Construction of a clinical nomogram to classify bladder outlet obstruction anr to classify bladder outlet obstruc-tion and detrusor underactivity

WANG Bin; JIANG Shao-jun; TANG Ping; WEI Xing-hua; YANG Wen-jun; WU Sui-shan; XIE Ke-ji

Abstract：Objective To construct a bladder outlet obstruction -bladder contractility nomogram for the purpose of classifying bladder outlet obstruction ( BOO) , detrusor underactivity ( DU) , and BOO complicated with DU .Methods Retrospectively analyzed the outpatients and inpatients with non -neurogenic male lower urinary tractsymptoms ( LUTS) who were undertook pressure -flow studies ( PFS) .The regularities of distribution and difference of the PFS pa-rameters in the study cohort was analyzed by data mining and statistical analysis , so as to develop the diagnosis nomogram . The nomogram was conducted using the computer program Matlab ( The Mathworks ) and the statistical analyses were done with SPSS ( Version 21 ) .Results A total of 1 278 patients were analyzed .Comparison among the different percentile groups subdivided by the program revealed that , the comparisonbetween the two lowest percentile groups didn′t show statis-tically significant differences for the majority of investigated parameters , while significant differences between patients of <25th percentile group and those of the 25th-50th percentile group were seen for most of the investigated parameters , such as PVR (86.4 vs 61.4 mL, P<0.001), voiding efficiency (40.3%vs 75.4%, P<0.001), andcystometric bladder ca-pacity (275.9 vs 241.9 mL, P<0.001), which may indicate DU in clinical practice .Therefore, we propose the diagno-sis of DU for patients below the 25th percentile in the nomogram.Conclusion Based on the clinical urodynamic dataset , we construct a bladder outlet obstruction -bladder contractility nomogram , which may be useful to classify BOO , DU, and BOO complicated with DU in mlae LUTS .This nomogram may also provide valuable reference and guidance in the clinical practice .