The diagnosis of overactive bladder (OAB) depends on identifying urinary symptoms of frequency, urgency or urgency incontinence. Diagnosing OAB is not like checking for high blood pressure or diabetes. The symptoms that identify OAB are typically reported by patients rather than being directly observed by the health provider. It seems natural to question what would be the best way to identify and measure these symptoms.
Short questionnaires of a dozen or so questions about urinary symptoms are often used to classify bladder symptoms as well as to measure their severity. These are attractive because they can be completed quickly and easily and do a very good job of characterizing OAB.
The bladder diary is a written log that may include information about how frequently urination happens, how much urine is produced with each void, how much liquid is consumed, whether any urine leakage occurs, and what was happening when leakage occurred. A recent review article by Dixon and Nakib expertly summarizes the important studies that show the usefulness of voiding diaries in bladder care.
The authors begin by pointing to several studies that demonstrate that voiding diaries are completed by the vast majority of patients asked to do so. Furthermore, most patients find these diaries easy to complete and they report that completing a diary was helpful to them. We often find that patients gain significant insight about how frequently they void and the relationship of their symptoms to behaviors such as how much they may be drinking. It is not unusual to see improvement from the first to the last day of a diary as the patient begins to modify her behavior in response what she sees in the diary.
Voiding diaries can be very useful for identifying specific problems. Patients who consume too much fluid will quickly be identified and can be given very specific recommendations as to how much to reduce intake. A voiding diary showing an excess of urine produced at night can give a clue to medical problems including sleep apnea or congestive heart failure. Finally, a voiding diary can be a very useful way to distinguish between stress incontinence and urgency incontinence.
In modern medicine, we frequently focus on complex, sophisticated and often expensive tests that often do provide useful information. But, when evaluating OAB, we would do well to remember a very simple study that costs just pennies in copy costs but can provide a wealth of information.
Colin M. Goudelocke, M.D.