History as a diagnostic tool in female urinary incontinence
By Hogne Sandvik

The symptoms presented by the incontinent woman constitute the basis for decision making in general practice. Different clues presented by the patient trigger the early generation of multiple hypotheses, which are subsequently tested by collecting additional information.(1) Any discussion of symptoms of micturition disorders is, however, complicated by the wide spectrum of normality.(2) Additional gain from clinical examinations is probably marginal, but good studies from general practice are lacking.

When judging the predictive value of a diagnostic procedure, one must also consider the pretest probability of disease (the prevalence).(3) A high positive predictive value is not very impressive if the prior probability is also high. The real value of the test is reflected in the difference between posttest and pretest probability, that is the additional gain in diagnostic accuracy by performing the test.

In this section the main emphasis is placed on the possibility of recognizing the major types of incontinence by history alone. Is it possible, on the presence/absence of specific symptoms, to predict the conditions of stress or urge incontinence?(4) Several studies have addressed this question. Responses to standardized questionnaires have been compared with the results of urodynamic investigations. Jensen et al. reviewed 19 papers combining data from 3 092 patients with stress symptoms and 2 950 patients with urge symptoms.(5) Their findings are summarized in table 3.

Stress and urge incontinence may coexist, and in this analysis the diagnoses were not mutually exclusive.(5) Thus, patients with mixed incontinence (n = 1 368) were included in all three groups.

Table 3 Validity of symptoms in predicting incontinence conditions. The table is based on 19 studies reviewed by Jensen et al.(5)

If stress incontinence is diagnosed only in the absence of urge and vice versa (excluding those with mixed incontinence), the diagnostic value of the symptoms changes considerably. Three authors, describing a total of 729 patients, have presented their data in a way that makes such a comparison possible.(6-8) Table 4 sums up the comparative results.

Table 4 Validity of symptoms in predicting incontinence conditions, depending on whether one condition is diagnosed only in the absence of the other (excluding mixed incontinence) or not (including mixed incontinence). Results from three studies are combined in the table.(6-8)

When mixed incontinence is excluded, the main changes are increased specificity for urge incontinence and decreased sensitivity for stress incontinence. Accordingly, the predictive values for urge incontinence improve, while those for stress incontinence are worsened.

The trade-off between high sensitivity (many false positives) and high specificity (many false negatives) will depend on several factors, including the potential harm if a diagnosis is missed, the potential benefit of treatment, and possible risks associated with the treatment. The main concern is the risk of performing unnecessary or harmful surgical operations. Therefore, urodynamic examination is recommended when surgical repair is contemplated.(5,7,8)

The results presented above, however, indicate that the optimal diagnostic strategy in general practice will be to diagnose stress incontinence without considering the urge component. Treatment options for stress incontinence in general practice are usually without side effects. In addition, there are indications that pelvic floor exercises and vaginal cones may benefit also those who have urge incontinence.(9,10)

The trade-off is less clear when it comes to urge incontinence. Considering the predictive values of the diagnostic questions and the potential side-effects of anticholinergic therapy,(11) it may be argued that urge incontinence should only be diagnosed in the absence of stress incontinence. The lower prevalence of urge incontinence may also favour this strategy, few patients will be missed. On the other hand, there are indications that bladder training may benefit also those who have stress incontinence,(12) and the efficacy of the available anticholinergics is highly questionable, even when prescribed on accepted indications.(13-15)

In a hospital setting it is important to identify patients who are candidates for surgical treatment. Accordingly, the major border is drawn between those with pure stress incontinence and the rest. In general practice, however, this line is better drawn between those with pure urge incontinence and the rest.

A completely different question is, however, what should be regarded as the real gold standard for diagnosing the different types of incontinence. Again, the pivotal question concerns the diagnosis of urge incontinence. Who is to be trusted most, the patient or the urodynamic investigation? Detrusor instability, a predictor of surgical failure, may be objectively demonstrated in patients who deny classical symptoms of urgency or urge incontinence.(5-8)

On the other hand, a normal urodynamic test cannot disprove the accuracy of a patient's history of urge incontinence. According to Petros & Ulmsten the sensitivity of detecting detrusor instability is only 40%.(16) A urodynamic test will only reflect the events of real life to the extent that the provocative measures reflect those experienced outside the laboratory. Therefore, the more sensitive method of ambulatory urodynamics has been developed. Paradoxically, all authors who have examined the validity of this new, sophisticated test use history as the gold standard.(17-19) A urodynamic evaluation should be regarded as a diagnostic test, along with other tests. All tests have a certain, limited validity with regard to real life, and urodynamics are no exception to this rule.

