyses.) Of the 1,953 household respondents interviewed 1,806 seniors were invited through telephone calls to visit the University of Michigan Turner Accepted for publication January 11, 1988. Supported by Grant 1 POl AGO 3742 from the National Institute on Aging. * Requests for reprints: University of Michigan Medical School, 1510B MSRB 1, Box 0666, 1150 West Medical Center Drive, Ann Arbor, Michigan 48109.
Geriatric Clinic. The free clinic evaluation included answering a 40-minute questionnaire similar to the one that they answered in their homes, a complete physical examination, including rectal and pelvic examination, and an analysis of the urine (dipstick and microscopic). At the end of the clinic visit all incontinent and most of the continent subjects were invited to undergo a free urodynamic testing. A total of 169 women and 94 men ultimately participated in the testing. The urodynamic testing started with an initial noninstrumented uroflowmetry and post-void residual urine measurement. An esophageal membrane catheter was inserted into the rectum for continuous abdominal pressure readings. A double sensor 8F microtransducer then was inserted and the sensors were placed appropriately with the aid of the fluoroscope. The tip sensor was placed inside the bladder and the proximal sensor was placed at the mid urethra in women or membranous urethra in men. Cystometry with simultaneous urethral and rectal pressure measurements was performed with a flow rate of 100 ml. per minute of 25 per cent sodium diatrizoate solution. Bladder capacity was considered to be reached when tonus limb 3 was observed, the subject complained of severe urge or an intense desire to void, or a strong uninhibited detrusor contraction occurred. At the conclusion of cystometry passive (static) and dynamic urethral profilometry was performed with the subject in the supine and standing positions. At the conclusion of the urethral pressure profile, a pressure flow study was performed. At the termination of the tests all subjects were sent home with either 50 mg. nitrofurantoin macrocrystals 3 times a day or trimethoprim-sulfamethoxazole twice a day for 3 days. Data analysis. It was desired to invite sufficient continent subjects to the clinical and urodynamic examinations to have approximately equal sample sizes of continent and incontinent
567
568
DIOKNO AND ASSOCIATES
subjects who underwent the urodynamic testing. Therefore, subjects were stratified into 8 groups by gender (men or women), continence status (continent or incontinent) and age (less than 75 years, or 75 or more years old). All incontinent subjects were invited to the clinic. To obtain similar numbers of continent and incontinent subjects in each age and gender grouping, all continent women and all continent men in the younger group were invited to the clinic but only 70 per cent of the older continent men were invited. When the observations were categorized by the household self-reported continence status, rates or proportions were combined across the 8 groups to reflect the relative sizes of the groups in the original household survey. (The age and sex distribution in the original household survey is similar to that of the census for Washtenaw County.) 4 These rates or proportions are referred to as adjusted estimates and they represent estimates that would be obtained by a random sample of the entire population of seniors 60 years and older. When the observations were categorized by the clinical diagnosis rates or proportions again were combined to reflect the relative sizes of the groups in the original household survey; an extra step was needed to define the appropriate factors, since the proportions of incontinent subjects reported by the clinician must be converted into proportions of the original 8 household groupings. Again, rates or proportions obtained in this manner are referred to as adjusted estimates and they may be interpreted as described previously. The proportions (or factors) used to combine groups are presented in table 1. Estimates of prevalence of a condition or symptom were obtained for each of the 8 groups. Group estimates were combined by multiplying by the factors (values) in table 1 and dividing by the sum of the factors. Standard errors were computed for these adjusted prevalence estimates using an asymptotic expansion to adjust for the use of these factors. Comparisons between continent and incontinent subjects were obtained by 2-sample tests (z test for proportions or t test for continuous variables), which were computed as the difference between the estimates for the 2 groups divided by the appropriate standard error (the square root of the sum of the squares of the 2 standard errors).
Response rates to clinical and urodynamic invitations. The participation rates to the clinical invitation among the household respondents in each of the 8 groups (gender by self-
1. Factors used to combine results across age groupings and
continence status Factors Used With Age (yrs.)
Household Self-Report*
Clinician Diagnosist
Women Continent Incontinent
<75 75+ <75 75+
Total No.
0.432 0.192 0.264 0.112 1,151
0.396 0.187 0.300 0.117 456
0.642 0.170 0.136 0.052 802
0.672 0.164 0.106 0.058 298
Men Continent Incontinent Total No.
<75 75+ <75 75+
TABLE 2.
Participation rates (per cent) of household respondents to clinic and urodynamic invitations Clinic
Continence Status
RESULTS
TABLE
reported continence status by age) are presented in table 2. Based on these participation rates the adjusted participation rates were 37.3 per cent for self-reported continent women and 38.5 per cent for continent men. For self-reported incontinent respondents the adjusted participation rates were 4 7.6 per cent for women and 59.5 per cent for men. For both genders these rates of participation differed significantly by continence status (z = 2.99, p <0.003 for women and z = 3.69, p <0.0003 for men). Younger women were more likely to accept the clinical invitation (z = 2.91, p <0.004 for continent and incontinent subjects) than were older women, while for men age did not significantly affect the participation rates. The response rates to the urodynamic invitation of all clinic participants also are presented in table 2. Of self-reported continent subjects the adjusted rates of participation were 28.8 per cent for women and 26.6 per cent for men. For incontinent respondents the rates were 46.6 per cent for women and 44.2 per cent for men. The adjusted participation rates for incontinent subjects were higher than for continent subjects (z = 3. 72, p <0.0002 for women and z = 2.64, p <0.01 for men). Demographic data and health status. The mean ages for continent men and women seen at the clinic were 68.2 and 69.4 years, respectively. For incontinent responders the mean ages were 70.7 and 68.5 years, respectively. The self-assessed health status at the time of the clinical interview was considered good to excellent by 91.1 per cent of continent men and 95. 7 per cent of the continent women, while among incontinent respondents it was 78.9 per cent in men and 89.3 per cent in women. Comparison of the continence status in the household survey and the clinical evaluation. The continence status at the household interview was based on a set of questions presented in our earlier study. 4 The continence status at the clinical evaluation was based on the impression of the clinician. This evaluation was made from the response to the clinical questionnaire and the result of the physical examination, which included a simple provocative stress test without instrumentation.
* The factors used to report continence status are the proportions of the strata from the household survey. The sizes of the strata (N) are used in the computations of standard errors. The total sample size (1,151 + 802 = 1,953) is 2 less than that reported by Diokno and associates.4 Two subjects refused to give their ages. t The factors used to report continence status are the proportions of strata from the household survey multiplied by the relative frequencies of the clinician diagnosis.
Accepted No.
