Hypothesis / aims of study
To investigate patient bother in nocturia using the patient reported questionnaire (Overactive Bladder Symptom Score (OABSS)1)), frequency volume chart (FVC) and the OABSS-VAS questionnaire, which describes bother for each item of the OABSS on a 0-100 mm VAS scale.
Study design, materials and methods
A total of 102 patients (33 males and 69 females) who visited our outpatient clinic with LUTS and whose OABSS, OABSS-VAS2) questionnaire, and FVC were available were retrospectively evaluated. Bother from nocturia were examined in relation to self-reported nocturia frequency (using the OABSS-Q2) and nocturia frequency at FVC. Bother from nocturia was assessed on 100mm VAS scale (0; very happy to 100; terrible).
Noctural frequency by FVC was averaged over 3 days and rounded to the nearest whole number for comparison with the OABSS-VAS. This study was approved by the Ethics Committee of our hospital(ERB-C-1127).
Results
The mean±SD age of the patients was 73 ± 13 years, and the OABSS total score was 8.1 ± 3.1. According to FVC, daily voided volume was 1623 ± 623 ml, nocturnal urine volume was 540 ± 283 ml, 24 hour frequency was 11 ± 4.2 times, nocturnal frequency 2.1 ± 1.6, and nocturnal polyuria index was 34 ± 13％. Nocturnal frequency on OABSS (Q2) and bother from nocturnal frequency (OABSS-VASQ2) was 2.1±0.9 and 62±29, respectively. The OABSS-VAS for each OABSS-Q2 value was 43±38 for Q2=0 (nocturia 0 times, n=6), 41±23 for Q2=1 (nocturia 1 time, n=19), 56±28 for Q2=2 (nocturia 2 times, n=39), and 81±18 for Q2=3 (nocturia ≥3 times, n=37). The OABSS-VAS for each nocturnal frequency on FVC was 39±27 for 0 time (n=10), 55±29 for 1 time (n=22), 64±32 for 2 times(n=33), and 70±23 for 3 or more times (n=36).
Analysis from OABSS-Q2, patients with two or more nocturia (OABSS-Q2>1) were significantly more bothersome than those with one or less nocturia (OABSS-Q2≤1) (mean 69±27 vs 49±28, p=0.0009). Analysis from FVC, patients with two or more nocturia were also significantly more bothersome than those with one or less nocturia (mean 68±27 vs 42±26, p=0.0001).
In the comparison with FVC and OABSS-Q2, the actual number of nightly voids in the FVC and the OABSS nocturia score were modestly intercorrelated (r = 0.603, P <0.001). The agreement was achieved in 51 (52/102) % for the number of voids per night recorded by the FVC and reported by the OABSS . However, in the patients who underestimate (18% (18/102)) or overestimate (31%(32/102)) the frequency in OABSS-Q2, only 6(6/102)patients had a difference of more than two points.
Interpretation of results
In the comparison with FVC and OABSS-Q2, the actual number of nightly voids in the FVC and the OABSS nocturia score were modestly intercorrelated. The difference of the scores were small and the OABSS-Q2 seemed to be reliable for the assessment of nocturia.
As in previous reports, patients who urinated two or more times during the night were significantly more distressed than those who urinated once or less in both FVC and patient reported nocturia frequency.