Council test reveals blood glucose monitors to be less than completely accurate and precise
What are the essential qualities of a reliableblood glucose monitor?
According to a Consumer Council test on 8 modelsof blood glucose monitor, they are, namely, accuracy, consistency and precision.
And do all the test samples measure up to thesecriteria?
First and foremost, accuracy is assessed by theobserved differences between the readings given by individual meters and thecorresponding values generated by the conventional hexokinase method carried outin the laboratory.
On the basis of the ADA (American DiabetesAssociation) recommendation, the maximum allowable error is ±15%. The testresults revealed that none of the models met the ADA criteria in 100% of theirreadings.
But some models were more accurate than theothers as the results showed that the frequency of their readings falling within±15% of the reference values ranged from 52.5% to 84%.
So, how will blood glucose monitors which areless than completely accurate, affect the management of a diabetes patient'shealth?
By means of a method developed by experts in thefield, the readings of the models were rated on a scale of 5 zones (A, B, C, D,E) in terms of the clinical significance of the relative difference between thereading of the meter and that of the laboratory.
Most of the readings were within Zone A and B.The former represents that the difference "would lead to clinically correcttreatment decisions" while the latter "the therapeutic decision wouldbe inappropriate but without any serious immediate consequence". 2 modelswere in Zone A for all their readings.
Only a few readings were in Zone D("dangerous failure to detect and treat errors"). None was in Zone C("the difference may lead to an over-correcting of a normal or subnormalglucose level") and Zone E ("erroneous treatment zone").
On consistency which assesses the differencesbetween the results obtained by two meters of the same model simultaneouslymeasuring the same blood sample, all models were observed to possess highconsistency.
On precision which is assessed by performingrepeated measurements of the same blood sample by the same meter, most modelswere found to produce acceptable precision in the normal and high blood glucoseconcentrations. At lower concentration, however, the precision was generallymuch poorer.
Overall, most models were able to generateresults comparable to laboratory values. However, 2 of the samples were shown todisplay greater deviations from the reference values and poorer precisionespecially at low blood glucose concentration. These 2 samples, incidentally,were at the top end of the price scale ($670 - $1,650) in this test.
Healthcare personnel and patients should be awareof the limitation when using these devices. In case of doubt, they are advisedto seek confirmation by laboratory measurements.
Council warns household organic solvents could pose potential fire and blast hazards
The potential hazards of household organic solvents have come under the scrutiny of the Consumer Council in the wake of rising public concerns over home safety.
Organic solvents are used for a multitude of chores at homes such as dissolving grease and fat, cleaning, diluting paint,etc. Among the common organic solvents are: turpentine, thinner, kerosene,spirit and toluene.
According to the statistics of the Fire Services Department, 3 fire accidents related to the use of organic solvents were recorded between September 1998 and August this year.
One of the accidents killed an interior decorator and injured another in an explosion in a flat under decoration.
In the accident, all windows and doors of the flat were closely shut to keep the polished floor free of blemishes - a common,but highly dangerous, practice in the decorating industry to prevent circulating air from making the surface of varnished floor uneven. This caused the flammable vapours to confine in the flat resulting in the deadly blast.
On the other hand, at least 19 accidents related to the use of household organic solvents were reported in newspapers during January 1997 and September this year. Typical examples of these accidents, which reportedly claimed 2 deaths and 42 injuries, include:
- A 50-year-old man used the heat from a gas stove to melt the solidified paint. As all the windows were closed, the risingheat caused the flammable xylene (an organic solvent) to concentrate in the room, which burst into fire when it encountered the flame. The man was critically burned and died the next day.
- A 23-year-old painter apprentice was suspectedto have breathed in too much of the thinner vapour and was found unconscious inan enclosed room. The vapour was generated from the solvent used to dilute theoil paint.
- An interior decorator mistook the thinner,which was stored in a distilled water bottle, as distilled water and drank it.
Besides the hazards of fire and burns, organicsolvents can affect the human central nervous system, irritate skin, eye andupper respiratory tract, posing risks of contact dermatitis, liver and kidneydamages.
The Consumer Council has long been concerned withthe unsatisfactory state of many hazardous household chemicals being soldwithout adequate safety labelling. It highlighted the problem in a survey reportin 1998, and urged the Government to strengthen the legislative protectionpresently afforded to consumers of household chemicals.
In response to these concerns, the Fire ServicesDepartment has drawn up a set of guidance notes on the bilingual labelling ofchemical products including some household chemicals.
The guidance notes are designed to provideconsumers clear labels denoting the dangerous nature of the goods and thenecessary instructions on the proper usage and storage of these chemicalproducts. Manufacturers, suppliers and retailers are urged to comply with theseguidance notes and take the necessary action to put this measure into practice.
Consumers are cautioned to always exercise greatcare when handling organic solvents and in particular when entering a flat afterthe completion of work on varnished floor:
- no smoking and ignition;
- don't switch on or off electrical appliances;
- open all windows immediately to effect naturalventilation for at least 10 minutes; and
- switch on or off any electrical appliances only when the flammable vapour has dispersed away.