Urodynamic No. Contacted*
%
Accepted No.t
%
Women Continent: Age: <75 75+ Total %:j: Incontinent: Age: <75 75+ Total %:j: Over-all§ Continent: Age: <75 75+ Total %:j: Incontinent: Age: <75 75+ Total %:j: Over-all§
197 61
40.8 29.5 37.3 ± 2.0
484 207
59 16
29.9 26.2 28.8 ± 2.9
151 47
52.1 37.0 47.6 ± 2.8 41.2 ± 1.8 Men
290 127
77 17
51.0 36.2 46.6 ± 3.8 35.5 ± 2.4
178 36
38.0 40.4 38.5 ± 2.3
468 89
48 9
27.0 25.0 26.6 ± 3.1
57 27
56.4 67.5 59.5 ± 5.2 42.4 ± 2.1
101 40
26 11
45.6 40.7 44.2 ± 5.9 29.9 ± 2.8
456
298
169
94
* The number contacted for the clinic excludes those known to be deceased (14 women and 23 men), those omitted owing to the sampling scheme (36 men) and those with whom contact could not be re-established. t The number contacted for the urodynamic examination is equal to the number of acceptances of the clinic invitation. :j: The 2 age groupings are combined using the factors in table 1. Estimated proportions ± standard error are presented. § All 4 groupings are combined using the factors in table 1. Estimated proportions ± standard error are presented.
569
CYSTOlViETRIC STUDIES IN ELDERLY
Among the female respondents there was an 83 per cent agreement between the household self-reports and the clinician assessments (86.5 per cent agreement with the clinical diagnosis of continence and 79.2 per cent agreement with the diagnosis of incontinence). For men the over-all rate of agreement also was 83 per cent with the clinical diagnosis (84.6 per cent agreement for continent and 75.9 per cent for incontinent subjects). A review of the records for men showed that sev~ral of the disagreements were owing to men who were characterized by the clinicians as having post-void dribbling that the c.li~icians did not consider as incontinence but who were classified as incontinent by the household incontinence profile. The clinical diagnosis of continence status, rather than the household self-reported continence status, was used to compare continent to incontinent subjects with respect to the results of the urodynamic tests. The clinical diagnosis closely replicates the diagnosis of a clinician in an office setting by using not only the history (questionnaire) but also other clinical information that are critical to arrive at a specific diagnosis. Residual urine. Estimates of the proportion of subjects within various ranges of post-void residual urine measurements are presented in table 3. The adjusted estimates of the proportions of subjects with a value greater than 50 ml. were 18.4 per cent for men and 16.3 per cent for women. There was no statistical difference between continent and incontinent men or women with regard to the prevalence of a residual urine volume greater than 50 ml. There also was no significant difference owing to continence status for residual urine expressed as a percentage of the total bladder capacityo Uninhibited detrusor contraction. The adjusted estimates of prevalence of uninhibited detrusor contractions are preser_ited in table 4. The diagnosis of uninhibited detrusor contractions was based on the definition of the International Continence Society. 5 An uninhibited bladder is estimated to occur in 35.2 per cent of the male but only in 7.9 per cent of female subjects (z = 4.25, p <0.0001). As expected, there was a tendency for the estimates of prevalence of uninhibited detrusor contractions to be greater for incontinent than for continent subjects, 50.0 to 32.3 per cent in men and 1202 to 4.9 per cent in women, respectively, although these differences were not statistically significant owing to the large standard errors. A test. that combined the information from both genders was margmally significant (z = 2.02, p <0.05). The uninhibited detrusor contractions were observed while in the supine position in 56 per cent of the men and 58 per cent of the women with the conditiono The remaining proportions were observed only with the subject in the provocative standing position. Lower urinary tract symptomatology. Of the 23 men who reported bladder emptying symptoms 4 (17 per cent) ha~ uninhibited detrusor contractions, as did 4 of the 9 respondents (44 per cent) with irritation and infection symptoms and 17 of Estimated prevalences (per cent) of subjects classified by amount of residual urine and by clinician diagnosis
TABLE 3.
Clinician Diagnosis
Residual Urine (ml.)* 0-50
Continentt Inconti· nentt Over-all:j:
78.1 ± 5.8 86.5 ± 5.4
Continentt Incontinentt Over-all:j:
51-100
101-150
151+
Total No.
Women 9.7 ± 3.2 8.4 ± 2.9
2.4±1.7 1.6 ± 1.5
9.7 ± 3.7 3.5 ± 2.0
69 92
2.1 ± 1.2
7.1 ± 2.3
161
85.7 ± 5.5 73.4 ± 11.8
9.2 ± 2.2 Men 7.7 ± 3.7 21.5 ± 8.2
4.2 ± 2.9 0
2.5 ± 2.3 5.1 ± 4.8
54 22
83.6 ± 5.0
9.9 ± 3.4
3.5 ± 2.4
2.9 ± 2.1
76
81.6 ± 4.5
* Estimated proportions and their standard errors are presented. t The 2 age groupings are combined using the factors in table 1. :j: All 4 groupings are combined using the proportions in table 1.
TABLE 4.
Estimated prevalences of subjects classified by uninhibited bladder and clinician diagnosis Continent
% with uninhibited bladder * Total No. % with uninhibited bladder Total No.
*
Women 4.9 ± 2.9 65 Men 32.3 ± 6.8 50
Incontinent
Over-All
12.2 ± 3.7 99
7.9 ± 2.3 164
50.0 ± 11.7 22
35.2 ± 6.0 72
Subjects lacking information about diagnoses are omitted. * Mean ± standard error.
