5 medical reasons why accurate weighing scales should be used

Accurate weighing scales in a medical setting are essential if you are to deliver your duty of care.

An incorrect reading can mean that the patient receives incorrect treatment or medication, with serious or fatal consequences.

In 2015 the National Measurement and Regulation Office (NMRO) issued a report assessing the suitability of weighing scales in GP surgeries, health centres, health visitors and pharmacies.

The report recommended improvements to ensure that accurate weighing scales were used, patients were only weighed in metric and staff received proper training.

But what are the implications of an inaccurate weighing scale - and why should accurate weighing scales always be used for medical purposes? Marsden explains.

1. It could be a matter of life and death

According to Cllr Geoffrey Theobald OBE, Chairman of LACORS in 2015, “An inaccurate petrol pump or supermarket scales isn’t exactly a matter of life or death but getting accurate, consistent weight readings for hospital patients could be. When you consider why a patient would be weighed – to calculate dosage for medication, anaesthetic or even radiation – you realise the importance of getting weight right.

“According to the results of the National Medical Weighing Project, one-third of all hospital scales are inaccurate. Some of these inaccuracies could be tiny and have little effect on patient care, for example when monitoring adult obesity. However when weighing a premature baby to calculate medication, pinpoint accuracy is crucial.”

In fact, 300 patients are killed due to faulty machinery according to the Institution of Medical Engineers. ‘Inaccurate weighing scales’ was among the equipment highlighted in the report.

2. They allow you to deliver your duty of care

The duty of care refers to the obligations that healthcare practitioners may have where it is ‘reasonably foreseeable’ that harm may be caused to patient through actions, such as inaccurate weighing, by a member of staff.

In 2008, an alert was sent out by the Medicines and Healthcare products Regulatory Agency, warning that incorrectly calibrated weighing scales had led to a number of patients being given an incorrect dose of medicine.

The BBC reported that in one case NHS staff had used defective bathroom scales to weigh a four-year-old cancer patient in order to calculate her radiation dosage. In her case, the error was spotted in time – but others may not be as fortunate.

According to Marsden’s ‘Accurate Assessment of Patient Weight’ white paper, in 70% of occasions that errors do occur, the patient is affected.

3. Not using accurate scales goes against LACORS recommendations

The 2009 LACORS report found one third of national weighing equipment to be inaccurate and issued the following recommends:

1. Any inaccurate equipment should be removed from service pending replacement or repair.
2. And all scales used for medical applications should be Class III accuracy or higher

Further recommendations of the report can be found here.

Since 2003, medical weighing equipment has been subject to regulation. The weighing scales body, the UK Weighing Federation (UKWF) states: “As part of the Non-Automatic Weighing Instruments (NAWI) Directive, any weighing equipment used for medical purposes sold after 1st January 2003 must be of an Approved type and be verified before being put into service or following repair.”

4. They are subject to more testing

The Non-Automatic Weighing Instruments (NAWI) directive states ‘all scales used in the determination of mass in the practice of medicine for weighing patients for the purpose of monitoring, diagnosis and medical treatment must be medically approved’.

Class III Approved scales have been subject to greater testing to meet the standards required to become Class III. An EU notified body will test approved scales rigorously. The amount of testing required ensures there is no discrepancy between weight readings - two different Class III Approved scales should give the same weight reading. Class III is therefore used in order to protect the patient (or the user).

It is strongly recommended Class III scales are used when calculating prescriptions or monitoring health signs, and specific accuracies of scale need to be used for certain medical tasks.

5. The patient is assured

By using an accurate weighing scale the patient is reassured that they are good hands for the care they are receiving. A patient may be aware of their own weight - for example through a recent visit to their GP where they may have been weighed by default.

It is important to have complete confidence in providing a patient with their weight reading and knowing that it is correct.

When ordering your scales it is important to consider the weighing tasks they carry out – as each weighing purpose must be undertaken using scales with specific graduations.

It is also recommended that scales are subject to an annual calibration check to ensure they are maintaining their accuracy.

For help in choosing accurate weighing scales for your needs, call Marsden on 01709 364296 or contact us here.