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Individualized volume ‐ corrected maximum flow rate correlates with outcome from bladder outlet surgery in men with lower urinary tract symptoms

View Article: PubMed Central - PubMed

ABSTRACT

Objectives: To develop a per‐patient volume correction for maximum flow rate using multiple home uroflowmetry, and to carry out a pilot study to determine the most prognostically useful volume at which to evaluate this measurement and estimate its relationship with outcome from disobstructive bladder outlet surgery.

Methods: A total of 30 men carried out home uroflowmetry using a portable device and completed symptom scores before surgery. This was repeated at least 4 months after surgery. For each man's presurgery flow data, voided volume was plotted against maximum flow rate, and a line of best fit with logarithmic form calculated. This allowed maximum flow rate to be corrected for any volume. Percentage reduction in symptom score and increase in mean maximum flow rate were correlated with volume‐corrected maximum flow rates.

Results: Corrected maximum flow rate at all volumes showed the expected negative correlation with both outcome measures. A statistically significant correlation occurred for volumes >190 mL, with the best performance at volumes >300 mL.

Conclusions: We have devised a novel method allowing estimation of maximum flow rate at any volume, which is a step forward for non‐invasive diagnostics. We found this volume‐corrected maximum flow rate to correlate significantly with treatment outcome at sufficiently high volumes.

No MeSH data available.


Volume‐corrected Qmax at 300 mL versus (a) increase in mean Qmax from home uroflowmetry and (b) percentage decrease in total IPSS score after surgery, with linear best‐fit relationships. The vertical dotted lines show Qmax@300 = 14 mL/s.
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iju13099-fig-0005: Volume‐corrected Qmax at 300 mL versus (a) increase in mean Qmax from home uroflowmetry and (b) percentage decrease in total IPSS score after surgery, with linear best‐fit relationships. The vertical dotted lines show Qmax@300 = 14 mL/s.

Mentions: For every patient, Qmax@Vol was calculated at 5‐mL intervals from 0 to 500 mL from presurgery home uroflowmetry data. At all volumes, Qmax@Vol for the group showed the expected negative correlation (ρ < 0) with both outcome measures, showing that men with lower presurgery flow rates tended to experience better outcomes. Qmax@Vol values for volumes above 190 mL correlated significantly (P < 0.05) with both objective and symptom outcome. Figure 4 shows how rho and P‐values changed depending on the volume at which Qmax@Vol was corrected. For objective outcome, correlation improved with increasing volume, plateauing at 300 mL, where rho was less than −0.46 (95% confidence interval −0.12 to −0.70) and P < 0.01 (moderate correlation; Fig. 4a). A similar, but less pronounced, pattern was observed for the correlation between Qmax@Vol and symptom outcome (Fig. 4b). Figure 5 shows volume‐corrected Qmax at 300 mL (Qmax@300) versus (i) increase in mean Qmax from home uroflowmetry and (ii) percentage decrease in total IPSS score after surgery, both with linear least squares line of best fit.


Individualized volume ‐ corrected maximum flow rate correlates with outcome from bladder outlet surgery in men with lower urinary tract symptoms
Volume‐corrected Qmax at 300 mL versus (a) increase in mean Qmax from home uroflowmetry and (b) percentage decrease in total IPSS score after surgery, with linear best‐fit relationships. The vertical dotted lines show Qmax@300 = 14 mL/s.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4979675&req=5

iju13099-fig-0005: Volume‐corrected Qmax at 300 mL versus (a) increase in mean Qmax from home uroflowmetry and (b) percentage decrease in total IPSS score after surgery, with linear best‐fit relationships. The vertical dotted lines show Qmax@300 = 14 mL/s.
Mentions: For every patient, Qmax@Vol was calculated at 5‐mL intervals from 0 to 500 mL from presurgery home uroflowmetry data. At all volumes, Qmax@Vol for the group showed the expected negative correlation (ρ < 0) with both outcome measures, showing that men with lower presurgery flow rates tended to experience better outcomes. Qmax@Vol values for volumes above 190 mL correlated significantly (P < 0.05) with both objective and symptom outcome. Figure 4 shows how rho and P‐values changed depending on the volume at which Qmax@Vol was corrected. For objective outcome, correlation improved with increasing volume, plateauing at 300 mL, where rho was less than −0.46 (95% confidence interval −0.12 to −0.70) and P < 0.01 (moderate correlation; Fig. 4a). A similar, but less pronounced, pattern was observed for the correlation between Qmax@Vol and symptom outcome (Fig. 4b). Figure 5 shows volume‐corrected Qmax at 300 mL (Qmax@300) versus (i) increase in mean Qmax from home uroflowmetry and (ii) percentage decrease in total IPSS score after surgery, both with linear least squares line of best fit.

View Article: PubMed Central - PubMed

ABSTRACT

Objectives: To develop a per&#8208;patient volume correction for maximum flow rate using multiple home uroflowmetry, and to carry out a pilot study to determine the most prognostically useful volume at which to evaluate this measurement and estimate its relationship with outcome from disobstructive bladder outlet surgery.

Methods: A total of 30 men carried out home uroflowmetry using a portable device and completed symptom scores before surgery. This was repeated at least 4 months after surgery. For each man's presurgery flow data, voided volume was plotted against maximum flow rate, and a line of best fit with logarithmic form calculated. This allowed maximum flow rate to be corrected for any volume. Percentage reduction in symptom score and increase in mean maximum flow rate were correlated with volume&#8208;corrected maximum flow rates.

Results: Corrected maximum flow rate at all volumes showed the expected negative correlation with both outcome measures. A statistically significant correlation occurred for volumes &gt;190 mL, with the best performance at volumes &gt;300 mL.

Conclusions: We have devised a novel method allowing estimation of maximum flow rate at any volume, which is a step forward for non&#8208;invasive diagnostics. We found this volume&#8208;corrected maximum flow rate to correlate significantly with treatment outcome at sufficiently high volumes.

No MeSH data available.