the 48 (39 per cent) without symptoms. These prevalences did not differ significantly. Of the 166 women there was no significant difference between those with and without symptoms in the occurrence of uninhibited detrusor contractions. These prevalences were 7 per cent for asymptomatic respondents, 8 per cent for women with irritative symptoms and 7 per cent for those with bladder emptying symptoms. Toileting history. The question "Do you ever have trouble getting to the bathroom on time?" was highly significant in predicting the occurrence of uninhibited detrusor contractions on cystometry. Of the 72 male responders to this question who underwent cystometry 14 (19 per cent) said yes and 58 (81 per cent) said no. Of the 14 positive responders 11 (79 per cent) have uninhibited detrusor contractions, compared to 16 of the 58 negative responders (28 per cent) (p = 0.001). Among the women the difference also was significant (p = 0.01). The question "What about finding the toilet is occupied and you are delayed in getting in?" was asked only of respondents who self-reported incontinence of urine. Of the men 22 respondents were asked the question and had cystometry. Of the 9 positive responders 7 (78 per cent) had uninhibited detrusor contractions, as did 3 of the 13 (23 per cent) with a negative response (p = 0.03 for this difference). Among the women, of the 34 positive responders 8 (24 per cent) had uninhibited detrusor contractions, compared to 1 of the 56 negative responders (2 per cent) (p = 0.003 for this difference). Urination frequency. The 24-hour frequency of urination among men and women was not correlated to the presence or absence of uninhibited detrusor contractionso Among the men, 5 of 14 (36 per cent) who voided 9 times or more and 17 of 54 (31 per cent) who voided 8 times or less had uninhibited detrusor contractions, compared to 4 of 41 (9.8 per cent) and 8 of 120 (6. 7 per cent), respectively, among the women. Men who reported voiding 0, 1, 2 and 3 or more times at night were observed to have 31 (4 of 33 (12 of 36), 20 (2 of 10) and 50 (5 of 10) per cent rates of uninhibited detrusor contractions, respectively. In women these rates were 2.6 (1 of 38), 7.6 (6 of 79), 12 (3 of and 4,3 (1 of 23) per cent, :respectively, For both genders these rates did not differ significantly. Prostatic surgery. There were 66 men who responded to questions on whether they had had prostate surgery. The prevalence of uninhibited detrusor contractions among those who did not have an operation was 33 per cent (17 of 52), while for those who did it was 29 per cent (4 of 14). These prevalences did not differ significantly. Bladder capacityo Among all male respondents the cystometric bladder capacity was 300 ml. or more in 42 of 67 (63 per cent): 30 of 4 7 (64 per cent) for the continent and 12 of 20 (60 per cent) for the incontinent respondents. Among the women 116 of 166 (70 per cent) had a 300 ml. or more bladder capacity: 55 of 70 (79 per cent) among the continent and 61 of 96 (64 per cent) among the incontinent respondents. Comparison of the bladder capacity between the continent and incontinent respondents shows no significant difference in men and women. Among the respondents with uninhibited detrusor contractions the mean bladder capacities of male and female respondents were 323 and 364 ml., respectively, whereas they were 419 and 404 ml., respectively, for those who did not have any uninhib-
570
DIOKNO AND ASSOCIATES
greater than 150 one would expect that urinary incontinence of the overflow type would be more prevalent. Since there are as many continent as incontinent respondents at any level of residual urine elevation it appears that elevated residual urine alone does not cause urinary incontinence. It is possible that incontinence develops in someone with high residual urine only when there is total detrusor failure, superimposed detrusor overactivity or sphincteric dysfunction. A major finding in our study is the significant difference between the prevalence of uninhibited detrusor contractions between genders. The over-all prevalence of 7.9 per cent among all women is significantly lower than the 35.2 per cent prevalence among men. In women as in men there is a tendency to observe more occurrences of uninhibited detrusor contractions among the incontinent subjects than their continent counterparts. Our 12 per cent prevalence of uninhibited detrusor contractions among incontinent women is substantially lower than the reported prevalence by Brocklehurst and Dillane (53 per cent), 7 Hilton and Stanton (39 per cent), 1 and Castleden and associates (61 per cent). 2 The discrepancy may be explained by the fact that our subjects are community dwellers who are relatively healthy compared to the mostly inpatients and stroke victims in the series by Brocklehurst and Dillane and the highly selected referred incontinent patients in the other 2 series. The prevalence in our continent group of 4.9 per cent is closer to the report of Jones and Schoenberg who reported an 11.1 per cent prevalence among 38 hospitalized women without any urological symptoms8 but far lower than the 30 per cent prevalence of "large" uninhibited contractions among continent subjects reported by Brocklehurst and Dillane. 9 However, 40 per cent of their subjects had central nervous system disease (predominantly cerebrovascular accidents). Our observations suggest that uninhibited detrusor contractions are uncommon in noninstitutionalized elderly women. The high prevalence observed by others suggests that hospitalized or institutionalized women with multiple health problems are more likely to have uninhibited bladder contractions than their noninstitutionalized counterparts. In men uninhibited detrusor contractions are a common finding regardless of the continence status. Our findings of 32 per cent among continent subjects and 50 per cent among incontinent subjects are compatible with the 43 per cent prevalence among men with benign prostatic hyperplasia reported by Schoenberg and associates10 but lower than the 53 per cent ·prevalence among continent volunteers reported by
ited detrusor contractions. The differences in mean bladder capacity between those with and without uninhibited detrusor contractions were significant (p <0.05). Urethral pressure profile. The passive (static) maximum urethral pressure and the maximum closure pressure with the subject in the supine and standing positions showed no association between subjects with and without uninhibited detrusor contractions, and between continent and incontinent respondents (table 5). Voiding pressure flow study. The total bladder pressure and detrusor pressure (the difference between bladder and rectal pressures) when correlated with continent and incontinent respondents with or without an uninhibited bladder showed no significant differences (table 5). There were 23 subjects whose detrusor pressure was 60 cm. or greater and the peak flow rate was -1.5 or less standard deviation according to the nomogram of Siroky and associates. 6 These subjects would be considered to have an obstructed outlet pattern (normal or above normal voiding pressure plus poor peak flow). There were 7 subjects whose detrusor pressure was less than 60 cm. and the peak flow rate was in the normal range of -1.4 standard deviation or better (normal voiding pattern). When correlated with the presence or absence of uninhibited detrusor contractions, there were more uninhibited bladders (43 per cent) among subjects with normal than with abnormal voiding (17 per cent). However, given the low number of subjects with normal voiding this difference was not significant. DISCUSSION
The participation rates to the clinical and urodynamic evaluations as expected are more among incontinent than continent subjects. There is an almost equal proportion of men and women who participated in the urodynamic evaluations. Surprisingly, a higher proportion of incontinent men accepted the clinical invitation than incontinent women. The set of survey questions used to establish the continence status appears to be valid for male and female respondents. However, the set of questions from the household survey identified several cases of post-void dribbling in men as incontinent episodes, while the clinician considered these post-void dribbles as nonincontinent episodes. Future epidemiological survey questionnaires on the continence status in men should be expanded to define post-void dribbling in relation to the incontinence status, preferably categorizing it as a separate entity. The post-void residual urine volume at any level does not show any correlation to continence status. At residuals of TABLE
5. Results of urethral profilometry and pressure flow studies in men Uninhibited Detrusor Contractions Yes
Urethral pressure profile: No. pts. {total 60) Maximum urethral pressure:* Supine position Standing position Maximum closure pressure:* Supine position Standing position Voiding pressure: No. pts. (total 44) Bladder voiding pressure* Detrusor pressure (bladder - abdominal pressure)* Pressure flow study:t Detrusor pressure ii:60 and peak flow rate <-1.5 standard deviation (23 pts.) Detrusor pressure <60 and peak flow rate >-1.5 standard deviation (7 pts.) Other (16 pts.) Totals * Pressures given in cm. water. t Number of patients (per cent).
