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Special investigation on medical laboratories
Are your test results correct?
By Dr. Susil W. Gunasekera, Dr. T.K.P.K. Kaluarachchi & Dr. S. Ranasinghe
How sure are you of the accuracy of the laboratory report of your health test? If your answer is: 'I am absolutely sure that, what I got is correct', then, you need not read this article. However, if you are in doubt and wonder: 'How accurate is my lab report? Shall I try another lab?' then please read on.

The expansion of health care naturally creates room for an increase in the number of diagnostic health laboratories. In recent years, diagnostic health laboratories have mushroomed!

The General Hospital Diagnostic Health Laboratory is the only one run by the state sector. All the other laboratories are private sector managed. With the competition that ensues, the public has to expect a varying quality in diagnostic laboratory reports (i.e. test results) and an unacceptable inter-laboratory variation. Recently, discussing the blood (serum) cholesterol report of a patient who came to our institute, the following facts surfaced. During a period of six months he had had his blood (serum) cholesterol done on four separate occasions (an unnecessary process) in three different private sector diagnostic laboratories and lastly in our institute - the four results varied in four different ways! According to the first test result, the patient was alright blood cholesterol-wise (normocholesterolaemic). However, the next test done two months later in another laboratory indicated his cholesterol was unacceptably high (hepercholesterolaemic). As appropriate, he was prescribed diet and exercise therapy by his physician. The third report, two months later, by a third laboratory gave an alarmingly high blood serum cholesterol report. The patient being somewhat aware of the associated health risks (atherosclerosis, heart attack, etc.) got very worried. He then had to go on cholesterol lowering drug therapy prescribed by the physician.

Two months after therapy, on the fourth occasion, his blood serum cholesterol concentration was perfectly normal, contrary to expectation as per the previous result. Cholesterol lowering drugs could not do wonders in such a short time. Somewhere, something had gone wrong in laboratory testing. The patient was misled. Doctors found the laboratory reports misleading and unacceptable.

There are hundreds of such stories! Wrong laboratory reports mislead the doctor, more often than not. The patients' suffering cannot be overlooked. Hours of hanging around and money being wasted are further penalties on the patient through no fault of his own, but due to laboratory error!

The public must be aware that results from medical laboratory tests are used in many practical contexts. The most common uses are:

* for the doctor to confirm, strengthen or even weaken a preliminary diagnosis made by self (doctor).

* for the doctor to monitor the course of an illness or disease.

* for the doctor to monitor the success or failure of treatment.

* for the doctor to check untoward side-effects of treatment when necessary.

Incorrect laboratory results are dangerous. They can delay proper diagnosis; hence the patient will not receive proper treatment at the proper time. An incorrect result could mean no treatment when treatment is necessary, or treatment when treatment is unnecessary. Incorrect results of blood groupings have killed patients. Incorrect microbiology test reports have been dangerous to the patient, the family and the community.

Strict adherence to quality control measures is the key to acceptable laboratory reports. Both the diagnostic laboratory and the patient must know and remember that test report is not a paper note a patient takes to please the doctor.

The good diagnostic health laboratory

Reputed diagnostic health laboratories are well supervised and well managed. Trained and experienced Medical Laboratory Technologists (MLTs) do laboratory testing. These health laboratories do not compromise on quality with substandard practices for better profit (i.e. doing more for less money). Laboratory measurements are complicated. Even the good health laboratory makes mistakes, less often though, but on such occasions the laboratory rectifies mistakes.

There is a well-established rapport and dialogue between the doctor and the laboratory personnel in a health laboratory of repute.

The way to achieve good standards is to apply stringent quality control procedures. Though such procedures are somewhat time consuming, every health laboratory in the state or private sector must adopt and adhere to required quality control programmes, diligently and regularly. Quality control is the watchdog that assures patients that they are receiving quality assured correct reports of their health tests. In a country like ours, where good doctoring and health care related facilities are satisfactory, laboratories must remain unequivocal in testing and reporting.

The reader must know that, to be a Medical Laboratory Technologist of the health laboratory of a government hospital, one has to have a good academic record or apt experience for selection to the MLT training programme. The trainee is admitted to one of the three MLT Training Schools in the island (i.e. the MRI - Colombo, NIHS - Kalutara or TH - Peradeniya).

During the training period of two years, the trainee MLT imbibes a vast amount of knowledge (cognitive matter), and gains practical skills (psychomotor skills). Further the MLT training programme drives in affective elements (feeling) in the trainee MLT. MLT trainees are educated through learning inputs provided by senior MLT tutors, medical specialists and even university lecturers. The trainee MLT receives rigorous bench training in the MLT training school and in hospitals, under supervision. The final examination that certifies a trainee MLT suitable for the job is a fine-tooth-comb, and not second to university final science examinations.

If you look around, you will see that a number of private health laboratories are manned by part-time government hospital MLTs. Such part-timers cannot be held responsible, nor is there the element of accountability on their part.

It is vital that all laboratories are made to follow Quality Control Regulatory Guidelines.

The automated modern health laboratory

Laboratories are started, renovated and modernized with sophisticated analytical instrument systems. These analytical instrument systems are capable of running with minimum technician intervention. These are speedy and handle a large number of samples of different patients. Further, these are capable of giving attractive displays and printed test result reports. Though fully automated, with digital readouts and computer interfacing, the performance of these instrument systems must not be taken for granted as truly accurate. We have to be sure that the results are correct. So, the tests performed with these analytical instruments have to have the same quality control checks as much as the manually performed tests. Just because you went to a modern health laboratory, paid more money and got an attractive looking report, unless the laboratory assures you that the result is truly quality guaranteed you can't be too sure!

Guidelines for choosing the correct health laboratory

The following are some considerations in choosing a good health laboratory;

* make sure the laboratory is the one recognized by your doctor for quality service.

* recall your past experiences and talk with your friends to get some idea of the health laboratories in your area and how reliable they are.

* make sure that the laboratory is supervised by a laboratory manager and served by experienced full-time laboratory technologists (particularly for clinical chemistry and haematology) and not by partially trained or trainee staff.

* be certain that the health laboratory is adequately equipped and not running with meagre resources.

* be bold enough to ask the health laboratory "What measures do you adopt to ensure accuracy of results?"( Experts will tell you that if the laboratory does internal standardisation only, it is wholly inadequate to guarantee the desired accuracy.)

* It is best not to hand your specimens to "collecting centres", unless a reputed health laboratory manages the collecting centre.

* do not be guided by broadcasts and advertisements.

* do not think that a laboratory equipped with modern analytical instruments is the one that can be trusted for accuracy just because of the modern equipment. Such a laboratory too has to use quality control programmes.

The joint authors of this article are Biochemists of the Medical Faculty of Peradeniya.


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