Despite the availability of effective treatments, primary care clinicians often do not inquire about incontinence or recommend treatment (8
). We believe that this is partly because national guidelines (8
) recommend an extended evaluation for classifying type of incontinence that is not practical in primary care settings. The 3IQ questionnaire is a simple, quick, and reproducible test with acceptable accuracy for classifying urge and stress incontinence among women who are appropriate for evaluation and treatment in primary care settings. Using the 3IQ questionnaire might encourage primary care physicians to classify and treat incontinence in women.
The reproducibility of the 3IQ was fair to good, with κ statistics ranging from 0.65 to 0.69. For urge incontinence, the sensitivity was about 75%, which suggests that approximately 25% of women with urge incontinence will be missed by using the 3IQ; the specificity was 77%, which suggests that about 23% of women with other types of incontinence will be inappropriately treated for urge incontinence. For stress incontinence, the sensitivity was higher (86%), suggesting that only approximately 14% of women with stress incontinence will be missed by using the 3IQ, but the specificity was 60%, which suggests that about 40% of women with other types of incontinence may be inappropriately treated for stress incontinence.
The probability that a woman with incontinence has urge rather than stress incontinence increases with age (2
). Using this information, we estimated pretest probabilities of urge or stress incontinence according to age and calculated the post-test probability of urge or stress incontinence depending on the 3IQ results (). Among young women with incontinence, approximately three quarters have stress incontinence (2
). Among those classified by the 3IQ as having urge incontinence, the probability of having urge incontinence is increased from 25% (pretest) to 52% (post-test). In contrast, among those classified as having stress incontinence by the 3IQ, the probability of having stress incontinence is increased slightly from 75% (pretest) to 87% (post-test). Among women of middle age, prevalence of urge and stress incontinence are about equal. In this group, probabilities for both urge and stress incontinence are increased similarly from 50% (pretest) to 77% (post-test) for urge incontinence and to 68% (post-test) for stress incontinence, according to the test result. Among older women, where urge incontinence accounts for three quarters of total prevalence, estimated post-test probability of urge and stress incontinence is 91% and 42%, respectively.
Post-Test Probability of Stress or Urge Incontinence among Women with Incontinence and Positive or Negative 3IQ Results*
The accuracy of the 3IQ is modest but acceptable given that the risk for misclassification and inappropriate treatment by primary care physicians is low. Urge-suppression training for urge incontinence and pelvic floor muscle-strengthening exercises for stress incontinence are safe and effective treatments that can be learned by using a self-help booklet. Misclassifying a patient, however, may result in patient inconvenience and unnecessary expenditure of resources. Treatment with antimuscarinic or anticholinergic drugs for urge incontinence can cause dry mouth but is rarely associated with more clinically significant adverse effects, such as urinary retention. Stress incontinence that is unresponsive to behavioral therapy may be treated with surgery, but surgery would not be performed without first completing an extended evaluation. Given the simplicity and ease of use of the 3IQ questionnaire and the fact that it avoids an invasive and expensive evaluation, we believe that the accuracy documented in our study is acceptable.
Seven participants in our study who were classified by the extended evaluation as having other incontinence were not identified by the 3IQ, and 7 participants had abnormal postvoid residual volumes. Urologists and urogynecologists reviewed these cases and determined that no danger to the participants was related to the missed diagnosis, abnormal postvoid residual volume, or delay in appropriate treatment. These women would have been referred for specialty care under current guidelines. In addition, women who do not improve after several months of therapy should be referred. This proportion is difficult to estimate but will be markedly lower than the 100% that would be recommended for referral to specialty care under current guidelines.
On the basis of a MEDLINE search from January 1965 through October 2005, we identified 7 published studies that evaluated the accuracy of questionnaires to classify type of incontinence (). The questionnaires used in 6 of the studies were substantially longer (5 to 18 questions) than the 3IQ, classification required calculation of a score, and all were evaluated in specialty clinic populations at a single site. Sandvik and colleagues' study (10
) included 250 women referred to a Norwegian gynecology clinic for evaluation of incontinence. A nurse asked 2 questions to classify incontinence as stress-only, urge-only, or mixed. The test results were compared with a gynecologist's classification that was based on an extensive evaluation (10
). The accuracy of the test was fair, with especially good specificity. However, the study was conducted at a single gynecology site, and a trained interviewer administered the questions. In addition, women with predominantly urge or stress incontinence were classified as having mixed incontinence, which does not provide direction for treatment.
Published Studies Evaluating the Accuracy of Questionnaires To Classify Type of Urinary Incontinence in Women*
We aimed to improve the questionnaire used by Sandvik and colleagues and to replicate the findings in a more diverse population of women. For the 3IQ questionnaire, we added an initial question to establish that incontinence occurred in the previous 3 months. The second question incorporates both questions used in the Sandvik questionnaire. We also added a third question to classify incontinence in categories to direct initial treatment: urge (urgeonly, urge-predominant, or mixed) or stress (stress-only, stress-predominant, or mixed) incontinence. We designed DAISy to determine the accuracy of the 3IQ among women with incontinence who were most appropriate for treatment by primary care providers, with a broad spectrum of type and severity of incontinence, and we tested the 3IQ questionnaire at 5 sites across the United States.
The accuracy of Sandvik and colleagues' questionnaire and the 3IQ was similar, although the 3IQ questionnaire was more sensitive but less specific. These differences could be because a nurse administered Sandvik and colleagues' questionnaire and the questionnaire limited the categorization of incontinence to urge-only, stress-only, or mixed. These categories, although less clinically useful, are more specific. Participants were enrolled at academic medical centers, and urologists and urogynecologists led the study. In contrast, only 23 women in our study (6%) were recruited from specialty clinics, and we designed our inclusion and exclusion criteria to reflect patients typically seen in primary care settings. We excluded women with active urinary tract infections because infection may cause or worsen all types of incontinence and treatment often markedly improves incontinence. While our results are generalizable to racially diverse women with a broad spectrum of incontinence severity, our study did not include women with complex urinary incontinence (such as those with neurologic problems or those whose surgery failed), women who did not speak English, or men. The 3IQ may not be accurate in these populations. In addition, our study does not provide information on the number of extended evaluations that would occur if treatment were based on the results of the 3IQ or on the clinical outcomes that would result from using the 3IQ.
In the primary care setting, evaluation of incontinence should include a urine screening to exclude urinary tract infection and hematuria and the 3IQ to classify type of incontinence. If urinalysis results are normal, treatment of urge, stress, or mixed incontinence can be based on the results of the 3IQ. Patients with other incontinence and those with complex urinary tract problems should be referred to a specialist for an extended evaluation. The initial treatment for both urge and stress incontinence is behavioral (reduced oral fluid intake, regular voiding, pelvic musclestrengthening exercises for stress incontinence, and urge-suppression exercises for urge incontinence). Antimuscarinic or anticholinergic medications are effective for treating urge incontinence. If primary care management does not adequately control incontinence after 6 to 12 months, patients should be referred for evaluation and treatment by an incontinence specialist.
In summary, the 3IQ questionnaire is a simple, quick, and noninvasive test with acceptable accuracy for classifying urge and stress incontinence among the mostly middleaged women included in our study. Our findings should be replicated in other primary care clinical settings. In addition, clinical outcomes should be assessed in a trial comparing treatments based on the 3IQ and the extended evaluation.