Hypothesis / aims of study
The geriatric syndrome of Urinary Incontinence includes the under-recognised nocturnal lower urinary tract symptoms (nLUTS) of nocturia, enuresis, urinary urgency, urgency incontinence, stress incontinence and voiding dysfunction. Although bladder symptoms at night are predictive of poor health, on the causal pathway of frailty and mortality, and associated with increased length of hospital stay and higher medical care costs (1-2), prevalence has never been elucidated. nLUTS in older hospitalized patients are usually undetected, poorly investigated and rarely treated. The aim of this study was to describe the presence and incidence of bladder dysfunction at night in a tertiary hospital aged-care environment.
Study design, materials and methods
Geriatrician trainee registrars performed an audit to establish prevalence and incidence of nLUTS in consecutive patients admitted to one tertiary referral sub-acute aged care hospital ward over a three-month period. This methodology was selected because medical notes did not report the symptoms of interest and nursing staff were unable to discriminate between different nLUTS. Patients were screened during their medical admission process (i.e. within 3 hours of on-boarding) and excluded if they had an in-dwelling catheter or were cognitively impaired to the extent that they were unable to provide answers when questioned. Non-English speaking patients were included if they had an interpreter present.
Standardised bedside questioning was used to establish prevalence during the hospital stay of nocturia (waking to pass urine), nocturnal urgency (imperative urgency after waking), nocturnal incontinence (leakage en route to toilet), nocturnal enuresis (wet on awakening) and daytime incontinence. Stress leakage and voiding mechanics were not investigated. Participants were also questioned about any history of LUTS prior to the current hospital admission, any use of bladder medication or discussion of urinary symptoms. The audit added <5 minutes to the admission process.
Data from the initial 73 eligible subjects (45% male; 55% female; mean age 82 years) is reported; 4 patients were excluded due to indwelling catheter and 9 due to cognitive impairment. Overall 19% of patients were free from bladder symptoms at night. The prevalence of nLUTS while hospitalised was: nocturia 79.4%; nocturnal urgency 67%; nocturnal enuresis 40% and nocturnal incontinence 60%. Half of the patients reported incontinence during the day; this always co-existed with at least one nLUTS.
Only nocturia (9.5%) and nocturnal enuresis (1.3%) occurred in the absence of any other nLUTs. Table 1 shows the proportion of patients with paired co-existing LUTS symptoms. 31/73 patients (42%) reported experiencing all nLUTS during hospitalization. Three nLUTS together, nocturia, urgency and incontinence at night, were reported by 86.3% of patients.
Overall 46.5% of patients described a positive history of bladder symptoms before admission; of these 2.7% of patients reported no nLUTS and 6.8% no day symptoms while hospitalised. Of the patients with no bladder symptom history nLUTS prevalence during hospitalization was: nocturia 66%, nocturnal urgency 43.5%, nocturnal enuresis 20.5% and nocturnal incontinence 44%. Overall, 20% of patients without a history of bladder symptoms reported daytime incontinence while hospitalised.
Interpretation of results
This first study to describe different nocturnal LUTS during sub-acute hospitalisation established that 80% of older patients have bladder issues during the night. This finding warrants formal epidemiological study. Nocturnal LUTS cluster together and at least half the time co-exist with incontinence during the day. This inter-relationship should be further investigated. Incident nLUTS occurred in half the participants likely implicating both acute illness and hospital environmental factors. Predictive and modifiable risk factors for onset of nLUTS require investigation. A specific nLUTS screening program implemented within 48 hours of admission to an aged-care ward is justified.