Lower urinary tract symptoms (LUTS) are common in older men and one of the main reasons for this is the enlargement in prostate gland volume caused by hormonal changes. The gold standard diagnosis of Bladder Outlet Obstructıon  is pressure-flow studies. However, its widespread use is limited since it is an invasive procedure, requires specific equipment and experienced personnel, and is a worrying method for the patient. 
The international prostate symptom score (IPSS) is a proven diagnostic tool in the diagnosis and follow-up of LUTS .There are problems such as having wrong results due to low educated or advanced age patient groups having difficulty understanding the IPSS questions or getting support from the healthcare professionals in answering the questions. This support requirement also puts an extra workload on healthcare professionals. Visual Prostate symptom score (VPSS) has been developed as an alternative to IPSS due to these problems. 
It is claimed that IPP causes urinary obstruction and increases LUTS by a "ball-valve" mechanism . Bladder Outlet Obstruction Number (BOON) is a formula with non-invasive parameters and suggested to be used in the diagnosis of BOO in patients with BPE.  
In this study, it is aimed to determine the use of VPSS instead of IPSS when needed, the importance of IPP in evaluating LUTS, and the correlation of IPP with VPSS and IPSS, based on BOON in the diagnosis of obstruction.

The study included 95 male patients aged 50 and over. Patients completed Visual Prostate Symptom Score (VPSS) along with International Prostate Symptom Score (IPSS). Intravesical prostatic protrusion (IPP), prostate volume, bladder volume, and post voiding residual urine (PVR) were measured by suprapubic ultrasound. Urethral resistance was calculated using the Bladder Outlet Obstruction Number (BOON), and patients over -20 were considered obstructed.The patients were divided into three groups according to their IPP results (< 5mm, 5-10mm, > 10mm). Uroflowmetry and PVR values of the patients were measured.
Patients were asked to fill out IPSS and VPSS forms on their own. 1st, 3rd, 5th and 6th questions of IPSS scores were collected and accepted as the “IPSS (voiding)” group. Total scores of the 2nd, 4th and 7th questions of IPSS regarding storage symptoms were accepted as “IPSS (storage)” group. Likewise, the third pictogram of VPSS for voiding symptoms was accepted as “VPSS (voiding)” and the sum of the 1st and 2nd pictogram values for storage symptoms was also accepted as “VPSS (storage)”.
BOON was used to detect the obstruction. BOON = Volprostate (cc) - 3 x Qmax (ml / sec) - 0.2 x Vvoid (ml). If the value was above -20, the patients were considered obstructed. The power of IPP, IPSS and VPSS in predicting these patients was examined with the ROC curve.

The number of patients with a BOON value greater than -20 were 34 (obstructed), and less than -20 were 61 (non-obstructed). The patients were divided into these two groups and there was a significant difference between the two groups in PSA, prostate volume, IPP, Qmax, PVR, IPSS, and VPSS (p = 0.004, <0.001, 0.009, <0.001, 0.009, <0.001, <0.001). It was observed that IPSS and VPSS were correlated (r = 0.786, p = 0.001). Positive correlations of IPSS with prostate volumes (r = 0.298, p = 0.001) and PVR (r = 0.334, p = 0.000) were also observed in VPSS (r = 0.319, p = 0.001). Obstructive (r = 0.779, p = 0.000) and irritative symptoms (r = 0.813, p = 0.000) of IPSS and VPSS were also observed to be correlated.

According to the IPP results (<5mm, 5-10,> 10), the patients were distributed as 25, 26, and 44, respectively.  There is a significant negative correlation with the Qmax and Qavg values of IPSS (r = -0.283, p = 0.003 and r = -0.386, p = 0.000) as well as a significant negative correlation between VPSS (r = -0.235, p = 0.005 and r = -0.299, p = 0.001).
The power of IPSS and VPSS in predicting the patient considered obstructed due to BPE (BOON > -20) was found to be significant (p = 0.001). The area under the curve (AUC) was higher in IPSS than VPSS (0.811 and 0.798).
A significant positive correlation was found between IPP value and BOON, prostate volume, and PSA (r = 0.351, 0.287, 0.268, p = 0.001, 0.005, 0.009). The negative correlation of IPP and Qmax was statistically significant (r = -0.242, p = 0.019). In the correlation curves of IPP and BOON values, it was seen that the cut-off value for IPP was 12 mm (65% sensitivity, 80% specificity). Likelihood ratio (LHR) was 3.85. In the Post-Hoc (Bonferroni) analysis of the patients who were divided into 3 groups according to their IPP values, considering the BOON value as the dependent variable, there was no significant difference between the 1st and 2nd groups. The difference between the 3rd group and the 1st and 2nd group was significant (p = 0.002, 0.018). It was observed that the predictive power of prostate volume and IPP values in the obstructed patient (BOON > -20) was significant (p = 0.000). Area under the curve (AUC = 0.805, 0.760) was greater in prostate volume.

In the study, it was found that both voiding and storage symptom scores of IPSS and VPSS were correlated with each other, although VPSS was not found to be superior to IPSS, it was concluded that it is equivalent (p = 0.001) and can be used instead of IPSS.In the study, it was observed that prostate volume and IPP values’ predictive power of the obstructed patient (BOON > -20) were significant. The reason for the higher AUC in the prostate volume was evaluated as the presence of prostate volume in the BOON formulation and its direct effect on the result. However, it should be accepted that IPP is also an important parameter in predicting obstruction with its undeniably higher AUC and significant p-value. While IPP was negatively correlated with Qmax, it was positively correlated with other parameters, and this correlation rate was higher at the BOON value. It has been observed that IPP provides information about the severity of obstruction. It has also been shown that the greater the IPP, the higher the BOON, likewise IPP is associated with prostate volume, Qmax, PVR, IPSS, and VPSS.

Non-invasive tests can also be used safely in the detection of BOO. Although urodynamic tests are the gold standard in the diagnosis of LUTS, non-invasive scoring systems should be used in the daily outpatient clinic. While IPP gives us information about the severity of LUTS, VPSS stands out with its high correlation and ease of use with IPSS, which is currently used in outpatient clinics.