Av.+
No
Standard Error
Incontinent
Continent
Incontinent
Continent
8
13
10
29
91.4 139.5
114.9 156.3
84.6 110.9
82.6 129.3
91.1 ± 5.4 131.7 ± 7.8
77.9 98.3
98.8 121.1
67.1 75.9
65.1 92.3
74.4 ± 5.4 95.0 ± 7.5
3
7 97.9 67.1
10 118.0 76.4
24 105.4 74.4
106.2 ± 7.1 72.6 ± 5.8
93.3 58.3 4 (17.4)
19 (82.6)
3 (42.9)
4 (57.1)
2 {12.5) 9 (19.6)
14 (87.5) 37 (80.4)
571
CYSTGMETHIC STUDIES IN ELDERLY 11 and the 88 per cent prevalence Andersen and among incontinent men obtained by Castleden and associates. 2 The significant difference in the prevalence of uninhibited contractions between men and women in our series cannot be explained on the basis of general health status, since their health statuses are comparable. One obvious difference is the presence of a prostate gland in men. Whether the prostate gland or the prostatic urethral mucosa in itself is a factor or whether the detrusor acting on an obstructing prostate gland becomes unstable is not known. It has been reported that the uncontrolled detrusor contractions disappear in a proportion of men undergoing prostatectomy. 12 For those in whom it persists one may presume that the etiology is either extravesical (neurological) or that the deranged detrusor is irreversibly unstable. Our findings suggest that urological symptoms of obstruction, irritation and frequency of voiding do not correlate with the occurrence of uninhibited detrusor contractions. Furthermore, objective urodynamic findings of an outlet obstruction pattern did not show increased prevalence of detrusor overactivity. Although the number is small, those with normal voiding pressure and normal flow have more prevalence of uninhibited bladders. These new unexpected findings raise more questions as to the etiology of uninhibited bladder contractions in men. Could the uncontrolled detrusor contraction be related more to the enlarged prostate gland regardless of whether it is obstructing the outlet? Could asymptomatic uninhibited detrusor contractions be an early sign of an asymptomatic or subclinical obstructive prostate that would soon manifest clinically? More cross-sectional and longitudinal studies are needed especially among asymptomatic subjects in the young and elderly to clarify these questions. The asymptomatic subjects with uninhibited detrusor contractions may also be a reflection of the subject's adjustment to the overactive detrusor. To avoid symptoms the subject consciously or unconsciously may have reduced fluid intake, and adjusted the voiding and even sleeping habits. Such behavioral modification in fact has been proved to be effective in managing certain cases of symptomatic uninhibited bladders. A lesson learned from these observations is that there could be a discrepancy in the prevalence and etiology of uninhibited contractions between genders, Therefore, it is paramount that the results in future studies and reports regarding bladder and urethral dysfunction be separated according to gender to avoid confusion in their interpretation. The majority of our subjects, regardless of gender and continence status, had a cystometric
bladder capacity of 300 ml. or more, As expected, the mean bladder capacity of men and women with uninhibited bladder contractions is significantly smaller than those without uninhibited contractions. In general, there is no significant difference in the bladder capacity of all subjects among the different age groups. These findings suggest that the bladder capacity is not influenced by age unless there are uncontrolled detrusor contractions or other dysfunctions that as expected will reduce the cystometric bladder capacity. REFERENCES
1. Hilton, P. and Stanton, S. L.: Algorithmic method for assessing urinary incontinence in elderly women. Brit. Med. J., 282: 940, 1981. 2. Castleden, C, M., Duffin, H. M. and Asher, M. J.: Clinical and urodynamic studies in 100 elderly incontinent patients. Brit. Med. J., 282: 1103, 1981. 3. Overstall, P. W., Rounce, K. and Palmer, J. H.: Experience with an incontinence clinic. J. Amer. Geriatr. Soc., 28: 535, 1980. 4. Diokno, A. C., Brock, B. M., Brown, M. B. and Herzog, A. R.: Prevalence of urinary incontinence and other urological symptoms in the noninstitutionalized elderly. J. Urol., 136: 1022, 1986. 5. Bates, P., Rowan, D., Bradley, W. E., Sterling, A. M., Glen, E., Zinner, N., Griffiths, D., Hald, T. and Melchior, H.: Standardization of terminology of lower urinary tract function. First and second reports: International Continence Society. Urology, 9: 237, 1977. 6. Siroky, M. B., Olsson, C. A. and Krane, R. J.: The flow rate nomog:ram: I. Development. J. Urol., 122: 665, 1979. 7. Brocklehurst, J.C. and Dillane, J.B.: Studies of the female bladder in old age. II. Cystometrograms in 100 incontinent women. Gerontol. Clin., 8: 306, 1966. 8. Jones, K. W. and Schoenberg, H. W.: Comparison of the incidence of bladder hyperreflexia in patients with benign prostatic hypertrophy and age-matched female controls, J. Urol., 133: 425, 1985. 9. Brocklehurst, J.C. and Dillane, J.B.: Studies of the female bladder in old age. I. Cystometrograms in non-incontinent women. Gerontol. Clin., 8: 285, 1966. 10. Schoenberg, H. W., Gutrich, J. M. and Cote, R.: Urodynamics studies in benign prostatic hypertrophy. Urology, 14: 634, 1979. 11. Andersen, J. T., Jacobsen, 0., Worm-Petersen, J. and Hald T.: Bladder function in healthy elderly males. Scand. J. Urol. Nephrol., 12: 123, 1978. 12. Abrams, P. H., Farrar, D. J., Turner-Warwick, R. T., Whiteside, C. G. and Feneley, R. C. L.: The results of prostatectomy: a symptomatic and urodynamic analysis of 152 patients. J. Urol., 121: 640, 1979.
'THE JCUR~!AL OF UROLOGY
Printed in U.S.A.
Copyright© 1988 by The Williams & Wilkins Co.
