Frequency volume charts provide an objective measure of bladder function, which is essential to support the correct diagnosis and treatment of urological problems
Many people experience bladder and urinary problems and the reasons for them are manifold. Charting fluid intake and urinary output is an essential part of a continence and urology assessment, which will help practitioners diagnose problems and decide on treatment. This article describes the different charts in use; it also analyses and discusses examples of completed charts.
Citation: Colley W (2015) Use of frequency volume charts and voiding diaries. Nursing Times; 111: 5, 12-15.
Author: Wendy Colley OBE is a freelance writer and lecturer, and former continence nurse specialist.
- This article has been double-blind peer reviewed
- Scroll down to read the article or download a print-friendly PDF here
Urinary symptoms are common and may be due to conditions affecting the urinary tract or as a result of illness affecting other systems (for example, heart failure is associated with nocturia). Accurate diagnosis is essential to ensure prompt, effective treatment of the underlying cause.
Using charts to record the times urine is passed and the volumes voided over a period of time gives an objective measure of bladder performance. The charts are usually completed by patients after they have been taught how to do so by a health professional. They provide invaluable information and are used in the following circumstances:
- As part of the initial assessment of lower urinary tract symptoms (National Institute for Health and Care Excellence, 2010);
- To aid diagnosis as part of a continence assessment (NICE, 2013);
- As a baseline in planning a bladder training regime;
- To plan an individual toileting programme;
- To measure progress during treatment, for example for overactive bladder.
The information that must be recorded on the chart will be determined by the assessor and based on the capabilities of the patient, who must be able to safely void into a container, and measure and record the volume of fluid.
What is measured and when
There are a variety of charts in use; this article follows the International Continence Society definitions (Abrams et al, 2002), which recognise three main types of recording:
- Micturition time chart: records the times of micturition during the day and night;
- Frequency volume chart (FVC): records the volumes voided as well as the time of each micturition, during the day and night;
- Bladder diary: records the times of micturition and voided volumes, episodes of incontinence, pad use, other information such as the degree of urgency, degree of incontinence and fluid intake and type.
Charts or diaries should be completed for a minimum of three days (NICE, 2013) although a period of 3-7 days is usually used; this is recommended by the European Association of Urology (Lucas et al, 2014). The patient should be asked to include work and leisure days where applicable as this may indicate exacerbating factors. Charts should include a time column covering each 24-hour period; this can be blank for the patient to insert times, but is often labelled at hourly intervals.
A bladder diary is likely to be used as part of a continence assessment to aid diagnosis and inform a treatment plan. It is an invaluable tool, giving a baseline against which progress can be monitored, which helps to motivate patients.
Preparation and instructions
To ensure accurate, meaningful data is recorded, health professionals should help patients understand what is required and reinforce the importance of the chart in diagnosing and managing their condition.
- Determine the information required based on assessment;
- Assess patients’ capabilities when deciding what to record and ensure they are not at risk of falls when voiding into a container;
- Confirm that the patient understands fluid measurements;
- Provide a suitable chart for recording information.
They should tell patients:
- To use a jug to measure the volume of urine and record this on the chart against the time;
- If patients do not use a jug, to measure the contents of any cups/glasses they use and make a note of these. Recording the volume of drinks is easier if the container volume is already known. Practitioners can do this for patients unable to do so;
- To wash and dry the jug after each use, keeping it for this purpose only;
- To start recording with the first void on rising;
- That if they are unable to measure urine volumes - for example, when using a public toilet, or because they are opening their bowels at the same time - to place a tick in the column next to the time;
- Record the time prescribed diuretic therapy is taken, as this will increase urine output;
- Record times of going to bed and getting up.
Collating the results
When a chart is returned, the assessor should collate the information for each day to identify:
- Daytime frequency: the number of voids recorded during waking hours, including the last void before sleep and the first void after rising in the morning;
- Nocturia: the number of voids recorded during a night’s sleep, where each void was preceded and followed by sleep;
- 24-hour frequency - the total number of daytime voids and episodes of nocturia during a specified 24-hour period (Abrams et al, 2002).
An FVC or bladder diary must be used to determine the maximum voided volume (the largest volume of urine voided during a single micturition).
