Quantitative Assessment of Nocturia Patient’s Urination Pattern and Drug Treatment Effects using a Joint Ordered Categorical Model

Background: Nocturia occurs in about 70% of the elderly, lowering the quality of life seriously. However, due to the lack of understanding of the disease, no objective tool is available for evaluating drug effects.
Objective: To develop a model for quantitative assessment of disease characteristics and drug effects in nocturia
Design, Setting, and Participants: This study analyzed data retrospectively obtained from 20 male Korean outpatients with severe nocturia (≥ 3 urinations /night) over three periods, before treatment (Period 1), after 1 month of mono-therapy of tamsulosin (Period 2), and after 3 months of combination therapy of tamsulosin and solifenacin (Period 3).
Outcome Measurements and Statistical Analysis: Outcome measurements were the urination frequency every 2-h (FREQ) and the average urine volume per void every 2-h (FBC, functional bladder capacity) within a 24-h interval, taken from Frequency Volume Chart (FVC) recorded by study patients, which were analyzed using the joint ordered categorical model using NONMEM 7.2
Results and Limitations: FREQ was divided into 0, 1, and 2 urinations, and FBC into 0, 1-100, 100-200 and >200 ml (no, small, medium and large FBC, respectively). Drug effect assessed by the model increased the probability of no-urination at nighttime from 17% up to 45% and 52% in period 2 and 3, respectively, while that of large FBC from 26% up to 41% in period 3, where the drug effect on FBC has not been found by the conventional approach yet. Another new finding identified from this model was that solifenacin has significant effect on decreasing nocturia frequency, a supportive evidence justifying the use of this drug in nocturia patients which has been controversial. The results for the combination treatment were similar to previous studies. One limitation with the current work is that no demographics information was included in the model, resulting in the model with limited prediction ability. Nevertheless, we expect that the developed model can be used as a supportive tool in the treatment of nocturia.
Conclusions: These results demonstrate the feasibility of applying the proposed method to quantitative understanding of nocturia characteristics and objective assessment of drug effects.

Hyerang Roh

  • Yonsei Univ. College of Medicine