CLINICAL AND CYSTOMETRIC CHARACTERISTICS OF CONTINENT AND INCONTINENT NONINSTITUTIONALIZED ELDERLY ANANIAS C. DIOKNO, * MORTON B. BROWN, BRUCE M. BROCK, A. REGULA HERZOG DANIEL P. NORMOLLE
AND
From the Department of Surgery-Urology, Medical School, University of Michigan, Ann Arbor and Department of Urology, William Beaumont Hospital, Royal Oak, Michigan
ABSTRACT
A survey of the clinical and cystometric characteristics of continent and incontinent elderly subjects living in a community has not been reported previously. Household respondents identified initially from a random probability sample were invited to undergo a free clinic evaluation followed by an invitation to free urodynamic testing. Of the 1,955 household respondents 456 women and 298 men attended the clinic. From this group 169 women and 94 men accepted the urodynamic invitation. Cystometric studies reveal a significant difference between the over-all prevalence of uninhibited detrusor contraction between genders, 7.9 per cent for women and 35 per cent for men. The occurrence of uninhibited detrusor contractions is more prevalent among incontinent than continent subjects and this difference is marginally significant. There is no significant association between uninhibited detrusor contractions and symptoms of difficult bladder emptying, irritative symptoms, voiding frequency, nocturia and urodynamic diagnosis of outlet obstruction (normal or high pressure and poor flow) but there were significant associations with responses to questions about the delay in getting to a toilet. The mean bladder capacities of men and women do not differ significantly between the different age groups but the capacity is significantly smaller for those with uninhibited detrusor contractions. The post-void residual urine volume shows no association with the continence status. These findings raise questions regarding our conventional thinking as to the etiology of uninhibited detrusor contractions, especially in men, and of urinary incontinence in general. (J. Ural., 140: 567-571, 1988) Urodynamic characteristics of incontinent elderly patients have been reported in recent years. 1- 3 Major discrepancies exist in the results of the urodynamic characteristics among the different reports, which may be owing to differences in the urodynamic protocols and the types of subjects examined. Most subjects were a mixture of incontinent inpatients or outpatients referred to an incontinence clinic setting and, therefore, they may not be representative of the incontinent person living in the community. Information also is lacking on the urodynamic characteristics of the continent noninstitutionalized elderly. To define the urodynamic characteristics of the continent and incontinent elderly living in a community, a prospective study was done under the sponsorship of the National Institute on Aging. Estimates of the prevalences of urinary incontinence and related urological symptoms obtained by this study have been reported previously.' MATERIALS AND METHODS
The subjects included in this report consisted of 1,953 respondents 60 years and older who were identified and consented to be interviewed in their home from a random probability sampling of 13,912 households in the county of Washtenaw, Michigan.4 (Two additional subjects who refused to give their ages are omitted from the analyses.) Of the 1,953 household respondents interviewed 1,806 seniors were invited through telephone calls to visit the University of Michigan Turner Accepted for publication January 11, 1988. Supported by Grant 1 POl AGO 3742 from the National Institute on Aging. * Requests for reprints: University of Michigan Medical School, 1510B MSRB 1, Box 0666, 1150 West Medical Center Drive, Ann Arbor, Michigan 48109.
Geriatric Clinic. The free clinic evaluation included answering a 40-minute questionnaire similar to the one that they answered in their homes, a complete physical examination, including rectal and pelvic examination, and an analysis of the urine (dipstick and microscopic). At the end of the clinic visit all incontinent and most of the continent subjects were invited to undergo a free urodynamic testing. A total of 169 women and 94 men ultimately participated in the testing. The urodynamic testing started with an initial noninstrumented uroflowmetry and post-void residual urine measurement. An esophageal membrane catheter was inserted into the rectum for continuous abdominal pressure readings. A double sensor 8F microtransducer then was inserted and the sensors were placed appropriately with the aid of the fluoroscope. The tip sensor was placed inside the bladder and the proximal sensor was placed at the mid urethra in women or membranous urethra in men. Cystometry with simultaneous urethral and rectal pressure measurements was performed with a flow rate of 100 ml. per minute of 25 per cent sodium diatrizoate solution. Bladder capacity was considered to be reached when tonus limb 3 was observed, the subject complained of severe urge or an intense desire to void, or a strong uninhibited detrusor contraction occurred. At the conclusion of cystometry passive (static) and dynamic urethral profilometry was performed with the subject in the supine and standing positions. At the conclusion of the urethral pressure profile, a pressure flow study was performed. At the termination of the tests all subjects were sent home with either 50 mg. nitrofurantoin macrocrystals 3 times a day or trimethoprim-sulfamethoxazole twice a day for 3 days. Data analysis. It was desired to invite sufficient continent subjects to the clinical and urodynamic examinations to have approximately equal sample sizes of continent and incontinent
567
568
DIOKNO AND ASSOCIATES
subjects who underwent the urodynamic testing. Therefore, subjects were stratified into 8 groups by gender (men or women), continence status (continent or incontinent) and age (less than 75 years, or 75 or more years old). All incontinent subjects were invited to the clinic. To obtain similar numbers of continent and incontinent subjects in each age and gender grouping, all continent women and all continent men in the younger group were invited to the clinic but only 70 per cent of the older continent men were invited. When the observations were categorized by the household self-reported continence status, rates or proportions were combined across the 8 groups to reflect the relative sizes of the groups in the original household survey. (The age and sex distribution in the original household survey is similar to that of the census for Washtenaw County.) 4 These rates or proportions are referred to as adjusted estimates and they represent estimates that would be obtained by a random sample of the entire population of seniors 60 years and older. When the observations were categorized by the clinical diagnosis rates or proportions again were combined to reflect the relative sizes of the groups in the original household survey; an extra step was needed to define the appropriate factors, since the proportions of incontinent subjects reported by the clinician must be converted into proportions of the original 8 household groupings. Again, rates or proportions obtained in this manner are referred to as adjusted estimates and they may be interpreted as described previously. The proportions (or factors) used to combine groups are presented in table 1. Estimates of prevalence of a condition or symptom were obtained for each of the 8 groups. Group estimates were combined by multiplying by the factors (values) in table 1 and dividing by the sum of the factors. Standard errors were computed for these adjusted prevalence estimates using an asymptotic expansion to adjust for the use of these factors. Comparisons between continent and incontinent subjects were obtained by 2-sample tests (z test for proportions or t test for continuous variables), which were computed as the difference between the estimates for the 2 groups divided by the appropriate standard error (the square root of the sum of the squares of the 2 standard errors).
Response rates to clinical and urodynamic invitations. The participation rates to the clinical invitation among the household respondents in each of the 8 groups (gender by self-
1. Factors used to combine results across age groupings and
continence status Factors Used With Age (yrs.)
Household Self-Report*
Clinician Diagnosist
Women Continent Incontinent
<75 75+ <75 75+
Total No.
0.432 0.192 0.264 0.112 1,151
0.396 0.187 0.300 0.117 456
0.642 0.170 0.136 0.052 802
0.672 0.164 0.106 0.058 298
Men Continent Incontinent Total No.
<75 75+ <75 75+
TABLE 2.
Participation rates (per cent) of household respondents to clinic and urodynamic invitations Clinic
Continence Status
RESULTS
TABLE
reported continence status by age) are presented in table 2. Based on these participation rates the adjusted participation rates were 37.3 per cent for self-reported continent women and 38.5 per cent for continent men. For self-reported incontinent respondents the adjusted participation rates were 4 7.6 per cent for women and 59.5 per cent for men. For both genders these rates of participation differed significantly by continence status (z = 2.99, p <0.003 for women and z = 3.69, p <0.0003 for men). Younger women were more likely to accept the clinical invitation (z = 2.91, p <0.004 for continent and incontinent subjects) than were older women, while for men age did not significantly affect the participation rates. The response rates to the urodynamic invitation of all clinic participants also are presented in table 2. Of self-reported continent subjects the adjusted rates of participation were 28.8 per cent for women and 26.6 per cent for men. For incontinent respondents the rates were 46.6 per cent for women and 44.2 per cent for men. The adjusted participation rates for incontinent subjects were higher than for continent subjects (z = 3. 72, p <0.0002 for women and z = 2.64, p <0.01 for men). Demographic data and health status. The mean ages for continent men and women seen at the clinic were 68.2 and 69.4 years, respectively. For incontinent responders the mean ages were 70.7 and 68.5 years, respectively. The self-assessed health status at the time of the clinical interview was considered good to excellent by 91.1 per cent of continent men and 95. 7 per cent of the continent women, while among incontinent respondents it was 78.9 per cent in men and 89.3 per cent in women. Comparison of the continence status in the household survey and the clinical evaluation. The continence status at the household interview was based on a set of questions presented in our earlier study. 4 The continence status at the clinical evaluation was based on the impression of the clinician. This evaluation was made from the response to the clinical questionnaire and the result of the physical examination, which included a simple provocative stress test without instrumentation.
