HHD patient weighing scales

[Snehal Patel]

Hello Everyone,

Can you please guide me what type of weighing scales do we provide to HHD patients? what about maintenance of weighing scale? Do we provide inhouse calibration of weighing scale or replace it annually?

[Roger Moore]

Hi Snehal

At Wolverhampton we ensure that all patient weighing scales (this is across the Trust and not just HHD) are subject to annual verification.

Our scales are Class III.

Class III scales should be used in healthcare because they provide the strict precision, reliability, and legal compliance required for safe patient diagnosis, treatment, and medication dosing.

Medication Dosing: Drug quantities often depend directly on a patient's body weight. Small errors from lower-class or domestic scales can cause dangerous under-dosing or over-dosing.

Clinical Decisions: Weight guides critical care choices, including fluid management, nutritional assessments, diagnosis, and monitoring long-term conditions.

Tighter Tolerances: Class III devices display fine increments (such as 0.1 kg or 0.2 kg) with minimal permitted error, unlike domestic or Class IIII scales that use larger whole-kilogram steps.

Legal and Regulatory Standards
Official Guidance: Health authorities and regulations state that any weighing equipment used for medical diagnosis, monitoring, or treatment planning must achieve Class III approval or higher.

Rigorous Testing: Independent bodies test these devices for repeatability and consistency so that two different Class III scales yield identical results.

[Gareth Murcutt]

Thanks Roger. Agreed.
How do you manage the calibrations - are they done annually at HHD site or are the scales calibrated in unit and switched out?
Do you do the same for PD patients?
Thanks
Gareth

[Ian Wilde]

Just think, you go to all that effort and does the patient measure out drinks and weigh food to the same accuracy 🤔 A better option may be to send patients home with a weight that they use to check the scale before stepping on. You know it’s accurate every time then. The patient could drop the scales the day after being returned from calibration and then they could be inaccurate for a further 12 months and nobody is any the wiser.

[Roger Moore]

Hi Gareth

Scales for patients at home, regardless of modality, are swapped out for a verified set every 12 months.

[Roger Moore]

Hi Ian

All scales across the Trust are annually verified and observing the following processes:

• Linearity / Increasing Load Test: Applying test weights incrementally from zero up to the maximum capacity.

• Eccentricity (Corner Load) Test: Placing a single test load at the center and then successively on each of the four corners or load-cell supports.

• Repeatability Test: Placing the same test load on the platform 5 to 10 consecutive times under identical conditions to verify consistency.

• Zero-Return Test: Removing all weight after applying a heavy load to check if the display reliably and promptly returns to zero.

[Gareth Murcutt]

Thanks again Roger.

I understand the sentiment Ian and agree that HHD patients probably know/feel their wt gain pretty accurately.

We have over 100 patients on PD/HHD so really significant costs involved. Ultimately the scales should be checked on site as my real concern is that after calibration the scales then need to be moved to the patients' home. That may involve being driven through Haringey - The Home of the Speed Hump!!! If they then differ from the original ones at HHD location it could induce an error in UF calcs. This may be a more serious error than any small amount of drift in precision.

Rules are rules but a risk analysis would also look at the above issue.

Anyone else to comment on what they do?