Nearly 13% of Internet surfers use e-shopping
Shopping on the Internet is undoubtedly the growing trend of the future. Already in Hong Kong Internet users are joining the ranks of e-shoppers worldwide.
A Consumer Council survey based on 1,000 Internetusers has revealed that nearly 13% of Internet users here had the experience ofpurchasing through the net. And over 80% of them were satisfied with theirpurchases.
Among the most common purchases on e-shoppingwere: books/magazines/audio video tapes and CDs (39.2%), daily supermarket items(25.4%), and computer software (23.8%).
But the survey also found that over 60% of therespondents were unaware of such vital information as terms and conditions,privacy policy and payment security, before placing their purchase orders.
Consumer complaints related to Internet shoppinghave risen over the years. According to the Consumer Council, there were 5 in97, 3 in 98, 33 in 99 and 39 in the first 9 months of this year.
Here are some e-shopping tips for the consumer:
- Choose only reliable websites for your Internetshopping.
- Understand clearly how the companies protectyour personal data. Check the security information beforehand and do not sendyour personal information through a non-secured channel.
- Search for alternative contact methods apartfrom the company email address or web-site.
- Pay attention to hidden additional costs ashandling fees, transportation fees, packaging fees, etc.
- Read the terms and conditions and in particular the redress and returns policy beforehand.
- Save or print a copy of the important information such as order confirmation sheet, receipt, price lists, etc.
- Remember to check your credit card statement afterwards.
Council recommends use of old edition textbook swith only minor revision to reduce parent burden
Parents should not be compelled to purchase new editions of textbooks which have been revised only slightly.
Schools should draw attention of parents and students to such revised editions on the booklists with wordings such as"edition X can be used" so that they are free to decide for themselves whether or not to buy the new editions.
Publishers are urged to provide a conversiontable showing the differences between the old and new editions for the referenceof schools.
This recommendation was put forward by theConsumer Council in a survey on 9 revised textbooks comparing the new editionsagainst their old editions.
The Council further recommends publishers toconsider where existing workbooks are applicable, separating exercisesespecially for those fill-in-the-blank or multiple-choice exercises, fromtextbooks and putting them in the appropriate workbooks, so as not to reducedesire in the use of old editions.
In the survey, the assessment criteria were basedon opinions from school principals, parents and teachers. Highlights of thefindings include:
- On necessity of revision, of the 9 revisedtextbooks, only 3 were assessed conclusively as "necessary to revise".Of the remainders, 5 were assessed as "quite necessary" and 1 as"should be treated as reprint with minor amendments".
- In the majority of cases, the revised editionscontained more pages and their prices were increased accordingly.
- On publication years of the old editions, the samples in the survey ranged from 1993 to 1998. As the one revised sample published in 1998 was an EPA textbook, it does not violate the rule of the Education Department which forbids revision within 3 years of publication with the exception of Social Studies, EPA or GPA textbooks.
Falls from ladders are common household accidents
The Consumer Council has sounded a cautionarywarning on the use of household ladders.
In Hong Kong, 5 ladder-related accidentsresulting in 1 death and 4 injuries were reported during the 10-month periodbetween December 1999 and September this year.
In the United States, the US Occupational Safetyand Health Administration (OSHA) estimates that 18,757 injuries and 24fatalities per year are caused by falls from ladders.
Causes of ladder mishaps result from severalunsafe acts and conditions:
- Ladders placed on unstable surfaces, orimproper positioning of the ladder.
- Users on ladders reaching too far beyond thesides of the ladder. (Beyond the center of the body)
- Users standing too high on the ladder henceable to maintain balance.
- Defective or broken ladders (e.g. broken rails,rungs, missing hardware).
- Users hand carrying loads while ascending ordescending.
- Selecting the wrong ladder for the job.
Further, the OSHA statistics on victims of fallsfrom ladders show that:
- 80% of victims fell or slipped.
- 73% were not provided written instructions onthe safe use of ladders.
- 66% were not trained in how to inspect ladders.
- 57% were holding object(s) with one or bothhands.
- 30% had wet, greasy or oily shoes.
In this October issue of CHOICE was published theoverall findings of a test on 42 step ladders, and 17 multipurpose ladders.
According to the test, the situation on stepladders is rather alarming. 67% of the samples was found to have quality belowthe set criteria. Some of the reasons for failure were attributed to lack ofstrength of steps, rungs and platforms, the materials being used are not of therequired thickness.
For multipurpose ladders, 41% of the samples was found not to comply with the requirements. Reasons of failure included fingers getting injured or squeezed by the hinges or between ladder parts, lack of stability or strength.
Supermini safety shows significant improvement
Small cars are safer than ever before, according to the latest Euro NCAP (New Car Assessment Programme) crash test results published in CHOICE today. The Consumer Council is a member of the International Consumer Research and Testing which is involved with the Euro NCAP programme.
The results showed that 6 of the 17 supermin is tested achieved a 4 out of 5 star rating. Overall, while frontal and side impact crash worthiness has improved considerably for the supermini class of car, the levels of pedestrian safety are still disappointing. Also the safety performance of child seats has become an increasing cause of concern.