Assoc Prof Ng Lay Guat
Director, Clinical Services, SingHealth Duke-NUS Pelvic Floor Disorders Centre;
Senior Consultant, SingHealth Duke-NUS Transplant Centre;
Department of Urology, Singapore General Hospital;
Division of Surgery and Surgical Oncology, National Cancer Centre Singapore
 

Overactive bladder is a common clinical condition seen in primary care with many of these cases presenting with no identifiable cause. We share a structured and evidence based approach on how idiopathic overactive bladder can be managed and treated in primary care.

INTRODUCTION

Overactive bladder (OAB) is a common clinical condition encountered in primary care, characterised by rinary urgency, usually accompanied by frequency and nocturia, with or without urge incontinence, in the absence of urinary tract infection (UTI) or other obvious pathology.

When no identifiable cause is found, the condition is termed idiopathic OAB. This condition affects an estimated 12-16% of adults, roughly 30% of women and 16% of men, increasing with age.

Early recognition, comprehensive assessment and effective management are essential components of primary care practice.

This article aims to provide primary healthcarephysicians with a structured and evidence-based approach to the assessment and management of idiopathic OAB, focusing on essential history-taking, physical examination, appropriate investigations, and both non-pharmacological and pharmacological treatment options.

UNDERSTANDING IDIOPATHIC OVERACTIVE BLADDER

Definition
According to the International Continence Society (ICS), OAB is defined by a symptom complex that includes:

• Urgency (the sudden, compelling desire to void that is difficult to defer)
• Usually accompanied by:
  • Increased daytime frequency
  • Nocturia
  • With or without urgency urinaryincontinence (UUI)

Idiopathic vs. Secondary OAB
OAB may be classified as:

• Idiopathic: No underlying pathology found
• Secondary: Due to identifiable causes like neurological diseases (e.g., Parkinson’s disease, multiple sclerosis), bladder outlet obstruction, UTI, bladder stones or malignancy.

The focus here is on idiopathic OAB, where the diagnosis is made after ruling out secondary causes.

A Structured and Evidence-Based Approach to the Assessment and Management of Idiopathic OAB

1. ESSENTIAL HISTORY
History-taking is the cornerstone of OAB assessment. It provides the context for diagnosis and guides further evaluation.

A. Presenting Symptoms

Ask about the four hallmark symptoms:

• Urgency: Onset, frequency, and severity
• Frequency: Number of voids per day(>8 is abnormal)
• Nocturia: Number of voids at night
• Urge incontinence: Frequency and impacton daily life

B. Precipitating or Relieving Factors

• Caffeine, alcohol, fluid intake
• Diuretic use
• Cold weather or specific triggers

C. Voiding and Continence History

• Pain on urination (suggests UTI or bladder pathology)
• Hesitancy, weak stream, straining (suggests BPH in men)
• Incomplete emptying
• Stress incontinence (when sneezing, coughing or laughing

D. Medical and Neurological History

• Diabetes mellitus
• Stroke, spinal cord injury, multiple sclerosis
• Parkinson’s disease
• History of pelvic surgery or radiation
  

E. Medications

• Diuretics
• Anticholinergics
• Alpha-adrenergic agonists or antagonists
• Sedatives
• SGLT2 inhibitors

F. Obstetric and Gynaecologic History (in women)

• Parity
• Vaginal deliveries, instrumental deliveries
• Pelvic organ prolapse
• Menopause

G. Impact on Quality of Life

Ask how the condition affects:

• Sleep, Work, Social interactions, Sexual activity

2. PHYSICAL EXAMINATION

A. General Examination

• Cognitive assessment in elderly patients

B. Focused Exam to Rule Out Alternative Causes

• Abdominal exam: Palpable bladder suggests retention
• Genital/pelvic: Check for prolapse, atrophy, signs of oestrogen deficiency, pelvic floor power
• Digital rectal examination (in men): Assess prostate size and consistency
• Neurological examination: Perineal sensation, anal tone and reflexes, gait and coordination

3. INVESTIGATIONS

Investigations are aimed at excluding secondary causes and establishing a baseline.

A. Urinalysis

• To rule out infection, haematuria or glycosuria.
• If positive for nitrites or leukocyte esterase, send urine culture.

B. Bladder Diary

• A 3-day record of fluid intake, voiding times, volumes, incontinence episodes, urgency and pad use provides a more objective picture for the symptoms.
• Figure 1 shows a typical bladder diary of a patient with OAB. Note that the patient indicated urine urgency (U) with 50-100 ml voided. ‘w’ indicated wet and ‘p’ indicates change of pad. Assessment of post-void residual urine in the patient with this diary is important to differentiate between a patient with OAB and one of voiding dysfunction.
• Figures 2 and 3 illustrate the importance of a bladder diary of patients also presenting with urinary frequency, urgency and nocturia, but figure 2 shows that the cause is that of polydipsia, and figure 3 shows a picture of nocturnal polyuria.

C. Post-void Residual (PVR) Volumem

• Measured by bladder ultrasound or catheterisation
• A normal PVR is <50 ml; >200 ml may suggest retention or detrusor under activity.

D. Urine Cytology (if haematuria)

To rule out bladder malignancy, especially in older adults or smokers.

E. Serum PSA and Renal Panel

F. Imaging (Selective)

• Renal and bladder ultrasound if obstruction orstones are suspected.
• MRI spine if neurological symptoms are present.

Diagnosis

Idiopathic OAB is a clinical diagnosis made after:

• Excluding infection, structural and neurological causes.
• Confirming the symptom complex of urgency, with or without frequency, nocturia and urge incontinence.