Dual unit weighing scales can be harmful to health – official

In a damning report on the state of medical weighing equipment and procedures in hospitals across the country, LACORS, the Local Authorities Coordinators of Regulatory Services, has highlighted the dangers of using weighing equipment that can display units other than the standard metric units which are used for calculating medication and radiotherapy dosages, diagnosing illnesses and monitoring treatment.

The report states:

“One of the most potentially harmful issues is that of switchable scales – those that can display metric, imperial and other units. The risk is that medication could be administered based on a readout that was assumed to be metric.”

In the first official recognition for many years of the serious issues that arise from a muddled approach to units of measurement, the report includes the following recommendation to hospital trusts:

“From now on, scales purchased for medical purposes should only be capable of metric display. There should be no capacity for switching or dual readouts. Trusts should be aware of the pitfalls of using switchable scales and may wish to consider replacing them, or having the switches removed. Conversion charts can be provided for those patients who wish to know their weight in imperial.”

The report concludes that, should their recommendations be followed, hospitals will benefit from significant improvements in patient care, and the potential to demonstrate due diligence in relevant clinical negligence claims.

See the LACORS report and press release.

Author: UK Metric Association

Campaigning for a single, rational system of measurement

17 thoughts on “Dual unit weighing scales can be harmful to health – official”

  1. Why do hospitals still use imperial for weighing babies?
    Because that’s what granny did!
    But the length is often given in cm. I’ve had two like that recently. Maybe hospitals have only got metric rulers, and you don’t often see a switchable ruler.


  2. Any move to simplify the work of doctors, nurses, midwifes and so on can only be a good thing. Having to know two weights for babies and patients can ultimately lead to confusion especially as hospital staff at any level can be over-tired and/or stressed.

    I’m glad we’re not going to make the NHS work in two measures any more, and they’re not going to work in imperial… so the rest of us may as well get used to metric!


  3. Sears asked “Why do hospitals still use imperial for weighing babies?” They don’t. They convert to imperial for the “benefit” of the mother.

    Some ten or so years ago a baby died because its loss of weight was not noticed as a result of a mixture of metric and imperial units. After soem strong words by the coroner, I believe that all hospitals now keep all their records in metric units.


  4. Respondents please note:

    The LACORS web site has the same internet address for its PDF file (report document) as the one used in the article above. It sometimes fails to load so there is obviously a technical problem their end. In case of difficulty the LACORS press release page (see the link at end of modified article) is more reliable.


  5. It is clearly time now for the UK to take stock of the ludicrous situation with regard to two systems muddle over measurement. Had metrication been handled properly in the first place everyone both medical staff and patients would be happily using metric exclusively without any confusion or risk.

    To achieve a safe environment we have to complete the change in all public areas not just behind the scenes in industry and public services.

    To get to know metric properly, understand its advantanges and gain the benfits from it you have to use it continuously and phase out the unnecessary duplication of imperial measurement practices.


  6. When my children were born (between 12 and 5 years ago) they were weighed correctly in kg, but the weights were converted into lb and oz by the staff before we were told. It would make life so much simpler for the hospital staff if they quoted the number from the scales. If the parents complain they should be given the conversion charts and told the to figure it out for themselves. This country uses the metric system for our health service. If individuals want to use some other system in their private lives then they should do the work of converting.


  7. i’m glad that LACORS has said this in there report! the question & i mean no offence by this but how long before the media start a campaign to use imperial only? just my opinion! the looks i get when i say my height and weight in metric is amazing


  8. People have for some time seen metric as an official & scientific tool and imperial as a personal one and this needs to change. In the same way as “jargon” may be used by a particular industry to keep the general public at arms length, differentiating between metric and imperial in this manner does the same thing and is clearly dangerous!

    Medical staff are no less likely to make mistakes in conversion from metric to imperial as market stall holders, the main difference is that the latter are only going to deprive people of their money and not their health. Medical staff should be banned from using “supplementary indications” for this reason alone.

    The diet industry and the press could also assist… if people started to weigh everything in metric and stop converting they would more easily see mistakes for themselves!


  9. The following articles show that even the USA cannot escape the need to use standard metric units for weighing hospital patients.


    There was a safety alert issued earlier this year by the Joint Commission, the American-based healthcare accreditation organisation.


