Nocturnal polyuria may decrease the treatment efficacy of overactive bladder syndrome (OAB); and adjuvant medication, such as desmopressin, may be needed for the treatment of nocturnal polyuria. The knowledge of prevalence and risk factors of nocturnal polyuria might be important for the treatment of OAB. Thus, our aim is to describe the prevalence and risk factors of nocturnal polyuria in women with OAB.

Between July 2009 and January 2018, all women with OAB visiting a medical center for evaluation were reviewed. The classification of OAB-wet or OAB-dry is based on the record of the three-day bladder diary of each patient. The diagnosis of OAB in each patient was based on the presence of at least one episode of urgency in her three-day bladder diary and with the absence of stress urinary incontinence. The presence of at least one episode of urgency associated incontinence was defined to be OAB-wet, otherwise, OAB-dry.

Nocturnal polyuria was defined when the proportion of nighttime voided volume over 24-hour voided volume was greater than 33% for ≥65-year-old women, and when the proportion of nighttime voided volume over 24-hour voided volume was greater than 20% for <65-year-old women.

Inclusion Criteria:

1. More than 20-year-old
2. Female
3. Diagnosed with overactive bladder

Exclusion Criteria:

1. Younger than 20-year-old
2. Pregnant or planned to be pregnant

Between July 2009 and January 2018, all women elder than 20-year-old with OAB visiting a medical center for evaluation were enrolled.