Correspondence of uroflowmetry and voiding diary in evaluation of voiding volume in children with lower urinary tract dysfunction

Abstract

Abstract Background Objective assessment of voided volumes in children with lower urinary tract dysfunction is important. This study aimed to compare and evaluate voided volumes obtained from a 48-h voiding diary and uroflowmetry in children with lower urinary tract dysfunction. Methods In this retrospective cohort study, voided volumes obtained by 48-h voiding diary and contemporaneous uroflowmetry were compared in terms of age, sex, and the three most common subtypes of lower urinary tract dysfunction (monosymptomatic nocturnal enuresis, overactive bladder, and dysfunctional voiding) in children. Patients were stratified according to voided volume differences between uroflowmetry and 48-h voiding diary. Results A total of 242 children were included in the study. Maximum and average voided volumes in uroflowmetry were higher than those in 48-h voiding diaries in the entire population (P < 0.001). While there was a significant difference between maximum voided volume in the two methods when evaluating patients with overactive bladder and dysfunctional voiding, there was no significant difference in those with monosymptomatic nocturnal enuresis (P = 0.001, P = 0.030, P = 0.206, respectively). A significant difference was observed between the three subtypes of lower urinary tract dysfunction in voided volumes (P < 0.001). When maximum and average voided volumes were compared for age subgroups, there was no significant difference in maximum and mean voided volumes only in voiding diary measurements (P > 0.05). When the two methods were compared, there was a difference in maximum and average voided volumes of more than 30% of the estimated bladder capacity in 94 (38.9%) and 86 (34.3%) children, respectively. Conclusions Uroflowmetry and a 48-h voiding diary should not be used interchangeably when evaluating children with lower urinary tract dysfunction. The results of uroflowmetry measurements should be used to support the diagnosis of underlying lower urinary tract dysfunction.