Detrusor overactivity (DO) can be classified into phasic or terminal ones. However, to our knowledge, clinical and urodynamic differences between phasic or terminal DO have never been reported. Therefore, the objective of this study is to elucidate the above differences.

Between July 2009 and December 2023, medical records, including urodynamic data, bladder dairy data, and questionnaires, including patient perception of bladder condition (PPBC), urgency severity scale (USS), overactive bladder symptom score (OABSS), urogenital distress inventory (UDI), incontinence impact questionnaire (IIQ) and King's health questionnaire, of all women with lower urinary tract symptoms who underwent urodynamic studies in the urogynecological department of a medical center were reviewed. The medical records of phasic or terminal DO were selected for comparison. Those with phasic and terminal DO were excluded.
STATA software was used for statistical analysis. Wilcoxon rank sum test or chi-square test were used for statistical analysis, as appropriate. A p < 0.05 was considered statistically significant.

Twenty-one women with phasic and terminal DO were excluded. A total of 290 women were reviewed (Table 1). Except for the higher percentage of overactive bladder syndrome, bladder oversensitivity and urodynamic stress incontinence in phasic DO, age, parity, and stress urinary incontinence were similar in the phasic and terminal DO groups (Table 1). 
Despite the fact that there was no difference in PPBC, USS, OABSS and UDI scores between the phasic and terminal DO groups. However, the phasic DO group had higher scores in IIQ and some domains of the King's Health Questionnaire, such as  incontinence impact, role limitations, physical limitations, social limitations, emotions and sleep/energy, compared to terminal DO (Table 1). Furthermore, the phasic DO group had higher scores on frequency, nocturia, and nocturnal enuresis, compared to terminal DO (Table 1). However, bladder diary parameters did not differ between these two groups.
Despite the fact that  there was no difference in pad weights, maximum flow rate and post-void residual between the phasic and terminal DO groups. However, the phasic DO group also had a lower volume at a strong desire to void and a lower detrusor pressure at maximum flow, compared to terminal DO (Table 2).

Women with phasic DO have  smaller bladder capacity, probable lower bladder outlet resistance, greater severity of overactive bladder symptoms, and a poorer quality of life related to urinary incontinence, compared to terminal DO.

Women with phasic DO appear to have smaller bladder capacity, greater severity of overactive bladder symptoms, and therefore a poorer quality of life, compared to terminal DO.