* The factors used to report continence status are the proportions of the strata from the household survey. The sizes of the strata (N) are used in the computations of standard errors. The total sample size (1,151 + 802 = 1,953) is 2 less than that reported by Diokno and associates.4 Two subjects refused to give their ages. t The factors used to report continence status are the proportions of strata from the household survey multiplied by the relative frequencies of the clinician diagnosis.
Accepted No.
Urodynamic No. Contacted*
%
Accepted No.t
%
Women Continent: Age: <75 75+ Total %:j: Incontinent: Age: <75 75+ Total %:j: Over-all§ Continent: Age: <75 75+ Total %:j: Incontinent: Age: <75 75+ Total %:j: Over-all§
197 61
40.8 29.5 37.3 ± 2.0
484 207
59 16
29.9 26.2 28.8 ± 2.9
151 47
52.1 37.0 47.6 ± 2.8 41.2 ± 1.8 Men
290 127
77 17
51.0 36.2 46.6 ± 3.8 35.5 ± 2.4
178 36
38.0 40.4 38.5 ± 2.3
468 89
48 9
27.0 25.0 26.6 ± 3.1
57 27
56.4 67.5 59.5 ± 5.2 42.4 ± 2.1
101 40
26 11
45.6 40.7 44.2 ± 5.9 29.9 ± 2.8
456
298
169
94
* The number contacted for the clinic excludes those known to be deceased (14 women and 23 men), those omitted owing to the sampling scheme (36 men) and those with whom contact could not be re-established. t The number contacted for the urodynamic examination is equal to the number of acceptances of the clinic invitation. :j: The 2 age groupings are combined using the factors in table 1. Estimated proportions ± standard error are presented. § All 4 groupings are combined using the factors in table 1. Estimated proportions ± standard error are presented.
569
CYSTOlViETRIC STUDIES IN ELDERLY
Among the female respondents there was an 83 per cent agreement between the household self-reports and the clinician assessments (86.5 per cent agreement with the clinical diagnosis of continence and 79.2 per cent agreement with the diagnosis of incontinence). For men the over-all rate of agreement also was 83 per cent with the clinical diagnosis (84.6 per cent agreement for continent and 75.9 per cent for incontinent subjects). A review of the records for men showed that sev~ral of the disagreements were owing to men who were characterized by the clinicians as having post-void dribbling that the c.li~icians did not consider as incontinence but who were classified as incontinent by the household incontinence profile. The clinical diagnosis of continence status, rather than the household self-reported continence status, was used to compare continent to incontinent subjects with respect to the results of the urodynamic tests. The clinical diagnosis closely replicates the diagnosis of a clinician in an office setting by using not only the history (questionnaire) but also other clinical information that are critical to arrive at a specific diagnosis. Residual urine. Estimates of the proportion of subjects within various ranges of post-void residual urine measurements are presented in table 3. The adjusted estimates of the proportions of subjects with a value greater than 50 ml. were 18.4 per cent for men and 16.3 per cent for women. There was no statistical difference between continent and incontinent men or women with regard to the prevalence of a residual urine volume greater than 50 ml. There also was no significant difference owing to continence status for residual urine expressed as a percentage of the total bladder capacityo Uninhibited detrusor contraction. The adjusted estimates of prevalence of uninhibited detrusor contractions are preser_ited in table 4. The diagnosis of uninhibited detrusor contractions was based on the definition of the International Continence Society. 5 An uninhibited bladder is estimated to occur in 35.2 per cent of the male but only in 7.9 per cent of female subjects (z = 4.25, p <0.0001). As expected, there was a tendency for the estimates of prevalence of uninhibited detrusor contractions to be greater for incontinent than for continent subjects, 50.0 to 32.3 per cent in men and 1202 to 4.9 per cent in women, respectively, although these differences were not statistically significant owing to the large standard errors. A test. that combined the information from both genders was margmally significant (z = 2.02, p <0.05). The uninhibited detrusor contractions were observed while in the supine position in 56 per cent of the men and 58 per cent of the women with the conditiono The remaining proportions were observed only with the subject in the provocative standing position. Lower urinary tract symptomatology. Of the 23 men who reported bladder emptying symptoms 4 (17 per cent) ha~ uninhibited detrusor contractions, as did 4 of the 9 respondents (44 per cent) with irritation and infection symptoms and 17 of Estimated prevalences (per cent) of subjects classified by amount of residual urine and by clinician diagnosis
TABLE 3.
Clinician Diagnosis
Residual Urine (ml.)* 0-50
Continentt Inconti· nentt Over-all:j:
78.1 ± 5.8 86.5 ± 5.4
Continentt Incontinentt Over-all:j:
51-100
101-150
151+
Total No.
Women 9.7 ± 3.2 8.4 ± 2.9
2.4±1.7 1.6 ± 1.5
9.7 ± 3.7 3.5 ± 2.0
69 92
2.1 ± 1.2
7.1 ± 2.3
161
85.7 ± 5.5 73.4 ± 11.8
9.2 ± 2.2 Men 7.7 ± 3.7 21.5 ± 8.2
4.2 ± 2.9 0
2.5 ± 2.3 5.1 ± 4.8
54 22
83.6 ± 5.0
9.9 ± 3.4
3.5 ± 2.4
2.9 ± 2.1
76
81.6 ± 4.5
* Estimated proportions and their standard errors are presented. t The 2 age groupings are combined using the factors in table 1. :j: All 4 groupings are combined using the proportions in table 1.
TABLE 4.
Estimated prevalences of subjects classified by uninhibited bladder and clinician diagnosis Continent
% with uninhibited bladder * Total No. % with uninhibited bladder Total No.