    The alert states:
    “Since patient weight is used to calculate most dosing (either as weight-based dosing, body surface area calculation, or other age-appropriate dose determination), all pediatric patients should be weighed in kilograms at the time of admission (including outpatient and ambulatory clinics) or within four hours of admission in an emergency situation. Kilograms should be the standard nomenclature for weight on prescriptions, medical records and staff communications.”

    This follows a safety notice issued in 1999, which included a recommendation resulting from the confusion caused by the non-metric labelling of a drug.


    “Problem: A patient received phenobarbital 0.5 grams (500 mg, obtained from 4 x 130 mg unit dose syringes) IV daily for three days instead of 0.5 grains after the prescriber misread the apothecary dose listed on the patient’s prescription bottle.
    Recommendation: Only the metric system should be used when prescribing and labeling drugs.”

    Using more than one system of measurement for a given purpose will always have the potential to cause confusion and errors. Such errors can be life-threatening when healthcare is involved.


  10. To add to the point that Alex Bailey makes about the diet industry; Calories/calories/kilocalories should be phased out as soon as possible. Nowadays a “calorie” is the same as a “kilocalorie” – more confusion!

    Historically a thousand “calories” were equal to one “Calorie”.
    1000 calories = 1 kilocalorie

    On the front of a food packet it may show “114 Cals” (or 114 cal) and on the side “114 kcal”. (In terms of nutrition calories and energy are used to mean the same thing).

    Food energy values and Guideline Daily Amounts should only be given in kilojoules (kJ) and megajoules (MJ).

    Conversion increases the chance that mistakes will be made. It’s time to archive or shed calories!

    http://www.simetricmatters.com / Philip Bladon


  11. People still talk of their weight in imperial although the NHS is metric and I don’t see the stone used anywhere except “informal” weighing. If the stone is already “obsolete” I might as well not use it. I think providing metric only equipment in hospitals is a good idea and I agree with David Brown on the weight of newborns!


  12. When I give my weight in kg (currently 67 kg), people often do then ask “How many stones is that?”. To which I reply “Depends on whether I dig the stones up from my front garden or back garden.” I usually get a laugh – but that is all. I cannot recall anyone pressing the point further. If they actually know weights in kg, then I don’t need to tell them in stones (I actually do not know my weight in stones). If they don’t know kg, then they can remain in ignorance, or take the trouble to find out for themselves.


  13. A few years ago I spent 18 months working in Germany. A British colleague said that he weighed “x stones” (I forget what x was). One of my Spanish colleagues asked “what kind of barbaric measurement is that?” (I do not recall the exact phrase, but she certainly used the word “barbaric”).


  14. As with anything else, it all comes down to user education and usage. If the media and all agencies (public and private) cooperate in using kilograms only for weight and meters or centimeters for height, over time the younger folks and many older ones will assimilate what numbers mean in those units and the archaic forms of stones and pounds will disappear.

    Those who want to be able to convert should have charts available to them in most agencies and online. This would minimize (though not eliminate) the grumbling of those who object while allowing the natural process of evolution to relegate those units to the dustbin of history.


  15. “A watchdog has issued a warning to hospital staff after almost 500 patients received the wrong dose of a sedative over the last four years.

    Three died and another 48 were moderately harmed after being injected with midazolam, a drug used to sedate patients undergoing minor procedures.

    It urged staff vigilance on dosing.

    In some cases staff gave the wrong dose in error or experienced difficulty in determining the appropriate dose for individual patients. Patients were being given whole ampoules of the drug instead of a tiny amount.”

    This was on the BBC News website today 2008-12-09. I just wonder how much of this wrong dosage was due to errors in measuring individual patients’ mass/BMI, or whether other factors were involved. Unfortunately the article does not say.


  16. As both a practicing pharmacist and a USMA officer, I applaud the LACORS decision to enforce metric-only measurement. Drugs are frequently dosed on a milligram-per-kilogram or milligram-per-square meter body surface area basis, and any risk of a mix-up in units for patient weight can result in a significant, possibly disastrous, dosing error. In the U.S., the Joint Commission has recently called for weighing PEDIATRIC patients in kilograms only, but I continue to call for the ending the use of pounds, feet, and inches in patient data in this country.


  17. Errors are so easy to make. Any measure that will reduce medical errors must be enforced. This is why a totally metric environment is essential. As a safety issue, the argument is overwhelming.

    All medicine and all pharmacy measures must be metric, including measures sold to the public. For example, medicine glasses must be exclusively in metric measures. Once medicine is exclusively metric, patients will be safer.


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