Methods
This prospective study was approved by the local ethics committee and patients were included after giving oral and written informed consent. All patients who had nocturia (≥1 nocturnal void/night) were included in the study from eight centers between February 2018 and August 2018 with face-to-face interview by a urologist. Patients under the age 18, with severe neurophysicological disorders (not able to fill questionnaires) and/or with urinary tract infection were excluded from study.
The demographic characteristics of patients were recorded. All patients filled the overactive bladder questionnaire (OABq), nocturia-quality of life (N-QoL) form and International Consultation on Incontinence Questionnaire - Male Lower Urinary Tract Symptoms (ICIQ-MLUTS) or International Consultation on Incontinence Questionnaire - Female Lower Urinary Tract Symptoms (ICIQ-FLUTS) forms at admission. Also 3-day frequency-volume chart was filled by patients and the pathophysiological mechanisms of nocturia were determined with this form. Uroflowmetry was performed to all patients. Mechanisms of nocturia were classified in five groups as nocturnal polyuria, global polyuria, reduced bladder capacity, mixed nocturia and isolated nocturia.3 We used ICS definition of nocturnal polyuria as nocturnal urine volume >33% or >20% of total 24-hour urine volume according to age.4 Reduced bladder capacity was described with using nocturnal bladder capacity index (NBCi).3 If NBCi is calculated as > 0 it states that the bladder itself cannot store the amount of urine produced at night and called as reduced bladder capacity. Global polyuria (24-h polyuria) was diagnosed when the overall urine volume >40ml/kg in adults.3 Mixed polyuria was defined as the combination of nocturnal polyuria and reduced bladder capacity. Nocturia which did not comply with the afore-mentioned subtypes was defined as isolated nocturia.
Patients were divided into three groups according to the severity of nocturia: group 1 consisted of patients with mild (1-2 voids/night), group 2 consisted of patients with moderate (3-4 voids/night) and group 3 consisted of patients with severe nocturia (>4 voids/night) and these groups were compared in terms of demographic characteristics, voiding symptoms, frequency-volume charts and nocturia subtypes.