Interpreting the results
Comparing the results with what is considered normal bladder function may indicate areas of dysfunction and be used to confirm a diagnosis.
It is important to remember that it is difficult to define a “normal” or healthy bladder function (Lukacz et al, 2011) as normal parameters depend on age and gender, as well as many other internal and external factors such as fluid intake and type.
The International Continence Society defines urinary frequency as a complaint by a patient that they void too often during the day (Abrams et al, 2002), which shows that patients’ perception of their symptoms must also be considered.
As a guide, “normal” parameters of voiding volumes and frequency in adults of average weight and height are outlined in Table 1 (attached).
Normal frequency is between five and eight voids in 24 hours. A high fluid intake may increase frequency.
Rising during sleeping hours with the need to void once may be considered normal.
If nocturia is excessive, the practitioner should ensure the patient is awakening due to the desire to void and not for other primary reasons, such as pain, and simply voiding while awake.
The production of the antidiuretic hormone vasopressin decreases with age so older people may void more frequently at night. Nocturnal polyuria is present when an increased proportion of the 24-hour urine output occurs at night (normally during the hours while the patient is in bed). The precise definition is dependent on age and is considered to be present when more than 20% (young adults) to 33% (over 65s) of urine is produced at night. Night-time urine output excludes the last void before sleep but includes the first void in the morning (van Kerrebroeck et al, 2002). Older people with nocturnal polyuria should be assessed to exclude underlying, undiagnosed heart conditions.
Maximum volume voided
Normal functional bladder capacity in adults is approximately 300-400ml (Lukacz et al, 2011), although volumes of 500-600ml are often recorded. The largest void is usually on rising; during the day, the bladder is emptied at lower volumes.
Total volume voided
The total volume voided depends on many factors but generally, in a healthy adult, should be 1,500-2,000ml. Patients who restrict fluid intake because they fear episodes of incontinence will have a low urine output, which can exacerbate symptoms as concentrated urine may both increase urgency and the patient’s risk of developing a urinary tract infection.
Low urine output that is not linked to low fluid intake should be investigated.
Fluid intake and type
An average adult in good health will require a fluid intake of 30ml per kg of body weight in 24 hours (Kobriger, 2005). Using this calculation, an adult weighing 67kg should have a daily intake of approximately 2,010ml. The European Food Safety Authority (2010) broadly recommends that women should have an overall intake of 2l and men 2.5l.
Caffeine is known to cause diuresis, urinary frequency and urgency at lower bladder volumes (Lohsiriwat et al, 2011). This is troublesome for some patients, who may benefit from advice about gradually reducing their intake of caffeinated drinks.
The fictitious case studies below illustrate differing types of bladder function or dysfunction.
Normal bladder function
Table 1 (attached) shows the FVC of Sarah Smith, a 38-year-old health professional with normal bladder function. Over three days, the chart shows:
- Micturition frequency: 6-7 times in 24 hours;
- Nocturia: up to once in 24 hours;
- Total volume voided in 24 hours: 1,900-2,000ml;
- Maximum void: 500ml.
Stress urinary incontinence
Table 2 (attached) shows the bladder diary of 29-year-old Sue Green, who enjoys exercise and jogging. She has two children, the youngest of whom is nine months old. She has urine leakage on exertion and has no frequency or urgency. Over a single day the chart shows:
- Daytime frequency: seven times in 24 hours;
- Nocturia: once in 24 hours;
- Total volume voided in 24 hours: 1,925ml;
- Maximum void: 450ml;
- Leakage on exertion: five times in 24 hours;
- Continence aids: buying own panty liners for leakage;
- Fluid intake: 2,080ml in 24 hours.
Mrs Green’s fluid intake and bladder function are within normal parameters, apart from episodes of leakage. Other investigations included urinalysis and physical examination. A diagnosis of stress urinary incontinence was then made and a treatment regimen of individualised pelvic floor muscle exercises commenced.
Table 3 (attached) shows the bladder diary of George Emerton, a 48-year-old science teacher. He complains of urinary urgency, and leaks urine if he is unable to reach the toilet quickly. On one occasion, he had to take a white coat from the classroom to cover his clothes as he could not control his urgency on the way to the toilet. Since he was unable to measure his voids, he was asked to put a tick in the column each time he passed urine.
