Multidisciplinary medical care regarding urinary continence has progressed in acute-phase general hospitals in Japan due to the high effectiveness of the Japanese health insurance system from 2016. In the course of multidisciplinary medical care, it has been recognized that elderly patients often have lower urinary tract symptoms (LUTS) regardless of the disease that requires hospitalization, including respiratory disease, circulatory disease, and digestive disease. In this study, we epidemiologically examined post-void residual urine (PVRU) in hospitalized elderly patients in an acute-phase general hospital, and analyzed the characteristics of the “potential” patients with LUTS.

The study design was a cross-sectional observational study. In this study, 655 patients aged 65 years or older who were hospitalized and screened from November 2018 to May 2019 in our institution were enrolled. PVRUs of the enrolled patients were measured one to three times by the ward nurse on first day of hospitalization using Lilliam-200®. The patients with indwelling catheterization on admission were excluded. LUTS in the enrolled patient was evaluated using Core Lower Urinary Tract Symptom Score (CLSS). The enrolled patients were divided into two groups: the patients with 100 ml or more of PVRU and those with less, and comparisons of the characteristics between two groups were analyzed using Pearson's chi-square test and the Mann-Whitney U test. This study was approved by the Ethical Committee, and the study protocol was in accordance with the Declaration of Helsinki.

Of 655 enrolled patients, 105 (16.0%) had 100 ml or more of PVRU at first the screening, and the mean volume of PVRU in these patients was 204.3 ml. These patients comprised the patient group with PVRU, and 58 of them (55.2%) had 100 ml or more of PVRU in the second screening and 37 patients (35.2%) in three times. Age of the patients in the group with PVRU was significantly higher than that of those in the group without PVRU (79.3 ± 7.2 years vs. 76.1 ± 6.9 years, p <0.001). Proportions of those aged 75 years or older were significantly higher in the group with PVRU than that in the group without PVRU (73.3% vs.  56.9%, p = 0.002). Proportion of the patients who had medical histories of urological disease was significantly higher in the group with PVRU than that in the group without PVRU (36.2% vs. 26.7%, p = 0.047). The frequency of nocturnal urinations in the patients of the group with PVRU was significantly higher than that of the group without PVRU (2.7 ± 1.9 vs. 2.0 ± 1.4, p = 0.001). Evaluation of the relationships between PVRU and CLSS revealed that the patients in the group with PVRU had LUTS including nocturia, urgency, urge urinary incontinence, small stream, and feeling of incomplete emptying compared to those in the group without PVRU. Consultation for urology was performed frequency in the group with PVRU during hospitalization compared to the group without PVRU (20.0% vs. 7.8%, p <0.001), and the intervention by the multidisciplinary team was 2.9% in the group with PVRU and 0.2% in the group without PVRU, respectively (p = 0.001).

In this study, 16.0% of hospitalized elderly patients in an acute-phase general hospital had 100 ml or more of PVRU. Of them, 36.2% had medical histories of urological disease; however, the others were thought to be “potential” patients with LUTS. The patients with PVRU may have LUTS, and multidisciplinary medical care regarding urinary continence during hospitalization will be clinically useful for these patients.

In this epidemiological survey in an acute-phase general hospital, 100 ml or more of PVRU was observed in 16.0% of the hospitalized patients aged 65 years or older. Predictive factors of PVRU were age, medical history, and nocturia, and the patients with PVRU had LUTS. Screening regarding PVRU and LUTS for hospitalized elderly patients may be clinically useful.