To examine the symptoms and noninvasive test parameters that clinically differentiate detrusor underactivity (DU) from bladder outlet obstruction (BOO) without using a pressure‐flow study (PFS) in male patients with lower urinary tract symptoms.
We examined 909 men who underwent PFS and also had the following data: International Prostate Symptom Score (IPSS), free uroflowmetry, postvoid residual (PVR), and prostate volume (PV). Using these data, significant symptoms and noninvasive test parameters that clinically differentiate DU from BOO were examined.
Significant parameters between DU patients and BOO patients were older age, smaller PV, and lower urgency symptom score (IPSS Q4). Optimal cutoff values were determined using receiver operating characteristic curves (≥74 years old, PV ≤ 34.8, and IPSS Q4 ≤ 1) and patients were categorized on the basis of the number of significant factors. The probability of DU or BOO in patients with three significant factors were 77% and 34%, respectively.
Three factors (older age, smaller PV, and fewer urgency symptom) were the predictive factors to differentiate DU from BOO, which might be useful for estimating the probability of DU in clinical practice without a PFS.