IMPROVING THE UTILITY OF URINE FLOW-RATE TO EXCLUDE OUTLET OBSTRUCTION IN MEN WITH VOIDING SYMPTOMS

OBJECTIVES: Many older men with voiding symptoms do not have bladder o utlet obstruction (BOO) but have conditions amenable to medical treatm ent. If primary care providers could reliably exclude men who have BOO , then they could initiate appropriate evaluation and treatment in a s ubstantial proportion of the remainder. Urine flow rate, although wide ly used, is insufficiently sensitive to exclude BOO reliably. We inves tigated whether the decline in flow rate with age could be utilized to improve the utility of flow rate for excluding BOO in symptomatic men , especially when combined with knowledge of the patient's postvoiding residual volume (PVR). DESIGN: Prospective study using two patient co horts. SETTINGS: A Veterans Affairs urology clinic serving community-d welling and institutionalized healthy older men. PARTICIPANTS: 111 men with voiding symptoms (mean age 72.4 +/- 9.2 years). MEASUREMENTS: Ma ximum urine flow rate, measured with standard flowmeter, and PVR, meas ured by catheterization. BOO was determined by multichannel videourody namic testing. RESULTS: The sensitivity of flowrate for BOO increased significantly with age (P =.0001) and did not appear to be confounded by comorbid conditions. An algorithm incorporating age, flow rate, and PVR had a sensitivity of 90%, specificity of 43%, and accuracy of 74% in screening for BOG. The algorithm's sensitivity was better than tha t of flow rate alone (55%); its sensitivity was also similar to a ''re fer all'' strategy (100%) but had improved specificity (41% vs 0%). CO NCLUSIONS: Flow rate alone is insufficiently sensitive as a screening test to exclude BOG, but a simple diagnostic algorithm using age, flow rate, and PVR was more sensitive and accurate. This algorithm allows p rimary care evaluation and initial management of men with voiding symp toms while potentially reducing unnecessary referrals and costs.