lower urinary tract symptoms (LUTS) in old male patients are usually secondary to prostatic hyperplasia. However, it is becoming clear nowadays that prostatic enlargement is not always the cause of male LUTS, and other factors could cause male LUTS in the presence of benign prostate enlargement (BPE).~Two clinical situations are common in elderly patients like Bladder Outlet Obstruction (BOO) and Detrusor underactivity (DU) they affect the voiding phase in elderly men markedly.~To distinguish one from another may be challenging and could be only done by urodynamic study (UDS), which is the gold standard for diagnosis.~A urodynamic study is an invasive procedure, with side effects of pain and urinary tract infection, and the need for special equipment and expertise has limited its widespread use and made it very stressful for the patients.~On the other hand, Uroflowmetry is a non-invasive procedure that could be used in patients' assessments. A term of Delta Q is being used that focuses on the difference between (Qmax) and (Q-average). The hypothesis is that Delta Q would be lower in Detrusor underactivity because of the undermined detrusor function decreasing both average and maximum urine flow rate, but it is higher in BOO, which has normal detrusor contraction during the voiding phase.~Based on the concept uroflow can be used to replace urodynamic studies to differentiate between these 2 entities and hence to determine the proper management plan and to be a prognostic factor before surgical intervention.
To determine the significance of delta Q value (Qmax - Qave) in discrimination between BOO and DU, to avoid invasive studies (pressure flow studies (PFSs)) and replace them with noninvasive study (uroflowmetry).