One day of three-day charting shows:
- Daytime frequency: 12 times in 24 hours;
- Nocturia: twice in 24 hours;
- Total volume voided in 24 hours: not recorded;
- Maximum void: not recorded;
- Leakage with urgency occurred once in 24 hours;
- Continence aids: pads not used;
- Fluid intake: 1,450ml, made up of six cups of strong black coffee and a pint of lager.
From Mr Emerton’s charting, the obvious causes for concern are the low fluid intake and the volume of strong black coffee. In addition, lager can irritate the bladder in some people. After urinalysis to exclude urinary tract infection and a full continence assessment, Mr Emerton was advised initially to gradually reduce his caffeinated drinks, replace these with non-caffeinated drinks and ensure his fluid intake was about 2l in 24 hours. He will be reviewed in four weeks for progress and further treatment, investigation and referral if required.
Fifty-five-year-old Jenny Carter complained of urinary frequency, urgency and leaks urine if unable to reach the toilet quickly. Lower abdominal pain occurs as her bladder fills. She is otherwise fit and active, but is very tired due to daytime frequency and nocturia occurring every hour.
One day of three-day bladder diary shows:
- Daytime frequency: 17 times in 24 hours;
- Nocturia: seven times in 24 hours;
- Total volume voided in 24 hours: 1,665ml plus leakage;
- Maximum void: 90ml;
- Leakage with severe urgency: five times in 24 hours;
- Continence aids: three rectangular pads used;
- Fluid intake: 2,150ml.
The bladder diary confirmed the severity of Ms Carter’s symptoms. Urinalysis and vaginal examination did not show any abnormality, and constipation was excluded. A post-void ultrasound scan showed her bladder was completely emptying. Referral to a urologist led to urodynamic studies; these showed a significant increase in bladder pressure during filling, resulting in severe urgency with high pressure and leakage at 90ml. A cystoscopy and biopsy confirmed interstitial cystitis as the cause of the symptoms. This can be a difficult condition to manage and Ms Carter is discussing the options with the urologist.
Charting bladder function and fluid intake gives invaluable information to the assessor, but the importance of the chart and the need for accuracy must be explained to the patient completing it. Although these charts are only a part of an assessment of bladder symptoms, no assessment is complete without them. Symptoms explained verbally can easily be misinterpreted, so an objective measure of bladder function is essential to support correct diagnosis and treatment.
- Charting bladder function and fluid intake is important for investigating symptoms and making a diagnosis
- It is important to understand what is being recorded and why
- Patients must be assessed to ensure they can record the information required
- Patients need to understand the importance of recording information accurately
- A completed chart forms the basis for further discussion with the continence/urology team
Abrams P et al (2002) The standardisation of terminology of lower urinary tract function: report from the Standardisation Sub-committee of the International Continence Society. Neurourology and Urodynamics; 21: 2, 167-178.
European Food Safety Authority (2010) Scientific opinion on dietary reference values for water. EFSA Journal; 8: 3, 1459.
Kobriger AM (2005) Hydration: Maintenance: Dehydration, Laboratory Values, and Clinical Alterations. Chilton, WI: Kobriger Presents.
Lohsiriwat S et al (2011) Effect of caffeine on bladder function in patients with overactive bladder symptoms. Urology Annals; 3: 1, 14-18.
Lucas MG et al (2014) Guidelines on Urinary Incontinence. Arnhem, The Netherlands: European Association of Urology.
Lukacz ES et al (2011) A healthy bladder: a consensus statement. International Journal of Clinical Practice; 65: 10, 1026-1036.
National Institute for Health and Care Excellence (2013) The Management of Urinary Incontinence in Women. London: NICE.
National Institute for Health and Care Excellence (2010) The Management of Lower Urinary Tract Symptoms in Men. London: NICE.
van Kerrebroeck P et al (2002) The standardisation of terminology in nocturia: report from the Standardisation Sub-committee of the International Continence Society. Neurourology and Urodynamics; 21: 2, 179-183.