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.
of health care naturally creates room for an increase in the number
of diagnostic health laboratories. In recent years, diagnostic health
laboratories have mushroomed!
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.
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!
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.
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.
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 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.
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).
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
modern health laboratory
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!
for choosing the correct health laboratory
are some considerations in choosing a good health laboratory;
* make sure
the laboratory is the one recognized by your doctor for quality
* 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.