*
Women 4.9 ± 2.9 65 Men 32.3 ± 6.8 50
Incontinent
Over-All
12.2 ± 3.7 99
7.9 ± 2.3 164
50.0 ± 11.7 22
35.2 ± 6.0 72
Subjects lacking information about diagnoses are omitted. * Mean ± standard error.
the 48 (39 per cent) without symptoms. These prevalences did not differ significantly. Of the 166 women there was no significant difference between those with and without symptoms in the occurrence of uninhibited detrusor contractions. These prevalences were 7 per cent for asymptomatic respondents, 8 per cent for women with irritative symptoms and 7 per cent for those with bladder emptying symptoms. Toileting history. The question "Do you ever have trouble getting to the bathroom on time?" was highly significant in predicting the occurrence of uninhibited detrusor contractions on cystometry. Of the 72 male responders to this question who underwent cystometry 14 (19 per cent) said yes and 58 (81 per cent) said no. Of the 14 positive responders 11 (79 per cent) have uninhibited detrusor contractions, compared to 16 of the 58 negative responders (28 per cent) (p = 0.001). Among the women the difference also was significant (p = 0.01). The question "What about finding the toilet is occupied and you are delayed in getting in?" was asked only of respondents who self-reported incontinence of urine. Of the men 22 respondents were asked the question and had cystometry. Of the 9 positive responders 7 (78 per cent) had uninhibited detrusor contractions, as did 3 of the 13 (23 per cent) with a negative response (p = 0.03 for this difference). Among the women, of the 34 positive responders 8 (24 per cent) had uninhibited detrusor contractions, compared to 1 of the 56 negative responders (2 per cent) (p = 0.003 for this difference). Urination frequency. The 24-hour frequency of urination among men and women was not correlated to the presence or absence of uninhibited detrusor contractionso Among the men, 5 of 14 (36 per cent) who voided 9 times or more and 17 of 54 (31 per cent) who voided 8 times or less had uninhibited detrusor contractions, compared to 4 of 41 (9.8 per cent) and 8 of 120 (6. 7 per cent), respectively, among the women. Men who reported voiding 0, 1, 2 and 3 or more times at night were observed to have 31 (4 of 33 (12 of 36), 20 (2 of 10) and 50 (5 of 10) per cent rates of uninhibited detrusor contractions, respectively. In women these rates were 2.6 (1 of 38), 7.6 (6 of 79), 12 (3 of and 4,3 (1 of 23) per cent, :respectively, For both genders these rates did not differ significantly. Prostatic surgery. There were 66 men who responded to questions on whether they had had prostate surgery. The prevalence of uninhibited detrusor contractions among those who did not have an operation was 33 per cent (17 of 52), while for those who did it was 29 per cent (4 of 14). These prevalences did not differ significantly. Bladder capacityo Among all male respondents the cystometric bladder capacity was 300 ml. or more in 42 of 67 (63 per cent): 30 of 4 7 (64 per cent) for the continent and 12 of 20 (60 per cent) for the incontinent respondents. Among the women 116 of 166 (70 per cent) had a 300 ml. or more bladder capacity: 55 of 70 (79 per cent) among the continent and 61 of 96 (64 per cent) among the incontinent respondents. Comparison of the bladder capacity between the continent and incontinent respondents shows no significant difference in men and women. Among the respondents with uninhibited detrusor contractions the mean bladder capacities of male and female respondents were 323 and 364 ml., respectively, whereas they were 419 and 404 ml., respectively, for those who did not have any uninhib-
570
DIOKNO AND ASSOCIATES
greater than 150 one would expect that urinary incontinence of the overflow type would be more prevalent. Since there are as many continent as incontinent respondents at any level of residual urine elevation it appears that elevated residual urine alone does not cause urinary incontinence. It is possible that incontinence develops in someone with high residual urine only when there is total detrusor failure, superimposed detrusor overactivity or sphincteric dysfunction. A major finding in our study is the significant difference between the prevalence of uninhibited detrusor contractions between genders. The over-all prevalence of 7.9 per cent among all women is significantly lower than the 35.2 per cent prevalence among men. In women as in men there is a tendency to observe more occurrences of uninhibited detrusor contractions among the incontinent subjects than their continent counterparts. Our 12 per cent prevalence of uninhibited detrusor contractions among incontinent women is substantially lower than the reported prevalence by Brocklehurst and Dillane (53 per cent), 7 Hilton and Stanton (39 per cent), 1 and Castleden and associates (61 per cent). 2 The discrepancy may be explained by the fact that our subjects are community dwellers who are relatively healthy compared to the mostly inpatients and stroke victims in the series by Brocklehurst and Dillane and the highly selected referred incontinent patients in the other 2 series. The prevalence in our continent group of 4.9 per cent is closer to the report of Jones and Schoenberg who reported an 11.1 per cent prevalence among 38 hospitalized women without any urological symptoms8 but far lower than the 30 per cent prevalence of "large" uninhibited contractions among continent subjects reported by Brocklehurst and Dillane. 9 However, 40 per cent of their subjects had central nervous system disease (predominantly cerebrovascular accidents). Our observations suggest that uninhibited detrusor contractions are uncommon in noninstitutionalized elderly women. The high prevalence observed by others suggests that hospitalized or institutionalized women with multiple health problems are more likely to have uninhibited bladder contractions than their noninstitutionalized counterparts. In men uninhibited detrusor contractions are a common finding regardless of the continence status. Our findings of 32 per cent among continent subjects and 50 per cent among incontinent subjects are compatible with the 43 per cent prevalence among men with benign prostatic hyperplasia reported by Schoenberg and associates10 but lower than the 53 per cent ·prevalence among continent volunteers reported by
ited detrusor contractions. The differences in mean bladder capacity between those with and without uninhibited detrusor contractions were significant (p <0.05). Urethral pressure profile. The passive (static) maximum urethral pressure and the maximum closure pressure with the subject in the supine and standing positions showed no association between subjects with and without uninhibited detrusor contractions, and between continent and incontinent respondents (table 5). Voiding pressure flow study. The total bladder pressure and detrusor pressure (the difference between bladder and rectal pressures) when correlated with continent and incontinent respondents with or without an uninhibited bladder showed no significant differences (table 5). There were 23 subjects whose detrusor pressure was 60 cm. or greater and the peak flow rate was -1.5 or less standard deviation according to the nomogram of Siroky and associates. 6 These subjects would be considered to have an obstructed outlet pattern (normal or above normal voiding pressure plus poor peak flow). There were 7 subjects whose detrusor pressure was less than 60 cm. and the peak flow rate was in the normal range of -1.4 standard deviation or better (normal voiding pattern). When correlated with the presence or absence of uninhibited detrusor contractions, there were more uninhibited bladders (43 per cent) among subjects with normal than with abnormal voiding (17 per cent). However, given the low number of subjects with normal voiding this difference was not significant. DISCUSSION
The participation rates to the clinical and urodynamic evaluations as expected are more among incontinent than continent subjects. There is an almost equal proportion of men and women who participated in the urodynamic evaluations. Surprisingly, a higher proportion of incontinent men accepted the clinical invitation than incontinent women. The set of survey questions used to establish the continence status appears to be valid for male and female respondents. However, the set of questions from the household survey identified several cases of post-void dribbling in men as incontinent episodes, while the clinician considered these post-void dribbles as nonincontinent episodes. Future epidemiological survey questionnaires on the continence status in men should be expanded to define post-void dribbling in relation to the incontinence status, preferably categorizing it as a separate entity. The post-void residual urine volume at any level does not show any correlation to continence status. At residuals of TABLE
5. Results of urethral profilometry and pressure flow studies in men Uninhibited Detrusor Contractions Yes
Urethral pressure profile: No. pts. {total 60) Maximum urethral pressure:* Supine position Standing position Maximum closure pressure:* Supine position Standing position Voiding pressure: No. pts. (total 44) Bladder voiding pressure* Detrusor pressure (bladder - abdominal pressure)* Pressure flow study:t Detrusor pressure ii:60 and peak flow rate <-1.5 standard deviation (23 pts.) Detrusor pressure <60 and peak flow rate >-1.5 standard deviation (7 pts.) Other (16 pts.) Totals * Pressures given in cm. water. t Number of patients (per cent).