Ramsay et al. performed a randomized controlled trial of standard urodynamic investigations prior to conservative treatment of female incontinence. Those investigated with urodynamics had their treatment tailored according to diagnosis, while the rest learned both bladder training and pelvic floor exercises. Sixty per cent were cured/improved in the investigated group, 71% in the group not investigated.(20) While urodynamic investigations have a definite place in a preoperative setting,(5,7,8) it seems that most patients in general practice may be treated without the aid of urodynamic diagnoses.(21)

References

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2. Farrar DJ, Whiteside CG, Osborne JL, TurnerWarwick RT. A urodynamic analysis of micturition symptoms in the female. Surg Gynecol Obstet 1975; 141: 87581.

3. Sackett DL, Haynes BR, Tugwell P. Clinical epidemiology. A basic science for clinical medicine. Boston/Toronto: Little, Brown and Company, 1985.

4. Abrams P, Blaivas JG, Stanton SL, Andersen JT. The standardisation of terminology of lower urinary tract function. The International Continence Society Committee on Standardisation of Terminology. Scand J Urol Nephrol 1988; 114 (suppl): 519.

5. Jensen JK, Nielsen FJ, Ostergard DR. The role of patient history in the diagnosis of urinary incontinence. Obstet Gynecol 1994; 83: 90410.

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7. Sand PK, Hill RC, Ostergard DR. Incontinence history as a predictor of detrusor stability. Obstet Gynecol 1988; 71: 25760.

8. De Muylder X, Claes H, Neven P, de Jaegher K. Usefulness of urodynamic investigations in female incontinence. Eur J Obstet Gynecol Reprod Biol 1992; 44: 2058.

9. Flynn L, Cell P, Luisi E. Effectiveness of pelvic muscle exercises in reducing urge incontinence among community residing elders. J Gerontol Nurs 1994; 20: 237.

10. Lentz G, Plevnik S, Stanton SL. Vaginal cones versus bladder drill for sensory urgency treatment. Abstract 102. ICS 24th Annual Meeting, Prague, Czech Republic 31.8 2.9 1994.

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12. Fantl JA, Wyman JF, McClish DK, Harkins SW, Elswick RK, Taylor JR, et al. Efficacy of bladder training in older women with urinary incontinence. JAMA 1991; 265: 60913.

13. Walter S, Hansen J, Hansen L, Maegaard E, Meyhoff HH, Nordling J. Urinary incontinence in old age. A controlled clinical trial of emepronium bromide. Br J Urol 1982; 54: 24951.

14. Williams AJ, Prematalake JK, Palmer RL. A trial of emepronium bromide for the treatment of urinary incontinence in the elderly mentally ill. Pharmatherapeutica 1981; 2: 53942.

15. Meyhoff HH, Gerstenberg TC, Nordling J. Placebo the drug of choice in female motor urge incontinence? Br J Urol 1983; 55: 347.

16. Petros PP, Ulmsten U. Urge incontinence history is an accurate predictor of urge incontinence. Acta Obstet Gynecol Scand 1992; 71: 5379.

17. KulsengHanssen S, Klevmark B. Ambulatory urethrocystorectometry. A new technique. Neurourol Urodyn 1988; 7: 11930.

18. Webb RJ, Ramsden PD, Neal DE. Ambulatory monitoring and electronic measurement of urinary leakage in the diagnosis of detrusor instability and incontinence. Br J Urol 1991; 68: 14852.

19. Van Waalwijk van Doorn ESC, Remmers A, Janknegt RA. Extramural ambulatory urodynamic monitoring during natural filling and normal daily activities: evaluation of 100 patients. J Urol 1991; 146: 12431.

20. Ramsay I, Hassan A, Hunter M, Donaldson K. A randomised controlled trial of urodynamic investigation prior to conservative treatment of urinary incontinence in the female. ICS 24th annual meeting in Prague, Chez Republic, 30.0802.09. Abstract 74. Neurourol Urodyn 1994; 13: 4556.

21. Jolleys JV. Diagnosis and management of female urinary incontinence in general practice. J R Coll Gen Pract 1989; 39: 2779.

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