Wu PC, Hsiao SM, Lin HH, et al. - Females with overactive bladder syndrome (OAB) commonly experience nocturnal polyuria (NP), especially those with more than 5 nocturia episodes in their 3-day bladder diaries. There is a requirement for adjuvant therapy for better treatment efficacy.

• This study involved 1,071 women with OAB.

• Definition for NP included: nocturnal polyuria index (NPI) (nighttime voided volume over 24-h voided volume) > 33% (NPI33) in females  ≥ 65 years-old and > 20% (NPI20) in females < 65 years old.

• Overall prevalence of NP was estimated to be 30% (319/1,071), with the highest prevalence in those in the perimenopausal period, while NP was diagnosed by age-dependent NPI.

• NP’s overall prevalence was 12% (128/1,071), and a rising trend was evident with increasing age, while NP was diagnosed by the NPI33 definition only.

• In the 3-day bladder diary, more than 5 nocturia episodes reported were an optimal cutoff value to predict nocturnal polyuria [(sensitivity = 85.6%, specificity = 61.0%; area = 0.80) and (sensitivity = 88.3%, specificity = 65.9%; area = 0.83), respectively, in the two definitions].