Av.+
No
Standard Error
Incontinent
Continent
Incontinent
Continent
8
13
10
29
91.4 139.5
114.9 156.3
84.6 110.9
82.6 129.3
91.1 ± 5.4 131.7 ± 7.8
77.9 98.3
98.8 121.1
67.1 75.9
65.1 92.3
74.4 ± 5.4 95.0 ± 7.5
3
7 97.9 67.1
10 118.0 76.4
24 105.4 74.4
106.2 ± 7.1 72.6 ± 5.8
93.3 58.3 4 (17.4)
19 (82.6)
3 (42.9)
4 (57.1)
2 {12.5) 9 (19.6)
14 (87.5) 37 (80.4)
571
CYSTGMETHIC STUDIES IN ELDERLY 11 and the 88 per cent prevalence Andersen and among incontinent men obtained by Castleden and associates. 2 The significant difference in the prevalence of uninhibited contractions between men and women in our series cannot be explained on the basis of general health status, since their health statuses are comparable. One obvious difference is the presence of a prostate gland in men. Whether the prostate gland or the prostatic urethral mucosa in itself is a factor or whether the detrusor acting on an obstructing prostate gland becomes unstable is not known. It has been reported that the uncontrolled detrusor contractions disappear in a proportion of men undergoing prostatectomy. 12 For those in whom it persists one may presume that the etiology is either extravesical (neurological) or that the deranged detrusor is irreversibly unstable. Our findings suggest that urological symptoms of obstruction, irritation and frequency of voiding do not correlate with the occurrence of uninhibited detrusor contractions. Furthermore, objective urodynamic findings of an outlet obstruction pattern did not show increased prevalence of detrusor overactivity. Although the number is small, those with normal voiding pressure and normal flow have more prevalence of uninhibited bladders. These new unexpected findings raise more questions as to the etiology of uninhibited bladder contractions in men. Could the uncontrolled detrusor contraction be related more to the enlarged prostate gland regardless of whether it is obstructing the outlet? Could asymptomatic uninhibited detrusor contractions be an early sign of an asymptomatic or subclinical obstructive prostate that would soon manifest clinically? More cross-sectional and longitudinal studies are needed especially among asymptomatic subjects in the young and elderly to clarify these questions. The asymptomatic subjects with uninhibited detrusor contractions may also be a reflection of the subject's adjustment to the overactive detrusor. To avoid symptoms the subject consciously or unconsciously may have reduced fluid intake, and adjusted the voiding and even sleeping habits. Such behavioral modification in fact has been proved to be effective in managing certain cases of symptomatic uninhibited bladders. A lesson learned from these observations is that there could be a discrepancy in the prevalence and etiology of uninhibited contractions between genders, Therefore, it is paramount that the results in future studies and reports regarding bladder and urethral dysfunction be separated according to gender to avoid confusion in their interpretation. The majority of our subjects, regardless of gender and continence status, had a cystometric
bladder capacity of 300 ml. or more, As expected, the mean bladder capacity of men and women with uninhibited bladder contractions is significantly smaller than those without uninhibited contractions. In general, there is no significant difference in the bladder capacity of all subjects among the different age groups. These findings suggest that the bladder capacity is not influenced by age unless there are uncontrolled detrusor contractions or other dysfunctions that as expected will reduce the cystometric bladder capacity. REFERENCES
1. Hilton, P. and Stanton, S. L.: Algorithmic method for assessing urinary incontinence in elderly women. Brit. Med. J., 282: 940, 1981. 2. Castleden, C, M., Duffin, H. M. and Asher, M. J.: Clinical and urodynamic studies in 100 elderly incontinent patients. Brit. Med. J., 282: 1103, 1981. 3. Overstall, P. W., Rounce, K. and Palmer, J. H.: Experience with an incontinence clinic. J. Amer. Geriatr. Soc., 28: 535, 1980. 4. Diokno, A. C., Brock, B. M., Brown, M. B. and Herzog, A. R.: Prevalence of urinary incontinence and other urological symptoms in the noninstitutionalized elderly. J. Urol., 136: 1022, 1986. 5. Bates, P., Rowan, D., Bradley, W. E., Sterling, A. M., Glen, E., Zinner, N., Griffiths, D., Hald, T. and Melchior, H.: Standardization of terminology of lower urinary tract function. First and second reports: International Continence Society. Urology, 9: 237, 1977. 6. Siroky, M. B., Olsson, C. A. and Krane, R. J.: The flow rate nomog:ram: I. Development. J. Urol., 122: 665, 1979. 7. Brocklehurst, J.C. and Dillane, J.B.: Studies of the female bladder in old age. II. Cystometrograms in 100 incontinent women. Gerontol. Clin., 8: 306, 1966. 8. Jones, K. W. and Schoenberg, H. W.: Comparison of the incidence of bladder hyperreflexia in patients with benign prostatic hypertrophy and age-matched female controls, J. Urol., 133: 425, 1985. 9. Brocklehurst, J.C. and Dillane, J.B.: Studies of the female bladder in old age. I. Cystometrograms in non-incontinent women. Gerontol. Clin., 8: 285, 1966. 10. Schoenberg, H. W., Gutrich, J. M. and Cote, R.: Urodynamics studies in benign prostatic hypertrophy. Urology, 14: 634, 1979. 11. Andersen, J. T., Jacobsen, 0., Worm-Petersen, J. and Hald T.: Bladder function in healthy elderly males. Scand. J. Urol. Nephrol., 12: 123, 1978. 12. Abrams, P. H., Farrar, D. J., Turner-Warwick, R. T., Whiteside, C. G. and Feneley, R. C. L.: The results of prostatectomy: a symptomatic and urodynamic analysis of 152 patients. J. Urol., 121: 640, 1979.